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Structure and Formation Kinetics of Mosi2 Composites Formed by Reactive Vapor Infiltration Process

Published online by Cambridge University Press:  15 February 2011

W.B. Hillig ,
R.M. Ramakrishnan ,
M. Broglio  and
N. Patibandla
W.B. Hillig
Affiliation:
Rensselaer Polytechnic Institute, Troy, NY 12180-3590
R.M. Ramakrishnan
Affiliation:
Xomox Corp., 4444 Cooper Rd., Cincinnati, OH 45242
M. Broglio
Affiliation:
Rensselaer Polytechnic Institute, Troy, NY 12180-3590
N. Patibandla
Affiliation:
New York State Energy Development Authority, Albany, NY, 12223
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Abstract

Reactive Vapor Infiltration is a convenient new process for producing high purity MoSi2 matrix composites by reacting compacted mixed Mo + MoSi2 powders ranging from 0 to 80 wt. % MoSi2 with H2 + SiCl4 vapors at temperatures from 1000 to 1400°C. Consideration must be taken of the volumetric increase that accompanies this conversion. The kinetics of the advance of the MoSi2 growth layer and the gravimetric uptake are given as a function of temperature and the composition. The parabolic growth rate constant was independent of composition at least up to 30% MoSi2 composition, but then showed a strong, linear increase with increasing MoSi2 content. There appeared to be a levelling off of rate above 70% MoSi2. The corresponding gravimetric rate constant was relatively insensitive to the starting MoSi2 content. This behavior is at variance with a simple one-dimensional diffusive growth model. Possible reasons for this variance are offered.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 365: Symposium M – Ceramic Matrix Composites–Advanced High-Temperature Structural Materials , 1994 , 153
Copyright
Copyright © Materials Research Society 1995

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References

1. Vasudevan, A.K. and Petrovic, J.J., Eds., High Temperature Structural Silicides, (Elsevier Science Publishers, Amsterdam, 1992).Google Scholar
2. Patibandla, N. and Hillig, W.B., “Processing of Molybdenum Disilicide Using a New Reactive Vapor Infiltration Technique,” J. Am. Ceram. Soc., 76 [6],123–7(1993).Google Scholar
3. Patibandla, N., Hillig, W.B., Ramakrishnan, M.R., Alman, D.E. and Stoloff, N.S., “In-Situ Processing of MoSi2-Base Composites,” (Mat. Res. Soc. Symnp. Proc., 322, 1993), p. 59.Google Scholar
4. Adjerid, S., Flaherty, J.E., Shepard, M., Wang, Y., Hudson, J., Hillig, W. and Patibandla, N., “Adaptive Numerical Technique for Reactive Vapor Infiltration,” Cer. Eng. And Sci. Proc., 15 [5], 925–931 (1994).Google Scholar
5. Fitzer, E. and Matthias, K. in Hochtemperaturwerkstoffe, 6th Plansee Conf., Vienna/New York (1969), p. 740–766.Google Scholar
6. Gage, P.R. and Bartlett, R.W., “Diffusion Kinetics Affecting Formation of Silicide Coatings on Molybdenum and Tungsten,” Trans. Met. Soc. AIME, 233, 832–834(1965).Google Scholar