THE MECHANICAL BEHAVIOR OF MAGNESIUM OXIDE AT HIGH TEMPERATURES,

Abstract

Magnesium oxide crystals show a wide variety of deformation and fracture modes under tension at high temperatures depending on the number of slip systems operating concurrently in a given volume. At low temperatures slip is confined to a single <110> (110) system and plasticity is limited by stress concentrations which develop where slip switches from one plane to another. At intermediate temperatures <110> (110) slip systems at 90 degrees to each other can interpenetrate but those at 60 degrees cannot. At high temperatures dislocations can interpenetrate on all systems and polygonization can occur. After easy glide the crystals work harden and elongate over 100 percent before fracturing in a completely ductile manner. The transition from one mode to another depends on strain rate. The relative ability for 90 or 60 degree systems to intersect is discussed in terms of dislocation interactions. (Author)

Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1964
Accession Number
AD0431615

Entities

People

  • R. B. Day
  • R. J. Stokes

Organizations

  • Honeywell International, Inc.

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Dislocations
  • High Temperature
  • Low Temperature
  • Magnesium
  • Magnesium Compounds
  • Plastic Properties
  • Strain Rate
  • Stress Concentration
  • Stresses
  • Transitions

Readers

  • Materials Science and Engineering.
  • Mechanical Engineering/Mechanics of Materials.