Journal of Materials Science

, Volume 20, Issue 9, pp 3230–3238 | Cite as

The influence of iron on the preparation of silicon nitride from silica

  • S. A. Siddiqi
  • A. Hendry


The thermodynamics of carbothermal reduction and nitriding of silica in the temperature range 1200 to 1600° C have been evaluated and may be used to determine the conditions required to form silicon nitride, silicon oxynitride or silicon carbide. The products of reaction are, however, frequently dictated by kinetic rather than thermodynamic considerations and the presence of impurities in the silica and carbon reactants is especially important. α-silicon nitride has been prepared from high purity silica and carbon but under identical conditions of temperature and nitrogen pressure the chemistry of the process changes markedly when a small amount of iron is added to the reactants. Below 1320° C iron has no effect and pure α-silicon nitride is formed but with increasing temperature the proportion of silicon carbide in the product increases. Above 1550° C silicon carbide is the stable solid phase in the Si-C-O-N system at 1 atm pressure. The process chemistry has been investigated by high-temperature reaction studies and X-ray diffraction and reaction mechanisms are proposed on the basis of microstructural observations of reactants and products.


Nitride Silicon Carbide Silicon Nitride Fume Silica Excess Carbon 


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  1. 1.
    A. Szweda, A. Hendry and K. H. Jack, “Special Ceramics 7”, Proceedings of the British Ceramic Society No. 31, edited by J. Taylor and P. Popper (British Ceramic Society, Stoke-on-Trent, 1981) p. 107.Google Scholar
  2. 2.
    A. Hendry and K. H. Jack, “Special Ceramics 6”, edited by P. Popper, (B.C.R.A., Stoke-on-Trent, 1975) p. 199.Google Scholar
  3. 3.
    K. Komeya and H. Inoue, J. Mater, Sci. 10 (1975) 1244.CrossRefGoogle Scholar
  4. 4.
    J-G. Lee, PhD thesis, University of Utah (1976).Google Scholar
  5. 5.
    J-G. Lee and I. B. Cutler, “Nitrogen Ceramics”, edited by F. L. Riley (Noordhof, Leyden, 1977) p. 175.CrossRefGoogle Scholar
  6. 6.
    S. C. Singhal, Ceramurgia Int. 2 (1976) 123.CrossRefGoogle Scholar
  7. 7.
    A. Hendry, “Nitrogen Ceramics”, edited by F. L. Riley (Noordhof, Leyden, 1977) p. 183.CrossRefGoogle Scholar
  8. 8.
    M. B. Fegley, Comm. Amer. Ceram. Soc. 64 (1981) C124.CrossRefGoogle Scholar
  9. 9.
    O. Kubaschewski and C. B. Alcock, “Metallurgical Thermochemistry” (Pergamon Press, Oxford, 1979).Google Scholar
  10. 10.
    P. L. Smith and J. White, Trans. J. Brit. Ceram. Soc. 82 (1983) 23.Google Scholar
  11. 11.
    Y. K. Rao and H. G. Lee, ibid. 82 (1983) 123.Google Scholar
  12. 12.
    J. Weiss, H. L. Lukas, J. Lorenz, G. Petzow and H. Kreig, Calphad 5 (1981) 125.CrossRefGoogle Scholar
  13. 13.
    I. Colquhoun, S. Wild, P. Grieveson and K. H. Jack, Proc. Brit. Ceram. Soc. 22 (1973) 207.Google Scholar
  14. 14.
    J. L. Woodhead, Sci. Ceram. 4 (1968) 105.Google Scholar
  15. 15.
    T. G. Chart, High Temp. — High Press. 2 (1970) 461.Google Scholar
  16. 16.
    H. Rein and J. Chipman, J. Phys. Chem. 67 (1963) 839.CrossRefGoogle Scholar
  17. 17.
    D. R. Messier and W. J. Croft, “Preparation and Properties of Solid State Materials” Vol. 7, edited by W. R. Wilcox (Marcel Dekker, New York, 1982) p. 131.Google Scholar

Copyright information

© Chapman and Hall Ltd 1985

Authors and Affiliations

  • S. A. Siddiqi
    • 1
  • A. Hendry
    • 1
  1. 1.Wolfson Research Group for High Strength Materials, Crystallography LaboratoryUniversity of Newcastle upon TyneNewcastle upon TyneUK

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