Microstructural modification of W–SiC bonded plate during high temperature exposure

Abstract

R&D and technology integration of high performance materials for plasma facing components (PFCs) are important to realize in fusion reactor. Tungsten is becoming a prime candidate as a PFCs material because of the low plasma spatter rate, low hydrogen retention, and the high melting point. The utilization of tungsten is expected to suppress the plasma contamination. Although ITER employs full tungsten divertors, many issues are still remaining and need to be researched for fusion reactor after DEMO. The SiC/SiC composite is a candidate material for components of after DEMO reactor, and especially, SiC/SiC composites fabricated by Nano-Infiltration and Transient Eutectic phase (NITE) method have various advantages. From the view of divertor structural materials, because of small mismatch in coefficient of thermal expansion between tungsten and SiC is a great advantage, the application of SiC/SiC composites armored by tungsten will be an attractive option of divertor concepts in future. This paper provides the stability of W–SiC bonded plate at high temperature. The W–Si and W–C phases are observed around the interface of W–SiC bonded plate. Microstructural modification of W–SiC interface before and after high temperature exposure test is characterized using shear test and microscopes.