Modeling the effects of reactor wall reaction on isothermal CVI process of C/SiC composites

Abstract

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.