Influences of Thermal Molding Process on the Flexural Properties of SiC/SiC Composites with a New Precursor Polymer

Abstract

Silicon carbide (SiC) fiber reinforced SiC matrix composites (SiC/SiC) were fabricated by precursor impregnation and pyrolysis (PIP) process with a new precursor polymer, liquid polyvinylcarbosilane (LPVCS). The molding process was conducted during the cross-linking reactions of LPVCS for the first PIP cycle. The influences of molding pressure and molding time on the flexure properties of the SiC/SiC composites were studied. The results indicated that the optimal molding pressure and molding time were 3MPa and 5h respectively due to the fine interfacial bonding between fiber and matrix. The density of the SiC/SiC composites was 2.16g/cm3. The flexural strength and fracture toughness of the SiC/SiC composites were 637.5MPa and 29.8MPa·m1/2 respectively.