Surface morphology changes in a SiC/SiC composite as caused by simultaneous triple-ion-beam irradiation

Surface morphology changes of silicon carbide (SiC) fiber reinforced SiC matrix (SiC/SiC) composite materials occurring after simultaneous triple-ion-beam irradiation were studied. Irradiation tests were performed with helium (He) ions, hydrogen (H) ions, and self-ions (carbon (C) ions or silicon (Si) ions). The peak displacement damage was 10 dpa (displacements per atom), and the irradiation temperatures were 600, 800 and 950 degreesC. The concentrations of He and H at the damage peak region were 1000 atomic ppm and 385 atomic ppm, respectively. Observations of the irradiated surface and the measurement of morphology changes were performed. The shrinkage of SIC fibers and the apparent shrinkage of the interfacial material, carbon, between the matrix and the fibers at the irradiated surface were observed. These phenomena were mainly attributed to displacement damage caused by irradiation.