Sintering 2026

30 Aug 2026, 08:00 → 3 Sept 2026, 17:00 Europe/Berlin

Important Dates of Sintering 2026

 

1^st November 2025: Start Abstract Submission

31^st January 2026: Deadline Abstract Submission

15^th February 2026: Extended Deadline Abstract Submission

15^th April 2026: Information for Authors / Start Registration for Participation

10^th June 2026: End Early Bird registration

 

Homepage: https://www.sintering2026.org/en

 

 

 

 

Sunday 30 August

12:00 → 14:00 Registration

14:00 → 17:00 Tutorial

14:00 The Fundamentals of Grain Growth in Sintering

Understanding grain growth and microstructural evolution is essential for controlling the properties of sintered materials. This lecture presents an overview of the mechanisms governing grain coarsening in both liquid-phase and solid-state sintering. It begins by examining the implications of grain growth for densification, with emphasis on capillarity and related driving forces.
Grain growth in liquid-phase sintering is reviewed through classical and contemporary models, including Ostwald ripening theory and the mixed-mechanism theory that describes coarsening behavior in liquid matrices. The lecture then addresses grain-growth phenomena in solid-state sintering, covering dense single-phase systems as well as the effects of second-phase particles, solute segregation, and residual porosity on boundary migration and grain growth. Within the framework of unified growth descriptions, the mixed-control mechanism of boundary migration and the mixed-mechanism principle of microstructural evolution are discussed, supported by experimental results from both ceramic and metallic systems. The lecture concludes by summarizing strategies for microstructural design in ceramics and powder-processed materials, and by outlining current challenges and emerging research directions.

Speaker: Suk-Joong Kang (Korea Advanced Institute of Science and Technology)

19:00 → 20:30 Welcome Reception

Monday 31 August

08:00 → 09:00 Registration

09:00 → 09:20 Plenum: Opening and Welcome

09:20 → 10:20 Plenary Talk 1: Advanced Sintering and the Future of Electroceramic Component Manufacturing: From HighSpeed Production to Energy Savings in a Low-Temperature Innovation

Speaker: Clive Randall (.)

10:20 → 10:40 Coffee break

10:40 → 11:40 Plenary Talk 2: Key Technologies for Additive Manufacturing of Multi-materials

Speaker: Hui-suk Yun (.)

11:40 → 12:40 Plenary Talk 3: Atomic-Level Diffusion, Migration, and Dynamics in Oxide Grain Boundaries

Speaker: Yuichi Ikuhara (.)

12:40 → 13:40 Lunch

13:40 → 14:10 Field assisted sintering technology/Spark Plasma Sintering FAST/SPS

13:40 COUPLING 3D PRINTING WITH FAST/SPS SINTERING: AN APPROACH TOWARDS FAST PROTOTYPING OF METALLIC COMPONENTS

In recent years, metal binder jetting has emerged as one of the most promising and efficient technologies for the additive manufacturing of small metal components in mass production, offering a cost-effective and environmentally friendly alternative to other powder-based AM methods, such as L-PBF (Laser Powder Bed Fusion). Despite its high productivity, one of its main limitations is the need for a standalone sintering step, which impacts processing time and energy consumption. Accelerated sintering strategies, such as FAST/SPS, may offer a viable means of shortening processing times; however, the capabilities of this approach for binder-jetted materials and geometries remain under thorough investigation. In this work, we analyze 17-4PH components produced via a metal binder jetting system (Shop System by Desktop Metal) and investigate the potential of combining binder jetting with FAST/SPS sintering for the rapid prototyping of metallic components. Both pressureless and pseudo-isostatic sintering of the green object have been investigated. In the second case, an inert pressure-transfer powder has been used to maintain the green-body geometry. The influence of the various parameters involved in the printing and sintering process have been investigated. In all cases, the use of FAST/SPS reduces the time required for debinding and sintering, enabling the production of fully sintered samples in considerably less time than conventional sintering.

Speaker: Umberto Anselmi-Tamburini (University of Pavia)

13:40 → 15:40 Microstructure evolution during sintering and Microstructure-property relationships: (1)

13:40 The Mechanism of Solute-Drag and Catalyzed Grain Growth in Alumina

Grain boundary mobility in ceramics can be extremely sensitive to segregating dopants or impurities. Using α-Al2O3 as a model system, we examined how Ca2+ and Fe dopants (with mixed Fe3+/Fe2+valencies) influence GB mobility. In Al2O3 doped with Ca below the solubility limit, Ca segregates to grain boundaries and increases the GB mobility, likely through charge-compensating oxygen vacancies. Dense Fe-doped Al2O3 (0.18–2.93 wt.% Fe), well below the solubility limit at 1600 °C (8.9 wt.%), was annealed in air or Ar. In air, grain growth was suppressed by solute drag: the GB mobility decreased with increasing Fe content, consistent with Fe3+ segregation at grain boundaries. In contrast, annealing in Ar increased the GB mobility and produced anisotropic grain growth, similar to Ca-doped Al2O3. X-ray photoelectron spectroscopy (bulk) and electron energy-loss spectroscopy (grain boundaries) show that lowering the oxygen partial pressure shifts Fe toward Fe2+ and increases the oxygen-vacancy concentration. White-line ratio analysis of the Fe L2,3 edges indicates that anisotropy arises from selective segregation of Fe3+/Fe2+ to specific GBs, which alters their mobility and promotes elongated grains. Fast-moving GBs are enriched in Fe2+ relative to slow-moving boundaries. These results demonstrate control of alumina grain size and morphology by tailoring dopant valence states and oxygen-vacancy concentrations.

Speaker: Prof. Wayne Kaplan (Technion - Israel Institute of Technology)

14:10 Dissolution in Yttria-Ceria Composites

Dissolution between $Y_2O_3$ and $CeO_2$ was studied with the goal to understand microstructure and sintering in $CeO_2$-particle reinforced $Y_2O_3$ composites. In one type of experiment the microstructure of composites made by hot pressing and by spark plasma sintering were compared. Subsequent heat treatments in air were performed to study dissolution of $CeO_2$ into $Y_2O_3$. In a second type of experiment, diffusion bonded couples of $Y_2O_3$ and $CeO_2$ were prepared by heating at elevated temperature in air. The results of these experiments reveal that the evolution of the microstructure is more complicated than expected based on existing literature. At least one intermediate phase forms between $Y_2O_3$ and $CeO_2$ and may dictate the dissolution kinetics. Interdiffusion between $Y_2O_3$ and $CeO_2$ leads to significant microstructure changes, including porosity in $Y_2O_3$ and columnar grain growth in C$eO_2$. These microstructure observations are discussed in the context of dissolution mechanisms.

Speaker: Ivar Reimanis (Colorado School of Mines)

14:40 Dopant effects on grain boundary distributions and mechanical response in alumina

Over the past decades, rapid sintering techniques have expanded access to the density-grain size space by promoting densification over grain growth. This has accelerated progress in non-cubic transparent ceramics, where birefringence makes optical properties highly grain-size sensitive. Beyond this paradigm, rapid sintering enables full densification within minutes or seconds and allows tailored heat treatments for advanced microstructural design, particularly grain boundary engineering.
In this study, alumina powders doped with rare-earth elements were spark plasma sintered under controlled conditions. Large-area EBSD maps were acquired to characterize the microstructures. Stereological analysis of grain boundary (GB) distributions revealed temperature- and dopant-dependent changes in boundary structure and habit planes associated with complexion transitions toward lower-energy states. Mechanical spectroscopy was performed on fully dense samples without significant grain growth to analyze GB changes in situ at high temperature. Abnormal grain growth initiated during the measurement, and the associated changes in mechanical response enabled cor-relation between structural changes related to a complexion transition and changes in GB populations.
Given the critical role of grain boundaries in macroscopic properties, this work demonstrates that rapid sintering can be harnessed for advanced materials design and ceramic performance optimization beyond the density-grain size space.

Speaker: Ms Annalena Erlacher (Empa)

15:00 Insight in densification improvement of sintering-aid-free Y-doped BaZrO3 functional tape for proton conductive application

Barium zirconate–based perovskites are promising electrolyte materials for proton-conducting electrolysis cells due to their high chemical stability and bulk proton conductivity at intermediate-to-high temperatures. However, their poor sinterability and the strong contribution of grain boundary resistance significantly limit the total conductivity. Understanding microstructure evolution during sintering and its relation to functional properties is therefore essential.

In this work, Y-doped BaZrO₃ (BaZr₀.₈Y₀.₂O₃–δ, BZY20) electrolytes were fabricated by water-based tape casting, avoiding the use of sintering aid. Grain growth and final density were controlled by systematically modifying intermidiate step of the thermal cycle.

A comparative microstructural and phase analysis was carried out to correlate sintering parameters with densification behavior, grain size distribution, and phase stability. Particular attention was given to the evolution of grain boundaries and their impact on the expected electrical performance.

The results provide insight into the relationship between processing conditions and microstructure development, highlighting the possibilities of sintering-aid-free routes for optimizing electrolyte performance in proton-conducting electrolysis applications.

Speaker: Fabio Torazzi (University of Trento)

15:20 Low-temperature sintering of titanium-based perovskite-type oxide semiconductors using alkali metal vapor

Introduction
Titanium-based perovskite-type oxide ceramics for variable resistors [1] are conventionally produced by sintering green compacts in reducing atmospheres at ~1400 °C. We report the use of Na or K metal vapor to obtain conductive ceramics of CaTiO₃, SrTiO₃, and BaTiO₃ below 1000 °C.

Experimental
Powder compacts of CaTiO₃, SrTiO₃, and BaTiO₃ were placed into a boron nitride crucible and enclosed in a stainless-steel (SUS) container with Na or K metal in an Ar atmosphere. The containers were heated at 600–1000 °C for 1–10 h. Relative densities (RDs) and microstructures of the samples were evaluated by the Archimedes’ method and scanning electron microscopy.

Results and Discussion
BaTiO₃ densified at the lowest temperature (~750 °C); maximum RDs (>96%) were achieved at 800–1000 °C for 2 h and the ceramics were conductive (~300 Ω cm) due to the reductivity of Na. Conductive ceramics of other perovskites were also obtained at 900 °C for 10 h. Cuboid grains in the ceramics suggests that a dissolution–precipitation process mediated by condensed Na vapor facilitates low-temperature densification. Furthermore, conductive BaTiO₃ ceramics were obtained in the same temperature range with K vapor.

Acknowledgement
Supported by the Izumi Science and Technology Foundation as well as the Murata Science and Education Foundation.

Reference
[1]Heywang, J. Am. Ceram. Soc., 1964, 47, 484.

Speaker: Akira Hosono (Tohoku University)

13:40 → 14:10 Fundamental aspects of sintering

This is the description of the Session.

13:40 Thermodynamics of Sintering: Grain Boundary Energy, Surface Energy, and Pore Stability

The lecture emphasizes the importance of solid–solid interface energy, or grain boundaries, in the thermodynamics of interfaces during the sintering of ceramic materials. Three chemical potentials are identified: the difference in chemical potential between grain boundaries and surfaces emerges as a crucial factor for pore elimination. However, once this equilibrium is attained, a second chemical potential related to grain size differences becomes dominant, driving grain growth and producing a new microstructural configuration that can restart the sintering process. The third chemical potential is linked to edges, contributing to the rounding of the neck region between grains and to neck formation without significantly changing pore stability. Modifications in chemical composition resulting from adsorption or segregation processes play a vital role in pore stability during sintering by altering the energy balance of the interfaces.

Speaker: Douglas Gouvêa (Universidade de São Paulo)

13:40 → 14:10 Fundamental aspects of sintering

This is the description of the Session.

13:40 From Flash Sintering to Field-Free Ultrafast Sintering and Electric-Field-Driven Microstructure Control

In 2015, we first reported that flash sintering generally initiates as a thermal runaway [Acta Mater. 94:87 (2015)]. Subsequent work demonstrated that ultrahigh heating rates of 100K/s, rather than the electric field, are the key factor enabling ultrafast sintering, via comparing flash sintering with rapid thermal annealing without an electric field [Acta Mater. 125:465 (2017)]. Subsequently, general ultrafast sintering methods based on the same mechanism, including ultrafast high-temperature sintering (UHS) [Science 368:521 (2020)] and plasma sintering [Nature 623:964 (2023)], have been developed in collaborative studies. Most recently, we further reported induction ultrafast sintering (IUS) [Scripta Mater. 272:117066 (2026)].

Although ultrafast sintering can be achieved without an electric field, electric fields can significantly influence microstructural evolution. We discovered an electrochemically induced grain-boundary disorder–order transition that triggers abnormal grain growth in Bi₂O₃-doped ZnO [Nature Commun. 12:2374 (2021)]. We further showed that applied electric fields can induce grain-boundary oxidation transitions near the anode, producing continuously graded microstructures in undoped ZnO [Mater. Today 73:66 (2024)]. Moreover, the polarity of graded microstructures in BaTiO₃ can be reversed through a grain-boundary disordering transition: grain growth occurs at the anode at 5 V, but shifts to the cathode at 15 V [J. Eur. Ceram. Soc. 46:118104 (2026)].

Speaker: Jian Luo (Unversity of California San Diego)

14:10 → 15:20 Photonic sintering: (1)

14:10 Photonic sintering of ceramics

For millennia, ceramics have been densified via sintering in a furnace, a time-consuming and energy-intensive process. The need to minimize environmental impact calls for new physical concepts. Here, we realize ultra-rapid heating with blue light. Bulk ceramics are sintered within seconds and with outstanding efficiency (≈2 kWhkg-1). Sintering on-the-spot with blacklight as versatile and widely applicable power source is demonstrated on various different ceramics (e.g. SrTiO3, BaTiO3, alumina, YSZ, LLTO and BaZrO3) needed for energy storage and conversion and in electronic and structural applications foreshadowing economic scalability.
Especially acceptor-doped BaZrO3, a proton conductor, has to be sintered at high temperature (> 1600 °C) for long times (~ 24 h). At these sintering conditions, BaO is prone to evaporate, increasing the difficulty to produce stoichiometric ceramics. By blacklight sintering with a high-power blue laser, bulk BaZr0.8Y0.2O3 δ (BZY20) was sintered in <four minutes, mitigating BaO evaporation and achieving promising proton conductivity.

Speaker: Mr Wolfgang Rheinheimer (Institute for Ceramic Materials and Technologies (IKMT))

14:40 Evaluation of Laser-Assisted Sintering as an Advanced Processing Technique in Traditional Ceramic Industry

Traditional ceramic products are widely used in the construction sector due to their high mechanical strength and chemical resistance. Owing to their ability to maintain performance throughout the lifetime of a building, these products offer significant sustainability advantages compared to alternative materials. However, the ceramic industry is an energy-intensive sector, mainly because of the high sintering temperatures required during production. In the ceramic industry, sintering energy supplied by natural gas–fired kilns, which leads to substantial carbon dioxide emissions. In addition, the thermal efficiency of continuously operated industrial kilns is relatively low due to substantial heat losses, which increases both production costs and emission levels. This situation constitutes a major constraint with respect to the sector’s objectives for reducing its carbon footprint. Within the scope of this study, the feasibility of laser-based energy sources in conventional ceramic manufacturing processes was investigated for both vitrified sanitary ware and ceramic tile products. The physical properties of the laser-assisted sintered samples were examined in terms of physical properties and microstructure. The integration of laser-based applications into ceramic manufacturing processes offers an alternative processing route that enables improved energy efficiency while aligning with strategies aimed at reducing sector-wide carbon dioxide emissions.

Speakers: Berkay Yazırlı (Kaleseramik Research Center, Çanakkale, Türkiye), Mr Mehmet Uğur Taşkıran (Kaleseramik Research Center, Çanakkale, Türkiye)

15:00 Photonic sintering of BaZrO3-based proton conductors

Conventionally, ceramics are densified by sintering in a furnace, a time-consuming and energy-intensive process. Several advanced sintering technologies such as FAST-SPS, UHS, and photonic sintering have been developed to improve the sintering process. For photonic sintering, ceramics are directly heated with a light source (e.g., a blue laser) enabling rapid heating rates of up to several 100 K/s reducing the overall sintering time. This is especially of interest for acceptor-doped BaZrO3, a proton conductor, which is challenging to sinter conventionally. BaZrO3 is sintered at high temperature (~ 1600 °C) for extended periods (~ 24 h). This leads to unwanted BaO evaporation, which has a negative impact on the microstructure and functional properties.
In the present study, the sintering behavior of acceptor doped BaZrO3 during photonic sintering is investigated. The influence of different parameters, such as heating rate, sample geometry, and substrate type, on power demand , shrinkage rate and material properties is explored. As the laser power is controlled by the temperature measurement of a pyrometer, power demand and temperature are easily documented. Furthermore, synchronized video documentation allows the determination of the shrinkage rate as well as a quick assessment of the sintering behavior during the process enabling efficient adjustments . The sintered samples’ phase composition, microstructure and functional properties were characterized by XRD, SEM and EIS.

Speaker: Julian Ebert (IKMT - Universität Stuttgart)

14:10 → 15:40 Sintering for additive manufacturing: (1)

14:10 Dimensional and Geometrical Changes During Sintering of Binder Jetting Components

In this study, the sintering behavior of stainless steel 316L components produced by binder jetting process is detailed. It explores the effects of initial particle/pores distribution, gravity, and friction on sintering, leading to anisotropic shrinkage and shape distortions. Dilatometry tests were conducted to experimentally investigate the anisotropy behavior and microstructural evolution at different sintering temperatures.
The influence of the gravity and friction forces during sintering are experimentally investigated through the analysis of the distortions developed in sintered parts with overhangs and tee-pipe connectors. Moreover, in this work, the novel sintering simulation framework for gravity-affected sintering of stainless-steel including the Rios-Olevsky-Hryha sintering model and the constitutive law which includes material constants to account for the powder packing effects and the delta-ferrite transformation occurring at high temperatures is presented.

Speaker: Elisa Torresani (San Diego State university)

14:40 Low shrinkage sintering of additively manufactured transparent silica glass

Silica glass is a versatile material prized for its transparency, chemical and thermal resistance. While it has been traditionally manufactured via glass blowing and the float glass method, recent advances in additive manufacturing (AM) for glass are enabling previously unattainable design freedom. One of the most widely used AM methods is based on powder processing, where a photoresin laden with fumed silica is structured via stereolithography, debound and sintered to produce transparent silica glass components. However, the rheological requirements that stereolithography imposes on these resins typically limit solid loading to moderate levels, inducing a linear shrinkage of approximately 25–30%. While the shrinkage inherent to this process can offer benefits such as sub-pixel resolution, it also necessitates careful heat treatment protocols to prevent cracking.
Here, we demonstrate a novel bimodal stereolithography photoresin formulation and corresponding post-treatment protocol that restricts linear shrinkage to less than 10 %. By minimizing dimensional change during heat treatment, this approach reduces the tendency for crack formation and facilitates the manufacturing of complex geometries with difficult-to-sinter features, such as abrupt cross-sectional variations and sharp internal angles. This opens the pathway to efficient and robust near-net-shape processing of silica glass components.

Speaker: Christopher Lankhof (Delft University of Technology)

15:00 A versatile binder system enabling co-debinding and sintering in multi-material vat photopolymerization

Vat photopolymerization (VPP) enables high-resolution additive manufacturing of ceramic components and offers significant potential for multi-material processing. A key challenge is the development of compatible binder systems that ensure defect-free debinding and subsequent sintering, particularly at material interfaces. In this work, a versatile binder system was developed and applied to ceramic slurries based on aluminum oxide (Al₂O₃), zirconium dioxide (ZrO₂), zirconia-toughened alumina (ZTA), alumina-toughened zirconia (ATZ), silicon dioxide (SiO₂), aluminum nitride (AlN), and titanium dioxide (TiO₂) with solid loadings between 45 and 56 vol-%, fulfilling VPP requirements regarding viscosity and curing behavior. Thermogravimetric analyses enabled the derivation of a unified debinding program suitable for all investigated materials. Following debinding, the components were successfully sintered under material-specific conditions, yielding dense, almost defect-free microstructures. Relative densities between 95 % and nearly 99 % were achieved. The sintering results demonstrate that the developed binder system enables reliable downstream processing and provides sufficient densification for an initial validation of the process chain. Overall, this work represents an important step toward robust multi-material VPP, forming a solid basis for future optimization of co-sintering strategies.

Speaker: Ms Chantal-Liv Lehmann (wbk Institute of Production Science)

15:20 SLA 3D Printing of high-conductivity Sc-Stabilized Zirconia electrolytes for Solid Oxide Cells

The development of alternative electrolyte materials with higher ionic conductivity than conventional 8mol% yttria-stabilized zirconia (8YSZ) is of strong interest for solid oxide cells, particularly when combined with techniques such as ceramic additive manufacturing. Among these materials, ScSZ exhibits superior ionic conductivity; however, Sc-doped electrolytes been reported to promote the formation of rhombohedral phase potentially compromising long-term stability.
In this work, stereolithography (SLA) 3Dprinting was used to shape ceramic electrolytes based on 10% Sc-stabilized zirconia (10ScSZ) and 10% Sc-1% Ce co-doped zirconia (10Sc1CeSZ), with the latter investigated to enhance phase stability. Post-printing sintering was optimized for both compositions, achieving relative densities above 95% while maximizing ionic conductivity. The electrolytes were first characterized in symmetric configuration, yielding ionic conductivities of ~0.1 S·cm⁻¹ at 800°C, significantly higher than values typically obtained for 8YSZ.
Based on these results, electrolyte-supported cells (ESC) were fabricated using LSCF-CGO oxygen electrodes and NiO-YSZ fuel electrodes. Full-cell testing on ESC, with thicknesses of ~250 µm for both materials, resulted in current densities of 0.5 A·cm⁻² at 0.7 V and 800°C, demonstrating the high ionic conductivity of the 3D-printed electrolytes at the device level. In addition, ageing tests were carried out to assess the degradation behavior of both materials.

Speaker: Antonio Maria Asensio (Catalonia Institute for Energy Research (IREC))

14:11 → 15:41 Field assisted sintering technology/Spark Plasma Sintering FAST/SPS: (1)

14:11 High-Intensity Electric Nano Pulsing

A novel field-assisted materials processing technique based on the electro-nano-pulsing (ENP) method has been developed, along with a device capable of applying electric pulses with ultra-high intensity (~10¹¹ A/m²) and ultra-short duration (<1 μs).
This technology activates non-equilibrium structural evolution at nanometer spatial scales and nanosecond temporal scales, primarily affecting grain boundaries in polycrystalline materials. Owing to the large difference in electrical resistivity between the grain interiors and grain boundaries, highly localized Joule heating can be achieved.
Additional effects include localized modification of the material structure at the micro- and nanoscale without significant changes in grain size. Ni–Cr wires processed by ENP exhibit unique structures and properties.
Beyond bulk materials processing, the ENP technology has been extended to electrically driven, non-equilibrium densification of powder materials. Ultra-rapid neck formation and densification occurring within milliseconds have been demonstrated, for example, in pressure-assisted ENP sintering of 316L stainless steel. Experimental observations of electrically driven mass transport and interfacial phenomena at the particle scale provide new insights into the fundamental mechanisms of electric field-assisted sintering.

Speaker: Prof. Eugene Olevsky (San Diego State university)

14:41 The effect of high-pressure induced plasticity on the microstructure and properties of nano-structured transparent ceramics fabricated using high-pressure spark plasma sintering

Transparent ceramics have great potential for applications in lasers, optical systems, armor and nuclear technologies. Magnesium aluminate spinel is a promising transparent ceramic that can be prepared by conventional multi-stage processes. However, single-stage spark plasma sintering (SPS) is a less time-consuming approach. Polycrystalline alumina is another widely used engineering ceramic. However, α-Al2O3 is birefringent (hexagonal crystal structure). Hence, high transparency in the visible domain can be only obtained with very low residual porosity (< 0.1%) and grain sizes smaller than the incident light wavelength to limit scattering losses. In this work, high-density nanostructured MgAl₂O₄ and α-Al2O3 ceramics were produced by high pressure SPS (HP-SPS) up to 5 GPa. High pressure densification produces green bodies with fine pores and high density, which improves the sintering process. In fact, application of 1.5 GPa pressure reduces significantly sintering temperatures (< 1000°C), resulting in dense, transparent ceramics without grain coarsening. It has been shown that high pressures induce not only high green density but also plasticity within the ceramic nanoparticles. The objective is to understand how this plasticity modifies the sintering mechanism and affects the final properties. Advanced analysis techniques have been used to monitor microstructure evolution and properties under high pressure and temperature (SEM, TEM, Real in line transmission, Hardness tests).

Speaker: Sandrine COTTRINO (Laboratoire MATEIS - INSA de Lyon)

15:01 Hard-to-Sinter materials in Easy-to-Sinter waveforms

Commonly the majority of SPS sintering studies, in research, development and production, are performed with the ON/OFF pulses. After the introduction of SPS some 30-40 years ago, much attention was focussed on finding an optimal ratio between ON and OFF times. During later years this has not been so much researched, instead people tend to stay with an almost “fixed” ratio, like 12/2 or 40/10. Not much optimisation is to be expected by varying the ratio. Even though ON/OFF is the absolutely most common wave current form, some very few studies use constant DC or AC.
During recent times we have been exploring a new wave-form which can be called Full wave. The findings in general can be summarized in the following sentences:
The sintering process starts at lower temperatures, consumes less energy and reaches often higher densities. There are differences between types of materials – metals/ceramics/hard-to-Sinter materials, which we try to systematize. There are also indications that reactions between different powder components proceed with different reaction rates under different wave forms.
The possibility to combine this effect with an advanced de-gassing process which cleans up the powder by removing moisture and impurities under heating at low pressure before sintering commences adds further advantages to be explored.

Speaker: Dr Lars Helldahl (Kagaku Analys AB)

15:21 Double-Cycle Spark Plasma Sintering of percolating refractory metal–ceramic composites for electrified high-temperature processing

The electrification of high-temperature industrial processes necessitates the development of a new class of materials that simultaneously withstand extreme environments and exhibit sufficient electrical conductivity. Composites combining refractory metals such as niobium and tantalum with the well-established alumina represent a promising approach to meet these requirements.
By systematic variation of particle size distributions, sintering parameters, and phase contents, key characteristics such as electrical conductivity, mechanical strength, and thermal stability can be adjusted while simultaneously reducing the percolation threshold of the metallic phase. Dense ceramic matrices containing finely distributed, percolating metallic networks can be produced, providing electrical heating capability together with the inherent high-temperature stability of a refractory composite.
A hierarchical composite architecture is realized by crushing the dense primary composite into granules, generating two-phase interpenetrating particles that are subsequently consolidated in a second SPS step. This processing route yields microscopically dense granules embedded in a macroscopically porous framework with reduced shrinkage, enabling additional control over thermomechanical properties while maintaining a conductive material system.
The presented processing strategy demonstrates a versatile pathway toward electrically heatable composites for next-generation high-temperature applications.

Speaker: Mr Gregory Kallien (Institute for Applied Materials (KWT)- Karlsruhe Institute of Technology)

15:20 → 15:40 Sintering of multi-material and multilayer systems

15:20 Rapid sintering to obtain tough and strong alumina-based ceramics

Layered ceramics have proved effective against contact damage and thermal shock, associated with the effect of compressive residual stresses and/or textured microstructure against surface crack propagation. In addition, the use of “rapid sintering” non-conventional techniques has made feasible tailoring the size and/or shape of grains in bulk alumina materials. In this study we explore the effect of rapid sintering on the mechanical response of layered ceramics, combining in-plane residual stresses with tailored microstructures in the different layers.
Two different layered designs are investigated, sintered using a pressure-less SPS with heating rates of up to 450 °C/min. In a first design, zirconia-toughened alumina (ZTA) is embedded between alumina (EA) layers, in order to generate in-plane compressive residual stresses in the surface and fine-grained microstructure. Biaxial bending tests are performed and compared to rapid sintered and conventionally sintered bulk alumina samples. In a second design, templated alumina (TA) layers are embedded within a fine-grained (EA) alumina matrix to combine the effect of internal compressive residual stresses and crack deflection potential. Selected Herztian contact and thermal shock experiments are performed in the rapid sintered samples. Results are analysed in regard to the microstructural features and crack deflection capability of the embedded textured layers.

