Effect of SiC particle dispersion on microstructure and mechanical properties of polymer-derived SiC/SiC composite

To improve the performance of SiC fiber-reinforced SiC matrix composite (SiC/SiC composite), a polymer impregnation and pyrolysis process (PIP process) has been developed by incorporating an inert filler with polyvinylsilane. Composites consolidated with slurries of various filler contents were thoroughly examined at each repetition of the PIP process. The fiber volume fraction and matrix microstructure in the composites were determined during consolidation as a function of the filler content. Densification behavior during multiple PIP processing was much dependent on the microstructure formed in consolidation. Transmission electron microscopy revealed the effect of filler content on the microstructure of the matrix and of the fiber/matrix interface. In addition, the relationships between the microstructure and the mechanical properties were evaluated from a fundamental viewpoint.