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Optimization of chemical vapor infiltration with simultaneous powder formationa)

Published online by Cambridge University Press:  31 January 2011

A. Ditkowski ,
D. Gottlieb  and
B. W. Sheldon
A. Ditkowski
Affiliation:
Division of Applied Mathematics, Brown University, Providence, Rhode Island 02912
D. Gottlieb
Affiliation:
Division of Applied Mathematics, Brown University, Providence, Rhode Island 02912
B. W. Sheldon
Affiliation:
Division of Engineering, Brown University, Providence, Rhode Island, 02912
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Abstract

A key difficulty in isothermal, isobaric chemical vapor infiltration is the long processing times that are typically required. With this in mind, it was important to minimize infiltration times. This optimization problem was addressed here, using a relatively simple model for dilute gases. The results provided useful asymptotic expressions for the minimum time and corresponding conditions. These approximations were quantitatively accurate for most cases of interest, where relatively uniform infiltration was required. They also provided useful quantitative insight in cases where less uniformity was required. The effects of homogeneous nucleation were also investigated. This does not effect the governing equations for infiltration of a porous body; however, powder formation can restrict the range of permissible infiltration conditions. This was analyzed for the case of carbon infiltration from methane.

Type
Articles
Information
Journal of Materials Research , Volume 15 , Issue 12 , December 2000 , pp. 2695 - 2705
Copyright
Copyright © Materials Research Society 2000

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References

REFERENCES

1.Fitzer, E. and Gadow, R., Am Ceram. Soc. Bull. 65, 326 (1986).Google Scholar
2.Gupte, S.M. and Tsamopoulos, J.A., J. Electrochem. Soc. 136, 555 (1989). 1104–9 (1991).CrossRefGoogle Scholar
3.Aris, R., The Mathematical Theory of the Diffusion and Reaction in Permeable Catalysts (Oxford University Press, London, United Kingdom, 1975.Google Scholar
4.Chang, H-C., Minimizing Infiltration Time during Isothermal Chemical Vapor Infiltration, Ph.D. Thesis, Brown University, Providence, RI (1995).Google Scholar
5.Dullien, F.A.L, Porous Media: Fluid Transport and Pore Structure (Academic Press, New York, 1979).Google Scholar
6.Mason, E.A., and Malinauskas, A.P., Gas Transport in Porous Media: The Dusty-Gas Model (Elsevier Science Publisher, New York, 1983).Google Scholar
7.Sheldon, B.W. and Chang, H-C., in Ceramic Transactions, edited by Sheldon, B.W. and Danforth, S.C. (American Ceramic Society, Westerville, OH, 1994), Vol. 42, pp. 81–93.Google Scholar
8.Chang, H-C., Morse, T.F., and Sheldon, B.W., J. Mater. Proc. Manuf. Sci. 2, 437 (1994).Google Scholar
9.Ofori, J.Y. and Sotirchos, S.V., AIChE J. 42, 2828 (1996).CrossRefGoogle Scholar
10.Chang, H-C., Morse, T.F., and Sheldon, B.W., J. Am. Ceram. Soc. 7, 1805 (1997).CrossRefGoogle Scholar
11.Chang, H-C., Gottlieb, D., Marion, M., and Sheldon, B.W., J. Sci. Comput. 13, 303 (1998).CrossRefGoogle Scholar
12.Feder, J., Russell, K.C., Lothe, J., and Pound, G.M., Adv. Phys. 15, 111 (1966).CrossRefGoogle Scholar
13.Loll, P., Delhaes, P., Pecault, A., and Pierre, A., Carbon 13, 159 (1975).Google Scholar
14.Delhaes, P. in Electrochemical Society Proceedings 97–25, edited by Allendorf, M.D. and Bernard, C. (Electrochemical Society, Pennington, NJ, 1997), pp. 486–95.Google Scholar
15.Besmann, T.M., Oak Ridge National Laboratory (1998, unpublished results).Google Scholar
16.Ditkowski, A., Gottlieb, D., and Sheldon, B.W., M2AN 34, 337 (2000).CrossRefGoogle Scholar
17.Bammidipati, S., Stewart, G.D., Elliott, G.R. Jr, Gokoglu, S.A., and Purdy, M.J., American Institute of Chemical Engineering J. 42, 3123 (1996).CrossRefGoogle Scholar
18.Besmann, T.M., Klett, J.W., and Burchell, T.D., in Materials for Electrochemical Energy Storage and Conversion II—Batteries, Capacitors and Fuel Cells, edited by Ginley, D.S., Doughty, D.H., Scrosati, B., Takamura, T., and Zhang, Z. (Mater. Res. Soc. Symp. Proc. 496, Pittsburgh, PA, 1998), pp. 243–248.Google Scholar