Speaker: Prof. RAUL BERMEJO (Technical University of Leoben)

15:41 → 16:00 Coffee break

16:00 → 17:10 Microstructure evolution during sintering and Microstructure-property relationships: (2)

16:00 Comparison of observed grain boundary migration to capillary driving forces

Recent studies of grain growth in polycrystals by three-dimensional high energy X-ray diffraction microscopy have been able to quantify grain boundary migration rates in a variety of materials. One of the principal findings has been that grain boundary curvature is not a good predictor of the direction or speed of grain boundary migration. This presentation will focus on the influence of grain boundary energy anisotropy on the driving force and, more specifically, the anisotropy associated with the grain boundary plane inclination. Grain boundary migration observations will be compared to the driving force that includes the grain boundary stiffness and to the weighted mean curvature driving force that includes the influence of the energies of connected grain boundaries that meet at triple lines. The latter driving force predicts that local grain boundary area changes are correlated to the difference in the energies of the grain boundaries that meet at a triple line. This prediction is consistent with experimental observations and causes low energy grain boundaries to expand and reduce the areas of higher energy boundaries.

Speaker: Greg Rohrer

16:30 Microstructure–Tribology Relationships in ZnO–MoS₂ Composites Consolidated by Advanced Sintering Techniques

ZnO-based ceramics are promising candidates for functional and wear-resistant components due to their combined electrical, optical, and tribological properties. In this work, ZnO composites containing 2.5 wt.% MoS₂ were consolidated using three distinct sintering routes: Microwave Sintering (MW), Spark Plasma Sintering (SPS), and the Cold Sintering Process (CSP), in order to establish how each densification mechanism governs microstructural development and, consequently, tribological behavior. Particular attention was given to the role of grain size, porosity distribution, and phase dispersion in enabling self-lubricating responses. Microstructural characterization by FESEM, together with density measurements, revealed marked differences among the three techniques, with variations in grain growth kinetics and residual porosity linked to the heating mode and processing parameters. These microstructural changes are expected to directly affect wear mechanisms and frictional performance by modifying contact conditions, load-bearing capacity, and the formation of lubricating tribofilms associated with MoS₂. Overall, the results demonstrate that tailoring the sintering route provides an effective pathway to engineer ZnO–MoS₂ composites with microstructures optimized for improved tribological functionality.

Speaker: Dr Andrés Mormeneo (Instituto Universitario de Tecnología de Materiales, Universitat Politècnica de València - Spain)

16:50 Particle size-dependent sintering-crystallization mechanisms in oxide glasses with surface crystallization

Viscous flow sintering is a key route in ceramic processing that promotes particle coalescence driven by surface energy minimization. This process is widely used in industry; it lowers manufacturing temperatures in ceramic processing and increasingly enables advanced photonic technologies. Achieving the desired material properties requires precise control of densification. In non-crystallizing glasses, microstructural evolution proceeds through neck formation, collapse of interconnected pores, and shrinkage of spherical pores within a continuous matrix. However, most glasses crystallize above the glass transition, which hinders viscous flow and makes densification and microstructural evolution more complex and less predictable. We analyzed the microstructural evolution of diopside glass powder compacts during sintering with concurrent crystallization, considering different particle sizes, using optical microscopy and 3D synchrotron X-ray tomography. There is a critical particle size for forming a continuous crystallized layer on the particle surface. The sinter-crystallization mechanism is governed by the number of surface nucleation sites per particle. Phase evolution (glass, crystals, and intra- and inter-particle pores) was quantitatively assessed via 3D phase segmentation. Applying this method for glasses with stoichiometric crystallization is challenging, as phase X-ray attenuation differs only in atomic structure. The implications of this limitation will be discussed.

Speaker: Roger Fernandes (Brazilian Center for Research in Energy and Materials (CNPEM), Brazilian Synchrotron Light Laboratory (LNLS))

16:00 → 17:30 Sintering for additive manufacturing: (2)

16:00 Printed Power: High-Performance Electrical Steels via Powder Metallurgy

Electrical steel sheets are conventionally produced by rolling followed by punching. With the ongoing electrification there is a growing demand for thinner laminations. However, further thickness reduction by conventional manufacturing is challenging. Moreover, alloy design is limited to compositions with sufficient ductility for mechanical processing.
Additive screen printing represents an alternative manufacturing route for next-generation electrical steels, enabling near-net-shape fabrication of thin sheets with tailored compositions independent of ductility. The sinter-based screen-printing process allows the production of ultra-thin laminations with minimal material waste and precise control over sheet thickness and composition. Reducing the sheet thickness below 200 µm and increasing the silicon content up to Fe-6.5Si significantly lowers eddy-current losses. Recent developments extend the approach to high-performance Fe-Co alloys, revealing distinct sintering behavior depending on powder characteristics and phase evolution. Furthermore, multimaterial screen printing of metal-ceramic composites enables the fabrication of electrically insulated steel stacks. The influence of powder type and alloy composition on densification, shrinkage behavior, and the resulting magnetic and electrical properties is discussed, providing a materials-based pathway toward thin Fe-Co laminations with reduced high-frequency losses and limited post-processing.

Speaker: Inge Lindemann (Fraunhofer IFAM Dresden)

16:30 Development of Sintering Methods for Near Net Shaping of Copper by Selective Powder Deposition

In the current day industry laser based Additive Manufacturing (AM) of metals is a well-established production technique. Its main limitation, linked to inherent the rapid melting and solidification, is the narrow range of compatible materials. In comparison, sintering based AM offer a potentially much larger library to select from, including many of the traditional Powder Metallurgical materials. Most commercially available solutions are based on binder jetting, material extrusion and stereolithography. These, however, all share the same disadvantage in the need to remove binder prior to consolidation by sintering. This can limit the applicable range of obtainable geometries, instilling a strong preference for thin-walled parts.
Previously the use of Selective Powder Deposition (SPD) combined with sintering was proposed as an alternative AM method avoiding the need for debinding. In SPD multiple powders can be stacked in a layerwise manner to form a 3D powder construct. If one of these powders is an inert non-sintering material, then in theory parts, mono- or multi-material, can be obtained via heat treatment of this powder construct. In this, the sintering is the crucial step determining both material properties and geometrical accuracy.
In the current work we present an extensive study into the densification of copper parts obtained via the SPD route. The influence of several sintering methods, atmospheres and thermal cycles are examined in relation to material properties.

Speaker: Dr Bram Neirinck (Schaeffler Aerosint SA)

16:50 Sinter-based Additive Manufacturing of Carbide-Rich Tool Steels AISI A11 and AISI M3

Metal Binder Jetting (MBJ) combined with sintering enables Additive Manufacturing (AM) of carbide rich steels that are standard in tooling but are prone to cracking in beam based AM.

For high-speed steel HS6 5 3 (1.3344, AISI M3) and cold-work steel X245VCrMo10 5 1 (AISI A11) we developed printing, debinding and sintering parameters to yield crack free, low distortion parts. We map the sintering window with respect to debinding quality, heating rate, sintering temperature, dwell, and atmosphere, and show how these parameters govern densification, shrinkage anisotropy, and microstructure. We present strategies to mitigate distortion and investigate how variations introduced during printing affect the final properties. Repeatable debinding and sintering cycles across multiple builds and powder lots result in near full densification and predictable linear shrinkage, despite the relatively low green density of MBJ parts. By testing a large number of samples and different geometries, we obtained statistically robust results that can be transferred to demonstrator-scale geometries.

The talk will report mechanical properties achieved for AISI A11; investigations for HSS (AISI M3) are ongoing. The results provide actionable guidelines for MBJ tool steel sintering, a foundation for systematic property benchmarking against conventional, PM HIP, and PBF LB routes, and pave the way to industrialization.

Speaker: Christian Weck

17:10 Printing-Induced Particles Segregation Governs Anisotropic Sintering in Binder Jet Additive Manufacturing

Anisotropic shrinkage during sintering is limiting the widespread adoption of Binder Jet Additive Manufacturing (BJAM) by undermining its ability to produce near-net-shape parts. While emerging evidence indicates that powder segregation during BJ printing induces particle-size heterogeneities, its influence on the anisotropic sintering of BJ-printed samples has not been explored. This study investigates the relative effect of pore and particle size heterogeneities on anisotropic sintering by developing a digital twin model to simulate the BJAM process. The model captures the dynamics of particles during the powder spreading process, including particle segregation, using the Discrete Element Method (DEM), enabling spatially resolved representations of packing density and particle-size heterogeneities. It also simulates the sintering response using the continuum theory of sintering implemented in finite element (FE) codes. Capability of the developed model is verified and validated using experimentally measured results for binder jet printed samples from literatures. It is revealed that particle-size heterogeneities, caused by powder segregation during printing, govern anisotropic shrinkage during sintering of binder-jet-printed samples. The work highlights the need for optimizing feedstock particle size distributions and powder spreading parameters to control anisotropic shrinkage in BJAM process.

Speaker: Tesfaye Molla (The University of Melbourne)

16:00 → 16:30 Fundamental aspects of sintering

This is the description of the Session.

16:00 Grain boundary structure and chemistry as an effect of external fields and processing

Dopant adsorption at a grain boundary is described by the number of atoms per unit area of unit interface area in comparison to the adjacent bulk phase. The so-called excess quantity can be positive or negative dependent on whether there is an enrichment or depletion of dopant atoms at the grain boundary. In the first part of the talk suitable techniques to determine grain boundary excess quantities will be reviewed and discussed. Subsequently examples will be discussed that include twist in tilt grain boundaries in doped and undoped SrTiO3 that were exposed to externally applied electric fields, and Y-doped BaZrO3 that was densified by conventional sintering techniques and ultra-fast high-temperature sintering.
For near 45º twist grain boundaries in Fe-doped SrTiO3 HAADF-STEM imaging revealed an equilibrium grain boundary thickness irrespective of the bulk chemical potential for Fe [3]. However, STEM-EDS measurements reveal that grain boundary excess quantities vary with the total amount of dopant added to each bicrystal. It will be demonstrated that, in some cases, extended thermal annealing is required post diffusion bonding to achieve equilibrium grain boundary configurations. Electric fields exposed to undoped tilt grain boundaries in SrTiO3 reveal significant modifications of grain boundary structures owing to the redistribution of oxygen vacancies along the interface plane that is accommodated by disconnection movement.

Speaker: Klaus van Benthem (The University of Alabama, Department of Metallurgical and Materials Engineering, Alabama Materials Institute, Tuscaloosa, CA, United States)

16:01 → 17:31 Field assisted sintering technology/Spark Plasma Sintering FAST/SPS: (2)

16:01 Elemental grain boundary segregation and geometry during spark plasma sintering of multi-component carbides

Multi-component carbides are promising materials for ultra-high temperature applications, offering greater tunability of properties and design flexibility. However, they still suffer from processing challenges that must be addressed before full advantage can be taken during use in advanced technologies. In this study, we describe the spark plasma sintering and grain boundary characterization of (Mo-Nb-Ta-V-W)C (MNTVW-C) multi-component carbides. Specifically, we describe variations in grain boundary chemistry in MNTVW-C, sintered from either the single-phase rock-salt carbide powder, or from powders that include the rock-salt carbide phase, Mo2C and W2C. Grain boundaries in the sintered ceramic fabricated from the pure carbide powder possess greater levels of tungsten segregation. Additionally, the grain boundary geometry varies significantly between samples. The concentration (measured in percent length) of lower energy special grain boundaries is increased measurably in the ceramic prepared from multi-phase powder. These microstructural variations may have consequences in the bulk MNTVW-C behavior connected to fracture strength, creep resistance, oxidation behavior, and thermal or electrical transport. Grain boundaries can act as fast diffusion pathways and preferred sites for chemical reactions, making their local composition especially influential in high-temperature and extreme environments. These effects will be considered in detail during this talk.

Speaker: Olivia Graeve (University of California San Diego)

16:31 Pseudoelasticity in LaNbO4 micropillars

Pseudoelastic materials are distinguished by their ability to undergo fully reversible stress induced phase transformations. In bulk ceramics, this effect is rarely observed due to their intrinsic brittle nature and low fracture toughness. To mitigate critical flaws such as grain boundaries and bulk defects that hinder pseudoelasticity, researchers have focused on microscale specimens, including microspheres and micropillars, which can exhibit pseudoelasticity, often accompanied by residual transformation strain. In this work, we report pronounced pseudoelastic behavior in LaNbO4 ceramic. First, we micromachined monolithic micropillars from a densified specimen produced by spark plasma sintering. Under cyclic uniaxial compressions, these micropillar structures exhibited a remarkable pseudoelastic response with high resilience. These findings establish LaNbO4 as a promising responsive ceramic material for durable actuator mechanisms operating in extreme environments, such as elevated temperatures and pressures, where ceramic materials performance exceeds that of conventional alloys and polymers. This behavior opens significant opportunities for applications in the automotive, energy and aerospace industries.

Speaker: Mr Cesar I. Martinez-Cruz (University of California San Diego)

16:51 Application of Spark Plasma Sintering to Simulate Volatile Fission Products in High Burn-Up Spent Nuclear Fuel

Waste management remains an important issue in nuclear energy. To safely handle spent nuclear fuel (SNF), it is important to study the behaviour of volatile fission products (FP) in it, which is challenging, particularly regarding Cs and I, because the relatively low boiling point of CsI makes traditional sintering of CsI-included UO₂ pellets impossible. In contrast, spark plasma sintering (SPS) can be used here to synthesise such pellets, avoiding the evaporation of CsI due to lower temperatures and shorter sintering times. The latter also allows the sintering process to be optimised more quickly to achieve the desired microstructure. In the current study, the combined effect of different factors on the chemistry and release of Cs and I was investigated by optimising the SPS parameters to achieve a nanostructure relevant to high burn-up and homogeneous CsI distribution. Ceramic samples sintered using the optimised parameters were studied employing various methods to analyse the CsI chemistry. The results showed that the presence of certain FP in nanostructured UO₂ leads to CsI speciation. Further analysis using Knudsen effusion cell mass spectrometry revealed that this in turn affects the temperature-induced release of Cs I and CsI gaseous fractions. This study highlights the advantages of SPS for investigating how various factors can influence the behaviour of volatile FP, which is critical for monitoring radioactive isotopes and ensuring the safety of SNF management.

Speaker: Daniil Shirokiy (Forschungszentrum Jülich)

17:11 Spark Plasma Sintering Technique for Cyclotron Solid Target Manufacturing for Nuclear Medicine

In recent years, Spark Plasma Sintering (SPS) has become a valuable technique in many industrial and scientific areas. It has also found application in the medical field, particularly in radionuclide production. INFN-LNL (National Institute for Nuclear Physics - National Laboratories of Legnaro) was the first group to demonstrate the promising results of using the SPS technique to produce solid targets, which are a crucial part of the medical radionuclide production chain. Manufacturing solid targets is a complex process that relies on different areas of knowledge and has its unique requirements. The starting material for the target is usually an expensive isotopically enriched powder, which requires attention to the material losses and method efficiency. Moreover, to withstand prolonged irradiation with high-intensity cyclotron beams and transportation to the hot cell, targets must possess certain mechanical characteristics. Additionally, the SPS was used for binding different materials, enabling the assembly of complex target designs.

This work will provide an overview of the solid targets design and production process using the TT_Sinter machine, designed and created for this application by the University of Pavia. Targets manufactured using SPS have been used to produce several promising radionuclides: 52/51Mn, 89Zr, 61/64/67Cu, and 155Tb. A reliable production chain for radionuclides enables more radiopharmaceuticals to be studied and made available to patients.

Speaker: Alisa Kotliarenko (National Institute for Nuclear Physics - National Laboratories of Legnaro)

16:30 → 17:10 Microwave sintering: (1)

16:30 Microwave Sintering of Li1.3Al0.3Ti1.7(PO4)3: A Fast and Efficient Route to Highly Conductive Solid-State Electrolytes

In this work, microwave sintering is demonstrated as a fast and efficient approach to obtain competitive Li1.3Al0.3Ti1.7(PO4)3 (LATP) suitable for solid-state batteries. LATP pellets were shaped by combined uniaxial and isostatic pressing at four and five tons, respectively, with a green relative density of 71%. Densification was carried out by between 800 and 1100 ºC, revealing a sigmoidal densification curve. A relative density of 91.4% was achieved at 1000 ºC with only 10 minutes of sintering. At temperatures above 1050 ºC, abnormal grain growth and rutile-TiO2 formation led to microstructural degradation. LATP electrolytes sintered at 1000 ºC exhibited an ionic conductivity of 0.5 mS cm-1 at room temperature and an activation energy of 0.20 eV. Symmetric Li|LATP|Li cells cycled for over 500 h at 0.05 mA cm-2 showed very low overpotentials (<40 mV). Overall, these results establish microwave sintering as a rapid, energy-efficient, and scalable route for producing high-performance NASICON-type solid-state electrolytes.

Acknowledgments: This publication is part of the grants PID2021-128548OB-C21&C22 and CNS2023-144190 funded by MICIU/AEI/10.13039/501100011033, “ERDF/EU” and the “European Union NextGenerationEU/PRTR”. A.M.-S. acknowledges the funding from the Aid for Early Research Projects (PAID-06-25) and the postdoctoral fellowship (PAID-10-24) programs from the Vice-Rectorate for Research of Universitat Politècnica de València.

Speaker: Dr Andrés Mormeneo-Segarra (Instituto Universitario de Tecnología de Materiales, Universitat Politècnica de València)

16:50 Microwave vacuum sintering of lunar mare regolith simulant LMS-1 for lunar construction

Lunar regolith can be used for construction of infrastructure such as landing pads, habitats and scientific labs required to support long-term future lunar surface missions. This study investigates microwave sintering of lunar regolith simulant, LMS-1, targeting three applications: (1) thermally insulating functional materials and (2) pellets as process materials in molten-salt electrolysis for oxygen and metal extraction - both applications require materials with high porosity and reasonable strength. For the construction of (3) landing/launching pads, the structural materials must have higher strength and density. Sintering is one of the proposed construction methods to form regolith structures of varying strength. It offers higher energy efficiency than melting. Microwave heating of materials provides volumetric heating and has significant advantages. However, microwave sintering poses significant challenge of temperature control inducing non-uniform temperature gradients. Lunar regolith and simulants are good absorbers of microwave energy at 2.45 GHz. Recent studies have demonstrated high energy savings and homogenous temperature distribution in susceptor-assisted (or hybrid) microwave heating of lunar soil simulants. Here, we demonstrate the experimental results of susceptor-assisted microwave sintering of LMS-1 in vacuum and characterize the products for porosity and microstructure analysis to understand the mineralogical changes governing the sintering process.

Speakers: Dr Dennis Harries (European Space Resources Innovation Center, Luxembourg Institute of Science & Technology, Luxembourg), Dr Vibha Levin Prabhu (European Space Resources Innovation Center, Luxembourg Institute of Science & Technology, Luxembourg)

17:10 → 17:30 Sintering of specific material systems

17:10 Reducing the Heavy Rare Earth Consumption in NdFeB Magnets via the 2-Powder Method

The 2-powder method (2PM) for manufacturing sintered NdFeB magnets, patented by TU Darmstadt and further developed by Fraunhofer IWKS, offers the possibility of significantly reducing the criticality of rare earth-based magnets. Heavy rare earth elements (HREs) such as Dy or Tb are used in green technologies like traction motors of electric vehicles to ensure sufficient temperature resistance of the magnets. In powder metallurgical production using the 2PM, a specific microstructure is set, whereby the HREs are only located in the outer areas of the hard magnetic grains. Compared to previous resource-optimized manufacturing processes like the conventional used grain boundary diffusion process (GBDP), the 2PM can also be used to process larger magnets (> 10 mm).
In this study, different jet mill powders, all in the single micron range, were mixed, and the influence of particle size differences on the magnetic properties was analyzed. Based on these results, huge 350 g magnets with dimensions of approximately 45 mm in height and 40 mm in diameter were prepared. Furthermore, the microstructure was examined using high-resolution analysis methods such as SEM, and atomic probe tomography. In addition, the 2PM was compared with conventional manufacturing methods using life-cycle-assessment.

Speaker: Konrad Opelt

Tuesday 1 September

09:00 → 10:30 Modelling and simulation of sintering at multiple scales: (1)

09:00 Challenges toward establishing a benchmark for sintering simulation

Recent advances in synchrotron X-ray tomography have shown that real microstructural evolution during sintering is far more complex than assumed in classical models [1]. To understand these complex phenomena and to move beyond a trial-and-error approach in process design, multiscale modeling and simulation of microstructural evolution are required.
At the particle or mesoscale, various methods—such as the discrete element method (DEM), Monte Carlo method (MC), and phase-field method (PF)—are used to study microstructural evolution and grain growth. However, because many different approaches have been proposed, it is often unclear which is most suitable for a given problem. All these methods involve bold simplifications and approximations, so their validity, range of applicability, and respective advantages and disadvantages must be critically examined and compared [2].
We are currently developing a kinetic model for multiparticle sintering based on rigorous theoretical analysis [3]. By using this model as a benchmark, we aim to facilitate the development of more advanced, large-scale sintering simulation methodologies.
1. G. Okuma, F. Wakai, Synchrotron X-ray multiscale tomography: Visualization of heterogeneous microstructures and defects in ceramics. J. Am. Ceram. Soc. 107, 1706-1724 (2024).
2. F. Wakai, Fundamentals of Sintering (Springer, 2025)
3. F. Wakai, G. Okuma, Rigid body motion of multiple particles in solid-state sintering. Acta Mater. 235, 118092 (2022).

Speaker: Fumihiro Wakai (National Institute for Materials Science)

09:30 Non-Isothermal Approaches to Evaluating Sintering Activation Energy

The determination of activation energy of thermally activated processes is conventionally carried out through a series of isothermal experiments and application of the Arrhenius equation. However, this approach cannot be directly applied to ceramic sintering, as it proceeds continuously through multiple stages across a broad temperature interval. The correct determination of non-isothermal kinetic parameters involves the use of experimental data recorded at several heating profiles and their evaluation using various theoretical models. Among the most employed approaches are the Constant-Rate-of-Heating (CRH) and the Master Sintering Curve (MSC) methods. In this study, the sintering behaviour of selected monolithic and composite oxide ceramics was investigated by high-temperature dilatometry, and the corresponding activation energies were determined. Furthermore, modified methodologies based on the Master Sintering Curve, including the Two-Stage Master Sintering Curve (TS-MSC), the Master Shrinkage Curve (MShC), and the Master Sintering Surface (MSS), were developed to describe more complex sintering schedules, anisotropic shrinkage, and pressure assisted sintering, respectively. With their help, for example, Two Step Sintering of monolithic ceramics and sintering of laminated composites were described. In such systems, more activation energies are required here to adequately characterize the sintering process, and their physical significance is discussed.

Speaker: Karel Maca (Brno University of Technology)

09:50 Numerical Evaluation of Nonuniform Sintering Shrinkage and Residual Stress in Bulk Ceramics Induced by Internal Temperature Gradients

This study presents a numerical evaluation of deformation and stress in bulk ceramic bodies induced by internal temperature gradients during the sintering process. Finite element simulations are conducted using a model previously proposed by the authors, in which the total deformation is decomposed into four components: thermal-reversible, thermal-irreversible, mechanical-reversible, and mechanical-irreversible. Large deformation theory is employed to account for the significant sintering shrinkage of approximately 20 %, and Master Sintering Curve is adopted to describe the thermal-irreversible deformation behavior. The model is implemented into the commercial finite element software ANSYS via User Programmable Features (UPFs).
Several numerical examples are presented to investigate deformation behavior and the development of stress during sintering. Particular attention is paid to the influence of internal temperature gradients on stress formation. The simulation results provide insight into the mechanisms of stress generation during sintering and are expected to contribute to a better understanding of macroscopic sintering behavior in bulk ceramics.

Speaker: Chikako Natsumeda (Saga University)

10:10 Simulation of grain morphology evolution during sintering

In the nuclear fuel industry, sintering is one of the key steps in the manufacturing fuel pellets. This process is driven by the solid-state diffusion of the ceramic, here either undoped/doped. At the microscopic scale, the green pellet consists of UO2 grain clusters. During the sintering, microstructure evolution depends on the competition between bulk, surface and grain boundary diffusion, which govern densification and grain growth.
Densification is mainly determined by grain boundary and bulk diffusion, which occurs mostly during the first stages. As the neck radius between two grains increases, grain growth dominates due to diffusion at grain interfaces, causing a boundary migration. Grain boundary diffusion reduces grain centre distances.
A 3D finite element software based on a mechanical approach, SALAMMBO, has been designed in our laboratory to simulate sintering. Each grain is modelled with a finite element mesh and is described as single crystal with an elastic constitutive law, all three diffusion paths included. A Lagrangian approach captures the irreversible shape evolution.
This model will study grain growth and morphology of two-grain systems and will later be extended to more complex configurations with more particles and unusual shapes. It will enable analysis of microstructural evolution for different compositions, such as undoped/doped UO2 or other compounds like U3O8; and the computation of sintering maps, relating grain size and relative density

Speaker: Evan Pereira (Commissariat à l'Energie Atomique)

09:00 → 09:30 Fundamental aspects of sintering

This is the description of the Session.

09:00 Liquid phase sintering an instrument of nanostructured materials architecture.

The comparison of traditional high-temperature liquid phase sintering and advanced low-temperature cold sintering processes will be discussed in the frame of new materials science paradigm and non-equilibrium thermodynamics.
At present, two big parts of materials science exist: hard-bonded materials (with bond’s energy higher than 1 eV) and soft-bonded materials (with bond’s energy less than 0.1 eV). The convergence of these two energy scales is more than a trend; it is the cornerstone paradigm of Materials Science. The New Paradigm treats the "soft" phase not as a secondary filler, but as a structural director and energy dissipator.
The "Hard" world such as ceramics, metals, and semiconductors is driven by enthalpy, processed at high temperatures. The "Soft" World includes polymers, liquids, and biological systems is driven by entropy and weak intermolecular forces such as Van der Waals, hydrogen bonding, processed at room temperature.
The paradigm represents a breakthrough in materials that self-assembled into complex 3D architectures that are thermodynamically impossible to reach via traditional melt-processing or hot liquid phase sintering. The CSP is the perfect manifestation of this statement. "Soft" chemistry of a solvent to reorganize "Hard" inorganic particles at near-ambient conditions.
If convergence is the "meeting" of two worlds (strong and weak bonds), then divergence is the explosive expansion of the state space made possible by that encounter.

Speaker: Prof. Andrey Ragulya (Frantsevych Institute for Problems in Materials Science NAS of Ukraine, and Private Institute International Research Center NANO)

09:01 → 10:31 Field assisted sintering technology/Spark Plasma Sintering FAST/SPS: (3)

09:01 Reactive pathways in zirconia based ceramics processing : when chemistry meets sintering

Yttria-stabilised zirconia (YSZ) is a key material in advanced ceramics, widely used in structural, biomedical and energy applications. Its processing relies on energy-intensive heat treatments, notably high-temperature sintering above 1400 °C. These processes have a significant environmental impact and, for biomaterials applications, lead to trade-offs between mechanical, optical properties and resistance to low temperature hydrothermal degradation. Recently, major efforts have focused on low-impact processing routes to reduce energy consumption. Wet chemical methods and non-conventional sintering processes, such as Spark Plasma Sintering and Cold Sintering, directly address eco-design challenges in ceramics. Reduced sintering temperatures and/or short sintering times enable the design of nanostructured ceramics, allowing optimized zirconia properties. However, these approaches raise questions on the mechanisms involved and the relationships between micro/nanostructures and properties. We propose strategies exploiting chemical reactivity combined with non-conventional processes within specific temperature windows, creating synergy between chemical reactions and densification. These strategies rely on reactive precursors, hydroxides and nanoparticles smaller than 10 nm, enabling enhanced reactivity and microstructure control. The results highlight the critical balance between densification and phases stability, the complexity of the mechanisms involved are discussed.

