MICROSTRUCTURE STUDIES OF POLYCRYSTALLINE REFRACTORY OXIDES

Abstract

Alumina and magnesia specimens were prepared having grain sizes from 20 to 300 microns. Transverse bend strength and elastic modulus determinations were made on 50-, 100-, and 300 micron grain-size alumina and 70- and 100-micron magnesia specimens. The strength of alumina showed a strong grain-size dependence at all test temperatures. The strength at higher temperatures appeared to be more temperature-dependent in the finer-grain specimens. The strength of magnesia appeared to be essentially independent of grain size up to approximately 700 C; effect of grain size on strength at higher temperatures is presently inconclusive. The effect of grain size on the elastic modulus is at present in doubt due to a possible calibration error in the recording instrument. The present data indicate that the high-temperature elastic modulus of alumina is more temperature-dependent in the finer-grain-size specimens.

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Document Details

Document Type
Technical Report
Publication Date
Apr 29, 1963
Accession Number
AD0403345

Entities

People

  • J. B. Mitchell
  • R. M. Spriggs
  • T. Vasilos

Tags

Communities of Interest

  • Air Platforms
  • Weapons Technologies

DTIC Thesaurus Topics

  • Corporations
  • Engineering
  • Grain Growth
  • Grain Size
  • Heat Treatment
  • High Temperature
  • Massachusetts
  • Materials
  • Mechanical Properties
  • Mechanics
  • Microstructure
  • Modulus Of Elasticity
  • New Jersey
  • New York
  • Polycrystals
  • Refractory Materials
  • Universities

Fields of Study

  • Materials science

Readers

  • Materials Science (Mechanical Engineering).
  • Materials Science and Engineering.
  • Surface Engineering/Surface Coating Technology.