Speaker
Description
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.
| Professional Status of the Speaker | Doctoral or Master Student |
|---|---|
| Invitation letter for visa | No |
| Interest in submitting a paper in a special issue of | Advanced Engineering Materials (Wiley) |