Speaker: Catherine ELISSALDE (ICMCB - CNRS)

09:31 High Entropy Oxides based on (Zr, Hf, Nb, Ta, Mo, W)Ox: From Powders to Resistively Switching RRAM Devices

Tailored densification of high entropy ceramic targets ( 2-inch) by SPS for RF-sputtering of resistively switching thin films of various compositions within the system ZrO2-HfO2-Nb2O5-Ta2O5-MoO6-WO6 are reported along with their microstructural and crystallographic characterization (SEM, HRTEM, XRD …). All single components of the high-order system are CMOS compatible and relevant to resistively switching thin film memristor devices, regarded as promising candidates for next generations of non-volatile memories (RRAM), with high storage density, fast switching kinetics, reduced power consumption, and the capability of in-memory computation. Compositions prepared show a kind of “cocktail effect” in the combinations of the original components: forming free behaviour of WOx, excellent retention of HfOx and high endurance of TaOx. Densification of such targets via natural sintering is challenging, due to the sluggish sintering kinetics generally observed in high entropy systems. Therefore, SPS of powders that were synthesized via (a) solid-state reaction or (b) by chemical precipitation (enhancing homogeneity and reactivity) has been applied. Thin films prepared from the targets were characterized analytically (XPS, AFM, XRD …) and used to fabricate memristor devices (4 m2) showing partially faster switching at lower voltages, with higher Off/On ratio between two resistance states, as well as an excellent cycling endurance of over 108 cycles compared to conventional TaOx-films.

Speaker: Christian Pithan (Forschungszentrum Jülich GmbH - Peter Grünberg Institute for Electronic Materials PGI-7)

09:51 Effects of Pulsed Current Sinter-Forging Parameters on the Performance of Ba0.6Sr0.4TiO3 Ceramics

Pulsed Current Sinter-Forging also known as Spark Plasma Texturing (SPT), a derivative of Spark Plasma Sintering (SPS), is an edge-free method in which a pre-sintered pellet undergoes radial deformation during sintering, leading to distinct grain growth behaviour. This work investigates the influence of key SPT processing parameters on the microstructure and dielectric performance of Ba0.6Sr0.4TiO3 (BST) ceramics. The study focuses on the effects of the pre-sintering route and onset pressure temperature on densification, grain size, and tunable dielectric properties. All SPT-processed ceramics achieved near-theoretical densities (>98.6%) and fine microstructures (0.44-0.76 µm), demonstrating the effectiveness of this method to enhance BST properties. Among all SPT approaches, the combination of conventionally pre-sintered pellets prepared at 800 ºC for 2 h, along with pressure applied from room temperature, resulted in BST ceramics with the highest tunable dielectric performance. This optimized condition led to enhanced dielectric permittivity, tunability, and k-factor while minimizing dielectric losses, establishing it as the optimal route for SPT processing of BST ceramics for tunable devices.

Speaker: Oleksandr Tkach (CICECO, University of Aveiro, Portugal)

10:11 Field-assisted sintering of biocompatible lithium sodium potassium niobate piezoceramics for bone regeneration

Piezoelectric materials have gained significant attention in the bioceramics research community. They can promote cell-material interactions that enhance bone tissue regeneration. However, conventional piezoceramics often face challenges such as cytotoxicity, degradation under physiological conditions, and difficulty achieving high density and functionality at low sintering temperatures. We demonstrated the successful synthesis of highly dense lithium sodium potassium niobate (LNKN) ceramics (~98.3% density) at a low sintering temperature of 825 °C using field-assisted sintering technology, exceeding the density of the conventionally sintered sample (~94% at 1060 °C). It is particularly advantageous for minimizing alkali volatilization, and enabling co-sintering with temperature-sensitive materials. The resulting LNKN showed a strong dependence of phase transformations between coexisting crystal structures on the sintering conditions. Grain growth was also controlled, and the enhanced hardness and a significant piezoelectric (~133.15 pm/V) response were observed. Piezoresponse force microscopy measurements on polarized and unpolarized surfaces also reveal that pre-osteoblast (MC3T3-E1) cell attachment was enhanced on polarized surfaces, and that individual cells simultaneously interacted with multiple regions of opposite polarity. These insights reveal a strong potential for LNKN, offering possibilities for control over material performance and promoting bone regeneration.

Speaker: Dr Abdullah Riaz (University of Rostock)

09:01 → 10:31 Photonic sintering: (2)

09:01 Laser Sintering of alumina

A direct laser sintering process that uses a high-intensity continuous wave (CW) laser as the heat source has been developed and 1 mm thick alumina was successfully sintered by laser irradiation for 1 minute. In this process, a YAG laser (or a fiber laser with a similar wavelength) with weak absorption was used instead of a conventional CO₂ laser, which is strongly absorbed by alumina. We found that preheating the alumina improved absorption. Laser sintering of high-purity alumina produced porous bodies with 60% porosity and a bending strength of 200 MPa due to selective powder surface heating. Sintered bodies composed of large crystals (1 mm in size) can be obtained from a mixture of coarse and fine alumina particles by selectively melting the fine particles under laser irradiation. Furthermore, we developed a novel laser sintering aid that preheats the alumina body under laser irradiation, functioning like conventional sintering aids. This aid was confirmed to enable high-density sintering in a short amount of time by promoting liquid-phase sintering under laser irradiation.

Speaker: Teiichi KIMURA (Japan Fine Ceramics Center)

09:31 Flash Lamp Annealing of Ferroelectric Films

Crystallization and sintering of ferroelectric oxides on non-conventional substrates enables flexible and/or transparent electromechanical devices. However, due to the mismatch between the processing temperatures of these oxides and the maximum thermal stability of the target substrates, such integration remains challenging.
Flash lamp annealing (FLA), where the film is selectively heated by high-intensity light while the substrate remains comparatively cold, offers a promising pathway for direct processing. It enables the annealing of large areas in a single exposure and its typical pulse length is in the order or millisecond or below.
We will demonstrate that perovskite lead zirconate titanate (PZT) thin films with thicknesses up to 1 µm can be crystallized and sintered directly from the amorphous phase on glass using FLA, achieving piezoelectric coefficients e33,f of 5 C m⁻². We further show that FLA enables the growth of PZT films on a wide variety of glass substrates, ranging from fused silica and soda-lime glass to modern flexible glasses such as Corning® Willow® Glass.

Speaker: Sebastjan Glinsek (Luxembourg Institute of Science and Technology)

09:51 Photonic Sintering of Fe-doped SrTiO3: Impact on sintering, microstructure evolution and functional grain boundary properties

Conventional sintering methods are costly, energy intensive and rather inefficient processes. Photonic sintering (illuminating ceramic samples with high intensity light) has been proven to be an effective method for sintering ceramics. The process readily works for many material systems, yet the fundamental understanding on how the process can be controlled, or how it impacts the ceramics properties is lacking.
The current study investigates the impact of different ultra-high heating rates on the sintering rates, grain growth rates and grain boundary properties of doped and undoped SrTiO3 material systems.
Sintering rates are determined by video documentation data and grain growth rates are determined by SEM imaging. The grain boundary properties are investigated using electrochemical impedance spectroscopy. All data of samples thermally treated by photonic sintering method will be compared to samples from conventional sintering methods.

Speaker: Pascal Zahler (Universität Stuttgart)

10:11 Microstructure and mechanical properties of photonic sintered silver doped yttria stabilized zirconia

Photonic sintering is a promising alternative to conventional furnace sintering, offering extremely high heating rates and significantly reduced processing times. The process relies on high-intensity light irradiation to directly couple energy into the surface of ceramic powder compacts, enabling rapid heating and densification.
In this work, photonic sintering of silver-containing 3 mol% yttria-stabilized zirconia (3Y-TZP) was investigated using short-wavelength laser irradiation. The small silver addition was used to improve optical absorption and enable efficient coupling of the laser energy into the ceramic powder compact. Cylindrical green bodies were sintered at peak temperatures between 1225 °C and 1550 °C with dwell times as short as 30 s and compared to conventionally sintered reference samples.
Rapid densification behavior, microstructural evolution, and mechanical performance were systematically investigated as a function of sintering temperature and dwell time. In addition, the temporal evolution of laser power during sintering was analyzed to gain insight into the dynamic laser–material interaction. The role of silver redistribution and evaporation, as well as transient thermal gradients across the sample thickness and their influence on local microstructural development, was also investigated.

Speaker: Carsten Teucher (IKMT Universität Stuttgart)

09:30 → 10:30 Sintering of multi-material and multilayer systems

09:30 Prediction and optimization of the sintering behavior of LaWO bilayer membranes for hydrogen separation

With the growing need for sustainable energy, efficient energy generation and conversion methods are becoming increasingly important. One of these conversion methods is hydrogen separation utilising ceramic membranes. These membranes consist of a thin, dense membrane layer and a porous support layer to ensure the membrane’s ability to withstand stresses is upheld. During sintering, the different porosities in the layers cause anisotropic shrinkage, resulting in the bending of the bilayer membrane. However, research on finding solutions to minimise this distortion during sintering is limited. The main objective of this numerical study is to optimise the interface between the dense membrane layer and the porous support layer and investigate adaptations to the sintering process to minimise the bending during sintering for Lanthanum Tungstate (LaWO). Experimental sintering data for each layer is combined with the Skorohod-Olevsky Viscous Sintering (SOVS) model and applied in COMSOL, where the bilayer model is then verified using experimental bilayer sintering data. After verification, the numerical model is applied to LaWO bilayer membranes with varying interfacial geometries. The numerical model provides experimentally unattainable information on the densification of the membrane and in the longer term, this work generates a platform for the design of geometries and manufacturing routines enabling the sintering of complex layered materials.

Speaker: Anne Timmermans (Eindhoven University of Technology)

09:50 Ceramic/metal multi-material parts by 3D extrusion printing and sintering: experiments and FEM modeling of the sintering stage.

Sintering-assisted 3D extrusion is an additive manufacturing process that enables the rapid, low-cost production of parts with complex geometries. The process involves 3D extrusion of a polymer (binder) filled to around 50% by volume with a metal or ceramic powder. After a debinding step, sintering is a critical stage during which shrinkage, deformation and cracking can occur. These phenomena are particularly important in the case of slender structures (creep under own weight) or multi-material parts (sintering kinetics and thermal expansion differentials). A comprehensive approach combining modeling and experimentation has been used to predict the sintering behavior of YSZ/Steel 316L bi-materials produced by 3D extrusion.

For this purpose, these deformations were described as the result of different contributions linked to reversible (elastic deformations, thermal expansion) and irreversible (densification, viscoplasticity) phenomena. Initial dilatometry tests enabled us to determine an Arrhenius-type sintering behavior law for each material. Then, dilatometry tests under load cycle were carried out to determine a viscous behavior law. A finite element model was then implemented and validated for the sintering of slender single-material part by comparison with optical dilatometry monitoring.
The model was then applied to the sintering of multi-material parts (bi-layers), and optical dilatometry was used to monitor the deformation of bi-materials in temperature in real time.

Speaker: Ms Elsa Nouguier (Laboratory SIMaP - Grenoble INP)

10:10 NiTiNb-316L co-sintering for multimaterial AM through liquid phase sintering

Multimaterial additive manufacturing (MMAM) promises to level up the fabrication of multifunctional parts by enabling the precise, voxel-level integration of different materials within a single component. While easier in soft matter, the integration of dissimilar metals in one printed component remains a significant challenge. This stems primarily from stark differences in materials processing, such as sintering temperatures for solid-state techniques.
Here, we discuss and demonstrate MMAM via filament-based AM of a "smart" active alloy (NiTi) and austenitic stainless steel (316L). Integration of NiTi, a shape memory alloy, within a 316L matrix is particularly attractive as it enables load-bearing structures with temperature-responsive functionality.
We outline a sintering strategy to exploit liquid phase sintering through Nb alloying of NiTi and to enable the formation of a continuous interface utilizing eutectic melts in the Fe-Ti system. This interface is notoriously difficult to process due to the formation of brittle intermetallics, detrimental for the mechanical performance. Beyond metallurgical bonding, the geometrical flexibility of AM is further explored to introduce “puzzle-like” interfaces that provide geometrical interlocking.
This combined chemical–mechanical approach provides a promising pathway toward more robust NiTi–316L multimaterial architectures for functional applications.

Speaker: Nerea Abando (ETH Zurich, Laboratory for Nanometallurgy)

10:31 → 10:50 Coffee break

10:50 → 11:20 Cold sintering

10:50 Transient chemistry evolution and defect formation in cold sintered dielectric ceramics

The rapid technological advancement has increased the demand for high-performance electroceramics. While extensive efforts have focused on discovering alternative materials, it is increasingly recognized that innovative processing strategies can unlock the full potential of established material systems. In this context, the cold sintering process (CSP) has emerged as a transformative approach, enabling densification at low temperatures (<350°C) and opening new pathways for microstructural and grain boundaries design. CSP is driven by a chemo-mechanical mechanism activated by a compatible liquid phase under applied pressure. This talk highlights the effect of liquid phase chemistry and processing conditions on densification, microstructural evolution and the resulting mechanical and electrical properties of cold sintered dielectrics. Emphasis is placed on tooling effects, an often overlooked yet critical parameter governing transient chemistry during CSP. By comparing different die designs, the roles of pressure and temperature homogeneity as well as controlled liquid phase confinement through tailored die clearances and sealing conditions are elucidated. These factors provide access to control the kinetics of the transient liquid phase, which are shown to affect densification, defect chemistry, and ultimately functional response. The results demonstrate the central role of chemical effects and defect formation in CSP, offering insights for the design of reliable dielectrics.

Speaker: Abdullah Jabr (Montanuniversität Leoben, Chair of structural and functional ceramics)

10:50 → 12:40 Modelling and simulation of sintering at multiple scales: (2)

10:50 Sintering Models Assessment from Experimental Tests to Inverse Learning Approaches: The Role of Sintering Moduli in Rapid Sintering and 3D-Printed Structures

Assessing sintering models experimentally is challenging, as it requires isolating both the thermally activated nature of sintering and the powder-specific behavior encoded in the sintering moduli. These parameters often exhibit strong interconnections, necessitating dedicated experiments such as instrumented sinter-forging tests. In parallel, inverse learning strategies based on gradient-descent optimization enable direct identification of model parameters and their interdependencies from dilatometry curves, using a framework inspired by machine learning. The resulting experimentally derived moduli accurately reflect the true behavior of the powder. We show that these experimental moduli are highly effective in reproducing ultra-rapid sintering kinetics, whereas theoretical models (based on simplified geometric assumptions) systematically underestimate the densification rate. Moreover, analyzing the final stage of densification provides reliable predictions of grain-growth behavior in particular for materials exhibiting strong grain-growth perturbations such as zirconia.
An additional perspective involves using representative volume elements (RVE) to determine effective sintering moduli for complex lattice architectures produced by 3D printing. Coupling finely extracted experimental parameters with machine learning tools enables robust finite element simulations capable of predicting the sintering of both bulk materials and architectured structures.

Speaker: Charles Maniere (CNRS CRISMAT)

11:20 Hybrid Constitutive Law with Machine Learning for Sintering of Advanced Ceramics

Predictive simulation of sintering-induced distortion remains challenging for ceramic components subjected to gravity and mechanical constraint. Classical constitutive sintering laws reproduce free densification reliably but lack the flexibility required to capture stress-driven deformation within finite-element (FE) frameworks when calibrated solely from dilatometer data. This study presents a hybrid machine-learning-assisted constitutive framework for modelling constrained sintering of an industrial ceramic material. Dilatometer densification data and a gravity-loaded beam-bending experiment were obtained for the same material system, enabling assessment of volumetric sintering kinetics and part-level deformation. Two independently calibrated parameter sets of an Olevsky-type constitutive law reproduce densification behaviour but underpredict gravity-driven curvature when applied in FE simulations, highlighting a trade-off between densification fitting and deformation prediction. To overcome this limitation, the analytical volumetric strain-rate term is replaced by an artificial neural network trained directly on experimental densification data, while analytical formulations for mean and deviatoric stress response are retained. The hybrid framework enables improved prediction of constrained sintering deformation without compromising physical interpretability or numerical robustness, providing a basis for industrial process optimisation and future digital-twin development.

Speaker: Dr Baber SALEEM (University of Leicester)

11:40 Sintering properties evaluation of metal powder compacts considering machine learning-based grain growth model

The sintering shrinkage of ceramic powder compacts is large because the organic binder is mixed in forming process, whereas metal powder compacts also experience large sintering shrinkage when formed using metal injection molding or sinter-based additive manufacturing technologies. To analyze the shrinkage deformation of powder compacts in the sintering process, material parameters in a constitutive equation, such as viscosity coefficient, sintering stress, and viscous Poisson's ratio should be obtained in experiments. In this study, we evaluate the sintering properties of pure nickel powder compacts, as a model material, using an atmosphere-controlled sinter-compression testing machine. At the same time, we measure the crystal grain size in the compact, which affects the viscosity coefficient, for each test, and use a machine learning to model the grain growth behavior as a function of the heating history and relative density. Using the machine learning-based model for crystal grain size, we identify the viscosity coefficient purely as a function of relative density, and examine its validity by comparing it with the existing constitutive models for sintering.

Speaker: Prof. Kazunari Shinagawa (Kyushu University)

12:00 Machine Learning–Enhanced Simulation and Optimization of Ceramic Sintering Processes

Sintering is one of the most critical stages in the ceramic manufacturing cycle, as it strongly affects the final properties and quality of ceramic products. The development of controlled process technologies for optimizing firing protocols and reducing production waste is therefore essential for modern ceramic manufacturing.

In this work, a novel process technology is presented that enables the entire sintering process to be virtually modeled, analyzed, and optimized through the combination of classical numerical simulation techniques and artificial intelligence methods. The proposed approach integrates multimodal heat transfer modeling within the oven with the prediction of the shape evolution during sintering. This is achieved by coupling physics-based simulations with Physics-Informed Neural Networks (PINNs). Based on this framework, comprehensive optimization of both the sintering process and the topology of the ceramic components can be performed. Optimization objectives include the reduction of waste through minimization of stress concentrations, shortening of process times via optimized firing schedules, and improvement of green body design while accounting for sintering-induced deformations. The model requires only readily accessible material parameters, such as density and porosity measurements of test specimens, results from three-point bending tests, grain size distributions, and the pyroplastic index.

Speaker: Jens Landgraf (sico-solutions scientific and technical soltuions)

12:20 Particle rotation as probe of resistance to interparticle sliding in the rheology of sintering

In conditions of constrained sintering, an aggregate's deformation may involve sliding along the interfaces of contact between particles. The boundary viscosity expressing the resistance to sliding is largely unknown. The motion of each particle is described by two vectors: the velocity of the particle centroid and the particle rotation rate. Interparticle sliding brings the decoupling of the two vectors, which adds degrees of freedom to the rheology. The work highlights two consequences: the dependence of shear viscosity on particle shape anisotropy, and the dependence of the flow on the gradient of rotation rate.

The flow of an isotropic 2D aggregate is analysed via two methods: (i) the computation of the mechanical equilibrium of the particles by minimization of dissipation; (ii) the simulation of the flow a micropolar (Cosserat) continuum mimicking the aggregate. Two straining modes are considered: a uniform strain rate created by periodic boundary conditions and a gradient of strain rate created by a couple applied on a nugget with variable size (possibly a single particle) centred into a crown of up to more than 900 particles. The work reveals that a low boundary viscosity coupled to a large particle shape anisotropy promotes particle rotation rate, which reduces the shear viscosity. The comparison of the two methods validates the micropolar viscosities to be ascribed to an aggregate and suggests potential routes for quantifying the resistance to boundary sliding.

Speaker: Prof. Laurent Delannay (UCLouvain)

10:51 → 12:40 Field assisted sintering technology/Spark Plasma Sintering FAST/SPS: (4)

10:51 Evaluation of high heating rates in FAST/SPS of WC/Ti powders

Field Assisted Sintering Technology/Spark Plasma Sintering (FAST/SPS) is considered one of the most efficient powder consolidation techniques, enabling the production of dense materials in very short processing times. Among the key process parameters, the heating rate plays an important role, as it affects both densification kinetics and microstructural evolution. Although FAST/SPS devices can in principle reach extremely high heating rates, their practical use is limited by several technological factors. Tool dimensions and geometry strongly influence energy transfer efficiency and therefore the maximum achievable heating rate. Increasing the heating rate also raises the risk of significant thermal gradients, especially in large or complex-shaped sintered compacts, which may lead to inhomogeneous densification, microstructural variations, and reduced performance of the final component. Additionally, local overheating of graphite tooling under extreme conditions can compromise process stability and tool lifetime. This work examines both the advantages, such as shorter processing times and potential microstructure refinement of WC/Ti systems, and the limitations associated with pushing heating rates to their extremes, offering insights that support more reliable and optimized FAST/SPS process design.

Speaker: Dariusz Garbiec (Lukasiewicz - Poznan Institute of Technology)

11:20 Influence of Deformation Speed on Final Density in Single-Discharge Sintering of Metallic Powders

The effect of deformation speed on the final density of copper and iron parts consolidated by a single-discharge sintering method was investigated experimentally. During the short electro-thermo-mechanical consolidation, the displacement speed of the press axis was systematically varied while all other process parameters were held constant. Samples of different heights and projected areas were evaluated to assess geometric sensitivity.

The results reveal a clear non-linear dependence of final density on deformation speed. Contrary to conventional quasi-static powder compaction, where lower strain rates generally favor higher density, the present experiments show that neither the lowest nor the highest deformation speeds maximize density. Instead, an intermediate range of deformation rates produces superior consolidation.

These findings demonstrate that press-axis displacement speed acts as an independent governing process variable in single-discharge sintering, rather than merely a mechanical boundary condition. The observed behavior suggests the presence of competing rate-dependent phenomena during the short-duration consolidation event, including transient thermal evolution and rate-sensitive plastic response.

The results provide new experimental insight into the process window of rapid field-assisted powder consolidation and establish deformation speed as a critical parameter for future modeling and optimization.

Speaker: Alessandro Fais (EPoS Technologies SA)

11:40 FULL SCALE INDUSTRILIZATION OF SPS/FAST FOR MANUFACTURING ADVANCED CERAMICS

The semiconductor manufacturing process has created one of the most extreme chemical and physical environments feasible through the use of halogen plasma dry etching for nano-fabrication. This environment requires ceramic chamber components of significant size (+600mm) that have exceptional chemical stability that produce zero defects on wafer. The extreme demands on semiconductor ceramics performance and supplier quality are the ultimate qualification for SPS as a manufacturing tool for making next generation material systems. Heraeus, a global supplier of semiconductor materials since the first transistor, has become the global leader in SPS manufacturing with more full scale production capacity than anywhere on the planet. The ceramic material requirements and development for etch applications will be discussed. In addition, the capabilities of high volume manufacturing a large scale ceramic product of exceptional quality using SPS will be demonstrated.

Speaker: Luke Walker (Heraeus)

12:00 Transfer of FAST / SPS technology from lab-scale to industrial usage for fusion energy, semiconductor and friction applications

Field Assisted Sintering Technology (FAST), also known as Spark Plasma Sintering (SPS), has become an established processing route in materials research and development due to its ability to consolidate and even join advanced materials with high heating rates, short cycle times, and excellent microstructural control. While often perceived primarily as a laboratory-scale technique, FAST/SPS has matured into a highly efficient and flexible manufacturing technology with high potential for industrial implementation.
In the presentation, it will be highlighted which efforts need to be made to transfer promising scientific results into large-scale industrial products. Main focus will be on two advanced, tungsten-based plasma-facing materials for fusion reactor applications: The SMART material (Self-passivating Metal Alloy with Reduced Thermo-oxidation) is designed to enhance safety by providing protective behaviour under accidental oxidation scenarios. The FIT material, a tungsten fibre-reinforced tungsten composite, targets improved ductility and extended lifetime compared to pure tungsten, and is particularly attractive for divertor applications. The work is part of the German BMFTR project “a-SMART-FIT” bringing together the expertise of German universities, research institutions and companies.
Additional case studies will be presented,underlining the potential of FAST as a mass production technology.
Keywords: Field-assisted sintering technology (FAST), Plasma Facing Components

Speaker: Mrs Ute Wilkinson (Dr. Fritsch Sondermaschinen GmbH)

12:20 Innovative Developments in Spark Plasma Sintering (SPS) Equipment Driven by Application Demands

GeniCore tracks market requirements to drive innovation in Spark Plasma Sintering (SPS) device design. Responding to evolving needs, the company developed the U-FAST Glovebox system—an integration of MBRAUN inert gas glovebox with U-FAST SPS technology. It enables continuous processing in inert atmosphere, preventing oxygen/moisture exposure for sensitive materials, achieving ultra-fast densification via <1 ms current pulses, minimizing grain growth and enhancing properties.

Key Innovations
Another advance is the U-FAST Compact PRO power supply. The upgrade delivers higher heating rates at equal power, with <1 ms pulse rise time and up to 5 kA currents. It supports DC (SPS), AC (induction), or combined modes controlled by a single PLC, blending both methods' benefits. Induction ensures efficient, rapid temperature control. Vacuum connectors prepare it for High-Voltage sintering.

Applications
Both systems target R&D and low-volume production of advanced materials like Bulk Metallic Glasses (BMG), High-Entropy Alloys (HEA), transparent ceramics, and thermoelectrics. Collaborations with top research centers validate their performance, accelerating progress in electronics, energy, aerospace, and beyond. Small-scale processes scale seamlessly to industrial volumes using identical parameters on production-grade equipment.

Benefits
This future-proof platform offers precise environmental control and process scalability, marking a breakthrough in plasma sintering technology.

Speaker: Damian Karpowicz (GeniCore Sp. z o.o. Warsaw, Poland)

10:51 → 12:40 Ultra-fast High Temperature Sintering UHS: (1)

10:51 Production of ceramic components via ultra-rapid sintering

Ultra-rapid high-temperature sintering has recently been proposed as a technique that enables the densification of ceramic materials in extremely short timeframes, thereby saving a considerable amount of energy. The process is based on the rapid heating of a carbon felt—in which the sample is placed—via Joule heating generated by an electric current. This approach is highly attractive for industrial applications, as it relies solely on electrical energy and avoids direct carbon dioxide emissions.
Nevertheless, several aspects must be investigated to scale up the process effectively. In the present work, fundamental processing parameters—such as felt configuration, sample size, current, and dwell time—were analyzed during the consolidation of alumina ceramics using a prototype furnace designed to resemble industrial equipment. The resulting materials were characterized in terms of microstructure, density, and porosity, and subsequently compared to specimens produced via conventional sintering. The results highlight the advantages of the UHS technique while identifying challenges related to surface contamination and the maximum processable dimensions of the samples.

Speaker: Prof. Vincenzo M. Sglavo (Department of Industrial Engineering, University of Trento)

11:20 Ultra-rapid, Pressureless, and Optically Instrumented Manufacturing of High-Performance Ceramics

A novel Pressureless Ultra-Fast Sintering (PLUFS) method has been developed through the integration of a dedicated tooling into Spark Plasma Sintering (SPS) systems. This approach enables heating rates up to 200 °C/s and reaching 3000 °C, allowing full ceramic densification to be achieved within seconds under pressureless conditions. PLUFS has been used to demonstrate high efficiency in producing dense ceramic materials while significantly limiting grain growth through optimized thermal profiles. Compared to conventional SPS, PLUFS achieves equivalent densification with approximately five-fold lower energy consumption, highlighting its potential for energy-efficient manufacturing. The method has been applied to a broad range of advanced ceramics, including refractory and structural materials. Real-time shrinkage evolution is monitored using in situ optical dilatometry, providing precise control over the sintering process and an optimization strategy based on PLUFS thermal control enables the identification of non-linear heating schedules that minimize grain growth while maintaining full densification.

