Strengthening Oxides by Reduction of Crystal Anisotropy.

Abstract

In single phase polycrystalline ceramic bodies composed of anisotropic crystals the stresses resulting from applied loads, large scale residual stresses and localized stresses combine to cause fracture. The localized stresses caused by crystal anisotropy are substantial in magnitude and in large grain size bodies cause local crack formation even in the absence of an applied load. In earlier investigations compositions with reduced thermal anisotropy were made by solid solution additions. In the present investigation the flexural strengths of alumina ceramics, and of a composition in the system Al2O3-Cr2O3 having reduced thermal anisotropy, were compared over a range of grain sizes in the machined and quenched conditions. The fracture surfaces were studied. Very high strengths were observed. (Author)

Document Details

Document Type
Technical Report
Publication Date
Apr 01, 1971
Accession Number
AD0724315

Entities

People

  • Henry P. Kirchner
  • Robert M. Grover

Tags

DTIC Thesaurus Topics

  • Anisotropy
  • Bodies
  • Ceramic Bodies
  • Crystals
  • Flexural Strength
  • Grain Size
  • Physical Properties
  • Polycrystals
  • Residual Stress
  • Residuals
  • Solid Solutions
  • Stresses

Readers

  • Materials Science (Mechanical Engineering).
  • Materials Science and Engineering.