【摘要】 利用X射线衍射仪(XRD)和扫描电子显微镜(SEM)等检测设备,观察并研究了原位自生C/C复合材料SiC涂层的物相组成和显微结构特点,并根据SiC固态相变规律和元素互扩散原理,探讨了低压Ar气氛反应烧结制备SiC涂层的形成机理。结果表明,低压保护气氛的引入显著提高了反应烧结过程中液态Si在C/C复合材料表面的润湿性,促进C、Si原子互扩散。在此条件下,多晶Si粉与石墨碳反应形成β-SiC稳定相,且该涂层内部衬度均匀,具有鳞片状和细针状纳米晶须结构,从而改善了C/C复合材料的生物相容性。更多还原

【Abstract】 SiC coating was prepared by low pressure reaction sintering in Ar atmosphere. The phase constituents and microstructure were characterized by means of XRD and SEM. Meanwhile,the SiC coating formation mechanism was studied in accordance with the element interdiffusion principle and the solid phase transformation law. The results indicate that the low-pressure protective atmosphere significantly improves the liquid Si wettability on C /C composite and atom interdiffusion during the coating preparation. Therefore,Si powders can react with graphite to form β-SiC under the annealing temperature slightly higher than the Si melting point. There are uniform contrasts on the planar microstructure images. The coating has scaly and fine needle-like nano-whisker structure,and the biocompatibility of C /C composite is improved.更多还原