The matrix phases of conventional CVI and whisker growing-assisted CVI (WA-CVI) SiCf/SiC composites were compared to analyze the effects of the whiskers grown in the matrix of WA-CVI composite on the properties. Microstructures of the matrices and fracture surfaces were observed and the hardness and elastic modulus were measured. The whiskers in the matrix as well as on the fibers acted as deposition core sites in WA-CVI composite. The whiskers remained on the pulled-out fibers after fracture resulted in the improved mechanical properties in WA-CVI composite.

Keywords: SiCf/SiC composite, Whisker, Chemical vapor infiltration, Microstructure, Hardness, Elastic modulus.