Iridium coating was deposited by double glow plasma on the polished, oxidized and heat - treated carbon/carbon composite. The morphology and microstructure of C/C composite and iridium coating were examined by scan electron microscopy. The results show that better deposition and surface coverage with iridium coating were obtained on the polished surface of C/C composite, but some microcracks appeared on the surface of the coating due to the thermal expansion mismatch between the coating and C/C composite during high temperature deposition process. The oxidized and heat - treated surfaces of C/C composites were not fully covered by iridium coating because of the big gaps and some defects on the surface after oxidation and heat treatment. These defects needed to be filled by several depositions.%采用双辉等离子技术分别在抛光、氧化和高温热处理的C/C复合材料表面制备贵金属铱涂层.C/C复合材料和铱涂层的表面微观结构通过扫描电镜观测.结果表明:在抛光的C/C复合材料表面获得沉积较好、覆盖良好的铱涂层,但铱涂层表面出现微裂纹.微裂纹出现是由于较高沉积温度下涂层与基体之间的热膨胀系数不匹配导致的.氧化和高温热处理的C/C复合材料基体表面出现较大间隙和缺陷,铱涂层没能完全覆盖其表面,需多次沉积填满这些缺陷.
展开▼
