Jy. Ofori et Sv. Sotirchos, MULTIDIMENSIONAL MODELING OF CHEMICAL-VAPOR INFILTRATION - APPLICATION TO ISOBARIC CVI, Industrial & engineering chemistry research, 36(2), 1997, pp. 357-367
Multidimensional (2D and 3D) chemical vapor infiltration models are fo
rmulated and used to simulate densification of isotropic or anisotropi
c preforms of various geometries using Sic deposition from methyltrich
lorosilane. A generalized form of the dusty-gas model for mass transpo
rt in anisotropic porous structures is used as a flux model in the por
e space, and the multidimensional model equations are solved using the
Galerkin finite element method. Structures consisting of freely overl
apping fibers parallel to a Line (one-directional), parallel to a plan
e (two-directional), or without preferred orientation (three-direction
al) are employed to model the microstructure of the preforms. The obta
ined results show that the effects of preform geometry can lead to par
tial pressure and deposition profiles in the preform that are consider
ably different from those suggested by one-dimensional analyses of the
chemical vapor infiltration process.