Oxidation of Non-Oxide Ceramics.

Abstract

Oxidation mechanisms of SiC were determined. It was found that cristobalite nucleates at the SiC/SiO2 interface with appreciable heterogeneous nucleation during the first hour. Identical oxidation mechanisms were found for both single crystal and sintered polycrystalline SiC. Oxidation of yttria stabilized silicon nitride was investigated to determine the cause of the catastrophic oxidation at 1000C. At high temperature, SiO2 covers the entire surface, but at low temperature it does not. This allows the unstable yttria silicon oxynitride phases to form and cause catastrophic failure. No evidence of the effect of tungsten was noted. (Author)

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Document Details

Document Type
Technical Report
Publication Date
May 25, 1982
Accession Number
ADA115947

Entities

People

  • A. H. Heuer
  • T. E. Mitchell

Organizations

  • Case Western Reserve University

Tags

DTIC Thesaurus Topics

  • Ceramic Materials
  • Crystals
  • Diffraction
  • Electron Microscopes
  • Electron Microscopy
  • Grain Boundaries
  • High Temperature
  • Low Temperature
  • Materials
  • Materials Science
  • Metallurgy
  • Microscopes
  • Microscopy
  • Oxide Films
  • Silicon Carbide
  • Single Crystals
  • Transmission Electron Microscopy

Fields of Study

  • Materials science

Readers

  • Materials Science and Engineering.
  • Reinforced Composite Materials
  • Thin Film Deposition Science.