为提高碳/碳复合材料抗氧化性能,以甲基三氯硅烷(MTS)为先驱体,利用低压化学气相沉积(LPCVD)技术在碳/碳复合材料表面制备SiC-MoSi2涂层,通过XRD和SEM分析了不同沉积温度下涂层结构、物相组成及其沉积机理。结果表明,沉积温度对涂层的成分、结构及致密度有较大影响,在1100~1250℃均可成功得到SiCMoSi2涂层,1100~C所得涂层结构疏松多孔;1250℃制备的涂层中间部位孔隙较多,表层为致密SiC涂层;1150~1200℃之间可得到均匀致密、以MoSi2颗粒为分散相、以CVD-SiC为连续相的SiC-MoSi2双相陶瓷涂层。
In order to improve the anti-oxidation of C/C composites, SiC-MoSi2 coating was prepared by low pressure chemical vapor deposition (LPCVD) using methyhrichlorosilane (MTS) as precursor. The morphologies, composition and deposition mechanism of the coating were analyzed by scanning electron microscope (SEM) and X-ray diffraction (XRD). The results show that the deposition temperature has a great effect on the morphologies, composi- tion and density of the coating. SiC-MoSi2 coating can be successfully produced during 1100℃ to 1250℃. The struc- ture of the as deposited coating is loose and brittle at 1100℃. And the middle of the layer is porous while dense in the outer layer that made up of SiC at 1250℃. In the temperature range of 1150--1200℃, uniform, dense SiC-MoSi2 dual phase ceramic coating can be obtained whose disperse phase is MoSi2 particles and continuous phase is CVD-SiC.