反应气体配比对C/SiC复合材料ICVI工艺沉积性能的影响

Effect of reaction gas mixing ratio on deposition performance of C/SiC in ICVI process

研究了均热法化学气相渗透工艺过程中反应气体浓度、配比及流动对沉积物和复合材料性能的影响 ,提出了一种简单反应气体在线监控法。XRD分析结果表明 ,当H2 /MTS摩尔比在 2～ 5之间时 ,可沉积出纯净均匀的碳化硅基体 ;而H2 /MTS摩尔比小于 1时 ,沉积物中含有大量自由碳。SEM分析表明 ,甲基三氯硅烷的浓度对沉积速率和沉积深度影响很大 ,随着甲基三氯硅烷的浓度减小 ,沉积深度增大 ,但甲基三氯硅烷的浓度减小引起沉积速率下降 ,沉积周期延长。确保炉内反应气体流动畅通 ,可提高沉积的均匀性和沉积速率。

The effects of the concentration,mixing ratio and flow of reactant gases on deposition and C/SiC (CVI) composite properties in ICVI process are investigated.A simple reactant gas controller in line method is put forward.The XRD analysis results show that pure and uniform SiC matrix can be formed when molar ratio of H 2/MTS (Methyl Trisilane) is between 2 and 5;whereas lots of free carbon will exist in deposition matrix when H 2/MTS molar ratio is less than 1.SEM analysis reveals that concentration of MTS has a strong effect on the depositing rate and depth.The depth increases along with decrease of MTS concentration,whereas decrease of MTS concentration can cause a drop of depositing rate and lengthen the depositing cycle.By making the reactant gases flow fluently the deposition rate and uniformity can be improved.