Abstract
Reaction rates observed during the microwave synthesis of titanium carbide powder via the carbothermal reduction of the oxide are more than three times faster than those observed during conventional processing at the same temperature. Although not dissimilar to other reports of “microwave effects” in the literature, this result is of interest because the microwave heating mechanism is quite different compared to work using ionic ceramics. The initial powder mix consisted of low dielectric loss titania mixed intimately with very fine carbon black powder. It is the latter phase which couples with the microwaves via a conventional ohmic dissipation mechanism. Calculations have shown that the faster diffusion rates might be explained by an increase in the Arrhenius pre-exponential factor A, with no change in the activation energy.
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M. A. Janney and H. D. Kimrey, in “Ceramic Powder Science II”, edited by G. L. Messing, E. R. Fuller and H. Hausner (American Ceramic Society, Westerville, OH, 1988) p. 919.
M. A. Janney, C. L. Calhoun and H. D. Kimrey, in “Microwaves: Theory and Application in Materials Processing”, Ceramic Transactions 21, edited by D. E. Clark, F. D. Gac and W. H. Sutton (American Ceramic Society, Westerville, OH, 1991) p. 311.
M. A. Janney and H. D. Kimrey, in “Microwave Processing of Materials II”, Materials Research Society Symposium Proceedings 189, edited by W. B. Snyder Jr, W. H. Sutton, M. F. Iskander and D. L. Johnson (Materials Research Society, Pittsburgh, PA, 1991) p. 215.
M. A. Janney, H. D. Kimrey, M. A. Schmidt and J. O. Kiggans, J. Am. Ceram. Soc. 74 (1991) 1675.
D. A. Lewis, in “Microwave Processing of Materials III”, Material Research Society Symposium Proceedings 269, edited by R. L. Beatty, W. H. Sutton and M. F. Iskander (Materials Research Society, Pittsburgh, PA, 1992) p. 21.
R. J. Giguere, ibid., p. 387.
J. D. Katz, R. D. Blake and V. M. Kenkre, in “Microwaves: Theory and Application in Materials Processing”, Ceramic Transactions 21, edited by D. E. Clark, F. D. Gac and W. H. Sutton (American Ceramic Society, Westerville, OH, 1991) p. 95.
M. Willert-Porada, T. Krummel, B. Rohde and D. Moormann, in “Microwave Processing of Materials III”, Material Research Society Symposium Proceedings 269, edited by R. L. Beatty, W. H. Sutton and M. F. Iskander (Materials Research Society, Pittsburgh, PA, 1992) p. 199.
P. Boch, N. Lequeux and P. Piluso, ibid., p. 211.
Z. Fathi, I. Ahmed, J. H. Simmons, D. E. Clark and A. R. Lodding, in “Microwaves: Theory and Application in Materials Processing”, Ceramic Transactions 21, edited by D. E. Clark, F. D. Gac and W. H. Sutton (American Ceramic Society, Westerville, OH, 1991) p. 623.
J. H. Booske, R. F. Cooper, I. Dobson and L. Mccaughan, ibid., p. 185.
J. H. Booske, R. F. Cooper, L. Mccaughan, S. Freeman and M. Binshen, in “Microwave Processing of Materials III”, Material Research Society Symposium Proceedings 269, edited by R. L. Beatty, W. H. Sutton and M. F. Iskander (Materials Research Society, Pittsburgh, PA, 1992) p. 137.
S. A. Freeman, J. H. Booske, R. F. Cooper, B. Meng, J. Kieffer and B. J. Reardon, in “Proceedings of the Microwave Absorbing Materials for Accelerators Conference”, Newport News, VA, 1993, to be published.
K. I. Rybakov and V. E. Semenov, Phys. Rev. B 49 (1994) 64.
K. I. Rybakov and V. E. Semenov, Phys. Rev. Lett. (1994) submitted.
A. C. Metaxas and J. G. P. Binner, in “Advanced Ceramic Processing and Technology”, Vol. I, edited by J. G. P. Binner (Noyes, New Jersey, NJ, 1990) p. 285.
S. A. Freeman, J. H. Booske, R. F. Cooper, B. Meng, J. Kieffer and B. J. Reardon, in “Microwaves: Theory and Application in Materials Processing II”, Ceramic Transactions 36, edited by D. E. Clark, W. R. Tinga and J. R. Laia Jr (American Ceramic Society, Westerville, OH, 1993) p. 213.
S. Freeman, J. Booske, R. Cooper and B. Meng, in “Microwave Processing of Materials IV”, Material Research Society Symposium Proceedings 347, edited by M. F. Iskander, R. J. Lauf Jr and W. H. Sutton (Materials Research Society, Pittsburgh, PA, 1994) p. 479.
S. J. Rothman, ibid., p. 9.
N. A. Hassine, J. G. P. Binner and T. E. Cross, Int. J. Refract. Metals Hard Mater., accepted for publication.
C. P. Lorenson, M. C. L. Patterson, G. Risto and R. Kimber, in “Microwave Processing of Materials III”, Material Research Society Symposium Proceedings 269, edited by R. L. Beatty, W. H. Sutton and M. F. Iskander (Materials Research Society, Pittsburgh, PA, 1992) p. 129.
A. Cottrell, “An Introduction to Metallurgy”, 2nd Edn (Edward Arnold, London, 1975) p. 455.
W. D. Kingery, H. K. Bowen and D. R. Uhlman, “Introduction to Ceramics” 2nd Edn (Wiley, New York, NY, 1976) Ch. 7.
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Binner, J.G.P., Hassine, N.A. & Cross, T.E. The possible role of the pre-exponential factor in explaining the increased reaction rates observed during the microwave synthesis of titanium carbide. JOURNAL OF MATERIALS SCIENCE 30, 5389–5393 (1995). https://doi.org/10.1007/BF00351548
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DOI: https://doi.org/10.1007/BF00351548