Speaker: Prof. Eugene Olevsky (San Diego State university)

11:40 Low-power minute-scale sintering of complex parts

The growing demand for agile manufacturing of technical components—particularly in small series—calls for sintering solutions that are fast, flexible and energy-efficient, while remaining economically realistic.
We present a patented current-assisted sintering approach developed at BCRC (WO2025/099305 A1). The process relies on resistive heating of a graphite powder bed in which the part is embedded. This configuration enables minute-scale thermal cycles, reaching sintering temperatures up to ~1600 °C within a few minutes, without external pressure, and with very low electrical power (typically a few hundred watts).
Process capabilities are illustrated through an in-depth study on cemented tungsten carbide (WC–Co), a benchmark material for high-performance tooling. We discuss parameter optimisation and the resulting properties (relative density and mechanical behaviour), benchmarked against industrial standards from conventional sintering routes. In particular, WC–Co parts produced by extrusion and densified with this method achieved ~99% relative density with a ~7-minute sintering time.
Beyond material performance, the approach supports direct densification of complex geometries, enabling near-net-shape parts and reducing or avoiding post-machining—an important lever for cost and lead-time reduction. Compatibility with multiple material families (ceramics and metals) will be shown through representative examples.

Speaker: Dr Laurent Boilet (CRIBC)

12:00 Kinetics and mechanisms on ultrafast high-temperature sintering of barium calcium zirconate titanate

The transition from lead-based to lead-free piezoelectrics is currently a key challenge in the electroceramics community, which aims to find suitable sustainable materials. In the last decade, the solid solution barium calcium zirconate titanate (BCZT) has received increased attention for room temperature applications due to high piezoelectric coefficient and remnant polarisation. The high temperatures and long times required to sinter electroceramics have motivated the use of alternative sintering methods, such as ultrafast high-temperature sintering (UHS). UHS uses a carbon-felt heater in vacuum and Joule effect to enable ceramic densification in minutes, resulting in an out-of-equilibrium process. UHS ceramics typically exhibit fine microstructures and are oxygen-deficient due to heating rates exceeding 10³ °C/min and reducing conditions. Precise control of these conditions as well as of electrical current and time is therefore essential to obtain dense ceramics suitable for piezo applications, while avoiding partial melting, trapped porosity and abnormal grain growth. This study comprises a kinetic analysis of BCZT by conventional dilatometry, as well as investigation of the sintering mechanisms operating in the piezoceramics during UHS. For the latter, the evolution of density and grain growth was studied as functions of temperature and time during the UHS process in order to determine the sintering trajectory of the material, in comparison with conventional ceramics.

Speaker: Mr Joao L. Miranda (CICECO - Aveiro Institute of Materials, University of Aveiro)

12:20 Fabrication of Al₂O₃ Ceramics via Vat Photopolymerization 3D printing and Ultrafast High-Temperature Sintering

Vat photopolymerization 3D printing has emerged as a promising additive manufacturing (AM) technology for producing high-precision ceramic components. However, long post-processing times remain a significant challenge for industrial implementation. To address this limitation, the present study systematically investigates the effects of Ultrafast High-Temperature Sintering (UHS) processing parameters on the densification and mechanical properties of vat-photopolymerization-printed alumina ceramics. A two-factor, two-level factorial experimental design with central point replication was employed, considering electric current (70–80 A) and isothermal dwell time (30–60 s) as the independent variables. Green bodies were fabricated using a commercial alumina slurry (LithaLox350). The UHS process was directly compared with conventional sintering performed at 1650 °C with a 2-hour dwell time. Comprehensive characterization included three-point flexural strength, Vickers microhardness, relative density, grain size distribution, and fracture toughness. The results obtained so far demonstrate that UHS enables rapid densification while promoting a refined microstructure, achieving relative densities above 95% and flexural strength values of up to 538.9 MPa. These findings highlight the potential of UHS as a viable post-processing route for accelerating the production of high-performance ceramic components fabricated by vat photopolymerization.

Speaker: Natalia Daudt (Universidade Federal de Santa Maria)

11:20 → 11:40 Fundamental aspects of sintering

This is the description of the Session.

11:20 Non-Equilibrium Relaxation during the Cold Sintering Process

Materials perturbed to non-equilibrium conditions will spontaneously relax to their equilibrium state. The cold sintering of ceramics can be understood in this way. Throughout the cold sintering process (CSP), various diffusional and creep mechanisms transfer material from grain boundaries to porous regions to drive densification. Here, we will show that a relaxation model can be used to describe these diffusional mechanisms during the CSP. Zinc oxide cold sintered with acetic acid is used as a model system. Under isothermal conditions we will show that the observed relaxations are first order in nature and characterized by a single time constant. Via. a Fast Fourier Transformation (FFT) of the shrinkage data, concurrent relaxations are separated. Respective sintering data is assessed in the perspective of a modified Kingery two particle model. An initial relaxation is identified as a dissolution aided particle rearrangement, and the second as pressure solution creep. Temperature and pressure effects on each relaxation time is studied. The activation energy and characteristic relaxation time calculated from isothermal experiments will then be shown to readily predict densification behavior under non-isothermal conditions. Utilizing the relaxation model, the effects of various polymer additives and chemistries on the kinetics and microstructural evolution during CSP are discussed.

Speaker: Sevag Momjian (The Pennsylvania State University)

11:40 → 12:20 Cold sintering: (1)

11:40 Mechanistic Insights into Cold Sintering of Aluminosilicate-Based Powders: Evidence from Dissolution and Intergranular Phase Evolution

Cold sintering has emerged as an effective low-temperature densification route for a wide range of ceramic systems, relying on dissolution–precipitation mechanisms promoted by a transient liquid phase under applied pressure. In this study, a natural aluminosilicate-based material, namely a volcanic ash originating from Mount Etna, Sicily, is investigated to elucidate the chemical and microstructural mechanisms governing cold sintering, with particular emphasis on dissolution-precipitation processes. The effects of key cold sintering parameters, including applied pressure, processing temperature, and the molarity of the transient KOH solution, are systematically evaluated in terms of densification behavior as well as chemical and microstructural evolution. The resulting materials exhibit relatively low thermal conductivity combined with good mechanical strength, which can be attributed to the nature and distribution of dissolution–precipitation products formed during sintering. The dissolved species and their subsequent reprecipitation at particle contacts can influence the characteristics of the intergranular phases and, consequently, enable tunability of the final mechanical properties.

Speaker: Levent Karacasulu (University of Trento)

12:00 In operando Impedance Spectroscopy: a tool to reveal the influence of Cold Sintering Process parameters on microstructure and electrical properties

Recent advancements in low-temperature sintering techniques are driven by two key objectives: reducing energy consumption and environmental impact while enabling the synthesis of novel materials, composites, and functional devices. Among these methods, the Cold Sintering Process (CSP) emerges as a highly efficient approach for producing high-density ceramics. This process combines ceramic powders with a transient liquid phase, followed by uniaxial pressing under controlled thermal conditions below 400°C.
However, the underlying mechanisms of CSP remain poorly understood. To address this gap, the development of in operando characterization techniques particularly impedance spectroscopy is critical. This method, distinguished by its experimental accessibility and ability to resolve frequency-dependent electrical responses, provides insights into microstructural evolution by discriminating between grain, grain boundary, and transient liquid phase contributions.
This study demonstrates the application of in operando impedance spectroscopy to investigate CSP using ZnO (a semiconductor) as a model system and YSZ (an ionic conductor) as a technologically relevant material. By analyzing electrical responses during densification, the work explores relationships between processing parameters and the resulting microstructure. The goal is to establish correlations between in operando impedance measurements and fundamental sintering mechanisms.

Speaker: Mr Emeric SANCHEZ (CIRIMAT)

12:40 → 13:40 Lunch

13:40 → 15:10 Cold sintering: (2)

13:40 In situ analysis of solid-liquid interfaces during Cold Sintering Process through impedance spectroscopy

The Cold Sintering Process has emerged as a breakthrough in sintering science. Related to the chemical mechanisms leading to densification, new concerns about the composition/nature/behavior of grain boundaries (GB) emerged, different than what is usually observed in high temperature solid-state diffusion sintering techniques. This leads to widely affected properties of sintered materials, and is of huge importance in the case of electroceramics, sensitive to GB properties. To better control this aspect, a first step is to highlight and track these GBs evolutions. An in situ impedance analysis, during the sintering process of ceramics, was developed and used to measure the evolution of electronic/ionic conductivity of GB and liquid phase present in the process. Applying this to various ceramic materials allowed to shed light on unique GB evolution phenomena, but also highlighted the role and behavior of liquid phases used during sintering. The use of ionic liquids, often used for materials facing incongruent dissolution, was also explored and will be presented. The discussion will focus on the major trends, lessons learned from the use of in operando impedance analyses during CSP, offering opportunities to widely tune the properties of electroceramics.

Speaker: Thomas Herisson de Beauvoir (CNRS, CIRIMAT Toulouse)

14:10 Kinetic study of Zinc Oxide sintered by Cold Sintering Process (CSP)

The emergence of low-temperature sintering techniques (e.g., Cold Sintering Process (CSP), Hydrothermal Sintering (HS), Cold SPS (C-SPS), or ultra-fast SPS (Flash SPS)) allows the production of technical ceramics by activating mechanisms different from those involved in conventional sintering, to stabilize and densify metastable materials and/or to control microstructures (composition and thickness of grain boundaries). This has paved the way for the development of new materials and/or materials with enhanced properties.
While their effectiveness has been demonstrated, their development is still limited by a lack of fundamental understanding of the mechanisms involved. The use of kinetic models developed to describe sintering under load allows us to define parameters associated with these mechanisms (activation energy) and thus control densification and microstructure during CSP. Adapting these models to CSP sintering conditions (presence of a transient liquid phase) makes it possible to predict the sintering behavior of the studied material.
Ultimately, it could be possible to develop materials suitable for a wide range of applications, such as energy, transportation, or structural materials.

Speaker: Nicolas Albar (CIRIMAT)

14:30 Insights into NASICON Solid Electrolytes Densification via Cold Sintering Process with Sodium Ionic Salt Compositing

Sodium-ion batteries have recently gained attention as a sustainable alternative to lithium-based systems. However, the use of liquid electrolytes remains a major safety concern, motivating the development of solid-state alternatives. NASICON ceramics, particularly Na3Zr2Si2PO12 (NZSP), exhibit high ionic conductivity and excellent electrochemical stability, thus being strong candidates for solid-state sodium batteries. Nevertheless, conventional processing typically involves sintering temperatures above 1200 °C and long residence times, which involve high energy consumption and environmental impact.
Here, Cold Sintering Process (CSP) is proposed as a low-temperature and energy-efficient alternative for NZSP sintering. In this work, dense ceramics are obtained at 150 °C under 720 MPa, evaluating the effects of powder milling and TLP chemistry. When acetic acid is employed, the resulting samples reach higher ionic conductivity (0.50 mS/cm) compared to those processed with sodium hydroxide (0.25 mS/cm). Additional performance improvements are achieved by incorporating NaPF6 and NaTFSI salts. Composites containing 20% NaPF6 achieve the highest relative density (94.3%) and ionic conductivity (0.80 mS/cm). Moreover, the optimized 2h_20% NaPF6 electrolytes demonstrate stable operation for over 500 hours in symmetric sodium cells, as well as discharge capacities of 85 mAh/g at C/2 and above 100 mAh/g at C/10 after prolonged cycling in half-cell configuration.

Speaker: Dr Sergio Ferrer-Nicomedes (Universitat Jaume I)

14:50 Influence of cold sintering parameters on the microstructure and transport properties in Li1.3Al0.3Ti1.7(PO4)3 / LiFePO4 composites for all-solid-state batteries

The Cold Sintering Process (CSP)(1) is used to densify composite cathodes consisting of $Li_1._3Al_0._3Ti_1._7(PO_4)_3$ (LATP) as the solid-state electrolyte and $LiFePO_4$ (LFP) as the active cathode material. First, the parameters governing the CSP (pressure, temperature, nature and quantity of liquid phase) were optimized to densify each material independently. The (thermo-)chemical stability was determined by X-ray diffraction, and electrochemical impedance spectroscopy measurements provided information on the charge transport properties of bulk ceramics. In a second step, the predefined parameters were adjusted to densify, composite cathode. These tests yielded mechanical interfaces of quality high enough to obtain self-standing catholytes with tunable residual porosity at temperature low enough to prevent (thermo-)chemical reactivity.

The presentation focuses on the relationship between the sintering parameters, the microstructure and the transport properties, particularly at the various interfaces formed (grain boundaries & interfaces between the two materials) to better control the batteries performances and ageing.

(1) Joo-Hwan Seo et al. 2021 Jpn.J.Appl.Phys. 60 037001

Speaker: Ambre Tanniou

13:40 → 15:10 Field assisted sintering technology/Spark Plasma Sintering FAST/SPS: (5)

13:40 Double-Tough Ceramics: Leveraging Multiscale Toughening via Material Design, FAST/SPS and Bayesian Optimization

The traditional labeling of ceramics as brittle materials has been challenged with a variety of strategies. Multiscale designs and controlled phase transformations have shown promising results. Both the processing and mechanical characterization of toughened ceramics, however, require innovative approaches.

We show here how multiple toughening strategies can be combined into bulk all-ceramic materials consisting of alumina and zirconia. We present an optimization-driven approach to create a double-tough ceramic with a brick-and-mortar microstructure, where the zirconia mortar surrounding the alumina bricks is transformation-toughened, engineered with the goal of simultaneously achieving high strength and fracture toughness. As the design of such a material requires a laborious trial-and-error approach, we propose Bayesian Optimization (BO) as an integral part of our methodology.

FAST/SPS is key to achieve our goal. It promotes densification and the development of a textured microstructure, and it enables the retention of nanograined zirconia with a prevalence of tetragonal phase. BO guides the experimental campaign. We use a Gaussian process to emulate the material's mechanical response and implement a cost-aware batch optimization to identify optimal design process parameters, accounting for the cost of experimentally varying them.

The result is an all-ceramic composite with an exceptional balance between bending strength (>700 MPa) and toughness (>13.5 MPa∙m0.5).

Speaker: Diletta Giuntini (Eindhoven University of Technology)

14:10 Digital twin for thermal management in spark plasma sintering

The transition of SPS from research to industry faces several challenges. Upsizing leads to temperature inhomogeneity within the sintered part. Another challenge is the enormous power required for heating. The proposed digital twin addresses these issues by optimizing the SPS tooling. The digital twin was validated by sintering 3YSZ samples at 1350 °C and then heating them to 800 °C. The die used had an internal diameter of 50 mm. In the first case (1350 °C), the K-type thermocouple measured the temperature at the external surface of the graphite felt insulation. In the second case (800 °C), the thermocouple measured the die wall temperature. Comparison of the measured temperatures with the digital twin predictions shows good agreement. The digital twin application is highly efficient. Optimizing the SPS tooling reduced the temperature difference between the edge and the center of a 50 mm 3YSZ disc from 88 °C to only 3 °C during the dwell at 1350 °C. At the same time, the power decreased 2.5-fold, and the total sintering energy was half that with non-optimized tooling. The effect of optimization increases with sample diameter. For example, optimizing the tooling for sintering 100 mm 3YSZ discs reduced the temperature difference between the edge and the center during the 1350 °C dwell from 302 °C to 12 °C. The accompanying power reduction was threefold. The total sintering energy was half that required with the non-optimized tooling.

Speaker: Prof. Alexander Laptev (Łukasiewicz Research Network – Poznań Institute of Technology, Poznań, Poland)

14:30 Experimental and numerical investigation of thermo-electric phenomena in SPS sintering

SPS is a powder consolidation process that employs electric current to generate heat (Joule effect) while simultaneously applying pressure to achieve densification. In conductive powders, as current flows through the network of particles, it can concentrate at interparticle contacts/necks due to high resistance. This may result in high current densities and local temperature increase (overheating). Such thermo-electric effects can influence microstructure and hence properties.
In this work, thermo-electric phenomena during SPS are investigated through a combined experimental and numerical study. NiAl powder is consolidated at different temperatures. The resulting microstructures are characterised using XRD, SEM and EBSD, with particular focus on particle contact regions that are most susceptible to local overheating. To complement the experiments, thermo-electric finite element simulations are performed using representative three-particle geometries with different neck sizes.
The combined experimental and numerical results indicate that the resulting overheating in NiAl is limited and insufficient to induce partial melting or microstructural changes under the investigated conditions. These findings contribute to a clearer understanding of thermo-electric phenomena in SPS and suggests that a numerical model of SPS can be simplified.
Acknowledgement: Research funded by National Science Centre, Poland, project no. 2019/35/B/ST8/03158

Speaker: Fatima Nisar (Institute of Fundamental Technological Research, Polish Academy of Sciences (IPPT PAN))

14:50 Fully coupled Discrete Element Model for integrated Thermal-Electrical-Mechanical Phenomena in Spark Plasma Sintering

Spark Plasma Sintering (SPS) is an advanced manufacturing technique that leverages electric current and uniaxial pressure to achieve rapid consolidation of powder materials. The efficiency of SPS stems from intrinsic multiphysics coupling, where electrical, thermal, and mechanical phenomena are dynamically interdependent. However, this also makes the system complex to understand and model, particularly at microscopic level.

This work presents a novel, fully coupled microscopic thermal-electrical-mechanical model within the Discrete Element Method (DEM) framework. The model explicitly represents individual powder particles as discrete elements, enabling direct simulation of microstructural evolution. It integrates validated sub-models including thermal and electrical model for conduction and effective properties and mechanical model for viscoelastic deformation and densification. The coupled model incorporates Joule heat generation from current distribution, temperature dependent sintering kinetics and material properties and densification dependent effective electrical and thermal conductivity. This study provides a powerful computational tool to understand the multiphysics phenomena in SPS, offering insights for process optimization to achieve targeted microstructures and properties.

Acknowledgement: Research funded by National Science Centre, Poland, project no. 2019/35/B/ST8/03158

Speaker: Jerzy Rojek (Institute of Fundamental Technological Research, Polish Academy of Sciences)

13:40 → 15:10 Microstructure evolution during sintering and Microstructure-property relationships: (3)

13:40 Visualizing heterogeneous microstructures and defects in ceramics using synchrotron X‑ray multiscale tomography

Synchrotron X‑ray multiscale tomography, combining micro- and nano-tomography, provides high-resolution 3D imaging of heterogeneous microstructures and defects in ceramics. This method reveals how powder heterogeneity, hierarchical structures, and complexity govern defect formation, reliability, and mechanical performance.
In multilayered ceramics, defects arise from raw powders or during tape casting, drying, thermo-compression, binder burnout, and sintering. Tape-cast alumina laminates show strength-limiting defects at layer interfaces and around large powder inclusions. Even uniform slurries exhibit heterogeneous particle packing, forming complex interconnected pores, while self-assembly of polyhedral alumina crystals can produce flake-like sheets for controlled 2D microstructures.
In high-purity submicron α-alumina, agglomerates and aggregates evolve into complex pores during sintering. Circumferential cracks form under matrix constraint, and fractography confirms these pores as fracture origins. Mechanical analysis using elliptical crack and pore-crack models explains the observed strength.
These studies demonstrate how synchrotron X‑ray multiscale tomography links powder heterogeneity, processing, and strength-limiting defects, guiding the design of high-reliability ceramics.

Speaker: Dr Gaku OKUMA (National Institute for Materials Science)

14:10 Quasi-Conservation of Microstructural Connectivity During Ceramic Densification

Sintering is a microstructure-driven transformation process in which discrete particles reorganize into a dense load-bearing solid. While classical models describe diffusion kinetics, grain growth, and densification behavior, the evolution of microstructural connectivity is rarely treated as a constrained variable. Experimental observations indicate that pore redistribution, contact formation, and crack initiation cannot be fully explained by density evolution alone.
We introduce a topology-constrained modelling framework based on the quasi-conservation of structural connectivity during ceramic densification. The microstructural state of a powder compact is characterized through coordination topology and connectivity measures. During sintering, local rearrangements modify geometry while preserving global structural degrees within bounded conditions. Densification is therefore interpreted as layered microstructural reallocation rather than purely monotonic density increase.
Simulation of early-stage neck growth and constrained shrinkage shows that structural instabilities correspond to threshold shifts in connectivity redistribution. This explains discontinuities in shrinkage rate and crack onset not fully captured by continuum descriptions.
Coupling connectivity tracking with sintering kinetics improves prediction of defect formation and failure. The framework provides a predictive multi-scale perspective for microstructure-controlled defects in advanced ceramics.

Speaker: Tomonori Yoshino

14:30 Influence of defect chemistry on microstructure evolution in CaTiO3

Microstructure plays a critical role in determining the performance of functional ceramics as the properties of grain boundaries can differ substantially from those of the bulk material. These differences often arise from the segregation of charged defect species during sintering. Such segregated defects form a space charge layer, impeding grain boundary motion due to reduced diffusion rates and applying a solute-drag force. The extent of defect segregation and its impact on microstructural and electrical properties depend on multiple factors, including the host material, sintering atmosphere (e.g. oxidizing vs reducing) and temperature, as well as the nature and concentration of dopant species present in the lattice.
In the present study, the defect chemistry of CaTiO3 was varied by introducing different dopants and sintering in different oxygen partial pressures. As such it is possible to investigate the influence of the defect chemistry on the grain boundary properties. The microstructural evolution and grain boundary mobility was investigated using scanning electron microscopy. Defect segregation, space charge and grain boundary mobilities were correlated by Electrochemical impedance spectroscopy measurements ,providing insights on the segregation behavior of different defects species in different sintering conditions and their impact on solute drag in CaTiO3.

Speaker: Mr Lukas Theis (IKMT - Uni Stuttgart)

14:50 FAST/SPS manufacturing of potassium-beta-aluminas for solid-state K-ion batteries

The development of all-solid-state potassium-ion systems depends on solid ionic conductors that provide sufficient ion transport performance. Potassium-beta-alumina is regarded as a relevant candidate; however, its functional behavior is highly sensitive to processing conditions and to the structure of the resulting ceramic material. The presented work investigates the application of the Field assisted sintering technology/Spark Plasma Sintering for the synthesis and densification of potassium-beta-alumina, with emphasis on understanding how rapid thermal processing influences material structure and properties. Particular attention is directed toward the evolution of phase composition and microstructure under varied processing regimes. X-ray diffraction was employed to assess phase stability, monitor phase evolution, and identify potential secondary phases, while scanning electron microscopy was used to evaluate grain morphology, porosity, and compositional uniformity. In summary, the study highlights the suitability of FAST/SPS for the manufacturing of potassium-beta-alumina ionic conductors and clarifies key processing-property relationships that are essential for their prospective integration into all-solid-state potassium ion systems.

Acknowledgement:This research is part of the Applied Doctorate programme funded by the Ministry of Science and Higher Education, Project Agreement No. DWD/7/0108/2023.

Speaker: Ms Wiktoria Krzyżaniak (1) Łukasiewicz Research Network – Poznań Institute of Technology; 2) Faculty of Materials Engineering and Technical Physics, Poznan University of Technology)

13:40 → 15:10 Ultra-fast High Temperature Sintering UHS

13:40 Heating rate impact on sintering and microstructural evolution of YSZ nanopowder

Rapid heating is a cornerstone of modern sintering approaches like flash sintering, ultrafast high temperature sintering (UHS), fast firing, microwave sintering, or spark plasma sintering. Besides the technological interest, fundamental answers are emerging about how the heating rate can tailor the ceramic structure from the micro- to the nano-scale.
Herein, we study the rapid consolidation of YSZ nanopowder by UHS, showing an impressive acceleration of the densification mechanisms induced by the fast heating process. Starting from those results, we tried to identify whether heating rate can impact the consolidation also in “conventional” conditions, i.e., under 2.5 – 50°C/min. It is shown that the particle size and the state of the green body play a crucial role. Also, the broadness of the particle size distribution has an impact on the heating rate-sensitivity of the densification process.
It is observed that tiny nanopowders, especially if strongly agglomerated, are extremely sensitive to the heating rate effects. In extreme cases, the work of sintering at a fixed density level can vary by 3 orders of magnitude, increasing the heating rate from 2.5 to 50°C/min. This is primarily ascribed to a deviation in the microstructure -density relations induced by surface-mediated phenomena.

Speaker: Mattia Biesuz (University of Trento)

14:10 Microstructure control in solid oxide cells by Ultra-fast high temperature sintering

Sintering of functional ceramics remains a critical and cost-intensive step in the manufacturing of advanced electrochemical devices. This challenge is amplified in multilayer systems requiring different sintering temperatures, such as solid oxide cells (SOC). Conventional manufacturing relies on prolonged high-temperature exposure to promote particle connectivity; however, grain growth is difficult to control and often leads to the loss of nanoscale features, directly impacting electrochemical performance.
To improve microstructural control while reducing processing time and limiting the volatility of temperature-sensitive elements (e.g. Ba), ultrafast high-temperature sintering (UHS) has emerged as a promising alternative. In this work, UHS was applied to study the densification of 8YSZ electrolytes and the sintering of LSC-based oxygen electrodes, both state-of-the-art SOC materials. UHS-sintered 8YSZ exhibited ionic conductivity comparable to conventionally sintered samples (0.036 S·cm⁻¹ at 750 °C) across all investigated conditions. In contrast, UHS processing of LSC64 electrodes, tested in complete anode-supported cells, preserved nanoscale features while maintaining good adhesion to the electrolyte, resulting in improved electrochemical performance with current densities of 1.84 A·cm⁻² for 0.7V at 750 °C in SOFC mode (38% higher than conventional cells).

Speaker: Lourenço Serra (Catalonia Institute for Energy Research (IREC))

14:30 Rapid densification of cubic AlCoCrFeNi high-entropy alloy via combining high-pressure field-assisted sintering and ultra-fast high temperature sintering

High-entropy alloys (HEA) are promising candidates as low-cost and precious metal-free catalysts for the alkaline exchange membrane (AEM) electrolysis. For this application, sputtering targets which require a pure phase composition, homogeneous microstructure, and high density, can be produced via FAST/SPS.

However, there is a challenge of sintering a single phased HEA without unwanted pore and secondary phase formation. These restrictions are caused by the pressure limitation of the tool material graphite and by the applied sintering temperature. Low temperatures result in low density and high porosity, while high temperatures lead to element-rich secondary phases that deteriorate the mechanical properties.

In this work, a combination of two innovative sintering processes, high-pressure field-assisted (HP-FAST/SPS) and ultra-fast high temperature sintering (UHS), serves as a remedy. A ball-milled HEA AlCoCrFeNi is utilized and the effects of different HP FAST/SPS pressures and UHS currents on the microstructure, phase composition, and hardness are characterized. A densification of up to 98%, a hardness of 800 HV 0.5, and a homogeneous single-phase structure without impurities is achieved within an UHS sintering time of only 30 s. In addition, a desired phase transformation from BCC to FCC can be specifically adjusted by increasing the UHS current. This new approach emphasizes the potential of the investigated HEA AlCoCrFeNi as a suitable catalyst for the AEM electrolysis.

Speaker: Alexander Ahrend

14:50 Reactive ultra-fast high temperature sintering of oxide electrolytes for all-solid-state batteries

Ultra-fast high temperature sintering (UHS) has recently emerged as a promising approach for the densification of ceramic materials, offering significantly reduced processing times and energy consumption as compared to conventional sintering routes. In this work, reactive UHS of oxide solid electrolytes is investigated, with particular focus on Al and Ta-doped $Li_7La_3Zr_2O_{12}$ (LLZO).
Reactive UHS is performed on the pelletized mixed oxide precursor powder uniaxially pressed at 240 MPa. For UHS, currents are applied in the range of 13-19 A using a homemade UHS setup. Special attention is given to the influence of current, heating rate, and dwell time on the phase formation, microstructure and ionic conductivity. A clear increase in relative density with increasing current is observed with values up to ~98%. X-ray diffraction confirms the formation of cubic LLZO phase with samples exhibiting ionic conductivities up to $0.5\ \text{mS cm}^{-1}$ at room temperature. Like conventional sintering routes, a tradeoff is observed. Low currents lead to incomplete reactions, while higher currents promote lithium volatilization and secondary phases. Overall, the results demonstrate that reactive UHS enables rapid synthesis (in 30 s) of cubic LLZO while simultaneously highlighting need for improved process control to enhance reproducibility and mitigate lithium loss. Future work includes reactive sintering of thin LLZO tapes as well as the simultaneous sintering of multiple samples.

