STATUS AND PROSPECTS FOR SIC-SIC COMPOSITE-MATERIALS DEVELOPMENT FOR FUSION APPLICATIONS

Silicon carbide (SiC) composites are very attractive for fusion applic ations because of their low afterheat and low activation characteristi cs coupled with excellent high temperature properties. These composite s are relatively new materials that will require material development as well as evaluation of hermiticity, thermal conductivity, radiation stability, high temperature strength, fatigue, thermal shock, and join ing techniques. The radiation stability of SiC-SiC composites is a cri tical aspect of their application as fusion components and recent resu lts will be reported. Many of the non-fusion specific issues are under evaluation by other ceramic composite development programs, such as t he US national continuous fiber ceramic composites. The current develo pment status of various SiC-SiC composites research and development ef forts is given. Effect of neutron irradiation on the properties of SiC -SiC composite between 500 and 1200 degrees C are reported. Novel high temperature properties specific to ceramic matrix composite (CMC) mat erials are discussed. The chemical stability of SIC is reviewed briefl y. Ongoing research and development efforts for joining CMC materials including SiC-SiC composites are described. In conclusion, ongoing res earch and development efforts show extremely promising properties and behavior for SiC-SiC composites for fusion applications.