3d needle-punched carbon/silicon carbide ceramic matrix composites and tribological properties

Carbon/carbon (C/C) composites with certain density were prepared by chemical vapor infiltration (CVI) of the three-dimensional needle-punched carbon fiber preform. By the reactive melt infiltration (RMI) method as a subsequent densification of C/C composites, the highly densified carbon/silicon carbide (C/SiC) composites were finally obtained. The studies on structure characteristics, braking performance as well as friction and wear mechanisms of C/SiC composites were systematically investigated in this paper. It was found that the CVI-carbon which filled the gap between carbon monofilaments in fiber bundles formed dense carbon/carbon region. The material distributed between fiber bundles were silicon carbide derived from RMI, residual silicon and carbon. C/SiC composites show excellent friction and wear behavior with the typical saddle shape of the coefficient of friction (COF) curve. The average COF obtained is 0.34 and the wear rate is low (1.9 μm at a time for one side). The frictional behavior is stable and almost immune to humidity with a decreasing rate of only 2.9% in hygrometric state. In the course of friction and wear, the contact surface of the carbon/silicon carbide brake disk turned to continuous and stable friction surface and grain-abrasion was the main wear form.