Interaction between a Reactive Preform and the Surrounding Gas-phase during Cvi

An integrated modelling approach of Chemical Vapour In ltration of a brous preform by methyltrichlorosilane, featuring coupled reactor uid mechanics and porous medium gas transport has been developed. The coupling between transport/reaction phenomena inside and outside the preform is rather strong, both physically and numerically. An important counter-e ect of the reactive preform on the surrounding gas-phase composition is evidenced; also, an appreciable dissymmetry of the densi cation rate inside the preform , even with negligible convective transport inside it . Such an approach brings new informations for understanding the physico-chemical phenomena of CVI and new guidelines for preform densi cation optimisation.