Oxidation resistance of SiCf/SiC composites with a PyC/SiC multilayer interface at 500 °C to 1100°C

SiC fiber-reinforced SiC ceramic matrix composites with a novel PyC/SiC multilayer interface were oxidized at 500 degrees C-1100 degrees C for more than 400 h. The oxidation resistance of the composites was evaluated by micro-structural and mechanical evolution. Results showed that the PyC layer of composites was completely consumed after oxidation at 500 degrees C and 700 degrees C, thereby resulting in significant mechanical-property degradation. By contrast, 97 % and 101 % strength remained after oxidation at 900 degrees C and 1100 degrees C, respectively. The transformation was associated with the self-healing characteristics of the composites beyond 900 degrees C.