Mathematical model for precursor gas residence time in isothermal CVD process of C/C composites  

等温CVD制备炭/炭复合材料过程中气体滞留时间的数模分析(英文)

作　　者：于澍[1] 郑洲顺[2] 张福勤[1] 蔡永强[2] 

机构地区：[1]中南大学粉末冶金国家重点实验室,长沙410083 [2]中南大学数学科学与计算技术学院,长沙410083

出　　处：《Transactions of Nonferrous Metals Society of China》2011年第8期1833-1839,共7页中国有色金属学报（英文版）

基　　金：Projects (50702078,50874123) supported by the National Natural Science Foundation of China;Project (2009AA03Z536) supported by the National High-tech Research and Development Program of China;Project (2011CB606306) supported by the National Research Program of China;Project supported by the Program for New Century Excellent Talents in University of China

摘　　要：In the chemical vapor deposition（CVD） process of C/C composites,the dynamics and mechanism of precursor gas flowing behavior were analyzed mathematically,in which the precursor gas was infiltrated by the pressure difference of the gas flowing through felt.Differential equations were educed which characterized the relations among the pressure inside the felt,the pressure outside the felt of the precursor gas and the porosity of the felt as a function of CVD duration.The gas residence time during the infiltration process through the felt was obtained from the differential equations.The numerical verification is in good agreement with the practical process,indicating the good reliability of the current mathematical model.在化学气相沉积(CVD)制备炭/炭复合材料的过程中,对采用强制通过毛坯的特定装炉方式下的碳源气体的流动动力学及其反应机理进行系统的理论分析。在一系列的计算基础上,得到毛坯内部空腔压强、毛坯外部空腔压强和毛坯的孔隙度随时间变化的微分方程模型,求出气体在炉体的滞留时间以及渗透毛坯的时间。该理论计算所得的CVD过程中毛坯孔隙度变化与实际生产过程中的孔隙度变化趋势一致,表明该研究理论分析结果具有较高的可信度。

关 键 词：chemical vapor deposition residence time mathematical model 

分 类 号：TB332[一般工业技术—材料科学与工程]