Speaker: Habib Ullah (Institute of Energy Materials and Devices, Material Synthesis and Processing (IMD-2), Forschungszentrum Jülich)

15:10 → 15:30 Coffee break

15:30 → 17:00 Cold sintering: (3)

15:30 Densification and recycling of perovskite ceramics using chemical reactions in base solution

In recent years, interest has grown in low-temperature ceramic sintering and fabrication of multi-materials for various devices. We have developed an acid-base chemical densification (ABCD) process capable of producing dense ceramic bulk materials at temperatures below 200ºC. This process applies the chemical reaction between metal oxide hydrous gels and alkaline hydroxide powders to nanoparticle synthesis and sintering. Utilizing highly reactive amorphous ZrO₂ gel as a raw material enables the application of the ABCD process to synthesize high-density bulk BaZrO₃, at the low temperatures of 100–150ºC. Furthermore, observation of the internal structure of BaZrO₃ prepared by this method revealed that extremely fine nanograins aggregate to form domains constituting the bulk structure. When this bulk material is subjected to high-temperature treatment in a high-concentration barium hydroxide solution or in a strong basic solution without barium, a dissolution-precipitation reaction occurs. The material does not dissolve as ions but instead disperses as particles in the liquid. This process converts bulk BaZrO₃ into powdered BaZrO₃ rather than directly dissolving the bulk material. This could be useful for reusing BaZrO₃ after device fabrication, such as in fuel cells. This process demonstrates the potential for a novel recyclable method that controls both bulk formation and powderization using the same alkaline solution.

Speaker: Dr Yuki Yamaguchi (National Institute of Advanced Industrial Science and Technology (AIST))

16:00 Role of Particle Size and Reaction Chemistry on the microstructure and properties of Reactively Cold-Sintered BaTiO₃

BaTiO3 is a lead-free piezoceramic of growing interest because of the new RoHS regulations on hazardous materials.Hence,there is a growing interest in the sustainable fabrication of BaTiO3 to be employed in piezoelectric devices e.g.,tunable devices for electronic and biomedical applications.Among various sustainable processing routes,Reactive Hydrothermal Phase Densification(rHLPD) is of particular interest.It consists of infiltration,hydrothermal reaction,and reactive crystallization of the titanate from the TiO2 precursor.The infiltration of Ba(OH)2 aqueous solution occurs via interconnected pores of an anatase preform,which is converted into BaTiO3 in hydrothermal conditions.The porosity is filled by reaction products having a higher molar volume than that of the reactants, giving a highly dense BaTiO3 ceramic.In this work, we investigate the kinetics of the phase transformation and correlate it with the microstructural evolution of the reactively sintered bodies.The effect of the different processing parameters governing the transformation is deeply studied, including temperature,time,composition of the solution, and particle size.The addition of mineralizer (NaOH/ KOH) can significantly change the reaction rate as well as the use of different particle sizes,nanopowder green bodies fully converting into the titanate in 48hr.Structural/electrical characterization studies are underway to confirm the promising potential of this environmentally friendly manufacturing process

Speaker: Mr Sheheryar Khan Awan (Universita di Trento (Italy))

16:20 Chemically driven Cold Sintering Process of silica down to room temperature

The Cold Sintering Process (CSP) is an innovative consolidation technique enabling densification at low temperatures (below 300 °C) through the combined action of uniaxial pressure and a transient liquid phase. Unlike conventional sintering, CSP relies on solution mediated mass transport, making it particularly suitable for materials such as amorphous silica (SiO₂), which usually require much higher temperatures for densification.
Recent studies report relative densities of 70–80% for cold sintered silica-based materials prepared via Strober method, while maintaining the amorphous structure. This is achieved by mixing silica with a small amount of water or a dilute alkaline solution (NaOH), thanks to the low processing temperature. However, preparing amorphous silica under acidic catalysis significantly alters the underlying chemistry, leading to the formation of not only SiO₂ and SiOH functions, but also Si(OH)₂. This modification enhances densification activation factors, both through in-situ water generation from the elimination of OH groups detected by protonic conductivity with impedance spectroscopy and by achieving nearly 98% densification down to room temperature.

These results highlight the potential of CSP as a low energy, scalable processing route for silica-based ceramics and composites prepared in acidic conditions, opening new perspectives for the development of advanced and functional hybrid and composite materials with reduced environmental impact.

Speaker: Mrs amna korbi (CIRIMAT - ICGM)

16:40 Break

15:30 → 17:00 Field assisted sintering technology/Spark Plasma Sintering FAST/SPS: (6)

15:30 Processing studies on the high entropy (MoNbTaVW)C

A processing optimization study was conducted to identify the influence of processing parameters on the chemical homogeneity, oxygen content, and ultimately, the functional properties of (MoNbTaVW)C. Processing variables tested included milling environment, precursor treatment before sintering, and sintering temperature. The ideal samples were fabricated through the following process. They were milled in an argon environment, pre-treated in vacuum in a tube furnace (1200°C), and held at an intermediate temperature hold (also 1200°C) prior to achieving the maximum sintering temperature. These samples exhibited low porosity, denser microstructure, and low oxygen content. The effect of pretreatment on density and mechanical properties was higher than the effect of sintering temperature (1900 vs 2200°C).

Speaker: Lavina Backman (Naval Research Laboratory)

16:00 Tuning the sintered microstructure of liquid-phase sintered SiC for corrosion resistance in HF acid.

This study reflects a need for fine comprehension of liquid-phase sintering of SiC-Al2O3/Y2O3 ceramics for an acid corrosion application. Although the overall sintering and densification behaviour of silicon carbide is well known, this work aims to bring some new insight on the relationship between grain growth of SiC particles, the structure of the oxide intergranular phase (IGP), and the sintering conditions. To do this, low pressure Spark Plasma Sintering on a commercial SiC-Al2O3/Y2O3 powder has been used. These experiments allowed to investigate different sintering conditions in order to obtain four different dense microstructures regarding grain size and the intergranular phase: 1) Significant grain growth/crystalline IGP; 2) Low grain growth/crystalline IGP; 3) Significant grain growth/amorphous IGP; 4) Low grain growth/amorphous IGP. The impact of the addition of a fine submicronic TiC powder by freeze-drying has also been tested. The present work provides a comprehensive microstructural characterisation of the samples through SEM/EDS (general microstructure), EBSD (grain size), XRD (nature and quantity of non-SiC phases) as well as TEM observation for deeper study of the grain boundaries. The influence of grain size and crystallisation of the oxide intergranular phase on aqueous hydrofluoric acid corrosion resistance and fluorine gas bubble behaviour has been also evaluated through mass evolution and microstructural comparison.

Speaker: Guillaume Rannou (CEA Liten)

16:20 Effect of Boron Nitride Nanotube Addition on ZrB2-SiC Composites Fabricated by Spark Plasma Sintering-Reaction Synthesis

This study presents a novel approach for fabricating boron nitride nanotube (BNNT)-reinforced ZrB₂-SiC composites with enhanced fracture toughness using spark plasma sintering-reaction synthesis (SPS-RS). Unlike conventional methods employing commercially synthesized SiC powder, we utilized ZrB₂, Si, and C powders to induce in-situ SiC formation during sintering. This approach enables densification at significantly lower temperatures, thereby preserving the structural integrity of thermally vulnerable BNNTs. The study elucidates the effects of BNNT addition on the microstructure and mechanical properties, particularly the correlation between BNNT structural survival and toughness enhancement. By lowering the processing temperature through reaction synthesis, matrix densification was achieved while maintaining BNNT integrity. Flexural strength reached its maximum at 3 wt% BNNT, showing a 35.7% improvement over BNNT-free specimens due to efficient load transfer. Fracture toughness increased with BNNT content, reaching 7.87 MPa·m^0.5 at 5 wt%, a 92.4% improvement attributed to energy absorption along crack paths. The SPS-RS process effectively enables composite densification while minimizing BNNT thermal damage. The addition of 3–5 wt% BNNTs compensates for the inherent brittleness, enabling simultaneous strength and toughness improvements, thus suggesting promising applicability for aerospace and ultra-high temperature components.

Speaker: Hyeondeok Jeong (Korea Institute of Science and Technology)

16:40 Development of Multicomponent (ZrHfTaTi)C via Sequential Addition of Oxides to ZrO2 using Carbothermal Reduction

The present study reports the investigation on the combined synthesis and densification of rock-salt type (ZrHfTaTi)C via carbothermal reduction and Spark Plasma Sintering. By systematic addition of metallic elements from ZrC to HfTaTiZrC , the effect of increasing chemical complexity on shrinkage behavior, microstructure, densification, and basic mechanical properties was investigated in ZrC, HfZrC, HfTiZrC, and HfTaTiZrC. While the densification onset temperature decreased with added components, shrinkage behavior became parabolic, indicating diffusion-limited kinetics. Notably, the densification rate significantly decreased from ~0.063 min⁻¹ to 0.025 min⁻¹ in the multicomponent system, quantitatively confirming the "sluggish diffusion" effect driven by compositional complexity. Microstructural analysis confirmed the formation of a homogeneous grain structure of carbide solid solution phases. Consequently, nanohardness rose significantly from ~27.5 GPa (ZrC) to ~34.2 GPa (ZrHfTaTiC) due to solid solution and lattice distortion effects. These findings establish a direct link between compositional complexity, retarded sintering kinetics, and enhanced mechanical property, providing a framework for designing high-entropy ultra-high temperature carbides and understanding the effect of systematic addition of element on multicomponent carbides

Speaker: Rahul Mitra (Indian Institute of Technology, Kanpur)

15:30 → 17:00 Flash Sintering: (1)

15:30 Accelerated cationic diffusion in oxide ceramics under AC-flash event

Flash sintering, in which densification occurs almost instantaneously above a threshold electric field strength and furnace temperature, has been widely demonstrated in various oxide ceramics. In addition, bulk ceramics show superplastic flow, accelerated sinter forging, good joining performance and crack healing under flash events, suggesting that flash events significantly promote diffusion of constitutive ions. It has been widely accepted that the onset of a flash event is triggered by thermal runaway through Joule heating and increased electrical conductivity. However, several studies suggested that the effect of flash events may involve athermal processes to accelerate diffusional mass transport.
In the present study, the diffusivity of Er³⁺ cations in Y₂O₃ was determined by interdiffusion experiments using Er₂O₃/Y₂O₃ diffusion couples under alternating current (AC) flash events. In the diffusion couple, Er³⁺ cations act as tracers of Y³⁺ in Y₂O₃, and vice versa. The increase in specimen temperature via Joule heating, which represents the important aspect of flash events, were carefully evaluated by coupling the experimental and numerical approaches. The interdiffusion experiments eventually revealed the athermal acceleration of both lattice and grain boundary diffusion coefficients under AC electric fields.

Speaker: Hidehiro Yoshida (The University of Tokyo)

16:00 Flash Sintering of B4C: simulation and experimental testing

B4C is a hard ceramic material that is used for armor protection and nuclear reactor walls. However, it is difficult to fully densify due to its strong covalent bonding; therefore, techniques that employ high temperatures (>2000 ºC) and pressure are often used, namely Hot Pressing or Hot Isostatic Pressing. Nonetheless, these techniques require high energy consumption and take a considerable amount of time to fully densify this material. New and faster sintering techniques have been developed in the last decades to densify materials in much shorter time and with lower energy input, as the Electric Current/Field Activated/Assisted Sintering (ECAS/EFAS) techniques, which employ an electric field and current to generate internally heat by Joule effect. Flash Sintering (FS) is a recent technique from this group that is more directed toward semiconductors, as is the case of B4C, typically enabling materials to sinter within few minutes, under the condition of the flash event occurrence with generation of enough Joule heating. In this work, the Joule effect on a B4C sample will be simulated by Finite Element Modelling (FEM), by varying the voltage and current, at 500ºC surrounding temperature, with the intent of estimating the attained sample temperature. The simulated results were compared with FS experiments and used to select the FS parameters able to sinter B4C and B4C-10 Ni (vol%) samples. The sintered samples were physically, structurally and microstructurally characterized.

Speaker: Ricardo Mineiro (University of Aveiro)

16:20 Flash Sintering-Enabled Defect Engineering of Functional Oxide Ceramics for Photocatalysis and Sodium-ion Batteries

Flash sintering has emerged as a powerful non-equilibrium processing route for engineering defect chemistry and unlocking enhanced functional properties in oxide ceramics. In this work, I demonstrate the versatility of flash sintering in synthesizing advanced TiO2-based functional ceramics for both photocatalysis and sodium-ion battery (SIB) applications. Through Fe–Cu co-doping and Fe hyper-doping strategies, flash sintering enables efficient dopant incorporation and the generation of a high density of non-equilibrium oxygen vacancies and Ti3+ species under an externally applied electric field. Compared to conventionally sintered counterparts, flash-sintered TiO2 exhibits pronounced electronic structure modification, including bandgap narrowing, enhanced visible-light absorption, and significantly improved electronic conductivity. These defect-induced effects promote efficient charge-carrier separation for visible-light-driven photocatalysis and accelerate sodium-ion transport and charge storage in SIB anodes. Consequently, flash-sintered TiO2 demonstrates superior photocatalytic degradation efficiency of methylene blue under white LED illumination and markedly improved rate capability and cycling stability in sodium-ion batteries. The results establish flash sintering as a unifying and scalable defect-engineering strategy for designing next-generation multifunctional ceramic materials for energy conversion and storage.

Speaker: Anupam Raj (Indian Institute of Technology Kanpur, India)

16:40 Energy-Efficient Ultra-Fast Spark Plasma Sintering of Binder Jetting 3D-Printed 316L Stainless Steel

This work presents an energy-efficient and ultra-fast sintering strategy (EU-SPS) based on a pressure-less ultra-fast sintering (PLUFS) approach implemented within a spark plasma sintering (SPS) apparatus. The proposed method enables rapid densification of binder-jetted components without the need for a separate debinding step. By integrating the ultra-rapid thermal capabilities of ultra-fast sintering with targeted modifications to the conventional SPS configuration, EU-SPS is designed to process fragile binder-jetted parts while mitigating common metallurgical issues such as carbon contamination and residual δ-ferrite. Finite element method (FEM) modeling grounded in continuum sintering theory was employed to investigate densification kinetics and grain growth during EU-SPS. In addition, a linearized perturbation analysis based on continuum constitutive parameters was used to assess sintering instability and densification inhomogeneity arising from the high heating rates and large thermal gradients intrinsic to the process. Complementary metallurgical characterization was conducted to elucidate the mechanisms governing microstructural optimization in binder-jetted 316L stainless steel. Overall, this work establishes a viable pathway for the rapid post-processing of additively manufactured metals and supports the industrial adoption of binder jetting as a scalable and reliable manufacturing technology.

Speaker: Elisa Torresani (San Diego State university)

15:30 → 17:00 Microstructure evolution during sintering and Microstructure-property relationships: (4)

15:30 Relationship among Grain Growth Behavior, Electrical Properties, and Crystal Structure in Dielectric Ceramics

Microstructure plays a key role in governing the functional properties of electronic ceramics. In this study, the relationship among grain growth behavior, crystal structure, and electrical properties is investigated based on the theory of two-dimensional nucleation–controlled grain growth. Perovskite systems, including barium titanate, barium calcium titanate, and sodium potassium niobate, are employed as model materials to examine the effects of various additives on grain growth and microstructural evolution. The results show that additive-induced modifications in interfacial and crystal structures significantly alter grain growth kinetics, resulting in distinct grain size distributions and growth behaviors. These variations are closely associated with phase stability, lattice distortion, and symmetry, depending on composition and additive chemistry. The underlying mechanisms are discussed in terms of interfacial energy and two-dimensional nucleation processes at grain boundaries. Dielectric properties, particularly relative permittivity and dielectric loss coefficient, are evaluated as functions of frequency and temperature. Strong correlations are observed between grain growth behavior, crystal structure, and dielectric response. The results demonstrate that controlled grain growth and structural tuning through additive engineering provide an effective approach to tailoring the frequency- and temperature-dependent dielectric performance of perovskite electronic ceramics.

Speaker: Prof. Kyoung-Seok Moon (Gyeongsang National University)

16:00 Intertwined Processes of Coarsening, Densification, and Grain Growth during Sintering of Nanosized Particles

Sintering is one of the main and few approaches for building bulk ultrafine-grain materials from the bottom up. One of the main challenges in sintering nanosized powders is controlling grain growth while achieving full densification. Considerable literature is now available for identifying unique mechanisms that could provide clues to achieving densification with minimal grain growth. It is critical to understand the detailed mechanistic steps to design processes that can lead to bulk materials with maximum density and minimum grain size. Using experimental data of sintering nanosized tungsten carbide and tungsten powders, this presentation examines the intertwined processes of neck growth, coarsening, densification, and grain growth. When the density of the compact of nanosized particles is very low, coarsening of particles is responsible for most of the observed initial grain growth. Coarsening also contributes to densification. Because initial coarsening depends on surface diffusion, surface diffusion indirectly also contributes to densification.

Speaker: Prof. Zak FANG (University of Utah)

16:20 Abnormal grain growth in pure iron during SPS in presence of a PVD carbon diffusion barrier

The elaboration of metallic parts by powder metallurgy techniques such as SPS, represents a relevant alternative to conventional manufacturing processes. This allows the elaboration in a single stage of dense and high-performance materials with high mechanical properties. One of the major problems during SPS of metallic powders is the carbon diffusion from the graphite tooling, and/or from the graphite foils inserted between the powder and the tools, to the powder. This carburization can lead to a degradation of the sintered material properties and to the formation of a surface composition gradients. Up to now, only few studies addressed this issue.
In a previous work, it has been demonstrated that a titanium coating (about 1 µm thick) deposited by Physical Vapor Deposition (PVD) on the graphite foil was efficient in avoiding carburization of pure iron during sintering. This minimal thickness was established based on thermodynamic simulations performed using ThermoCalc® DICTRA.
In the present study, an abnormal grain growth was observed when using thicker coatings were used, leading to the appearance of large columnar and equiaxial grains. The mechanisms underlying this phenomenon were investigated using SEM-EBSD and through variations in processing conditions to better understand this behavior.

This study was performed in the frame of the ANR OEDIPUS project (ANR-23-CE08-0028).

Speaker: Romain CHARVET (Université Bourgogne Europe, CNRS, Laboratoire Interdisciplinaire Carnot de Bourgogne ICB UMR 6303, F-21000 Dijon, France)

16:40 Correlating redox chemistry with microstructure evolution of heterogeneous nuclear ceramics supporting spent nuclear fuel disposal

Since the 1960s the use of mixed Pu-/U-oxide ceramic (MOX) increased for nuclear energy production. MOX spent nuclear fuel (SNF) presents strong challgenges for its disposal due to its complexity, high radioactivity and limited research experience. To understand how microstrucutre in MOX ceramics evolves, the development of laboratory-scaled synthesis methods are needed with precise control over key synthesis steps like sintering. Resorting to less radioactive materials like CeO2 allows synthesis in usual laboratory conditions. The present study focuses on how different preparation routes impact the microstructure and associated redox chemistry of Ce- and Pu-doped UO2 as MOX SNF materials. To synthesise Ce-based surrogate MOX, different UO2 precursors were used. The samples were analysed via SEM/EDS/EBSD. These are benchmarked against real MOX. The microscopy results show that the UO2 powder origin has a noticable impact on the final ceramics microstructure in terms of grain size and Ce distribution. Synchrotron HERFD-XANES analysis unveilded, that microstructure affects the ratio of contained Ce4+/Ce3+ and U4+/U5+. This can potentially impact the ceramics dissolution vulnerability, as phases containing Ce3+/U5+ are known to be more prone to dissolution than those with Ce4+/U4+. The results of this investigation will be discussed in relation to the geological disposal of MOX fuel, as well as the challenges involved in generating reliable Ce-based surrogate materials for MOX.

Speaker: Egor Iwaschko (Forschungszentrum Jülich GmbH)

17:00 → 18:30 Poster Session

17:00 Ultrafast high temperature sintering and synthesis of high entropy electrolytes

High-entropy oxides are opening a new set of opportunities to tailor material properties. Such high entropy concept can be extended to the design of new electrolytes for solid-state lithium-ion batteries.
Herein, we investigate the synthesis of new perovskite structures based on lithium-lanthanum titanate (LLTO) chemistry. Different solid solutions have been attempted by doping the A and B sites of the perovskite structure and manufacturing a new electrolyte composition. The use of an ultrafast high-temperature sintering (UHS) facility hugely accelerates material discovery by allowing multiple thermal treatments in a short time. This further contributes to the reduction of Li volatilization or its poisoning (e.g., the reaction with silica impurities in conventional muffle furnaces). In this regard, UHS is a promising tool to engineer new material compositions and tailor their properties and microstructures.

Speaker: Mattia Biesuz (University of Trento)

17:20 Challenges in Production of Ultra-high Temperature Ceramics for Aerospace

Advanced ceramics possess admirable properties, such as high operating temperatures and low thermal conductivity, that make them well-suited for extreme environments, including those in the aerospace and nuclear industries. One of the most significant drawbacks of ceramics is the challenge of processing, particularly in the production of ultra-high-temperature ceramics (UHTCs), which must be sintered at temperatures above 2000°C, even with the addition of sintering additives. Densification of these materials causes many problems, such as warpage, shrinkage cracks, and gas porosity, all of which are detrimental to the final properties of the part.

This research drove the development of a new gel-casting method for ZrB2 to reduce the toxicity of the traditional process. Parameters such as solids loading, viscosity, and drying stages were optimised to produce defect-free complex parts for the aerospace sector. The preceramic polymer material was sintered in an inert atmosphere at 2000 °C for 2 hours, increasing the bulk density to 98% for ZrB2-SiC UHTC parts, after addressing multiple macro and microstructural challenges. This included an investigation into the effect of microstructure on the sintering ramp rate between 10°C/min and 3°C/min. Following this, the material was investigated using microscopy to assess phase dispersion and grain size.

Speaker: Ethan Ellis (Lucideon)

17:40 Sintering aids for transparent high-entropy garnet ceramics

High-entropy ceramics are promising materials for advanced optical applications, particularly for their enhanced thermal stability and tunable spectral properties. However, achieving full density and eventually optical transparency remains challenging in multicomponent systems, as sluggish diffusion kinetics can hinder pore elimination. Furthermore, chemical complexity increases the risk of elemental segregation or secondary phase formation due to unwanted reaction with the sintering aid.
The present study focuses on optimising the sintering strategy for a garnet with the composition RE3Al3Sc1Ga1O12:Er3+ (RE = Lu, Yb, Y, Gd, La). The objective was to identify suitable sintering aids and a sintering regime for obtaining transparent ceramics. The high-entropy compound was synthesised via solution combustion and calcined at 1400 °C to produce a single-phase submicron powder without hard aggregates. Powders were dispersed with various sintering aids (SiO2, SiO2+MgO, borosilicate glass) at different concentrations, homogenised, and spray-dried. Following uniaxial and cold isostatic pressing, pellets were vacuum-sintered at various temperatures and dwell times.
Density was measured using Archimedes’ method, and SEM-EDX was used to characterise microstructure and chemical homogeneity. Optical transparency was quantified through RIT measurements. The influence of sintering aid type, concentration, and vacuum sintering parameters on densification and transparency was evaluated.

Speaker: Tereza Havlikova

18:00 Low-energy densification of LaMnO3 ceramics via spark plasma sintering

LaMnO3 ceramics (LMO) are well known for many electronic applications. In this report, LMO was synthesized using solid-state reaction process. The precursors oxides were weighed in stoichiometric proportions and mechanically mixed in a planetary ball mill. Calcination was carried out at 1000 °C for 3 h. The calcined powder was loaded into graphite dies lined with graphite foils and subsequently densified by spark plasma sintering (SPS) equipment. The sintering conditions were a pressure of 80 MPa, a temperature range from 1000 °C to 1200 °C, 100 °C/min and dwell times of 5, 10 and 15 min. Phase analysis was realized by X-ray diffractometry (XRD). Using focused ion beam scanning electron microscopy (FIBSEM), micrographs of the sintered ceramics were obtained. The densities of the samples ranged from 80 % of the theoretical density to 96 % (1200 °C, 10 min). Density decreased with a longer dwell time (>10 min) at 1200 °C. Activation energy for sintering was calculated as 44 kJ/mol. With grain size values, grain growth kinetics were determined. Grain growth exponent was 2.4, indicating diffusion on single-phase material combined with coalescence of second phase. Activation energy for grain growth was 262 kJ/mol.
Acknowledgments: Grants CIAICO/2023/264(Generalitat Valenciana), PID2023-147490OB-I00, CNS2023-144190(MICIU/AEI/10.13039/501100011033, “ERDF/EU” and the “European Union Next Generation EU/PRTR”, 316730/2023-8(CNPq), APQ-01856-22(FAPEMIG), 23038.003930/2024-79(CAPES).

Speaker: Prof. Amparo Borrell (Universitat Politècnica de València)

18:10 Development of a phase-field sintering model for highly accurate prediction of sintered microstructure and defects

Since the properties of sintered products are significantly affected by their microstructures and defects formed during the sintering process, accurate prediction and control of the microstructure evolution are essential. However, experimentally observing the sintering process in situ is not straightforward. Therefore, numerical simulation studies for predicting microstructural evolution are crucial. The phase-field (PF) method is the most accurate numerical approach that reproduces the material microstructure. Nevertheless, existing phase-field sintering models have challenges in reproducing densification behavior caused by particle rigid-body motion, especially in multi-particle systems. As a result, they are unable to accurately reproduce the formation of defects and cracks during sintering. In this study, we develop a rigid-body motion model based on beam elements. In this model, grain boundaries are represented by beam elements, whose two ends are connected to the centers of mass of particles via rigid offsets. This model enables high-accuracy reproduction of shrinkage, separation, and sliding between particles, and allows accurate simulation of microstructural evolution and defects during sintering. Using this model, we performed simulations and verified the validity and effectiveness of the developed model.

Speaker: Mr Aoi Nakazawa (Kyoto Institute of Technology)

18:10 Development of Fe-Cu Based Sintered Composites Reinforced with Graphite and SiC for Automotive Clutch Applications

This study investigates the sintering behavior and mechanical characteristics of Fe-Cu matrix composites designed for high-performance automotive clutch systems. To achieve a balance between high friction stability and durability, graphite was incorporated at high concentrations (10 wt.% to 20 wt.%) alongside SiC particles. Graphite was specifically employed to utilize its cushioning effect during the powder compaction and sintering stages, facilitating stress distribution within the Fe-Cu matrix.
The microstructural evolution and crystallographic orientations were analyzed using Electron Backscatter Diffraction (EBSD) to evaluate the interfacial integrity between the Fe-Cu matrix and the carbonaceous reinforcements. Furthermore, the local tribological response and lubricating film formation were characterized via Lateral Force Microscopy (LFM).
Results showed that increasing the graphite content up to 20 wt.% significantly reduced the coefficient of friction (COF) due to the enhanced lubricity of the graphite phase, which is critical for smooth engagement in clutch applications. However, the inherent reduction in hardness caused by the soft graphite phase was compensated by the addition of SiC, which reinforced the Fe-Cu matrix and maintained structural rigidity.

Acknowledgment
This work was supported by KEIT grant by Korean government (MOTIE) (RS-2024-00469455)

Speaker: Mr Ki-Taik Lee (Korea Institute of Industrial Technologty)

18:10 Effect of W-V Alloying on the FAST/SPS Densification of Wf/W Composites

Tungsten fiber-reinforced tungsten (Wf/W) composites are promising for fusion applications, but their performance is limited by insufficient matrix densification and fiber embrittlement during conventional high-temperature sintering. Alloying tungsten with vanadium(V) effectively enhances sinterability and modifies densification behavior.
In this study, W-V powders (0-4 wt.% V) were synthesized by mechanical alloying and consolidated via field-assisted sintering technology (FAST/SPS). The effects of V content, sintering temperature, and holding time on densification behaviour were systematically investigated. Relative density was measured using the Archimedes method, while microstructural evolution and elemental distribution were characterized by SEM/EDX.
FAST/SPS enabled rapid densification with limited thermal exposure. V addition significantly enhanced sintering kinetics, achieving relative densities up to ~98% at reduced temperature and shorter holding times. The improved densification is attributed to enhanced diffusion and alloying-activated sintering mechanisms. However, excessive temperature or holding time promoted V diffusion into fibers and microstructural degradation.
The results indicate that the synergistic effect of W-V alloying and optimized FAST/SPS processing enables precise densification control and significantly broadens the sintering window of Wf/W composites.

