Abstract: C/C composites were fabricated by a rapid chemical liquid-vaporized infiltration (CLVI) processing. The deposition temperatures were in the range of 850～1400℃,
and the system pressure was about 0.1MPa. The micro-morphologies and textural characteristics of pyrolytic carbon and fracture surfaces were observed by polarized light microscopy (PLM)
and scanning electron microscopy (SEM). For the special densification situations of CLVI, the forming conditions and densification course of three types of pyrocarbons were
investigated preliminarily. At the same time, mechanical properties of the composite were examined, and the fracture characters and failure mode were also analyzed.
The results show that rough laminar (RL) pyrocarbon grows with curved layers and the microstructure of RL pyrocarbon presents cone-like features. The materials damages with shear-tension
form, while tensile destruction dominates the failure mode; the binding strength of fiber/matrix interface is higher, and the weak positions are located within interlayers.

Key words: carbon/carbon composites, pyrolytic carbon, microstructure, mechanical properties