SiC/SiC Composites for Structural Applications in Fusion Energy Systems

Silicon carbide composites are attractive for structural applications in fusion energy systems because of their low activation and afterheat properties, excellent high-temperature properties, corrosion resistance and low density. Another attractive property includes the potential to engineer their properties by location within a component or system to meet variable performance requirements. This can be accomplished by tailoring the fiber type, volume fraction and architecture by location within the component. Also β SiC exhibits very low swelling (< 0.2%) over the temperature range of 800 to 1000°C.

These composites are relatively new materials with a limited data base; however, there is sufficient understanding of their performance to identify key issues in their application. These issues include: mechanical, chemical and radiation stability, nuclear transmutation, hermetic behavior, thermal conductivity, mechanical and thermal fatigue, thermal shock, joining and design methodology. Progress is being made on several of these issues in the U.S., European Union and Japanese fusion materials programs and through collaborations between these programs.