Densification of Porous Materials by Chemical Vapor Infiltration


Gupte S.M., Tsamopoulos J.A.


A mathematical model that describes the combined diffusion and reaction of trichloromethylsilane in a porous preform under typical chemical vapor infiltration (CVI) conditions is presented. The model utilizes a single pore to demonstrate the importance of the pore geometry, total gaseous pressure, temperature, and imposed temperature gradient on the degree of achieved densification. By focusing attention on a single pore, it is possible to account for changes in the pore shape that occur during deposition of silicon carbide on the pore boundaries. Process conditions for operation in the reaction-controlled regime in order to attain complete densification are quantitatively identified even for the longer pores and the relatively higher temperatures used. © 1989, The Electrochemical Society, Inc. All rights reserved.


DOI: 10.1149/1.2096681