Speaker: Chongyang Liu (Forschungszentrum Jülich GmbH)

18:10 Enhanced mechanical performance of BaZr0.7Ce0.2Y0.1O3-δ (BZCY721) proton-conducting membranes prepared by cold sintering and subsequent thermal-treatment

The conventional synthesis of barium zirconate cerate protonic membranes demands high sintering temperatures (~1600 °C) and lengthy dwell times (up to 24 h). This high-temperature processing results in Ba2+ loss, leading to impurity compounds and a reduction in overall conductivity. Therefore, a pre-cold sintering step was employed to densify BaZr0.7Ce0.2Y0.1O3-δ (BZCY721) ceramics at temperatures between 150 °C - 350 °C, followed by a subsequent thermal treatment at 1300 °C. The mechanical properties of the cold-sintered specimens were explored and compared with a sample sintered conventionally at 1600 °C. Similar densities were achieved regardless of sintering technique, although impurity phases, such as BaZr0.9Y0.1O2.68, NiO, and Y2O3, were observed in cold-sintered specimens. Additionally, fine-grain size and low apparent porosity were observed in cold-sintered specimens, which translated to higher elastic modulus and hardness values. The Vickers indentation fracture toughness for 150 °C and 250 °C cold-sintered specimens was 1.26 MPa·m0.5, in contrast to 0.93 MPa·m0.5 for the conventionally-sintered one. These differences in the fracture toughness were due to the porosity as shown via micropillar splitting, where all specimens exhibit the same values (~1.4 MPa·m0.5). Finally, the total conductivity of the 150 °C cold-sintered specimen (1.48×10-4 S/cm) and the conventionally-sintered specimen (4.46×10-4 S/cm) were found to be similar at temperatures of 400 °C.

Speaker: Mr Syed Ali Afzal (Forschungszentrum Jülich)

18:10 Fabrication of hierarchical porous transport layers for anion exchange membrane electrolyzers.

Ni felts are conventionally used as anode porous transport layers (PTL) in anion exchange membrane (AEM) elctrolysers. However, a better distributed contact between the PTL and the AEM can help reduce mechanical strain and current constriction in the AEM, thereby enabling higher differential pressure operation and improved performance, On the other hand, high degree of porosity and large pore sizes are desirable within the main body of the PTL to promote mass transport. PTLs with hierarchical porosity can encompass both requirements. In this work, tape casting of NiO, with average particle size ranging from 20 nm to 15 µm and reductive sintering of the NiO tapes is pursued as a novel Ni PTL production method that can help reduce production steps, energy consumption, and time. Reduction temperatures of 300-700 °C and sintering temperatures of 600-1000 °C are explored in order to find an optimum profile to achieve desired porosity (60-80%) and mechanical strength. Ni PTLs with a footprint larger than 25 cm2 and hierarchical porosity are fabricated using the optimized reduction-sintering profile. Sintered Ni PTLs are analysed for porosity, microstructure and electrochemical performance.

Speaker: Elo Overgaard Mogensen

18:10 Field-assisted sintering of NaSICON-type NZSP solid-state electrolyte for all-solid-state batteries in decentralized energy storage

Energy storage remains a key factor in the successful transition from carbon-intensive to renewable energy sources. However, the high cost and limited availability of lithium and cobalt accelerate research into cost-effective alternatives. Sodium-ion all-solid-state batteries, particularly those based on sodium superionic conductor (NaSICON) electrolytes, are promising candidates for next-generation energy storage. This work aims to develop an all-solid-state sodium-based battery for decentralized energy storage, offering a cost-effective and safer alternative to liquid-electrolyte battery technologies. Therefore, NaSICON-type powder with the chemical formula Na₃Zr₂Si₂PO₁₂ (NZSP) is synthesized using planetary ball milling followed by a calcination process. The milled powder is characterized in detail and further densified using field-assisted sintering to overcome the limitations of conventional sintering. The limitations include secondary-phase formation and insufficient densification, which promote dendrite growth and compromise battery safety and cycle life. A systematic study of sintering parameters, including temperature, heating rate, dwell time and applied pressure, is conducted to improve density, phase purity and ionic conductivity (targeting ~10⁻³ S·cm⁻¹). As a result sintering curves, surface morphologies, phase compositions and Nyquist plots are presented. The solid electrolyte is subsequently combined with a novel composite cathode and the hard carbon anode.

Speaker: Mr Christian Biermann (Universität Rostock)

18:10 Isoporous LaFeO3 catalysts for green hydrogen generation

The development of technologies for H2 production from waste resources plays a crucial role in the decarbonization of the hydrogen supply chain. This study investigated the fabrication of nanostructured LaFeO3 catalysts for H2 generation from biogas, emphasizing thermal processing strategies aiming at producing highly-porous structures with high gas permeability, surface area, and catalytic activity. LaFeO3 nanoparticles, synthesized via a sol-gel route, are combined with polystyrene (PS) monodisperse sacrificial templates to create an interconnected isoporous microstructure. A critical two-stage thermal treatment is performed: (i) the controlled debinding of the PS template to generate the highly-porous interconnected structure, and (ii) a co-reduction sintering process to promote the exsolution of metallic Fe nanoparticles. Reduction parameters are tailored to control the dispersion and size of Fe active sites emerging from the perovskite lattice while preventing excessive sintering that would destroy the porous structure. Unlike conventional impregnation methods, exsolution yields anchored nanoparticles with hypothesized redox reversibility, facilitating easy catalyst recovery. The correlation between sintering conditions and the resulting pore morphology is assessed. By optimizing the exsolution and sintering profiles, this research aims to produce high-efficiency, long-life catalysts that mitigate carbon poisoning during the reforming of complex biofuels.

Speaker: Bruno Assis da Rocha (Karlsruhe Institute of Technology (KIT), Institute for Applied Materials – Ceramic Materials and Technologies (IAM-KWT))

18:10 Low-Temperature Sintering Copper Powder with Self-Reducing Properties via Polyol Process

Copper (Cu) powders for low-temperature sintering are capable of bonding at temperatures significantly below their melting point. Consequently, they are expected to be applied in die-attach materials for power modules designed for high-temperature operation.

To achieve low-temperature sintering, it is effective to refine the particle size. In the case of Cu, an anti-oxidation coating which decomposes at low temperatures is required due to its high susceptibility to oxidation.

In this study, synthesis conditions for fine Cu powders using the polyol process were investigated. The polyol process, reducing metal oxides in polyhydric alcohols, is suitable as it forms an organic surface coating during synthesis. This provides better dispersibility and oxidation resistance than aqueous methods.

The powder synthesized under optimal conditions exhibited significant sinterability from approximately 170 °C in an inert atmosphere. By holding the temperature at 200 °C for one hour, the sintering progressed to achieve a volume resistivity of 2.2 μΩ·cm. Notably, it was clarified that the surface oxide layer was reduced during sintering, even under an inert atmosphere. This presentation discusses the thermal decomposition mechanisms of the organic species formed on the Cu surface and their contribution to the self-reducing properties that enable high-quality bonding at low temperatures.

Speaker: Naoki Yamaoka (Sumitomo Metal Mining Co., Ltd.)

18:10 Mechanistic Investigation of Densification and Na-ion Transport in Cold Sintered and Conventional Sintered Mg-doped NASICON-type Solid Electrolyte

Cold sintering processing (CSP) has emerged as a promising route for densifying ceramic solid electrolytes (SEs) at significantly reduced temperatures. Assisted by a transient liquid phase (acetic acid), CSP promotes dissolution–reprecipitation-driven particle rearrangement, leading to intimate grain contact and refined microstructures. However, the fundamental densification mechanism and its impact on grain-boundary conduction remain poorly understood. In this study, Mg-doped Na₃Zr₂Si₂PO₁₂ (NMZSP) prepared via CSP followed by annealing is systematically compared with conventionally sintered counterparts. Cylindrical pellets were fabricated by CSP with post-annealing at 600–1175 °C and by conventional sintering at 600–1250 °C. Phase evolution was analysed by X-ray diffraction with Rietveld refinement to quantify lattice parameters and phase fractions. Microstructural development and densification were examined using scanning electron microscopy. Electrochemical impedance spectroscopy was employed to separate bulk and grain-boundary contributions and to evaluate their temperature dependence. The variation of bulk and grain boundary resistances with annealing temperature reveals a strong coupling between transient-phase-assisted densification, grain boundary chemistry, and Na-ion transport. This work establishes a processing–structure–transport relationship, providing insight into low-temperature fabrication strategies for high-performance NASICON SE.

Speaker: Mr Sandipan Bhattacharyya (Indian Institute of Technology Kanpur)

18:10 Microstructural and Thermal Properties of a ZrO₂–30 wt% Diamond Composite Sintered by the SPS Method

Zirconia and alumina are widely used for wear-resistant components, while zirconium oxide also serves as a thermal barrier material. Diamond, with the highest thermal conductivity among all materials, can potentially improve the thermal shock resistance of zirconia. However, producing oxide–diamond composites is challenging due to the high sintering temperatures required for ZrO₂ and the tendency of diamond to graphitize under pressureless or low-pressure conditions. Direct sintering may also cause oxide reduction, carbon monoxide formation, and poor bonding between zirconia and diamond.
In this study, ZrO₂–30 wt% diamond composites were produced indirectly. Zirconium powder with 3 mol% Y₂O₃ and 30 wt% diamond powder was milled for 8 h in a planetary mill using zirconia milling media, enabling zirconium deposition on diamond surfaces. The powders were oxidized at 600 °C for 1 h and this process was repeated three times with intermediate mixing.
Sintering was carried out at 1250°C for 4 min in air using Spark Plasma Sintering. X-ray diffraction showed that the matrix mainly consisted of tetragonal ZrO₂, with minor monoclinic ZrO₂ and ZrO₃ phases. Microstructure was analyzed by X-ray computed tomography, while thermal diffusivity and conductivity were measured using the laser flash method.

Speakers: Dr Dorota Tyrała (AGH University of Krakow, Faculty of Metals Engineering and Industrial Computer Science), Prof. Lucyna Jaworska (AGH University of Krakow, Faculty of Metals Engineering and Industrial Computer Science)

18:10 Microstructural Tailoring of Nacre-Inspired Alumina Composites Via Molecular Layer Deposition and Hot Pressing

Nacre, or mother-of-pearl, exhibits exceptional mechanical properties due to its hierarchical brick-and-mortar structure, making it a promising model for lightweight, robust composites. Alumina based systems offer high thermal stability and strength but achieving controlled microarchitecture with low porosity remains challenging. This study investigates the fabrication of nacre-inspired ceramic–polymer composites where the polymeric interlayer (mortar) was produced by molecular layer deposition (MLD). Micron-sized alumina flakes were assembled into a brick-like framework via centrifugation, followed by deposition of a conformal polyurea layer using MLD with 1,4-phenylene diisocyanate and ethylenediamine as precursors. The resulting composites were hot pressed at low temperature under varying pressures, and cross-sections were analyzed by SEM after ion polishing, with porosity quantified using Trainable Weka Segmentation in ImageJ. The MLD process successfully deposited polymeric material between the alumina platelets, albeit showing low contact angle and apparent island-like coating. Hot pressing improved interfacial contact and densified the nacre-like structures, reducing porosity compared to unpressed samples. These results demonstrate that combining MLD-based polymer deposition with low-temperature hot pressing is an effective strategy for producing low-porosity, nacre-inspired ceramic–polymer composites with controlled microstructure and enhanced structural integrity.

Speaker: Nithin Thonakkara James (Karlsruhe Institute of Technology, Institute for Applied Materials, Ceramic Materials and Technologies.)

18:10 Monomer Chain Length Effects on DLP Ceramic Printing and Sintering

Vat photopolymerization based additive manufacturing enables the fabrication of complex ceramic components, but the final performance of printed parts is largely determined by debinding and sintering rather than by the printing step. In practice, low molecular weight acrylates are commonly used to obtain the rheology required for high ceramic loadings, yet understanding how binder chemistry affects green body behavior and thermal decomposition remains essential. Ethoxylated acrylates provide a controlled way to vary binder structure, as the same acrylate chemistry is explored while only the chain length is changed.
In this work, alumina slurries were formulated using ethoxylated acrylate binders with different degrees of ethoxylation. All formulations showed strong photopolymerization under blue light exposure (460 nm), while rheology, green part flexibility, and build plate adhesion varied with molecular weight, with longer chains improving handling.
Thermal analysis showed that increasing ethoxylation widens the temperature window of organic burnout, giving more gradual mass loss during debinding. Sintered density decreased with increasing ethoxylation, while higher densities were obtained for the lower ethoxylation monomers.
These results show that varying molecular weight within a single ethoxylated acrylate system provides a practical way to increase printability and green body properties, but at a cost of lower sintered density.

Speaker: Jošt Oblak (Jozef Stefan Institute, Advanced Materials Department)

18:10 Phase Evolution and Microstructural Development of Cu2O: A Spark Plasma Sintering Study

This study explores the phase evolution and microstructural development of Cu2O during spark plasma sintering (SPS), followed by post processing annealing. Starting with >99% pure powders, the SPS processing resulted in Cu2O as the dominant phase, with small traces of metallic copper, resulting from the partial reduction of the Cu2O powder. After annealing in air atmosphere, both metallic copper and Cu2O underwent oxidation, generating Cu2O/CuO composite structures with tunable phase ratios based on sintering parameters. X-ray diffraction shows mixtures of 16-33 wt.% CuO content at sintering temperatures of 800°C and 900°C, and 40-52 wt.% at 850°C, creating CuO-rich composites. Scanning electron micrographs illustrate the presence of well-defined grain structures after sintering. Relative density measurements show a densification above 94% for lower sintering temperatures and times, finally achieving a 100% density for an 850°C sintering temperature at a 2-minute hold time. Our mixed materials may have potential applications in photocatalysis, where tunable control of electronic properties is essential.

Speaker: Mr Sergio Ojeda-Santillan (University of California San Diego)

18:10 Plasma sintering application on advanced breeding functional materials for fusion applications

Beryllium intermetallic compounds, known as beryllides, such as Be12Ti and Be12V, are highly promising advanced neutron multipliers for JA demonstration (DEMO) fusion power reactors due to their low swelling and high stability at high temperatures. Advanced neutron multipliers are being developed by Japan and the EU as part of their Broader Approach (BA) activities within the International Fusion Energy Research Center (IFERC) project.
We have conducted research and development on beryllides in the past decade, targeting a high density including high stability under severe environments. According to many trier and errors to establish the optimized conditions for high density. By this experience, the tendence of the density depending on the sintering conditions has been well understood and we have succeed to establish database on dependence of the sintering density on sintering conditions, temperature, time and pressure for these materials.
In this study, we will address an overview of R&Ds on plasma sintering process for beryllides, focusing on temperature dependence to density and several properties.

Speaker: Dr Jae-Hwan Kim (National Institutes for Quantum Science and Technology)

Wednesday 2 September

09:00 → 09:30 Conventional sintering and sintering atmospheres

09:00 Sintering of UOX and MOX fuels

The sintering of UOX and MOX fuels has been investigated by high temperature dilatometer tests, in different atmospheres and in function of the plutonium content .

The presentation will focus on the construction of the sintering trajectories, on the determination of the apparent activation energy for densification and, when possible, on the determination of the densification mechanisms regarding the plutonium content and the atmosphere used.

Statistical tests have also been performed to compare the grain size at the periphery and at the center of some sintered pellets of interest.

Speaker: Guillaume BERNARD-GRANGER (CEA Marcoule)

09:00 → 10:30 Field assisted sintering technology/Spark Plasma Sintering FAST/SPS

09:00 Engineering of microstructures of ceramic oxides using Flash or High-Pressure Spark Plasma Sintering

In the field of materials processing, particularly in powder metallurgy, non-conventional sintering techniques such as Spark Plasma Sintering (SPS) have demonstrated strong potential for addressing key challenges in the development of functional ceramics with optimized microstructures and tailored properties. Technical ceramics play a critical role in a wide range of sectors, including energy, biomedical, and transportation industries such as automotive, aerospace, and space applications. Among these materials, yttria-stabilized zirconia (YSZ) is especially attractive due to its combination of outstanding properties, including high mechanical strength and electrical conductivity. However, YSZ is typically densified at temperatures of 1100 °C or higher, which results in grain sizes exceeding 0.3 μm. Achieving dense nanostructured YSZ (relative density > 95%, grain size < 200 nm, and pore size < 50 nm), even by conventional SPS, remains an unresolved challenge.
In this presentation, we demonstrate how advanced SPS variants—namely rapid sintering via Flash-SPS (F-SPS) and low-temperature sintering via High-Pressure-SPS (HP-SPS) applied to commercial nanopowders enable optimization of the microstructure and properties of YSZ nanoceramics. The mechanical properties of the resulting materials are discussed in relation to their structure and microstructure, and are compared with those obtained using conventional sintering and classical SPS routes.

Speaker: Dr Claude ESTOURNES (CIRIMAT)

09:30 Co-sintering of hydroxyapatite and bioglass: comparison between conventional sintering, Spark Plasma Sintering (SPS) and Ultra-fast High Temperature Sintering (UHS)

Co-sintering presents challenges when combining materials with markedly different chemical compositions and physical properties. In particular, the formation of secondary phases or discrepancies in thermal expansion may lead to failure.

Hydroxyapatite (HA) is known to provide excellent osteoconductivity and chemical affinity to bone but exhibits limited mechanical strength and may transform to tricalcium phosphate (TCP) at elevated temperatures. As an alternative to HA, 45S5 Bioglass® triggers rapid bioactivity and bonding to tissue yet shows low intrinsic strength and tends to devitrify during thermal exposure, narrowing its processing window. Coupling both is considered to combine mechanical performance and bioactivity.

Co-sintering, however, can fail due to dissimilar thermal expansion, viscous flow behavior of the glass, crystallization kinetics, and interfacial reactions that can destabilize HA.

In this study, we compare co-sintering of these materials by conventional sintering, Spark Plasma Sintering (SPS), and Ultra fast High Temperature Sintering (UHS). The study includes microstructural observations along with dilatometry characterizations.

Speaker: Dr Romain Trihan (Empa)

09:50 Manufacturing of monolithic heat shields using FAST/SPS and ACS technologies

The study presents a technology enabling the fabrication of ZrO₂–CNT composites for heat shield applications using the FAST/SPS method. As key components of vehicles traveling outside the Earth's atmosphere, heat shields require materials that meet strict performance criteria, particularly those related to thermal properties. The proposed methodology enabled the production of a monolithic heat shield demonstrator using FAST/SPS technology.
Zirconium dioxide (ZrO₂) exhibits properties that make it suitable for a wide range of applications, while carbon nanotubes (CNTs) show significantly higher electrical conductivity. Their combination in the 3YSZ-10MWCNT composite makes the material well suited for FAST/SPS processing. Additionally, a protective coating deposited by ACS (aerosol cold spraying) was applied to prevent CNT oxidation. The approach allows the fabrication of monolithic heat shield structures, but scaling is restricted by the maximum sample diameter feasible in current FAST/SPS systems.

This research is part of a project that has received funding from the European Union Horizon 2020 research and innovation programme under grant agreement No. 814632. The research is a part of the Implementation Doctorate program of the Ministry of Education and Science, Poland implemented in the years 2020–2024 (grant number DWD/4/23/2020).

Speaker: Maria Wiśniewska (Łukasiewicz Research Network – Poznań Institute of Technology, 6 Ewarysta Estkowskiego St., 61-755 Poznań, Poland;)

10:10 Field-assisted sintering technique as a crucial element in the thin-film Li-ion production chain

The development of thin-film lithium-ion batteries represents a critical area of research for specific applications, including miniature electronics. The increased safety of these batteries can be attributed to the application of solid-state LiPON electrolytes, which serve to limit leakage risk and enable operation at elevated temperatures.

The study focuses on demonstrating the potential of the field-assisted sintering technique (FAST) in the development of a novel generation of Li3PO4-based target. The primary objective is the implementation of this technology throughout the entire technological chain that has been developed within the DEPOION consortium, which comprises Łukasiewicz-PIT, BFH, EMPA and The Batteries. The presentation will provide insight into the different designs from the targets' materials (taking into consideration Li3PO4 allotropic forms and the influence of additives such as Al) and construction perspective. This will result in different microstructures, properties of targets and various deposition effects with magnetron sputtering techniques.

This work was co-financed by Switzerland under the 2nd edition of the Swiss-Polish Cooperation Programme (SPPW/DEPOION/0063/2024-00) within the framework of the project Novel Technology for Deposition of LIPON Solid State Ionic Conductors for Li-Ion Batteries (DEPOION). Supported by the Swiss Contribution to reducing economic and social disparities in the EU and from the state budget through the NCBiR.

Speaker: Mateusz Marczewski (Łukasiewicz Research Network - Poznań Institute of Technology)

09:00 → 10:30 Microstructure evolution during sintering and Microstructure-property relationships: (3)

09:00 Effect of additive and annealing on the ultra-high temperature strength of ZrB2

A simple method to obtain highly refractory boride-based ceramic nanocomposites is here discussed.
Fundamental requirement to preserve flexural strength above 500 MPa in the ultra-high temperature regime is to promote the development of a hierarchical structure. This includes core-shell grains, where the shell is a (Zr,Me)B2 solid solution grown around the native MB2 grain, already during sintering.
In the present case, introduction of W-, Mo- or Ta-based compounds enabled us to form micro-sized shells around the original MB2 cores. Subsequent annealing at high temperature further developed a nano-texturing in the shell, where metallic W, Mo or TaC nanoparticles precipitated within the shell and allowed to achieve unprecedented refractoriness up to 2100°C.
Here we show the microstructural features of different diboride composites and show how these microstructural change impact on local properties measured by nanoindentation and on the ultra-high temperature strength.
The unique microstructural findings here reported open vast opportunities for nano-composite ceramic development, manufacturing and applications.

Speaker: Laura Silvestroni (CNR-ISSMC)

09:30 Effect of manganese doping on sintering mechanisms and microstructure of UO₂

In nuclear reactors, the fuel consists of uranium dioxide (UO₂) pellets stacked inside zirconium alloy cladding. These pellets must withstand extreme temperatures and pressures while maintaining limited chemical interactions with the cladding, particularly during the migration of fission products from the pellet center to the periphery. One notable example is stress corrosion cracking assisted by iodine, which may occur under accidental transients.
A strategy to mitigate such interactions consists in doping UO₂ with metal oxides to control its microstructure and thermochemical behavior, thereby limiting both the mobility and corrosive nature of fission gases. Among potential dopants, manganese oxide (MnO) appears particularly promising as an alternative to chromium oxide (Cr2O3), which is currently an established industrial solution
In this study, we investigate the role of manganese in the sintering of UO₂. Mn-doped UO₂ ceramics were fabricated under varying conditions of Mn content, temperature, and oxygen partial pressure (pO₂). Experiments focused on the interplay between densification, grain growth, dopant solubilization, and dopant volatilization during sintering, providing insights into the optimization of the fabrication process when using Mn as an additive. The microstructure of the final samples is examined in relation to the amount of manganese dissolved in the UO₂ matrix, measured by EPMA, or present as a secondary phase.

Speaker: Mr Julien Moulin (CEA)

09:50 Low-temperature oxidative sintering of nano-sized (U,Pu)O₂: Effects on densification and microstructural homogeneity

Previous investigations demonstrated that micro-sized (U,Pu)O2 (MOX) powders sintered at 1200 °C in a mildly oxidative CO/CO2 atmosphere achieve high density and stoichiometry, yet exhibit limited homogeneity and coarse grain structures compared to conventional sintering at 1700 °C in a reducing H2/H2O environment. Conversely, nano‑sized MOX sintered under reducing conditions at 1700 °C reaches comparable density while exhibiting enhanced microstructural uniformity and finer grains. This work evaluates a hybrid approach: combining low‑temperature oxidative sintering with the intrinsic diffusional advantages of nano‑MOX. We test whether sintering nano-MOX at 1200 °C in CO/CO2 can reproduce the high density and homogeneity normally reserved for high‑temperature reducing conditions.
Using established micro-MOX parameters as a reference, nano-sized MOX pellets were sintered at 1200 °C for 2 h (CO:CO2 = 1:9) to determine if enhanced surface energy and shortened diffusion distances improve the low-temperature oxidative sintering process. Post-sintering characterization included geometrical density measurements, scanning electron microscopy, and X-ray diffraction (XRD) to assess grain size, phase purity, and compositional uniformity. The XRD analysis confirmed the formation of a single-phase solid solution. Here, we discuss the distinct impacts of starting powder morphology on the resulting microstructure and the evolution of the solid solution under oxidative sintering conditions.

Speaker: Dr Flavia Digiacomo (Joint Research Centre Karlsruhe)

10:10 Engineering UO2 Microstructures via Enhanced Grain Growth Sintering Methods for Next Generation Nuclear Fuels

A recent reinvigorated shift in interest of nuclear energy, has resulted in demand for enhanced new nuclear fuel ceramics which possess enhanced safety and efficiency margins, to increase energy output and reduce spent nuclear fuel inventories. In industry, this has primarily been achieved through the doping of UO2 with Al, Cr and Al/Cr mixtures a part of so-called “accident tolerant nuclear fuel programs”. The additions result in improved grain growth resulting in increased fission gas retention and enhanced microstructural performance. Despite their current in reactor deployment, the individual roles and effects of Cr and Al on the UO₂ microstructure and mechanical behavior remain poorly described. Particularly understanding how precise control on dopant addition, associated redox chemistry, combined with specific sintering conditions leads to optimized ceramic microstructure development. This work has focused on examining the microstructural, chemical and mechanical performance of UO2 ceramic pellets doped with Cr, Al and Cr/Al. Specifically, the work will describe the need to consider dopant redox states, balanced against secondary phase formation which can either detriment ceramics, such as via Zener pinning, or improve them, through enhanced grain coalescence. The work will highlight and discuss next directions in nuclear ceramic oxide materials, and their enhancement via precise microstructure control via strategic sintering and preparation methods.

Speaker: Dr Gabriel Murphy (Forschungzentrum Juelich GmbH - Institute of Nuclear Waste Management)

09:00 → 10:30 Modelling and simulation of sintering at multiple scales: (3)

09:00 Advanced phase-field modeling and simulation framework for practical sintering process design

In solid-state sintering, numerical prediction of microstructure and defect evolution is essential for the creation of high-performance products. The phase-field (PF) method is uniquely capable of accurately capturing both densification and grain growth during sintering. However, the high computational cost of PF sintering simulations remains a major obstacle. In addition, rigid-body motion models are still under development. Moreover, because sintering involves overall body shrinkage, the application of conventional periodic boundary conditions is not straightforward. In this talk, I will present our recent efforts to overcome these limitations. By implementing parallel computing with multiple GPUs and developing an efficient summation algorithm for calculating the rigid-body motion of particles, we have enabled large-scale PF sintering simulations. We have also proposed a pseudo-periodic boundary condition (PPBC) on fixed grids, in which periodic boundary planes migrate while microstructures are duplicated across these planes to eliminate surface artifacts. Furthermore, beam elements were introduced between particles to model rigid-body interactions, enabling the representation of particle bonding and separation, as well as translational and rotational motions. The integration of these techniques makes PF sintering simulations a practical and reliable design tool for sintered materials and products.

