MODEL FOR PREDICTION OF MATRIX MICROSTRUCTURE FOR CARBON CARBON COMPOSITES PREPARED BY FORCED FLOW THERMAL-GRADIENT CVI/

A model has been developed to predict the microstructure of the carbon matrix deposited during forced flow-thermal gradient chemical vapor i nfiltration (FCVI). This method employs previous thermodynamic-microst ructure and densification models to determine conditions throughout th e preform as a function of time. The model was verified by comparison with samples prepared over a range of deposition temperatures, reagent concentrations and flow rates. The model also showed that it should b e possible to deposit a matrix of uniformly high thermal conductivity onto conventional size carbon fibers, as well as small diameter, low c ost, high thermal conductivity carbon whiskers. Copyright (C) 1997 Els evier Science Ltd.