High-performance 3D SiC/PyC/SiC composites fabricated by an optimized PIP process with a new precursor and a thermal molding method

摘要

To improve the efficiency of the polymer impregnation and pyrolysis (PIP) process and the mechanical properties for SiC/SiC composites, 3-dimensional (3D) SiC/SiC were fabricated by a PIP process with a new precursor polymer and the thermal molding method. Liquid polyvinylcarbosilane (LPVCS) with active Si-H and -CH = CH_2 groups was adopted as the SiC matrix precursor. The SiC/SiC composites with superior mechanical properties were efficiently fabricated. The fiber volume of the SiC/SiC was 50.4%. The bulk density and porosity of the SiC/SiC composites were 2.16 g cm~(-3) and 15.4% respectively. The flexural strength and fracture toughness of the SiC/SiC composites were 637.5 MPa and 29.8 MPa m~(1/2) respectively. The influences of LPVCS and molding pressure on the performances of the SiC/SiC composites were discussed in-depth.