Speaker: Prof. Tomohiro Takaki (Kyoto Institute of Technology)

09:30 Coupling a mesoscale phase-field model with continuum mechanics principles to capture shrinkage during solid-state sintering

The majority of the existing phase-field sintering models is based on the seminal work of Wang that employs Cahn–Hilliard and Allen–Cahn equations to capture mass transport and grain-growth and introduces the concept of sintering forces to handle particle rigid-body motions responsible for shrinkage. However, in the original formulation, these sintering forces are converted to velocities which directly advect the phase fields. Despite simplicity, this approach neglects the underlying continuum mechanics principles and thus often renders non-physical results.

The current work targets these limitations by proposing a novel approach that enriches the Wang model with consistent mechanical behavior. The phase-field equations are coupled with the linear-elastic balance of momentum, where the latter incorporates Wang’s sintering forces as distributed body loads. This formulation enables the computation of consistent advection velocities for the phase fields and thereby establishes long-range interaction mechanisms between particles.

Using a simple test configuration consisting of a chain of identical particles, we analyze in detail the deficiencies of the original Wang sintering model and then show clearly how our coupled approach resolves them. We then investigate the two- and three-dimensional benchmarks to highlight the advantages of the proposed model. Finally, we show how the coupled model can be applied to qualitative numerical analysis of sintering of pure titanium powders.

Speaker: Vladimir Ivannikov (Helmholtz-Zentrum Hereon)

09:50 In situ Electron Tomography‑driven Bayesian Data Assimilation for High‑fidelity Phase‑field Simulation of Solid‑state Sintering

Phase field (PF) simulation has emerged as a promising tool for predicting microstructural evolution during solid state sintering, offering a continuum framework that can capture neck growth, grain growth, and densification at the nano- and mesoscales. However, PF simulations demand accurate material parameters—such as temperature-dependent diffusion coefficients, interfacial energies, and mobilities—that are often unknown or difficult to obtain experimentally, limiting their quantitative reliability. To overcome this limitation, we developed a Bayesian data assimilation (DA) workflow that integrates in situ electron tomography/scanning transmission electron microscopy (STEM) observations into a PF simulation of copper nanoparticle sintering. Using a non-sequential assimilation scheme named DMC-TPE, the time-series of 3D particle morphologies was used to inversely estimate seven material parameters. The calibrated PF model reproduced the experimentally observed neck growth and densification with high-fidelity. This approach established a practical workflow for constructing digital twins of solid-state sintering processes, bridging in situ microscopy and physics-based simulation. We demonstrated that even limited in situ datasets can improve model reliability, offering experimentalists a powerful tool to interpret and guide sintering experiments. This work was supported by JST CREST (JPMJCR18J4).

Speaker: Dr Akimitsu Ishii (National Institute for Materials Science)

10:10 Probing high heating rate sintering with the phase-field method

Sintering is an energy-intensive process used in many materials manufacturing routes.
High heating rate sintering promises to reduce the time and energy costs and possibly achieve better properties as well.
However, it may induce large thermal gradients which can lead to inhomogeneous microstructures and cracks forming.
In this work we seek to further the understanding of how the spatiotemporally evolving temperature field influences the microstructure evolution during sintering by using large-scale phase-field simulations.
The employed phase-field model builds upon recent work to more accurately model the motion of grains due to vacancy absorption, ensuring homogeneous densification in homogeneous settings.
This property can make the numerical Péclet number arbitrarily large, which can lead to artifacts if not accounted for.
Based on the simulations results, it is found that even a simple isothermal model reproduces common high-heating rate sintering observations, with order-of-magnitude matches to experiments without parameter adjustment.
Taking into account thermal gradients on a parts scale shows that the Biot number is still a good predictor for inhomogeneous temperature effects even in a evolving, porous microstructure.
Depending on the processing conditions, sintering fronts may form and hence cause temporal inhomogeneity but with a final homogeneous structure.
Finally, the effect of combining temperature gradients and constrained sintering is considered.

Speaker: Marco Seiz (Kyoto Institute of Technology)

09:30 → 10:30 Sintering of specific material systems: (1)

09:30 Impact of sintering techniques on the densification and transparency of high-entropy garnet ceramics

High-entropy ceramics with a garnet structure have recently emerged as a promising class of materials due to their exceptional thermal stability, chemical robustness, and the tunability of their properties through multication substitution. These materials offer broad potential for advanced functional ceramics with tailored mechanical, optical, and electronic properties. In this work, a transparent high-entropy garnet, (Er0.01Lu0.2Yb0.2Y0.34Gd0.2La0.05)3(Al0.5Sc0.5)2(Al2/3Ga1/3)3O12, was prepared and sintered, overcoming the challenges of full densification in complex multicomponent systems. To achieve optical transparency, appropriate sintering additives were employed. To minimise unwanted interactions between individual oxides during solid-state sintering, precursor powders were synthesised via combustion synthesis, producing fine, compositionally homogeneous particles with a stable garnet structure. Consolidation was carried out using two techniques: spark plasma sintering and vacuum sintering, each with distinct sintering additives. The effects of the densification method and additive type on densification behaviour, microstructural evolution, and material performance, with particular emphasis on photoluminescence, were systematically evaluated. This study provides insights into the relationships between synthesis route, sintering strategy, microstructure development, and optical functionality in high-entropy garnet ceramics.

Speaker: Prof. Daniel Drdlik (CEITEC BUT, Brno University of Technology, Purkynova 123, 612 00 Brno, Czech Republic)

09:50 Preparation of (VNbTaMoW)C High Entropy Carbide from a High Entropy Alloy Using Different Sintering Techniques

High entropy carbides (HEC) represent a promising class within the emerging field of high entropy ceramics. HEC are attractive due to their high hardness and excellent wear and oxidation resistance. However, achieving high densification while maintaining a homogeneous microstructure remains a significant processing challenge.
This study investigates the preparation of a HEC with (VNbTaMoW)C composition using three sintering approaches: spark plasma sintering (SPS), conventional pressureless sintering, and ultra-fast high-temperature (UHS) sintering. The carbide was synthesised from a high entropy alloy precursor combined with graphite, offering an alternative processing route for HEC fabrication compared to the commonly used mechanical alloying approach.

Sintering temperatures were set above 1800 °C for SPS, 2050 °C for conventional pressureless sintering, and over 3000 °C for UHS. The effect of UHS processing conditions on densification was also investigated. The prepared samples were characterised in terms of phase composition and microstructure by using SEM/EDX and XRD. Hardness was evaluated using Vickers indentation.

The influence of the sintering method on densification behaviour, hardness, and microstructural development was evaluated. The results provide insight into suitable sintering routes for processing HEC derived from alloy–carbon precursor systems and reveal significant differences in densification behaviour among the sintering methods.

Speaker: Daniel Valášek (CEITEC Brno University of Technology)

10:10 Sintering of Boron Carbide Powders Derived from Organic Precursors

Boron carbide is an advanced ceramic material of great interest for structural and functional applications due to its low density, high hardness, and chemical stability. Nevertheless, its covalent character represents an issue for sintering and densification which are also strongly affected by impurities and surface oxides presence.
In this context, the use of B₄C powders obtained from organic precursors could represent a promising strategy for improving sinterability, thanks to the enhanced control of chemical composition, stoichiometry, and particle size.
The present work has been carried out to investigate the densification mechanisms of boron carbide powders synthesized from organic precursors, focusing on microstructural evolution and the influence of residual precursor impurities on active sintering processes. Both conventional sintering methods and advanced techniques featuring extremely high heating rates, such as Ultrafast High-temperature Sintering (UHS), are considered.
A comparative characterization of the obtained materials is performed, aiming at correlating the process parameters with densification, microstructural features and phase stability. The comparison between the different sintering paths is intended to clarify the potential advantages and limitations of unconventional processes for the densification of B₄C, thus providing useful information for the development of high-performance ceramic materials.

Speaker: BEATRICE BONALDO (University of Trento)

10:30 → 10:50 Coffee break

10:50 → 12:20 Microstructure evolution during sintering and Microstructure-property relationships: (4)

10:50 Sintering Behavior of Highly-porous Nanostructured Materials

Macroporous ceramics are interesting for a wide range of applications, including catalysis, sensing, photonics, biomedicine, and energy conversion. Many applications require materials that retain their intricate porous architecture at high temperatures, where sintering-related transformations can otherwise degrade structural integrity and functionality. In this talk, I will present metal-oxide isoporous multiscale ceramic structures fabricated via atomic layer deposition (ALD) and their response to thermal exposure. Discrete element method (DEM) and finite element method (FEM) simulations is used to explain the structural evolution and mechanical response of highly-porous Al₂O₃ structures. Our findings reveal that the pore size distribution and volumetric arrangement critically influence thermal deformation, with a complex interplay between geometric parameters and mechanical performance. Building on these insights, we demonstrate the fabrication of thermally robust ZrO₂–Al₂O₃ and SiO₂–Al₂O₃ macroporous systems. Their enhanced resistance to sintering, phase stabilization, and suppression of grain coarsening are attributed to the combined effects of nanoscale structuring and the uniform phase distribution achieved through ALD super-cycling. This approach establishes a pathway toward designing next-generation macroporous ceramics with exceptional thermal and mechanical stability for advanced functional applications.

Speaker: Kaline Pagnan Furlan (Karlsruhe Institute of Technology (KIT), Institute for Applied Materials, Ceramic Materials and Technologies (IAM-KWT))

11:20 Preparations and characterizations of low-cost porous ceramic membranes

Porous ceramics are widely studied for their superior thermal and chemical stability compared to porous metals and polymers. Reticulated porous ceramics, in particular, offer low density and high permeability, making them promising for air filtration, although their relatively low compressive strength still limits broader application. Porous ceramic membranes have also gained importance in water treatment due to their robust thermal and chemical resistance. To reduce manufacturing costs, increasing attention has been given to low-cost raw materials such as diatomite, kaolin, pyrophyllite, and silicon carbide.

This study explores strategies to enhance the compressive strength of low-cost reticulated porous ceramics by optimizing process parameters including solid loading, particle size, and additives in ceramic slurries. In addition, we investigate the fabrication of extruded porous ceramic membranes with controlled pore characteristics—average and maximum pore size, pore distribution, and structure—while maintaining desirable mechanical strength and permeability. The analysis includes pore properties (density, size, and morphology), sintering behavior (linear shrinkage), and mechanical performance (compressive and flexural strength). Characterization techniques such as scanning electron microscopy, mercury porosimetry, capillary flow porosimetry, and dead-end microfiltration with particle counting are employed to systematically evaluate air and water permeability.

Speaker: Jang-Hoon Ha (Korea Institute of Materials Science)

11:40 Current R&Ds on plasma sintering for advanced neutron multiplier for fusion applications

JA demonstration (DEMO) fusion power reactors have adopted an advanced blanket design loaded with advanced neutron multiplier, beryllium intermetallic compounds (beryllides, in specific, Be12Ti) due to their low swelling, high thermal conductivity, and high stability at high temperatures. Advanced neutron multipliers are being developed by Japan and the EU as part of their Broader Approach (BA) activities within the International Fusion Energy Research Center (IFERC) project.
This study evaluates the mechanical properties of beryllide (Be12Ti) fabricated using plasma sintering process. To investigate the effect of sintering temperature on the density, hardness, etc. of Be12Ti, in specific, plasma sintering was performed at various temperatures and evaluated by several experiments. When beryllide was sintered at 1200 oC, the density of beryllide was evaluated to about 100%.
In this study, we reported dependence of sintering density on sintering conditions, details on the experimental results and address how we consider scaleup process to fusion applications.

Speakers: TAEHYUN HWANG, Dr Jae-Hwan KIM (National Institutes for Quantum Science and Technology,)

12:00 Upscaling production of SMART Material for Fusion Reactor using Field-Assisted Sintering

Self-passivating Metal Alloys with Reduced Thermo-oxidation (SMART) with a composition of W-11.4Cr-0.4Zr-0.6Y (in wt.%) are promising candidate materials for first wall applications in fusion reactors. Previous studies have demonstrated the oxidation resistance of SMART alloys at 1000 °C in humid air. However, these investigations were limited to small-scale specimens.
In this study, results on scaling up the SMART material to square-shaped ingots with dimensions of 10 × 10 × 0.5 cm are presented. It was found that increasing the sintering temperature from 1460 °C used at laboratory scale to 1550 °C was necessary to attain a relative density above 97%, comparable to that of smaller ingots. At the same time, residual porosity remained in the corner regions. The grain size changes across in the ingot, with an average size decreasing from 361 µm at the center to 103 μm toward the farthest corners along the diagonal. A single -phase W-Cr alloy was obtained within a central region of about 2 cm radius. Beyond this area the precipitation of the secondary Cr-rich phase occurred. Modelling of the sintering process revealed a temperature difference of up to 105 °C across the square ingot after 10 minutes holding at 1550 °C, a significant contributor to the observed microstructural gradient. Moreover, oxidation tests were performed on samples from different regions of the ingots and the fabrication of hexagonal ingots with a corner-to-corner distance of 10 cm was also explored.

Speaker: Jie Chen

10:50 → 12:20 Modelling and simulation of sintering at multiple scales

10:50 Last advances in Discrete Element Simulation of sintering

In this presentation, we will review the last advances in discrete element simulations of sintering processes. We present a free in-house code, dp3D, which can tackle the different processes related to powder metallurgy from compaction to sintering. dp3D introduces a coupling between densification and grain-growth. The simplifying assumptions and the limitations of the model are discussed together with the conditions necessary for the initiation of each mechanism (surface diffusion and grain boundary migration).
We apply this model to study the effect of particle size distribution on grain growth. We show that wider distribution results in earlier grain growth. We use our simulations to explore the reasons for the suppression of grain growth in the two-step sintering of alumina.
In dp3D, the standard assumption (reasonable for a large set of practical problems) is that particles are spherical and become indented spheres with densification. We have developed a Level-Set module that allows for non-spherical particles. We apply this model to elliptical particles and show that departure from spherical particles may have beneficial effects.
Finally, we show an application on Metal Binder Jetting where simulations reproduce the heterogeneities at the interface between two deposited layers as an input (from X-ray tomography). The resulting sintering anisotropic behavior is discussed together with the type of information provided at the particle scale and at the macroscopic scale.

Speaker: Prof. Christophe MARTIN (UGA-CNRS)

11:20 Microstructural sintering simulations for optimized microstructure evolution during sintering

A novel integrated microstructure model of sintering (IMS) has been developed to enable the simulation of realistic time-temperature cycles during sintering processes (F. Raether, G. Seifert, Open Ceramics, 25, 2026, 100900). Designed for solid-state sintering processes, the IMS includes grain boundary and surface diffusion, as well as grain growth. To obtain realistic results from the simulations, the model combines four established approaches: (i) analytical sintering equations; (ii) an ideal sintering model for minimizing interface energy; (iii) a Monte Carlo model for atomic diffusion processes; and (iv) a model for displacements and rotations of entire particles during sintering.
This contribution will present the concept of IMS and its practical implementation in a voxel-based representation. To validate the model, the results of simulations using typical alumina (Al₂O₃) material and process parameters will be presented and discussed. The simulation results will also allow conclusions to be drawn about practical strategies for improving homogeneity and reducing grain growth during sintering through the correct choice of temperature cycle. Finally, an outlook will be given on the next development stage of IMS, which is intended to provide specific input (e. g., parametrization functions) for improving continuum mechanical sintering models.

Speaker: Dr Gerhard Seifert (Fraunhofer ISC)

11:40 Monte Carlo Simulation of Microstructure Development in Alumina via Densification and Grain Growth

Most ceramic components are manufactured using a powder sintering process. The ceramic microstructure develops through the interaction of densification and grain growth, which is influenced by various process factors. Therefore, computer simulations are crucial. Among the various simulation techniques, the Monte Carlo (MC) method is a prominent approach. In this study, sintering experiments were conducted using alumina powders of different sizes. Corresponding MC simulations of densification and grain growth were then performed to verify the method’s effectiveness. The experimental results showed that higher temperatures activated both densification and grain growth. Notably, the kinetics of fine powder were faster than those of coarse powder, resulting in a larger grain size in the sintered body developed from fine powder. The computational parameters in the MC simulation were determined by referencing the experimental data, successfully reproducing the observed densification and grain growth behavior. Furthermore, simulations were conducted under varied conditions, followed by corresponding experiments. The simulations reproduced the experimental results, demonstrating that microstructural development in alumina is predictable. Therefore, the MC method is a highly promising technology for designing microstructures in sintering processes.
This work was supported by the New Energy and Industrial Technology Development Organization (NEDO) under project number JPNP22005.

Speaker: Dr Sota Terasaka (Japan Fine Ceramics Center)

12:00 Phase-field Simulation for Advanced Sintering

Advanced sintering techniques, distinguished from traditional methods by implementing treatments beyond heat or pressure, have recently gained attention for their efficiency, rapid heating/cooling capabilities, and precise shaping capabilities. The phase-field model has demonstrated its effectiveness in elucidating the in-process evolution of complex structures, taking into account factors such as heat conduction and surface melting. Nonetheless, as a type of diffuse-interface approach, these models utilize a finite interface width to represent transient microstructures. To ensure their quantitative accuracy, they must be asymptotically aligned with their corresponding sharp-interface equations.
In this presentation, we introduce the phase-field framework in advanced sintering considering the existence of local temperature field. We incorporate the Onsager phenomenological relations for non-equilibrium processes directly into the development of our non-isothermal phase-field model. This inclusion introduces additional kinetic terms that elucidate the interplay between mass and heat transfer as well as grain growth. Moreover, we have integrated aspects such as trapping effects and surface diffusion into the variational framework. Our phase-field sintering models have been applied to various advanced sintering techniques, encompassing selective laser sintering, field-assisted sintering, and blacklight sintering.

Speaker: Yangyiwei Yang (Technische Universität Darmstadt)

10:50 → 11:20 Fundamental aspects of sintering

This is the description of the Session.

10:50 Sintering-Driven Evolution of Grain Boundary Complexions: Linking GBPD, Energy Distributions, and Atomic Structure Across Oxide and Silicate Systems

The evolution of grain boundary complexions (Cantwell et al., 2014) during sintering remains insufficiently understood, despite its critical role in controlling transport and functional properties of polycrystalline materials. Here, we combine electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM/PED) to establish a unified framework linking sintering conditions, grain boundary plane distributions (GBPD), and grain boundary energy landscapes across oxide and silicate systems.

Across all systems, EBSD provides statistically robust, population-level descriptors of boundary networks, while TEM and PED resolve the associated atomic-scale structures and validate complexion states. The combined results demonstrate that sintering pathways govern not only densification and grain growth, but also the selection and stability of grain boundary complexions. This establishes a direct link between processing, interfacial thermodynamics, and emergent material properties.

Speaker: K. (T.) Marquardt (Department of Materials, University of Oxford, Oxford, United Kingdom)

10:51 → 11:20 Flash Sintering

10:51 Strong Electric Field/Current Effects on High Temperature processes in Zirconia (8YSZ) Polycrystal

Flash sintering, which occurs under strong electric fields larger than a critical value, has been known to successfully lower the sintering temperature and time of ceramic powder compacts. The flash event is known to work not only on the sintering of ceramic powders, but also on high temperature behavior of bulk ceramics, such as deformation and joining. Currently, it has been confirmed that the flash event is also effective to accelerate crack healing. For example, although the crack healing occurs even under the static annealing without the electric field (0V), the rate of the crack healing was 180 times faster than that of the static annealing (0V) and complete the crack healing at 1230 oC for 10 min. Under the flash event, the crack healing behavior is apparently accelerated in fine grained 8Y-CSZ than in coarse grained one, suggesting that the grain boundaries play an important role in the flash event. The enhanced processing cannot be explained only by the thermal effect caused by Joule heating, but by non-thermal effects caused additionally by the flash event. Especially, the flash healing behavior under the flash event would be accelerated through the field/current-enhanced diffusional processes, especially through the grain boundary diffusivity of the cations.
This work was financially supported by JST CREST (JPMJCR1996) and by KAKENHI (20H02444), Japan.

Speaker: Koji Morita (National Institute for Materials Science (NIMS))

11:20 → 12:20 Field assisted sintering technology/Spark Plasma Sintering FAST/SPS

11:20 Application of field-assisted sintering for diffusion joining of tungsten-based SMART alloys to Eurofer steel for future fusion reactors.

Robust joints between plasma facing material and the blanket structure are crucial for fusion reactors. This work studies the diffusion joining of W-11.4Cr-0.6Y-0.4Zr(also known as SMART alloy) to the structural material Eurofer steel using FAST/SPS. SMART alloys,- due to their self-passivating properties in oxidizing environments - are promising candidates for reactor walls and they are manufactured by mechanical alloying followed by consolidation using field-assisted sintering (FAST/SPS). However, joining SMART to steel is challenging due to mismatch in coefficients of thermal expansion between tungsten and steel.
FAST/SPS joining of SMART and Eurofer at temperature ≥950℃, pressure of 50Mpa, heating rate of 200K/min and dwell time ≤10 min produces a metallurgical bond with a distinct interdiffusion zone, while joining at temperature ≤950℃ results in minimal reaction. Results of EDX characterization and the presence of pores in the intermetallic layer formed at the bond seam indicate a vacancy driven solid-state diffusion, dominating in the direction of SMART to Eurofer. In addition to the bonding interface, the microstructures of SMART and Eurofer before and after joining are characterized, providing a baseline for subsequent tempering at 760℃. Such a post-bonding heat treatment should help retrieving the microstructure and mechanical properties of Eurofer. Future work for the qualification of joints includes high heat flux tests and mechanical strength tests.

Speaker: Ms Aparna Binu Varghese (Forschungszentrum Jülich)

11:40 Synthesis of rare earth free permanent magnets by spark plasma sintering

High-performance rare earth based permanent magnets such as NdFeB and low-performance ferrite magnets currently dominate industrial applications. However, the development of hard magnetic materials free from critical raw elements while maintaining superior magnetic performance remains a key challenge.
The widely established route for producing NdFeB-type magnets is the liquid phase sintering of previously compacted green bodies, consisting of monocrystalline NdFeB particles. The alternative route of producing polycrystalline NdFeB particles by melt spinning technique is well known, but so far mainly used for producing polymer bonded magnets.
With respect to rare earth free hard magnetic materials, the synthesis is often not possible by conventional liquid phase sintering. Therefore, the focus is moved towards alternative sintering processes, which offer a higher potential of successfully producing these materials on a bulk scale. We present results for rare earth free permanent magnets, namely Fe2P- and MnAl-based compositions, which were produced by melt spinning technique, subsequently ball milled to polycrystalline powders and finally densified by spark plasma sintering. We investigated the effects of melt spinning, ball milling and spark plasma sintering on microstructure and magnetic performance, in order to evaluate the potential for such materials synthesized with these processes.

Speaker: Oliver Diehl (Fraunhofer Research Institution for Materials Recycling and Resource Strategies IWKS)

12:00 Large-Scale Synthesis of the Ti₃AlC₂ MAX Phase by Pressureless FAST/SPS Supported by Thermal Modeling

Layered ternary carbides and nitrides, known as MAX phases, have attracted considerable attention due to their unique combination of ceramic and metallic properties. Among available fabrication methods, FAST/SPS sintering is a cost-effective and time-efficient approach that enables effective control of phase composition through rapid heating and cooling cycles. However, scaling up the FAST/SPS process, particularly under pressureless tool conditions, remains challenging due to thermal inhomogeneity and phase instability. This study reports on the large-scale synthesis of the Ti₃AlC₂ MAX phase under pressureless FAST/SPS conditions, supported by a coupled thermal modelling strategy. The influence of process parameters and tool design on temperature distribution was systematically analyzed to optimize thermal uniformity and phase stability. The modelling results were experimentally validated, enabling the successful synthesis of an 800 g batch of Ti₃AlC₂ with a homogeneous phase composition in a single FAST/SPS cycle. The proposed approach demonstrates a scalable and robust pathway for large-batch MAX phase production, providing a framework for further industrial implementation of pressureless FAST/SPS processing routes.

Funding:
This work was supported by the European Union through the Horizon Europe programme under GA number 101135965.

Speaker: Jakub Wiśniewski (Łukasiewicz Research Network - Poznań Institute of Technology, 6 Ewarysta Estkowskiego St., 61-755 Poznań, Poland)

11:20 → 12:20 Sintering of specific material systems: (2)

11:20 Fabrication and Characterization of Advanced Thermal Barrier Coatings for Hydrogen-fueled Gas Turbine Application: A Sintering Resistance in Water-vapor Environment

Ni-based superalloys are widely used in the hot sections of gas turbines due to their high melting points and mechanical strength. To protect these components from extreme temperatures, refractory ceramic thermal barrier coatings (TBCs) are applied. Recently, efforts to replace liquefied natural gas (LNG) with hydrogen fuel have been pursued to reduce greenhouse gas emissions. However, hydrogen combustion raises the turbine inlet temperature (TIT) to about 1500–1600 °C and creates a water-vapor-rich environment. Conventional TBCs such as 8 wt.% yttria-stabilized zirconia (8YSZ) exhibit limitations under these conditions due to phase transformations, sintering, and increased thermal conductivity from high-temperature degradation and water vapor exposure. Therefore, thermally and chemically stable materials are required for hydrogen-fueled turbines.
This study investigates advanced TBC materials that can replace 8YSZ or be used as multilayer coatings. Multi-component rare-earth-stabilized zirconia materials were fabricated and characterized for their thermal, thermophysical, microstructural, and phase behavior. The coatings were tested in dry and steam atmospheres for various durations to examine sintering behavior, and sintering resistance was evaluated through microstructural analysis.

Speaker: Min-Soo NAM (Korea Institute of Ceramic Engineering and Technology (KICET))

11:40 Strategy for solid-state recycling of metallic machining chips using FAST/SPS with focus on microstructure development

The efficient recovery of materials with high intrinsic economic value is gaining increasing importance. Driven by limited local resource availability and growing efforts toward strategic autonomy, processes enabling the direct and local reuse of materials, particularly critical raw materials, are attracting increasing interest. However, metallic scrap with a high surface-to-volume ratio, such as machining swarf and chips, is often unsuitable for remelting, as thermal processing efficiency is reduced by oxidation, gas uptake, phase transformations, and evaporation losses. Furthermore, alloy-specific segregation and phase dissolution may lead to the loss of tailored material properties.
Solid-state recycling routes overcome these limitations and are therefore gaining relevance, for example through hot extrusion or powder metallurgical approaches. FAST/SPS (Field Assisted Sintering Technique/Spark Plasma Sintering) is a fast and robust pressure-assisted sintering process that enables the production of dense semi-finished products from metallic chips. This contribution presents initial experimental results from a systematic, model-supported investigation of the sintering of aluminium-based chips, focusing on material yield, reuse potential, and the influence of chip morphology on the mechanical properties of secondary aluminium. In addition, novel modelling strategies for microstructural evolution during sintering are introduced to reduce experimental effort.

Speaker: Mrs Sarah J. Hirsch (Chemnitz University of Technology, Institute of Materials Science and Engineering)

12:00 Influence of the particle size distribution of multiple-classified fine powders on the properties of recycled NdFeB sintered magnets

The energy transition towards sustainable mobility is essential to reducing CO₂ emissions and combating climate change. The global expansion of electromobility, the electrification of industry, and the use of wind energy will significantly increase the demand for high-performance NdFeB magnets. In addition to recent efforts to expand magnet production outside of China, recycling end-of-life magnets offers numerous advantages and has the potential to make a wide range of products more sustainable and to improve the resilience of critical rare earth elements supply.
The so-called short-loop or functional recycling approach based on hydrogen decrepitation (HD) was used on a pilot plant scale (up to 50 kg) to recycle End-of-Life (EoL)-magnets from wind turbines. The magnets were decrepitated under hydrogen and subjected to inline classifying after jet-milling to remove particles smaller than 1 μm which should reduce the tendency to oxidize during the recycling process. The inline classifying leads to a narrower particle size distribution and an improved D90/D10 ratio of 3.0 compared to 4.2 before classifying, and an increase in the D50 value from 5.8 μm to 6.2 μm. With the use of the classified powder, the oxygen content of the recycled magnets could be successfully reduced from 0.33 wt.% to 0.18 wt.%. The magnetic properties of the recycled magnets (Br = 1.29 T) outperform the EoL-magnet properties (Br = 1.27 T) and high squareness of 98 % is reached.

