Gasdynamic Modeling of High-Temperature Siliconizing of Porous Silicon-Based Materials

An advanced physico-mathematical model of silicon vapor transfer from a melt mirror to a porous carbon article is proposed and tested in the conditions of medium vacuum in the case of vapor-phase siliconizing. The model proposed is compared both qualitatively and quantitatively with those suggested earlier. The novelty of the approach proposed lies in taking account for an additional effect in the form of possible redistribution of rarefied carrier medium, whose role is played by inert argon, as the result of displacement by silicon vapors. It is shown quantitatively to what extent the silicon vapors expel argon in the process of vapor-phase siliconizing. The dynamics of the displacement front is studied. The proposed model described by a system of partial differential equations makes it possible to calculate the mean-mass velocity of the gas mixture and the diffuse transfer of silicon vapors from the melt mirror to the specimen surface through the carrier medium.