ACTIVATION ENERGIES AND VOLUMES FOR THE PROPAGATION OF LUDER'S BANDS

Abstract

Activation energies and volumes have been determined for the deformation during the delayed yielding of a dilute aluminum alloy containing magnesium near the temperatures 80 and 130 K. The activation energies during the three stages of yielding have been associated with the intersection mechanism. According to present theories it would have been expected that the first two stages would be thermally dependent on the unlocking of dislocations from Cottrell atmospheres. However, it is expressed by the authors that the activation energy associated with this unlocking is much larger than previously assumed. Therefore, unlocking is essentially due to the stress concentration caused by the pile up of the dislocations which are mobile during the initial stage of the delayed yielding. The interpretation of the activation volumes also firmly support this interpretation. (Author)

Document Details

Document Type
Technical Report
Publication Date
Jul 21, 1961
Accession Number
AD0262710

Entities

People

  • J.e. Dorn
  • R.l. Nolder

Organizations

  • Materials Research Laboratory

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Alloys
  • Aluminum
  • Aluminum Alloys
  • Atmospheres
  • Dislocations
  • Energy
  • Heat Of Activation
  • Magnesium
  • Stress Concentration
  • Stresses

Readers

  • Materials Science and Engineering.