Fundamental Characteristics of Dynamic Slip-Band Propagation.

Abstract

High strain-rate deformation of niobium single crystals is accommodated by a combination of twinning and slip. At a high strain rate more slip systems are activated than at a low rate, and the slip is more homogeneous in character. The edge components of the glide dislocations are more mobile than the screws at a high strain rate, and are rapidly exhausted from the crystal during straining. Neither primary edges or screws react much with secondary dislocations at high strain rates, hence, there is no tendency for dislocations walls to develop during straining. By contrast, at a low strain rate primary dislocations react strongly with secondary dislocations to produce segments of sessile a (001) dislocations. Consequently, a stable array of dislocation walls develop during straining. Subsequent dislocation movement is concentrated in the vicinity of the dislocation walls, and slip becomes markedly non-homogeneous. (Author)

Document Details

Document Type
Technical Report
Publication Date
Mar 17, 1971
Accession Number
AD0720883

Entities

People

  • A. R. Rosenfield
  • G. T. Hahn
  • J. D. Boyd
  • M. F. Kanninen

Organizations

  • Battelle Memorial Institute

Tags

DTIC Thesaurus Topics

  • Contrast
  • Crystals
  • Deformation (Mechanics)
  • Dislocations
  • Personality
  • Single Crystals
  • Strain Rate

Readers

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