Journal of Materials Science

, Volume 14, Issue 10, pp 2439–2445 | Cite as

The microstructure of hot-pressed sialon polytypes

  • P. M. Johnson
  • A. Hendry


The sialons-phases in the Si-Al-O-N and related systems — form the basis of a new group of engineering ceramics, the successful application of which depends on their chemical stability and resistance to microstructural changes at elevated temperature. In the Si-Al-O-N system a new series of polytypes exists in which the structure is determined by the metal: non-metal atom ratio. The polytypes coexist in extensive two-phase regions which are important in determining the way that microstructure and properties develop during the fabrication and subsequent use of the material. In an electron microscopic investigation of some sialon polytypes, diffraction contrast and direct lattice imaging are used to follow changes in microstructure during hot-pressing, and to determine the nature of lattice imperfections and stacking arrangements.


Silicon Nitride Astigmatism Sialon Diffraction Contrast Image Resolution Lattice Image 


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Copyright information

© Chapman and Hall Ltd. 1979

Authors and Affiliations

  • P. M. Johnson
    • 1
  • A. Hendry
    • 1
  1. 1.Wolfson Research Group for High-Strength Materials, Crystallography LaboratoryThe UniversityNewcastle upon TyneUK

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