Study on the mechanical and tribological properties of C/C composites by CVI and PIP

Carbon/carbon (C/C) composites are created through chemical vapor infiltration and precursor infiltration and pyrolysis. The bending, compressive and tribological properties of C/C composites and graphite materials are compared and studied. The influence of the fiber volume fraction on the mechanical properties of the specimen is investigated. The results reveal that increasing the volume fraction of Z-direction fibers improves the mechanical characteristics of the composites significantly. The bending strength of C/C composites is 66.27-123.18% higher than that of graphite materials, while the compressive strength in the Z-direction is 13-31% greater than that of graphite. The wear is about 33% lower than that in graphite materials. The C/C composites have a more continuous infiltration structure, which promotes the smooth transfer of stress in the composites and enhances their mechanical bearing capacity. Besides, when C/C composites are subjected to friction and wear, it is difficult for the fiber bundles to come off due to the close surrounding of the matrix, resulting in less wear.