纳米SiC对C/C复合材料石墨化与抗氧化性能的影响规律

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

本文制备纳米SiC基体改性的SiC-C/C复合材料,利用X射线衍射技术、高分辨率透射电镜等研究SiC对碳材料的石墨化度的影响.纳米SiC能够显著促进碳基体材料的石墨化度,同时通过高分辨率透射电镜在纳米SiC颗粒周围观测到明显的石墨化结构,并且距离SiC越近,碳基体的石墨化程度越高.通过静态氧化实验研究SiC-C/C复合材料的抗氧化性能.结果表明,随着SiC加入量的增加复合材料的抗氧化性显著提高,纳米SiC在高温下生成较为均匀的Si O2保护层,覆盖在碳材料的表面,阻碍氧气与碳材料的接触,并且SiC含量越高,形成的保护层越厚,抗氧化能力越强.

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 Si O2 protective layer at high temperature,which could cover the carbon material surface to prevent the material from oxidation. In addition,the Si O2 protective layer is thicker and has a higher oxidation resistance property when the matrix material contains more nano-SiC.