Hostname: page-component-848d4c4894-xfwgj Total loading time: 0 Render date: 2024-06-28T14:11:39.106Z Has data issue: false hasContentIssue false

Modelling Transport, Reaction, and Pore Structure Evolution During Densification of Cellular or Fibrous Structures

Published online by Cambridge University Press:  21 February 2011

Stratis V. Sotirchos
Affiliation:
Department of Chemical Engineering University of Rochester Rochester, NY 14627
Manolis M. Tomadakis
Affiliation:
Department of Chemical Engineering University of Rochester Rochester, NY 14627
Get access

Abstract

A mathematical model is developed to describe mass transport, reaction., and structure evolution during densification of porous media of initially fibrous or cellular structure. The use of Monte Carlo simulation procedures for determining the variation of the local (average) structural properties of the porous structure and of the effective diffusion coefficients in the porous medium with the porosity is also discussed, and results are presented for Knudsen diffusion in cellular or fibrous media. The model is used to theoretically study the transient behavior of the densification process during preparation of SiC/SiC ceramic matrix composites by chemical vapor infiltration (CVI) of porous preforms. Particular emphasis is placed on the investigation of the effects of pressure pulsing on the density gradients in the densifying structure.

Type
Research Article
Copyright
Copyright © Materials Research Society 1990

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1.Stinton, D.P., Besmann, T.M., and Lowden, R.A., Am. Ceram. Soc. Bull. 67, 350 (1988).Google Scholar
2.Kaplan, R.B. and Tuffias, R.H., Res. and Dcv., p. 118, February 1989.Google Scholar
3.Stinton, D.P., Caputo, A.J., and Lowden, R.A., Am. Ceram. Soc. Bull. 65, 347 (1986).Google Scholar
4.Sugiyama, K. and Nakamura, T., J. Mat. Sci. Let. 6, 331 (1987).Google Scholar
5.Sugiyama, K. and Ohsawa, Y., J. Mat. Sci. Let. 7, 1221 (1988).Google Scholar
6.Fitzer, E. and Gadow, R., Am. Ceram. Soc. Bull. 65, 326 (1986).Google Scholar
7.Rossignol, J.Y., Langlais, F., and Naslain, R., in Proc. Ninth Int'l. Conf. on CVD, edited by M. Robinson et al. (Electrochem. Soc., Pennington, NJ, 1984), p. 596.Google Scholar
8.Starr, T.L., in Proc. Int'l. Conf. Whisk.-Fib.-Tough. Ceram., edited by Bradley, R.A. et al., (ORNL, Oak Ridge, TN, 1988), p. 243.Google Scholar
9.Gupte, S.M. and Tsamopoulos, J.A., J. Electrochem. Soc. 13, 555 (1989).Google Scholar
10.Tai, N.H. and Chou, T.W., J. Am. Ceram. Soc. 72, 414 (1989).Google Scholar
11.Kennard, E.H., Kinetic theory of gases (McGraw-Hill, New York, NY, 1938).Google Scholar
12.Burganos, V.N. and Sotirchos, S.V., Chem. Eng. Sci. 44, 2451 (1989).Google Scholar
13.Burganos, V.N. and Sotirchos, S.V., Chem. Eng. Comm. (to appear) (1989).Google Scholar
14.Burganos, V.N. and Sotirchos, S.V., Chem. Eng. Sci. 44, 2629 (1989).Google Scholar
15.Sotirchos, S.V., Chem. Eng. Sci. 42, 1262 (1987).Google Scholar
16.Tomadakis, M.M. and Sotirchos, S.V., (in preparation) (1989).Google Scholar
17.Mason, E.A. and Malinauskas, A.P., Gas Transport in Porous Media: The Dusty-Gas Model (Elsevier, New York, NY, 1983).Google Scholar
18.Brennfleck, K., Fitzer, E., Schoch, G., and Dietrich, M., in Proc. Ninth Int'l. Conf. on CVD, edited by Robinson, M. et al., (Electrochem. Soc., Pennington, NJ, 1984), p. 649.Google Scholar
19.Sotirchos, S.V., AIChE J. (to appear) (1989).Google Scholar
20.Sotirchos, S.V., (in preparation) (1989).Google Scholar