Room and high-temperature mechanical and thermal properties of SiC fiber-reinforced SiC composite sintered under pressure

Polycarbosilane-impregnated 2D woven SiC fiber-reinforced SiC composites with 52 vol % of fibers were fabricated by hot-pressing at 1650–1750°C under a pressure of 40 MPa using sintering additives of an Al2O3–Y2O3–CaO system. The composites fractured in a non-brittle manner. Maximum strength of the composites hot-pressed at 1700°C or 1750°C did not decrease up to a test temperature of 1200°C. The fracture energy increased with increasing test temperature and peaked at 1200°C. Thermal conductivity increased with increasing bulk density, and the values were 7–14 W/m K at room temperature.