Effect of microwave sintering time on the flexural properties of the SiC/SiC composites

In order to investigate the effect of microwave sintering time on the mechanical properties of SiC/SiC composites, four groups of SiC/SiC composites were fabricated via polymer impregnation and pyrolysis (PIP) process using microwave heating with different sintering time‐ 0.5 h, 1.0 h, 1.5 h and 2.0 h (at 1100 °C) at each PIP cycle. The flexural properties, the interfacial debonding strength between SiC fiber and matrix of the fabricated SiC/SiC composites and the SiC fiber filament strength after heat treatment were investigated. The results indicated that after heat treatment the residual strength of SiC fibers as reinforcement decreased and the interfacial debonding strength increased with the increase of the microwave sintering time at each PIP cycle, which together resulted in the changing tendency that the flexural strength and toughness of the as-fabricated SiC/SiC composites increased firstly and then decreased.