OBJECTIVE

Reliable and practical joining techniques are required to enable the use of silicon carbide composites in fusion energy systems. The variety of demanding criteria for the properties of joints will be described, including those pertaining to fusion energy systems. Issues concerning practical fabrication of joints will also be discussed. Preliminary results on the thermal stability of joints formed by a reaction based joining approach will be presented. SUMMARY Joining methods are required to allow affordable fabrication of large or complex SiC/SiC components for fusion energy systems. Previous analysis of the criteria for successful and functional joints indicate that reaction-formed and polymer-derived silicon carbide should be considered as candidate joint materials. Efforts have been initiated to investigate the issues involved with fabrication and durability of these joints. This report summarizes initial investigations of the long-term thermal stability of silicon carbide joints formed by a reaction-based approach. Results indicate that the joint may contain unreacted phases that react further during high-temperature exposure. These results, and their implications, must be confirmed by additional investigations. PROGRESS AND STATU