Advertisement

Gas Phase Production of Silicon Nitride Using a DC Plasma

  • P. D. Harmsworth
  • A. G. Jones
  • T. A. Egerton
  • S. R. Blackburn
Chapter

Abstract

Silicon nitride powder has been prepared by the gas phase reaction of the metal chloride with ammonia using a nitrogen DC plasma as the heat source. A wide range of particle sizes from 0.005 – 0.2μm can be prepared by control of the gas recirculation in the reaction zone.

This synthesis method results in a high purity ultra fine white powder with a spheroidal morphology. Either amorphous or crystalline forms of silicon nitride can be produced dependent upon reaction temperature. The product is associated with a surface oxygen layer as shown by XPS surface analysis. However fine tuning of the process to grow the particles can result in bulk oxygen contents of less than 1.5 % 0, whilst retaining a specific surface area greater than 25 m2/g.

Sintering studies using relatively low levels of common additives indicate that high density and high α — β conversion can be achieved at low temperatures. The sintered product has a sub-micron grain size and exhibits high strength.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Cannon, W.R., Danforth, S.C., Haggerty, J.S., Marra, R.A., Sinterable ceramic powders from laser-driven reactions: II powder characteristics and process variables. J.Am.Ceram Soc.. 1982, vol.65, no7, 330–335.CrossRefGoogle Scholar
  2. 2.
    Dransfield, G.P., Fothergill, K.A., Egerton, T.A., The use of plasma synthesis and pigment coating technology to produce an yttria stabilised zirconia having superior properties. In Euro Ceramics. vol 1, ed. G. de With, R.A. Terpstra, R.M Metsalaar, Elsevier Applied Science Publishers, London, 1989, pp. 275–279.Google Scholar
  3. 3.
    Blackburn, S.R., Egerton, T.A., Jones, A.G., “Vapour phase synthesis of nitride ceramic powders using a DC plasma” to be published in Proc.Br.Ceram Soc, Fine ceramic powders.Google Scholar
  4. 4.
    Pleukert, M., Greil, P., Oxygen distribution in silicon nitride powders J. Mater.Sci., 1987, 22, 3717–3720.CrossRefGoogle Scholar

Copyright information

© Elsevier Science Publishers Ltd and MPA Stuttgart 1992

Authors and Affiliations

  • P. D. Harmsworth
    • 1
  • A. G. Jones
    • 1
  • T. A. Egerton
    • 1
  • S. R. Blackburn
    • 1
  1. 1.Tioxide Technical DivisionCentral LaboratoriesStockton-on-Tees, ClevelandUK

Personalised recommendations