THE ROLE OF THE GRAIN BOUNDARY IN THE DEFORMATION OF CERAMIC MATERIALS

Abstract

The mechanical behavior of MgO grain boundaries at elevated temperatures was investigated. The shear strength of bicrystal specimens was obtained (constant loading rate tests) at 1400 C for a wide range of crystal misorientations. Large twist, low tilt boundaries fractured at extremely low stress compared to other misorientations. For a given tilt angle the fracture stress decrease with increasing twist component; the decrease being sharper for low tilt bound aries and more gradual for boundaries possessing large tilt components. The effect of temperature on the grain boundary fracture stress was investigated for varying misorientations in the range 1200 - 1500 C. For each type of boundary orientation there was a characteristic temperature where there was a sudden drop in strength, this transition temperature being lowest for bound aries with a high twist component. Experiments on tricrystals indicated that the weaker twist type boundaries controlled the fracture strength of the entire body.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1963
Accession Number
AD0407069

Entities

People

  • A. J. Mountvala
  • G. T. Murray

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Air Force
  • Ceramic Materials
  • Contracts
  • Crystal Lattices
  • Crystal Structure
  • Crystals
  • Government Procurement
  • Governments
  • Grain Boundaries
  • Materials
  • Materials Laboratories
  • Melting Point
  • Metals
  • Orientation (Direction)
  • Shear Strength
  • Shear Stresses
  • Transition Temperature

Fields of Study

  • Materials science

Readers

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