化学气相沉积法制备TiC涂层的相组成和表面形貌

Phase Composition and Surface Morphology of TiC Coating by Chemical Vapor Deposition

用化学气相沉积法 (CVD)在碳 /碳复合材料表面沉积 Ti C涂层。研究了工艺参数对 Ti C涂层的相组成和表面形貌的影响以及 CVD Ti C涂层的沉积机理。实验结果表明 ,当进入沉积室的气体流量 (m L· min-1 )比为 H2 ∶ Ti Cl4∶ CH4=30 0∶ 2 5∶ 1 0时 ,所得涂层中含较少的游离碳 ,Ti C纯度较高。随 CH4流量增加 ,游离碳含量增加。沉积温度对 Ti C的形貌有明显影响 ,较低温度下沉积的 Ti C粒子尺寸小 ,分布均匀 ,随温度升高 ,Ti C的粒径增大 。

The TiC coating on the surface of carbon/carbon composites was prepared by CVD method. The effects of process parameters on phase composition and surface morphology of TiC coating as well as the mechanism of depositing TiC were studied. TiCl 4 and CH 4 were used as reactant gas and H 2 as carrier gas. The temperature of deposition was 900～1 200℃. The experimental results show that when the ratio of gas flow (mL·min -1 ) entering the depostion chamber is H 2∶TiCl 4∶CH 4=300∶25∶10, there are few floating carbons in the coating. With the increase of CH 4 flow, the content of floating carbons is increased. The effect of deposition temperature on the morphology of TiC is that the crystal size of TiC produced at lower temperature is small and well distributed, while larger crystal size of TiC is formed at higher temperature, resulting in poor quality coating.