Fracture Behaviors and Mechanical Properties of SiCf/SiC Composites Prepared by the Whisker Growing Assisted CVI Process

SiCf/SiC composites with whiskers and pyrolytic carbon (PyC) coated whiskers in the matrix were fabricated for enhancement of the fracture behaviors by the whisker growing assisted chemical vapor infiltration (WA-CVI) process, respectively. SiCf/SiC composites were also prepared by the conventional CVI process as reference material. The mechanical properties and fracture behaviors were analyzed by comparison of the two types of composites prepared by WA-CVI and conventional CVI. The densities of SiCf/SiC composites were in the range of 2.6 similar to 2.65 g/cm(3). The flexural strengths of composite with whiskers and with those coated by PyC were 650 MPa and 600 MPa, respectively. The tensile strength of composites with whiskers was similar to 285 MPa.