Estimating the Strength of Single-Ended Dislocation Sources in Micron-Sized Single Crystals (Postprint)

Abstract

Three-dimensional (3D) discrete dislocation dynamics simulations were used to calculate the effects of anisotropy of dislocation line tension (increasing Poisson's volumes with free surfaces) and to compare them with the strength of double-ended sources of equal length. Their plastic response was directly modeled within a 1um3 volume composed of a single crystal fcc metal. In general, double-ended sources are stronger than single-ended sources of an equal length and exhibit no significant effects from truncating the long-range elastic fields at this scale. The double-ended source strength increases with v, exhibiting an increase of about 50% at v=0.38 (value of Ni) as compared to the value at v=0. Independent of dislocation line direction, for v greater than 0.20, the strengths of single-ended sources depended upon the sense of the stress applied.

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Document Details

Document Type
Technical Report
Publication Date
Oct 01, 2007
Accession Number
ADA476258

Entities

People

  • C. E. Woodward
  • Dennis M. Dimiduk
  • M. D. Uchic
  • Mingchu Tang
  • S.I. Rao
  • Triplicane A. Parthasarathy

Organizations

  • Universal Energy Systems

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Air Force
  • Air Force Research Laboratories
  • Anisotropy
  • Crystal Structure
  • Crystals
  • Dislocations
  • Dynamics
  • Geometry
  • Materials
  • Materials Science
  • Plastic Deformation
  • Shear Modulus
  • Shear Stresses
  • Simulations
  • Single Crystals
  • Surface Properties
  • Three Dimensional

Fields of Study

  • Physics

Readers

  • Electromagnetic Wave Scattering and Antenna Radiation Engineering
  • Materials Science and Engineering.
  • Organizational Psychology.