Microstructural stability of SiC and SiC/SiC composites under high temperature irradiation environment

Silicon carbide continuous fiber-reinforced silicon carbide matrix composites (SiC/SiC composite) are attractive as the structural material of advanced energy systems, including nuclear fusion. The irradiation may affect the fiber/matrix interphases which are responsible for the pseudo-ductile fracture behavior of SiC/SiC composites. In this work, the investigation of the microstructural evolution of SiC/SiC composites in a fusion environment is performed by the dual-ion irradiation method. Reinforcements were Tyranno™-SA and Hi-Nicalon™ Type-S. The displacement damage rate was up to 100 dpa. The irradiation temperature and He/dpa ratio were up to 1673 K and 60 appm, respectively. The microstructural modification induced by the dual-ion irradiation especially occurred in the interphase. The advanced SiC fiber did not shrink and the C/SiC multilayer interphase showed a superior microstructural stability against the dual-ion irradiation at high temperatures.