Modeling the effects of reactor wall reaction on isothermal CVI process of C/SiC composites
Modeling the effects of reactor wall reaction on isothermal CVI process of C/SiC composites
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DOI：
10.1016/j.commatsci.2006.05.005
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发表时间：
2007-02
影响因子：
3.3
通讯作者：
Xi Wei;Lai-fei Cheng;Litong Zhang;Yongdong Xu;Qingfeng Zeng
中科院分区：
文献类型：
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作者：
Xi Wei;Lai-fei Cheng;Litong Zhang;Yongdong Xu;Qingfeng Zeng
提出了两个比较数学模型来模拟反应器壁反应对C/SiC复合材料等温CVI工艺的影响。两种模型均考虑了渗透过程中动量、能量和质量的输运现象以及渗透引起的预制体结构变化。这两种模型的区别在于，一种模型是基于消耗的，忽略了ICVI反应器壁的反应，而另一种模型是考虑了反应器壁的反应。采用有限元法对模型进行求解。计算结果表明，在ICVI过程中，两种情况下预制体中甲基三氯硅烷的平均摩尔浓度之差小于2.5%，两种情况下C/SiC复合材料的整体孔隙率之差小于0.6%。这些微小的差异表明，忽略反应器壁面反应对于C/SiC复合材料ICVI过程的数值模拟是合理的和可以接受的。
Two comparative mathematical models were proposed to simulate the effects of reactor wall reaction on isothermal CVI process of C/SiC composites. Transport phenomena of momentum, energy and mass in conjunction with infiltration induced changes of preform structure were taken into account in both models. The difference between the two models is that one model bases on the consumption that reaction on ICVI reactor wall is neglected while another model is treated as a case that reactor wall reaction is taken into account. The integrated models were solved by finite element method. Calculation results show that the difference of mean molarities of methyltrichlorosilane in preform for the two cases varies less than 2.5% and that of global porosities of C/SiC composites for the two cases varies less than 0.6% during ICVI process. The trivial differences imply that ignorance of reactor wall reaction is reasonable and acceptable for numerical simulation of ICVI process of C/SiC composites.