收稿日期: 2015-03-18
网络出版日期: 2016-12-30
基金资助
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)
Monte Carlo simulation of pyrocarbon deposition process based on graphite crystallite surface model
Received date: 2015-03-18
Online published: 2016-12-30
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.
关键词： Monte Carlo方法; 迟滞; 石墨微晶表面模型; 织构转变; 热解碳
刘柄林1, 马骁1, 房金铭2, 汤哲鹏1, 李爱军1, 孙晋良1 . 基于石墨微晶表面模型的热解碳沉积过程Monte Carlo模拟[J]. 上海大学学报(自然科学版), 2016 , 22(6) : 691 -700 . DOI: 10.3969/j.issn.1007-2861.2015.04.005
The base plane of graphite crystallite was proposed as the surface model of pyrocarbon prepared in chemical vapor infil-tration (CVI) processes. The Particle-Filler(P-F) model and Langmuir-Hinshelwood (L-H) mechanism of CVI processes were applied to simulate the texture formation in the process of pyrocarbon growth using the Monte Carlo (MC) method, and the process of textural interface formation was studied. The results showed that the texture formation mechanism of pyrocarbon deposition presented an S-shape curve with bi-stability transition by variation of the ration of C6 species to C2 species in the gas phase. Moreover, there was a hysteresis in the bi-stability transition of pyrocarbon textures, and the hysteresis was clearly influenced by the composition of the gas-phase species.
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