Hostname: page-component-586b7cd67f-rcrh6 Total loading time: 0 Render date: 2024-11-26T16:52:36.705Z Has data issue: false hasContentIssue false

A micromechanistic model of the combustion synthesis process: Influence of intrinsic kinetics

Published online by Cambridge University Press:  31 January 2011

Cheng He
Affiliation:
Institute for Aerospace Research, National Research Council Canada, Ottawa, Ontario K1A 0R6, Canada
Chantal Blanchetiere
Affiliation:
Institute for National Measurement Standards, National Research Council Canada, Ottawa, Ontario K1A 0R6, Canada
Gregory C. Stangle
Affiliation:
School of Ceramic Engineering and Sciences, New York State College of Ceramics at Alfred University, Alfred, New York 14802
Get access

Abstract

A micromechanistic model of the combustion synthesis of NbC has been developed by combining the results of an experimental study of the intrinsic, pore-level kinetic mechanism [C. He. and G. C. Stangle, J. Mater. Res. 10, 2829–2841 (1995)] and a theoretical model developed previously [Y. Zhang and G. C. Stangle, J. Mater. Res. 9, 2592–2604 (1994); 9, 2605–2619 (1994)], in order to account for the various physical and chemical processes that take place during the combustion synthesis process. Results of the present investigation are interpreted from both a macroscopic and a microscopic point of view. Moreover, the relationship between the microscopic processes and macroscopic features of the combustion synthesis process is discussed. The results show that the formation of a combustion wave in the Nb-C system corresponded to establishment of a proper balance between the rates of enthalpy redistribution within the sample. Furthermore, the pore size had a significant influence on the combustion synthesis process: smaller pores gave rise to a higher area of contact between the reactants, which in turn gave rise to a higher rate of enthalpy increase due to the enhanced rate of product formation. The influence of the pore size distribution on the process is also discussed.

Type
Articles
Copyright
Copyright © Materials Research Society 1998

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

REFERENCES

1.He, C. and Stangle, G. C., J. Mater. Res. 10, 28292841 (1995).CrossRefGoogle Scholar
2.Zhang, Y. and Stangle, G. C., J. Mater. Res. 9, 25922604 (1994).CrossRefGoogle Scholar
3.Zhang, Y. and Stangle, G. C., J. Mater. Res. 9, 26052619 (1994).CrossRefGoogle Scholar
4.Munir, Z. A. and Anselmi-Tamburini, U., Mater. Sci. Rep. 3, 279365 (1989).CrossRefGoogle Scholar
5.Merzhanov, A. G., in Combustion and Plasma Synthesis of High-Temperature Materials, edited by Munir, Z. A. and Holt, J. B. (VCH, New York, 1990), pp. 153.Google Scholar
6.Wang, L. L., Munir, Z. A., and Holt, J. B., Metall. Trans. 21B, 567577 (1990).CrossRefGoogle Scholar
7.Low, I. M., J. Mater. Sci. Lett. 11, 715718 (1992).CrossRefGoogle Scholar
8.Varma, A. and Lebrat, J. P., Chem. Eng. Sci. 47, 21792194 (1992).CrossRefGoogle Scholar
9.Lebrat, J. P., Varma, A., and Miller, A. E., Metall. Trans. 23A, 6976 (1992).CrossRefGoogle Scholar
10.Dullien, F. A. L., Porous Media: Fluid Transport and Pore Structure (Academic Press, New York, 1979), p. 42.Google Scholar
11.Rudy, E., Ternary Phase Equilibria in Transition Metal-Boron-Carbon-Silicon Systems, Part V. Compendium of Phase Diagram Data, report issued under U.S. Air Force Contract AF33(615)-1249 (1969), p. 149.Google Scholar
12.Scheidegger, A. E., The Physics of Flow Through Porous Media, 3rd ed. (University of Toronto Press, Toronto, 1974).Google Scholar
13.Cussler, E. L., Mass Transfer (McGraw-Hill, New York, 1988).Google Scholar
14.He, C. and Stangle, G. C., J. Mater. Res. 13, 135145 (1998).CrossRefGoogle Scholar
15.He, C. and Stangle, G. C., J. Mater. Res. 13, 146155 (1998).CrossRefGoogle Scholar
16.Merzhanov, A. G., Combust. Flame 13, 143156 (1969).CrossRefGoogle Scholar
17.Merzhanov, A. G. and Averson, A. E., Combust. Flame 16, 89124 (1971).CrossRefGoogle Scholar
18.Lakshmikantha, M. and Sekhar, J. A., J. Am. Ceram. Soc. 77, 202210 (1994).CrossRefGoogle Scholar
19.Puszynski, J., Degreve, J., and Hlavacek, V., Ind. Eng. Chem. Res. 26, 14241434 (1987).CrossRefGoogle Scholar