Oxidation resistance of SiC_f/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 °C–1100 °C for more than 400 h. The oxidation resistance of the composites was evaluated by microstructural and mechanical evolution. Results showed that the PyC layer of composites was completely consumed after oxidation at 500 °C and 700 °C, thereby resulting in significant mechanical-property degradation. By contrast, 97 % and 101 % strength remained after oxidation at 900 °C and 1100 °C, respectively. The transformation was associated with the self-healing characteristics of the composites beyond 900 °C.