碳化硅CVI工艺沉积动力学模拟研究  

Sedimentation Kinetic Simulation Research of Silicon Carbide CVI Process

作　　者：汤哲鹏 王梦千 董凯 TANG Zhepeng;WANG Mengqian;DONG Kai(Eighth Research Institute of Nuclear Industry,Shanghai 201808,China)

机构地区：[1]核工业第八研究所,上海201808

出　　处：《中国陶瓷工业》2023年第1期1-6,共6页China Ceramic Industry

基　　金：国家自然科学基金(21676163)。

摘　　要：化学气相渗透(CVI)工艺被广泛应用于制备碳基及碳化硅(SiC)基复合材料,CVI工艺是实现制备高纯度和高晶粒度SiC基体的SiCf/SiC复合材料最佳方案。为了优化CVI制备SiC基体的工艺参数,本文主要研究了CVI工艺沉积SiC的动力学机理及数值模拟。对于CVI工艺SiC沉积的动力学,本文提出了SiC沉积过程的反应动力学机理模型,并通过耦合反应器内的流场和浓度场,模拟了甲基三氯硅烷(MTS)在CVI过程中的SiC沉积实验。通过对样品在CVI致密化过程中孔隙率的实验结果与模拟结果比较,表明该SiC沉积动力学模型的合理性。通过模拟获得了在反应器内的速度场和各组分(MTS,CH_(3),SiCl_(3))的浓度场分布情况,以及预制体致密化过程的密度分布情况。以上SiC的CVI工艺动力学模拟,对未来优化SiCf/SiC复合材料CVI工艺具有重要的指导意义。Chemical Vapour Infiltration(CVI)is a widely used process for fabricating Carbon and Silicon Carbide(SiC)matrix composites,and the CVI process is the best method to prepare the SiCf/SiC composites due to the high purity and crystalline come with the SiC matrix.In order to optimize the process parameters for the SiC matrix of SiCf/SiC composite in the CVI process,this study focuses on the kinetic mechanisms and simulations for the SiC.For the kinetic simulation of the SiC in CVI process,the SiC deposition kinetic model was proposed.By coupling the flow field and concentration field of the reactor with the SiC deposition kinetic model,the SiC deposition inside the carbon preform by methyltrichlorosilane(MTS)pyrolysis was simulated.Throuth comparing the experimental and simulated results of the porosity of the samples,the rationality of the proposed kinetic model was further proved.The velocity profile,the concentration profiles of the main species(MTS,CH_(3),SiCl_(3))inside the reactor,and the density profile of the preform during the CVI process were obtained by the simulation process.The above discussions about the kinetic simulation of SiC in the CVI processes will shed a light on the preparation of optimized SiCf/SiC composites in the future research.

关 键 词：SIC CVI工艺 工艺参数 动力学 

分 类 号：TQ174.75[化学工程—陶瓷工业]