Influence of nano-SiC on the graphitization and oxidation resistance of C/C composites

SiC-carbon/carbon (C/C) composites were prepared by doping nano-SiC, and the influence of nano-SiC on the graphitization degree of carbon material was investigated by X-ray diffraction and high-resolution transmission electron microscopy (HRTEM). The nano-SiC can promote the graphitization degree of carbon material. An apparent graphitization structure around the nano SiC was observed by HRTEM, and the carbon material has a higher graphitization degree when it is closer to the nano-SiC. The oxidation resistance of SiC-C/C composites was also studied through static oxidation experiment. It is found that the anti-oxidation performance of C/C composites increases with increasing nano-SiC content, and the nano-SiC forms a uniform SiO₂ protective layer at high temperature, which could cover the carbon material surface to prevent the material from oxidation. In addition, the SiO₂ protective layer is thicker and has a higher oxidation resistance property when the matrix material contains more nano-SiC.