摘要
以甲基硅烷(MS)为气源,采用化学气相沉积方法于不同温度下在石墨表面制备SiC涂层,并系统研究温度对SiC涂层的沉积速率、显微组织和抗烧蚀性能的影响规律。实验结果表明:当沉积温度为1000℃时,以MS为气源的SiC涂层的沉积速率为50~120μm/h,远高于以甲基三氯硅烷为气源的沉积速率(5~10μm/h)。当沉积温度较低(900~1000℃)时,以MS为气源所制备的SiC涂层整体光滑、平整,呈球形紧密堆积形貌;沉积温度较高(1100~1200℃)时,SiC涂层呈不规则菜花状颗粒堆积形貌,且微晶尺寸明显增大;当沉积温度为1000℃时,SiC涂层具有合适的致密性、粗糙度以及尺寸均匀的显微组织,同时,该涂层经2300℃等离子烧蚀80 s后,其质量烧蚀率和线性烧蚀率分别为0.0096 mg/s和0.3750μm/s,显示优异的抗烧蚀性能。本研究为以MS为气源的化学气相沉积法制备SiC涂层提供一定的理论基础和技术支撑。
Using the methylsilane(MS)as a gas precursor,SiC coatings were prepared on the surface of graphite by the chemical vapor deposition(CVD)method at different deposition temperatures.The effects of temperature on the deposition rate,microstructures and ablative properties of SiC coatings were investigated systematically.The results showed that the SiC deposition rate of SiC coating using MS at 1000℃ was 50-120μm/h,which was much higher than that using methyltrichlorosilane(5-10μm/h).The SiC coatings deposited at lower temperatures(900-1000℃)exhibited smooth and spherical compact packing morphology,while the SiC coatings deposited at higher temperatures(1100-1200℃)appeared to possess an irregular cauliflower morphology with an significantly increased size of SiC particles.Therefore,the SiC coating prepared at deposition temperature of 1000℃ had suitable density,roughness,and uniform size of coating microstructure.Meanwhile,the mass ablation rate and linear ablation rate of the obtained SiC coating were respectively 0.0096 mg/s and 0.3750μm/s after plasma ablation at 2300℃ for 80 s,exhibiting excellent ablative resistance.This study provided a theoretical and technical foundation for the preparation of SiC coating using the MS as the gas precursor by the CVD method.
作者
胡祥龙
罗骁
杨鑫
谭瑞轩
黄启忠
Xiang-long HU;Xiao LUO;Xin YANG;Rui-xuan TAN;Qi-zhong HUANG(National Key Laboratory of Science and Technology on High-strength Structural Materials,Central South University,Changsha 410083,China;Hunan Provincial Key Laboratory for Advanced Carbon Materials and Applied Technology,Hunan University,Changsha 410082,China)
基金
financially supported by the National Key R&D Program of China(No.2021YFA0715802)
the Joint Funds of the National Natural Science Foundation of China(No.U19A2088)。
关键词
甲基硅烷
化学气相沉积
SIC涂层
沉积温度
显微组织
烧蚀性能
methylsilane
chemical vapor deposition
SiC coating
deposition temperature
microstructure
ablative properties
