化学气相反应法制备SiC涂层

PREPARATION OF SiC COATING BY CHEMICAL VAPOR REACTION

采用化学气相反应法,以3种不同工艺在C/C复合材料表面制备了SiC涂层,并检测了其抗氧化性能。以工业用Si和辅助剂SiO2为原料,在高温、惰性环境中反应产生SiO蒸气,将其引入反应室与C/C复合材料在不同温度下进行气相反应,在试样表面生成一层致密的SiC涂层。X射线衍射分析表明:涂层是由βSiC组成。从试样截面的扫描电镜可知:不同工艺制得的SiC涂层界面过渡带颗粒的微观形貌各异。经最优工艺制备的涂层过渡带很窄,有βSiC纳米晶须生成,且其抗氧化性能最佳。

Silicon carbide coatings were prepared on the surface of C/C composites by chemical vapor reaction (CVR) with three different processes, and the oxidation resistance of SiC coatings was also measured. The compact coatings were gained on the surface of C/C samples at different temperatures by introducing SiO vapor, which generated by Si and auxiliary SiO2 at high temperature in inertial atmosphere, into reaction chamber with C/C samples by CVR. The results of X-ray diffraction analysis and scanning electron microscopy on cross section show that the SiC grains are β-SiC and micrographs in the transition zones existing in interface are different due to different processes, nano-whiskers β-SiC with a narrow transition zone and good oxidation resistance are obtained on prepared SiC coatings.