Influence of Interfaces on Mechanical Behavior of C/C Composites by CLVI Processing

C/C composites were fabricated by a rapid chemical liquid-vaporized infiltration (CLVI) processing. The fractured surfaces were observed by scanning electron microscope (SEM). In this paper, three types of interfaces in the composites, the fiber-matrix interface within a tow, the interface between carbon cloths or bundles, as well as the interface between pyrocarbon laminar, were discussed. Moreover, their influences on mechanical behavior of the composites were analyzed. In order to obtain high strength and pseudoductility, it is necessary for C/C composites to have proper interface bond strength between fiber and matrix, smaller residual pores between carbon cloths or bundles, and proper gaps between pyrocarbon laminar within the matrix.