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Journal of Materials Science

, Volume 20, Issue 7, pp 2639–2646 | Cite as

Transformation toughening and grain size control inβ″-Al2O3/ZrO2 composites

  • D. J. Green
Papers

Abstract

In order to fabricate transformation-toughenedβ″-Al2O3 and optimize its mechanical and electrical properties it was found to be necessary to carefully control the particle size distribution of the starting powders and their mixing. The ionic resistivity of the composites depended primarily on the volume fraction of ZrO2. Additions between 10 and 20 vol% produced materials with ionic resistivities (300° C) between 6 and 10 Ωcm and eliminated exaggerated grain growth of theβ″-Al2O3. Comparison ofβ″-Al2O3 composites containing either tetragonal (t-) ZrO2 or cubic (c-) ZrO2 with the single phase material showed that the major strengthening mechanism is the reduction in critical flaw size. This occurred by the elimination of the flaw population associated with abnormally large grains. For maximum increases in fracture toughness and strength, however, the use of t-ZrO2 (transformation toughening) as a second phase is preferred.

Keywords

Al2O3 Fracture Toughness Electrical Property Particle Size Distribution Single Phase 
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 1985

Authors and Affiliations

  • D. J. Green
    • 1
  1. 1.Structural Ceramics GroupRockwell International Science CenterThousand OaksUSA

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