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采用熔盐法,以NaCl-KCl作熔盐介质,利用Si粉与碳纤维反应在纤维表面制备出均匀的SiC涂层。研究了反应温度、热处理时间和Si/C比对SiC涂层结构和形貌的影响。研究结果表明:随着热处理温度、热处理时间以及Si/C比的增加,纤维表面涂层厚度与SiC晶粒尺寸增加,但是涂层厚度增加随着Si/C比的增加变化较小。与未涂层碳纤维相比,SiC涂层明显改善了碳纤维的抗氧化性能。1350℃热处理3h制备的SiC涂层致密均匀,其起始氧化温度由540℃增加至650℃。
Using molten salt method, NaCl-KCl as molten salt medium, the use of Si powder and carbon fiber reaction in the fiber surface prepared uniform SiC coating. The effects of reaction temperature, heat treatment time and Si / C ratio on the structure and morphology of SiC coating were investigated. The results show that with the increase of heat treatment temperature, heat treatment time and Si / C ratio, the fiber surface coating thickness and SiC grain size increase, but the coating thickness increases with the increase of Si / C ratio. Compared with uncoated carbon fiber, SiC coating significantly improved the oxidation resistance of carbon fiber. The SiC coating prepared by heat treatment at 1350 ℃ for 3h was dense and uniform, and the initial oxidation temperature increased from 540 ℃ to 650 ℃.