Cavity formation in Tyranno-SA SiCf/SiC composite irradiated with multiple-ion beam at elevated temperatures

The microstructural evolution of Tyranno-SA SiCf/SiC composite irradiated at 800 °C and 1000 °C was investigated by transmission electron microscopy. The irradiation was performed using multiple-ion beam in order to simulate the D-T fusion reactor environment. In this study, we irradiated SiCf/SiC composite made from advanced SiC fibers namely, Tyranno-SA, using dual-ion beam (6 MeV Si3+ and 1.13 MeV He+) and triple-ion beam (6 MeV Si3+, 800 keV He+, and 280 keV H+). The effects of He and H atoms on the cavity formation during irradiation are discussed. Cavities were found mainly on the grain boundary of SiCf/SiC composite, and cavity coarsening was observed after higher temperature (1000 °C) irradiation. Hydrogen atoms in the SiCf/SiC composite will enhance cavity nucleation.