基于石墨微晶表面模型的热解碳沉积过程Monte Carlo模拟

发布时间：2018-07-15 10:43

【摘要】：以石墨微晶的基平面作为碳/碳复合材料化学气相渗透(chemical vapor infil-tration,CVI)制备工艺热解碳基体的表面模型,基于CVI工艺中存在的Particle-Filler(P-F)热解碳沉积模型和Langmuir-Hinshelwood(L-H)模型,利用Monte Carlo(MC)方法对热解碳基体生长中所伴随的微观织构形成过程进行了模拟,对CVI工艺中热解碳基体织构内部的界面形成过程进行了分析.研究结果表明,随着气相成分组成参数R(C6与C2浓度比)的变化,热解碳基体的织构形成过程曲线呈现"S"形特征变化.线性稳定性分析结果表明,该曲线具有双稳态分布的特征.进一步的计算结果表明,不同织构的热解碳双稳态转变存在一个迟滞区域,且此区域大小明显受气相成分组成参数的影响.
[Abstract]:The surface model of pyrolytic carbon matrix prepared by chemical vapor permeation of carbon / carbon composites using graphite matrix as the base plane of carbon / carbon composites was studied based on Particle-Filler (P-F) pyrolytic carbon deposition model and Langmuir-Hinshelwood (L-H) model. Monte Carlo (MC) method was used to simulate the formation process of microtexture in the growth of pyrolytic carbon matrix. The interfacial formation process within the texture of pyrolytic carbon matrix was analyzed in CVI process. The results show that with the change of composition parameter R (C _ 6 / C _ 2 concentration ratio), the texture formation curve of pyrolytic carbon matrix shows "S" shape characteristic. The results of linear stability analysis show that the curve has the characteristics of bistable distribution. The further calculation results show that there is a hysteresis region in the bistable transition of pyrolytic carbon with different textures, and the size of the region is obviously affected by the composition parameters of the gas phase.
【作者单位】：上海大学复合材料研究中心;航天材料及工艺研究所先进功能复合材料技术国防科技重点实验室;
【基金】：国家重大基础研究发展计划(973计划)资助项目(61318403) 航空科学基金资助项目(2013ZFS6001) 上海市科委资助项目(13521101202)
【分类号】：TB332

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