Speaker: Chi-Chian Lin (Fraunhofer Research Institution for Materials Recycling and Resource Strategies IWKS)

12:20 → 13:20 Lunch

13:20 → 17:50 Exkursions

19:00 → 22:30 Banquet

Thursday 3 September

09:00 → 10:30 In situ measurements and analysis of sintering: (1)

09:00 Quantification of 3D particle morphological changes during the sintering process of Cu powder using in-situ X-ray CT

Understanding the true sintering mechanism of metal powders in the initial-stage remains challenging because most experimental and numerical studies rely on two-dimensional observations, which cannot fully capture the three-dimensional (3D) arrangement and topological evolution of particles. Recent in-situ X-ray computed tomography (CT) studies have enabled direct 3D observation of sintering processes; however, quantitative descriptions of early-stage sintering kinetics in three dimensions remain limited.
In this study, in-situ synchrotron X-ray CT was applied to observe the 3D morphological evolution of gas-atomized Cu powder compacts during the initial stage of sintering. Time-resolved CT measurements were performed during heating up and isothermal holding at 1073 K, and three-dimensional image analysis was conducted to quantify relative density and neck topology within an observation volume. Persistent homology was employed to define particle sizes, neck diameters, and number of contacts in three dimensions.
The results show that relative density decreases during heating up to 1073 K due to thermal expansion, followed by gradual densification during the isothermal holding. During ramp-up, the average neck diameter increased while the number of necks decreased, whereas the opposite trend was observed during isothermal holding. These behaviors indicate that particle rearrangement and coordination changes play a dominant role in the initial stage of sintering.

Speaker: Prof. Yukiko Ozaki (Joining and Welding Research Institute, The University of Osaka)

09:30 Sintering of oxides: the significant impact of carbon on densification kinetics

Advanced manufacturing processes for ceramics, such as non-conventional sintering techniques and additive manufacturing, frequently introduce carbonaceous contamination into oxide-based samples. In this study, we investigate how carbon affects the densification kinetics of Al₂O₃ and Y₂O₃-stabilized ZrO₂ ceramics, focusing on both the underlying mechanisms and the quantitative impact. The impact of carbon on the densification of these oxide ceramics through both free sintering and Spark Plasma Sintering (SPS) is discussed. While carbon's influence may be limited in pressure-assisted densification processes, its effect is significant in pressureless sintering. In fact, it can delay consolidation by hundreds of degrees Celsius, resulting in a reduction in the consolidation rate by several orders of magnitude. This suggests that carbon adsorption on the oxide surface significantly decreases the driving force for densification - specifically the surface excess energy. This conclusion is further supported by the observation that, when sintering is driven by an external force (such as uniaxial pressure in SPS), the influence of carbon is significantly reduced. Beyond densification, microstructural features, such as grain growth, are also impacted. These findings are particularly relevant in light of the increasing prevalence of carbon sources in ceramic processing, including additive manufacturing with high binder volumes and the use of unconventional sintering tools.

Speaker: Etienne Martin (Université de Toulouse, Toulouse INP, CNRS, CIRIMAT, Toulouse, France)

09:50 Grain boundary engineering of low yttrium doped barium cerate through lithium sintering aid infiltration

The development of efficient proton-conducting electrolytes is limited, in part, by strong grain-boundary (GB) blocking effects in acceptor-doped perovskites such as BaCe1-xYxO3-δ (BCY). In this work, we implement a grain-boundary engineering strategy to introduce controlled amounts of lithium nitrate at the BCY GB. The infiltration efficiency was evaluated using three different techniques: core-shell coating, cold sintering, and capillary infiltration. Because Li⁺ solubility is limited in the perovskite lattice, it selectively segregates to the GBs after nitrate decomposition, thereby modifying the interfacial defect chemistry. In addition, lithium acts as a sintering aid. Using Electrochemical Impedance Spectroscopy (EIS) it was possible to observe the successful retention of Li in the GBs environment, after optimization of the sintering protocol. Several Li loadings ranging from 1 to 9 at. % were introduced to assess the tunability of the engineered GBs and its influence on the relative density and ionic conductivity of BCY. EIS in symmetrical cells reveals that Li-infiltrated samples exhibit a significant decrease in the activation energy (from 0.81 to 0.56 eV) associated with GBs conductivity increase. This mitigation of GB resistance opens new pathways for the design of high-performance ceramic electrolytes operating at intermediate temperatures.

Speaker: Pablo Castellani (Kyushu university (Next-FC) and Massachusetts Institute of Technology)

10:10 Towards a better comprehension of high-pressure sintering mechanisms through in situ approach.

Powder sintering is based on diffusion mechanisms, densifying or not, activated by energy input. To enhance its energy efficiency, reduction of sintering temperature is a major challenge. Some advanced techniques (Hot Pressing, high pressure, Cold Sintering Process, Spark Plasma Sintering, …) enable reaching high density while reducing sintering temperature compared to conventional processes (Cottrino et al. 2025, Le Godec et al 2023).
Comprehension of the mechanisms at crystallites size, as well as the influence of sintering technique, parameters and material characteristics makes it possible to optimise these processes. This topic has already been studied mainly through ex situ/post mortem approaches, at material macroscopic scale. However, sintering is governed by high rate transitory mechanisms at the grain scale. An in situ approach, at micro or even nano scale is relevant (Pontoreau et al. 2023).
Using an eSEM in situ compression/heating stage, first-stage sintering (conventional, HP, CSP, etc) mechanisms can be followed at grain scale, first at low temperature and pressure, then at higher values approaching conventional sintering conditions. This “live” study allows monitoring the formation of necks between particle and progressive closure of porosities. Based on model materials (ZnO, TiO2) the combination of ex situ and in situ approaches allows a deepen understanding of the different sintering mechanisms in order to optimize them.

Speaker: Chloé OLLIVIER

09:00 → 09:30 Fundamental aspects of sintering

This is the description of the Session.

09:00 Sintering Hazards - A Non-Steady-State Approach to Kinetics

In situ TEM based sintering experiments indicate that sintering kinetics are inherently non-steady-state due to the need to nucleate point defect sinks. In materials science, kinetic laws are typically derived from differential equations describing the relationship between instantaneous rate and driving force. These formulations are not adequate for problems that are inherently non-steady-state, exhibit hysteresis, and stochasticity. To address this problem, we invoke lifetime and hazard analysis, which is better suited for such problems. We demonstrate that this analysis enables the formulation of a closed form kinetic equation that converges (i) on Coble's equation when the hazard is large, (ii) on a nucleation rate limited model when the hazard is low, and (iii) the sink-controlled regime first derived by Ashby et al for intermediate hazards. This provides a basis for predicting the general sintering response across all rate controlling mechanisms.

Speaker: Shen Dillon (University of California Irvine)

09:01 → 09:30 Flash Sintering

09:01 Expanding the Limits of Flash Sintering Through a Contactless, Plasma Based Approach

Flash sintering enables rapid ceramic densification at reduced furnace temperatures, but its use is limited by electrode degradation and scaling constraints. We present a contactless flash sintering (CFS) platform that replaces physical electrode with a plasma based charge transfer mechanism integrated with real time electrical control and robotic rastering. Tape cast coatings of 8YSZ, Y₂Si₂O₇, Al₂O₃, and ZrB₂ were selected to span a wide range of electrical and thermal properties. YSZ coatings show rapid densification and uniform microstructures under CFS. Y₂Si₂O₇ also densifies but develops cracks and isolated voids after full consolidation, potentially related to volatilization of silica rich phases; this mechanism remains under investigation. Al₂O₃ shows very limited flash induced densification under comparable conditions. An inert atmosphere configuration enables CFS of oxidation sensitive ceramics, and preliminary ZrB₂ flash sintering behavior will be presented. These results clarify material dependent responses in contactless flash sintering and support its extension to diverse ceramic systems.

Speaker: Dr Zhao Zhang (Lucideon M+P)

09:30 → 10:30 Field assisted sintering technology/Spark Plasma Sintering FAST/SPS: (9)

09:30 Contamination, Phase Composition and Microstructure of SPS Zr–50%Ti Produced from Powders Obtained by Mechanical Synthesis and Plasma-Based Ultrasonic Atomization

Commercial Zr–xTi powders are unavailable because zirconium alloys are difficult to synthesize due to high reactivity and ignition risk. High-zirconium Zr–xTi biomaterials have received limited attention, and the optimal Zr/Ti ratio for medical use is still unclear. Zirconium and titanium show infinite solid-state solubility; however, most research powders are produced by mechanical alloying (MA), which can markedly affect the phase constitution and microstructure of SPS-sintered parts. Here, Zr–50%Ti powder was prepared by two routes—MA and ultrasonic plasma atomization—using the same elemental Ti (APS, 98.5%; 45 µm) and Zr (APS, 99.9%; 45 µm) feedstock. Blends were mixed in a planetary mill (100 rpm, 36 h) with zirconia bowls and balls. Powder purity, morphology and particle size were evaluated, including laser particle-size analysis. MA produced finer particles (average 19.63 µm), whereas the atomized powder showed a bimodal distribution with a larger mean size (34.9 µm). Both powders were SPS-sintered at 1000–1100 °C. Phase composition was assessed by X-ray diffraction and microstructure by SEM; oxygen, nitrogen and hydrogen contamination was quantified in the sintered materials. Overall, MA-derived specimens exhibited more complex phase composition and microstructural features than those obtained from atomized powders. These results indicate that powder-production route is a key driver of structural heterogeneity and impurity uptake in Zr–Ti alloys processed by SPS.

Speakers: Prof. Lucyna Jaworska (AGH University of Krakow, Faculty of Metals Engineering & Industrial Computer Science), Dr Joanna Kowalska (AGH University of Krakow, Faculty of Metals Engineering & Industrial Computer Science), Dr Dorota Tyrała (AGH University of Krakow, Faculty of Metals Engineering & Industrial Computer Science)

09:50 Influence of air-atmosphere ball milling and SPS parameters on the microstructure and mechanical-tribological behaviour of Al-based MMCs

This study investigates the combined effects of high-energy ball milling under air and spark plasma sintering (SPS) parameters (Temperature, pressure) on the microstructure, mechanical, and tribological properties of pure aluminium and aluminium metal matrix composites (MMC-Al) reinforced with 10 wt.% (SiC, TiO2), consolidated at T = 550°C to 625°C and p = 50 to 100 MPa. Microstructural and phase analyses were performed using laser granulometry, XRD, SEM. Mechanical and wear properties were evaluated by Vickers microhardness, nanoindentation, and tribological tests. Ball milling led to particle refinement, crystallite size reduction, and increased lattice deformation. XRD analysis further confirmed the formation of aluminium oxide phases on the MMC-Al samples after SPS sintering. The MMC-Al showed significantly higher hardness values 239 HV for Al–SiC and 236 HV for Al–TiO₂ compared to pure aluminium (187 HV). Nanoindentation results revealed heterogeneous microstructural, with regions exhibiting markedly different mechanical properties. Under dry sliding conditions, tribological tests demonstrated a 60 % reduction in wear rate for the MMC-Al compared with pure Al, accompanied by a lower coefficient of friction, especially in localized regions exhibiting values as low as 0.25.

Speaker: Ms Hanen Ammari (Laboratory of Inorganic Chemistry, LR 17-ES-07, University of Sfax, B.P. 1171, Sfax 3018, Tunisia; Université Bourgogne Europe, CNRS, Laboratoire Interdisciplinaire Carnot de Bourgogne—ICB UMR 6303, BP 47870, F-21078 Dijon, France)

10:10 Upcycling of Incinerated Municipal Solid Waste via Spark Plasma Sintering for Sustainable Construction Materials

Municipal solid waste incineration generates large volumes of residues such as sewage sludge ash, which remain largely underutilised despite their mineral-rich composition. This work explores spark plasma sintering (SPS) as a rapid, energy-efficient method to transform incineration residues into load-bearing construction materials for structural applications. Sludge powders are solidified under optimised conditions up to 1100 °C, yielding cubic specimens measuring 10×10×10 mm with compressive strength up to ±100 MPa, providing a promising potential for construction applications. Microstructural analysis reveals a refined grain structure. At the same time, the process minimises porosity and enables short processing times, highlighting the efficiency of SPS in upcycling waste streams. These findings show a promising potential to transform a municipal solid waste byproduct into a load-bearing construction material via SPS, supporting circular-economy goals and offering a sustainable alternative to conventional construction materials.

Speaker: Mr H. Alkisaei (Delft University of Technology)

09:30 → 10:30 Modelling and simulation of sintering at multiple scales: (4)

09:30 A mesoscale simulation model of solid state sintering applied to X2CrNiMo17-12-2 stainless steel

Solid state sintering is governed by self-diffusion processes that induce the formation and growth of sinter necks. This may be accompanied with the successive approach of individual particles to each other that manifests in a macroscopic shrinkage and distortion. In this context, numerous studies contributed to a profound understanding of the interdependence between powder particle size distribution, relative density, temperature, the hereby induced changes of pore morphology and dimensional changes for various materials. This knowledge has been aggregated in different numerical models on both the macro- and the mesoscale. While macroscopic models largely rely on experimentally gathered phenomenological data, mesoscopic models offer the potential to incorporate physical material properties instead. Hence, a level-set model was developed that describes a two-dimensional microstructure as a signed distance function. Individual diffusion mechanisms are modelled based on physical descriptions of the velocity with which the pore surfaces evolve, while accounting for local surface curvature and the stress state underneath the surface. Simultaneously, mesoscopic shrinkage is modelled postulating mass constancy in the sinter neck. The applicability of the model is demonstrated by simulating sintering of X2CrNiMo17-12-2 processed by metal injection molding. Good agreement between experimental and numerical results is shown with regard to microstructural and dimensional changes.

Speaker: Oliver Schenk (RWTH Aachen University)

09:50 Modeling sintering of granulated WC-12Co powder manufactured by Metal Binder Jetting

The Metal Binder Jetting technology (MBJ) is a sinter-based additive manufacturing process gaining increasing interests due to its benefits to quickly produce complex parts for small to medium series. Despite its attractiveness, MBJ still faces many challenges at every stage of the process, such as low green part strengths, repeatability issues and precise control of dimensional accuracy after sintering. The latter is hindered by several aspects. First, the green part relative density is low in MBJ, leading to significant volumetric change during sintering to full density. Second, the layer-by-layer process leads to anisotropic shrinkage. Third, complex parts being targeted, those are often prone to sagging because of creep at high temperature.
In this work, cemented carbides (WC-12Co) were granulated, printed using MBJ and then sintered to reach full density (from ~35% to >98% relative density). Though the main densification mechanism was liquid phase sintering, the Skorohod-Olevsky Viscous Sintering model was used to predict sintering-induced deformation. To that end, material parameters were first identified using dilatometry experiments on MBJ printed parts. Then, the model was modified to account for anisotropy in the building direction and implemented in the code Mfront, for subsequent use in a finite element solver. Finally, calibration parts were used to fine tune the constitutive parameters so that to model shrinkage and creep with less than 5% of deviation.

Speaker: Alexis Burr (Univ. Grenoble Alpes - CEA)

10:10 Geometry prediction of Nickel-Based Alloy Components in Metal Injection Molding and Binder Jetting

Sinter-based additive manufacturing (SBAM) encompasses various processes such as Binder Jetting, Fused Filament Fabrication, Metal Injection Molding, Cold Metal Fusion, and many more. These processes involve the same steps: (i) formation of the so-called “green part” from powder and binder, (ii) debinding to remove the binder, and (iii) sintering to densify the part. The SBAM processes offer a competitive way to produce complex-shaped metallic parts while reducing machining and is cost-efficient compared to traditional additive manufacturing. The variety of these processes allows us to meet diverse needs, such as rapid prototyping, large-series production, or intermittent production.
One of the main challenges of these processes is the control of part geometry during the sintering step. For nickel-based alloys, the sintering temperature is close to or slightly above the solidus. Consequently, densification is fast, and so is the creep rate of the part. Modeling this phenomenon is a complex task, especially given the industrial context and the variability in powder composition.
This work aims to present the approach used at Safran in an industrial context to address these issues. The focus will be on nickel-based alloys produced by Metal Injection Molding and Binder Jetting. Some recent projects aiming to propose solutions will also be presented.

Speaker: Victor SZCZEPAN (Safran Tech)

10:30 → 10:50 Coffee break

10:50 → 11:10 Field assisted sintering technology/Spark Plasma Sintering FAST/SPS: (10)

10:50 Complete densification model of TiAl powder for Spark Plasma Sintering

TiAl alloys are used in aerospace industry thanks to their low density and good mechanical properties. These alloys can be produced by metal casting and powder metallurgy. This second technic is particularly interesting as it ensures good chemical and microstructural homogeneity. Thus, densification of TiAl powder by spark plasma sintering (SPS) is a very promising process for industrial applications. Moreover, the possibilities offered by SPS, especially when coupled with Sinter Based Additive Manufacturing techniques to produce complex shaped parts, made it industrially attractive. Yet, simulation is necessary to ensure the reliability of the process.
A robust and efficient numerical model for the sintering of a TiAl alloy in two numerical steps is created. The first step is dedicated to the thermal-electric simulation of the system and provides the temperature distribution in the tools and the powder by simulating the Joule effect. The second step models the densification of the TiAl powder into a fully dense material by creep (temperature dependent viscoplasticity) using the thermal results obtained in the previous step. The densification model takes into account the creep law of the densified material determined experimentally and a mechanical homogenized model of creep in a porous medium. The model is implemented via the Abaqus® software in a full thermal-mechanical-compaction process. A comparison with the experimental results shows the good adequacy of the simulation.

Speaker: Khalil Chaaban (Université de Bourgogne Europe)

10:50 → 11:50 In situ measurements and analysis of sintering: (2)

10:50 Study of the interaction between UO2 and U3O8 during the sintering of nuclear fuel pellets

Nuclear fuel pellets are manufactured by sintering UO₂ with addition of U₃O₈ to control the microstructure and porosity. The aim of this study is to determine the impact of morphology and grain size of the U₃O₈ powder on the sintering. To assess the presence of chemical interactions between the two uranium oxides, the early stages of sintering are studied using a combination of High-Temperature-XRD and TGA measurements. In addition, using different UO₂ oxidation cycles, U₃O₈ powders are produced with “lamellar”, “dense”, and “fine granular” morphologies to study their effects on the sintering process. Dilatometric analyses and interrupted sintering experiments followed by microstructural observations using EBSD are used to determine a sintering map describing the evolution of density, grain and pores sizes as the sintering thermal cycle progresses. Correlating these data with kinetic laws will enable the identification of the involved sintering mechanisms. Ultimately, these results will help establishing the characteristics that make U₃O₈ more efficient in an industrial context.

Speaker: Antoine Rousselot

11:10 In-Situ Informed Data-Driven Modelling of Fast-Firing Liquid-Phase Sintering of Aluminosilicates

The evolution of microstructure, reaction kinetics, and thermal and mass transport is tightly coupled when designing industrial sintering programs. For aluminosilicate systems, used for white-tiles and structural ceramics, densification is highly sensitive to local heterogeneities and thermal phenomena near the onset of liquid-phase formation. Under fast-firing conditions, high heating rates and short dwell times prevent local thermal-equilibration, influencing liquid-phase flow, pore-network percolation and decomposition reactions. While macroscopic kiln simulations were performed, the microscale activation of densification mechanisms and their upscaling into constitutive models are insufficiently understood [1]. Recent in-situ studies provide valuable insights but remain descriptive [2]. This work presents a data-driven framework that derives densification models from quantifiable in-situ experiments. Micrographs acquired via high-temperature environmental SEM (ESEM) of α-Al₂O₃ and soda-lime-silica glass samples at fast firing conditions are analyzed using automated image-analysis to quantify neck growth, particle rearrangement pore closure and liquid formation. The extracted descriptors are correlated with mass spectrometry and DSC–TGA data and implemented in a Dyssol flowsheet-simulation [3] to upscale sintering densification kinetics into stage-resolved industrial kiln models.
[1] Alves et al., JACerS 2023 [2] Bigeard et al., Materialia [3] Skorych et al., SoftwareX 12

Speaker: Alejandro Lejtman Rotberg

11:30 Enhancing Diamond Retention in Bronze Bonded Grinding Tools

Diamond grit retention is a critical determinant of the operational performance of bronze-bonded grinding tools, primarily governed by the mechanical interlocking induced by thermal expansion difference between diamond and bronze. This study investigates pressure-assisted densification kinetics of diamond reinforced (10, 46 and 107 µm) bronze composites to enhance interfacial bonding via Spark Plasma Sintering (SPS). Results revealed that grain boundary sliding and dislocation-induced plastic flow co-dominated densification of the unreinforced matrix (n≈2.5). As reinforcement size increased, the dominant densification mechanism shifted from grain boundary sliding (n≈2) to dislocation-induced plastic flow (n≈3). Furthermore, the periodic peaks observed in the densification curve, coupled with grain growth relative to the starting powder (D0<2Ds), indicated the occurrence of multi-peak discontinuous dynamic recrystallization (DDRX) mechanism within the microstructure during sintering. Depending on these kinetic insights, two distinct microstructural tailoring strategies were established to enhance interfacial bonding by manipulating process parameters: (i) shifting the DDRX mechanism from multi-peak to single-peak regime by increasing strain rate to induce localized grain refinement, and (ii) leveraging stages where dislocation-induced plastic flow is dominant to promote dislocation accumulation and increase local residual stress.

Speaker: Ertuğrul İşlek (Eskisehir Technical University)

10:50 → 11:50 Modelling and simulation of sintering at multiple scales: (5)

10:50 Graph Neural Network Surrogate Modeling for Sintering Distortion Prediction in Metal Binder Jetting

Metal Binder Jetting (BJT-MSt/M) offers high productivity, but sintering distortion limits dimensional accuracy and first time right production. High fidelity finite element (FEM) sintering simulations can predict distortion, yet their runtime restricts design space exploration and rapid design iterations. We present a graph neural network (GNN) surrogate that predicts sintering induced deformation directly from geometry, enabling fast solver-agnostic inference.
Parts are represented as attributed graphs built from mesh connectivity and local geometric descriptors. A message passing network maps the as printed state at step k to the next state k+1 and outputs node-wise displacement vectors. The model is trained on simulated BJT-MSt/M sintering trajectories and evaluated on unseen geometries. Results show close agreement between predicted and ground truth mean nodal displacement, including transient peaks, with small absolute errors in the mean displacement signal. Inference is orders of magnitude faster than FEM, enabling near real time distortion estimation and supporting iterative compensation loops.
This framework provides a scalable path toward geometry aware, data driven sintering distortion prediction and motivates future work.

Speaker: Luca Juris (RWTH Aachen University - Digital Additive Production DAP)

11:10 CONTINUUM MESO-MACRO MULTISCALE MODELING OF ANISOTROPY DURING SINTERING OF PARTS PRODUCED VIA ADDITIVE MANUFACTURING

In this study, the anisotropy of parts produced via binder jetting is investigated during sintering across multiple scales, using a coupled kinetic Monte Carlo–Finite Element simulation framework.
The process begins with the calibration and validation of a microscale Monte Carlo (kMC) sintering model, benchmarked against experimental data obtained through X-ray computed tomography (X-ray CT), discrete element modeling and optical microscopy at key densification stages captured via interrupted thermal cycles.
Once validated, the model provides microscale descriptors such as strain rate and pore orientation, which are then incorporated as anisotropic sintering stress inputs into a continuum-level sintering model. This macroscopic model is based on the Skorohod-Olevsky Viscous Sintering (SOVS) finite element framework, tailored for 316L stainless steel.
The continuum formulation accounts for key material behaviors, including the influence of initial relative density, grain growth kinetics, the δ-ferrite phase transformation that occurs at elevated temperatures, friction and gravity.
Using a combination of experimental imaging, tensor-based quantification, and numerical simulations, the proposed approach links microscopic directional dependencies to macroscopic responses. The results demonstrate that anisotropy evolves nonlinearly with structural hierarchy, and that cross-scale coupling plays a critical role in determining effective material behavior.

Speaker: Dr Thomas Grippi (CIRIMAT Toulouse)

11:30 Concepts, strategies and frontiers for the modelling and simulation of the FAST-Sintering Process

In recent years, advances in the mathematical modelling of sintering processes have led to continuous improvements in simulation efficiency and reliability. Current modelling approaches address different length scales, so from macroscopic simulations of shrinkage effects for offset-geometry design and production error minimization, to microscopic phase-field models that enable detailed simulation of microstructural evolution during sintering. Although significant progress has been achieved at both ends of this spectrum, frontiers in modelling remain. This contribution reviews and evaluates the state of the art in sintering process simulation, using the FAST/SPS sintering of aluminium chips as an example. Strategies and concepts basing on recent developments of numerical analysis and IT are discussed, aiming to collocate the respective models and their use and applicability. The contribution includes a discussion of a scalable approach to the inverse computation of physical and phenomenological material data. Based on the discussed models, strategies are derived to estimate process control variables in order to achieve targeted post-sintering microstructures. Finally, the applicability of the proposed approach to aluminium chip recycling is discussed, including strategies for experimental parameter identification and model validation.

Speaker: Stephan Daniel Schwöbel (Chemnitz University of Technology, Institute of Material Science and Engineering)

11:10 → 11:50 Pressure assisted sintering including Hot Pressing HP and Hot Isostatic Pressing HIP

11:10 Grain Growth Kinetics of WC–Ni Cemented Carbides During HIP Sintering

Cobalt-free cemented carbides have gained significant attention as sustainable alternatives to conventional WC–Co hardmetals, driven by concerns related to cobalt criticality, supply-chain vulnerability, and health hazards. Among the proposed alternatives, WC–Ni systems offer promising potential in fundamental understanding of those alternative systems. However, detailed study on kinetics of grain growth during sintering which critically influences the performance of cemented carbides and selection of other important process parameters remains limited. In this study, the grain growth behavior of WC–Ni cemented carbides during hot isostatic pressing (HIP) are investigated. Samples were sintered at a fixed temperature and pressure using four different holding durations to examine time-dependent microstructural evolution. Microstructural characterization was carried out using optical microscopy, scanning electron microscopy (SEM), and electron backscatter diffraction (EBSD) to assess WC grain morphology, size evolution, and other crystallographic features. Vickers microhardness measurements were performed to provide a preliminary link between microstructural changes and mechanical response. Mechanisms of grain growth are discussed from kinetic analysis.

Speaker: G M Sadrul Islam (Univ. Grenoble Alpes, CNRS, Grenoble INP (Institute of Engineering), SIMaP)

11:30 Hot-pressing – a recovery mechanism to severe plastically deformed ceramic BiCuSeO

Severe plastic deformation processes are an excellent way to attain grain refinements and introduce dislocations in the material without compromising on the dimensions of the sample and high-pressure torsion (HPT) is a prime example of a severe plastic deformation process. In this work, HPT processing is employed to introduce a dense network of dislocation structures in BiCuSeO and subsequently using hot-pressing (HP) as a recovery sintering mechanism to minimize crack and fracture in the ceramic thereby increasing the mechanical integrity while retaining the effects of the HPT. This methodology was represented as HPT-HP process. The effect of pressure and strain from the HPT-HP processing results in a reduction in the bandgap of the material BiCuSeO from 0.83 eV (HP) to 0.74 eV (HPT-HP1). The best HPT-HP condition was then taken forward for Pb-substitution to achieve a similar effect. The shear deformation from the HPT creates increased levels of dislocation density of about 5.02 x 10^(16) m^(-2) in HPT-HP Bi0.94Pb0.06Cu0.97SeO sample. These dislocations along with their corresponding lattice strains reduce the lattice part of thermal conductivity to a low 0.36 W/mK at 823 K while simultaneously having the reduced bandgap effect and positively observing 145.5 S/cm electrical conductivity in the HPT-HP Bi0.94Pb0.06Cu0.97SeO sample, resulting in a zT of 1.11.

Speaker: Mr Gowtham Venkatesan (Inter-disciplinary Centre for Energy Research, Indian Institute of Science)

11:50 → 12:10 Closing

12:30 → 16:30 Exkursion - Visit of Forschungszentrum Jülich