Effects of Preparation Conditions on the Microstructure and Properties of Hot Pressed SiC/SiC Composites

SiC/SiC composites were prepared by hot pressing using nano-SiC and sub-micrometer SiC powders for matrix formation. The effects of preparation conditions, such as particle size, sintering temperature and sintering pressure, on the microstructural evolution and mechanical properties were characterized. The composite using nano-SiC for matrix formation could promote densification at a relatively lower temperature. At 1780℃, 20MPa, a high performance composite, N-SiC/SiC, could be obtained. While using sub-micrometer SiC for matrix formation, fiber and matrix interaction was enhanced with the increasing of either sintering temperature or pressure, which would disbenifit for the performances of the composite.