Effects of deposition mechanisms in the modeling of forced-flow/temperature-gradient chemical vapor infiltration
- National Tsing Hua Univ., Hsing-chu (Taiwan, Province of China). Materials Science Center
- National Tsing Hua Univ., Hsing-chu (Taiwan, Province of China). Materials Science Center Univ. of Delaware, Newark, DE (United States)
- National Tsing Hua Univ. Hsing-chu (Taiwan, Province of China). Inst. of Chemical Engineering
A model for the forced-flow/temperature-gradient chemical vapor infiltration (FCVI) process has been proposed in a previous study. The results demonstrate that the arrangement of the heating elements is important in the matrix deposition within a fibrous preform. In the present analysis, two cases (first-order and zero-order reaction mechanism) of the CVI process are examined to evaluate the assumption of matrix deposition mechanisms. In the first case, the distribution of the deposited matrix depends on the competition between the temperature gradient within the preform and the rate of reactants consumed during infiltration. In the second case, the distribution of matrix deposition depends solely on the temperature gradient. The analysis concludes that the prediction of matrix deposition is influenced significantly by the selection of deposition kinetics in the model. A zero-order reaction mechanism is appropriate. Furthermore, it is suggested that the use of the reaction mechanism and activation energy in the FCVI model should be based on the experimental deposition results from an FCVI system.
- OSTI ID:
- 7233469
- Journal Information:
- Journal of the American Ceramic Society; (United States), Vol. 77:3; ISSN 0002-7820
- Country of Publication:
- United States
- Language:
- English
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