C/C复合材料MoSi_2-Mo_5Si_3/SiC涂层的制备及组织结构

Preparation and Structure of MoSi_2-Mo_5Si_3/SiC Multi-coating for Carbon/Carbon Composites

采用化学气相反应法和料浆刷涂反应法,在C/C复合材料表面制备了MoSi_2-Mo_5Si_3/SiC复合涂层,借助X射线衍射仪、扫描电镜及能谱等分析手段,对涂层的形成、组织结构进行了研究,并初步考察了涂层的高温抗氧化性能.结果表明:制备的复合涂层厚度为400μm左右,主要由β-SiC、MoSi_2及少量的Mo_5Si_3组成.1350℃等温氧化10h后,复合涂层试样的氧化失重率只有1.21%,明显低于C/C复合材料SiC单涂层试样,其高温抗氧化性能得到明显的提高.因此,与C/C复合材料SiC单涂层相比,经封填改性制得的复合涂层结构更致密,具有良好的高温抗氧化性能.

To prevent carbon/carbon composites from oxidation, a MoSi2-Mo5Si3/SiC multi-coating was prepared by the chemical vapor reaction （CVR） technique and slurry method. The formation mechanism and structure of the multi-coating were studied by using XRD, SEM and EDS analysis, and then the anti-oxidation property of the multi-coating was investigated. The results show that the thickness of obtained coating is about 400μm, and the main phase are composed of β-SiC, MoSi2 and Mo5Si3. After oxidation in air at 1350℃ for 10h, the weight loss of the multi-coating is only 1.21%, which is obviously lower than that of single-layer SiC coating. The phases of MoSi2 and Mo5Si3 formed in the MoSi2-Mo5Si3/SiC multi-coating fill the cracks and holes in the monolayer SiC coating, which can improve the anti-oxidation ability of the multi-coating. So the multi-coating made by the complex technology possesses more compact structure and better anti-oxidation property.