Effects of the PyC interface coating on SiC nanowires of SiCf/SiC composite

The incorporation of SiC nanowires in the SiC fiber preform was clearly shown to be effective in increasing the efficiency of the matrix infiltration for the fabrication of SiCf/SiC composites, and thus resulted in a higher density in a shorter CVI (chemical vapor infiltration) time. Generally, tailoring the interface between fibers and the matrix is known to be a way to control the mechanical behaviors of SiCf/SiC composites. In this study, the PyC interface was coated on SiC nanowires as well as SiC fibers to supply the additional interfaces and enhance the mechanical properties of SiCf/SiC composite prepared by the nanowire-growth assisted CVI process (NW-CVI). NW-CVI composites with or without PyC coating on the SiC nanowires had the average flexural strength of 450 and 510 MPa and the average tensile strength of 226 and 253 MPa.