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Journal of Materials Science

, Volume 6, Issue 10, pp 1292–1302 | Cite as

Microstructural studies on silicon nitride

  • A. G. Evans
  • J. V. Sharp
Papers

Abstract

Thin specimens of reaction sintered and hot pressed silicon nitride have been prepared by ion beam thinning and examined in the Harwell million volt microscope. It has been found that reaction sintered material consists of large grains, which are mostlyβ-Si3N4, in a fine grained matrix ofα-Si3N4. Fibres are frequently observed within the pores, the type of fibre depending on the size of the pore. The hot pressed material consists largely of two types of grain, small angular grains ofβ-Si3N4 and larger irregular grains. There is also some non-crystalline material between the angular grains and there are numerous small unidentified inclusions.

The grains ofβ-Si3N4 generally contain dislocations and examination of these shows that most have a 〈0001〉 Burgers vector. The remaining dislocations appear to be more complex, frequently occurring as multiple images, and have not been unambiguously identified. An analysis of dislocations inβ-Si3N4 shows that 〈0001〉 dislocations are the most stable and are also likely to be most mobile with {10¯10} as the primary slip plane.

Keywords

Polymer Silicon Nitride Silicon Nitride Burger Vector 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Chapman and Hall Ltd. 1971

Authors and Affiliations

  • A. G. Evans
    • 1
    • 2
  • J. V. Sharp
    • 1
    • 3
  1. 1.Atomic Energy Research EstablishmentHarwell, DidcotUK
  2. 2.Materials Development DivisionUK
  3. 3.Metallurgy DivisionUK

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