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采用化学气相反应法,以同种工艺分别在石墨和C/C复合材料表面制备了SiC涂层,借助X射线衍射仪(XRD)、扫描电镜(SEM)及能谱分析等手段分析了涂层的微观结构,研究了不同碳基体对SiC涂层结构和表面形貌的影响,并初步对比考察了涂层的高温抗氧化性能.结果表明:制备的SiC涂层整体致密,与基体结合良好,但存在明显的结构差异.石墨表面制得的SiC涂层呈梯度分布,涂层主要由致密外层及过渡内层组成,而C/C复合材料表面制得的SiC涂层仅由致密外层组成;在1823K的空气氧化氛围中,与C/C复合材料SiC涂层试样相比,石墨SiC涂层试样表现出更好的高温抗氧化性能,经30h氧化及7次循环热震实验后,涂层试样的氧化失重率仅为0.182%.
SiC coatings were prepared on the surface of graphite and C / C composites respectively by chemical vapor phase reaction. The coatings were analyzed by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy spectrum analysis The effects of different carbon matrix on the structure and surface morphology of the SiC coating were investigated, and the high temperature oxidation resistance of the coating was also contrasted.The results show that the prepared SiC coating has the advantages of compactness and good bonding with the matrix, But there are obvious structural differences.The SiC coating prepared on graphite surface has a gradient distribution, the coating mainly consists of dense outer layer and transitional inner layer, while the SiC coating obtained on the surface of C / C composite material is only composed of dense outer layer . Compared with the C / C composite SiC coating samples, the graphite SiC coating samples showed better high temperature oxidation resistance under 1823K air oxidation atmosphere. After 30h oxidation and 7 cycles thermal shock test After the coating, the loss of weight of the sample was only 0.182%.