SHEAR ALONG GRAIN BOUNDARIES IN ALUMINUM BICRYSTALS,

Abstract

Aluminum bicrystals 99.99% pure having a pure tilt boundary about the less than 110 greater than axis were subjected to different stresses at various temperatures. The relative boundary displacements were observed for constant stresses. The initial rate of grain boundary gliding was found to be almost linear and a plot of the logarithm of the initial rate versus the reciprocal of the absolute temperature resulted in a series of parallel straight lines. The usual rate equation r = A sub e -Q/RT was used to calculate the activation energy for grain boundary shear. It was found to increase continuously as the boundary angle increased, and approached a maximum value for the maximum angle of mis-orientation. The mechanism for grain boundary shear was considered to be a combination process involving grain boundary self-diffusion associated with grain boundary slip (stress relaxation).

Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1956
Accession Number
AD0101327

Entities

People

  • R. Maddin
  • Shiu-kang Tung

Organizations

  • University of Pennsylvania

Tags

Communities of Interest

  • Materials and Manufacturing Processes

DTIC Thesaurus Topics

  • Aluminum
  • Boundaries
  • Diffusion
  • Displacement
  • Energy
  • Equations
  • Grain Boundaries
  • Heat Of Activation
  • Orientation (Direction)

Readers

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