Atomistic Simulations of Intersection Cross-Slip Nucleation in Ll2 Ni3Al (Preprint)

Abstract

Using atomistic (molecular statics) simulations with embedded atom potentials, we evaluate the activation barrier for a dislocation to form the PPV lock intersecting a forest dislocation in Ll2 Ni3Al as a function of the superpartial core width. The activation energies were obtained by determining equilibrium configurations (energies) when variable pure tensile or compressive stresses are applied along the [111] direction on the partially cross-slipped state. We show that the PPV lock is stable at the intersection, unlike bulk and that the activation energy for cross-slip at the forest dislocation intersection is significantly lower than that for cross slip in bulk [energy of two separate constrictions]. These results suggest that cross-slip should be preferentially observed at selected screw dislocation intersections in Ll2 Ni3Al.

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Document Details

Document Type
Technical Report
Publication Date
Nov 01, 2011
Accession Number
ADA553463

Entities

People

  • Christopher F. Woodward
  • Dennis M. Dimiduk
  • M. D. Uchic
  • S.I. Rao
  • Triplicane A. Parthasarathy

Organizations

  • Air Force Research Laboratory

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Air Force
  • Air Force Facilities
  • Air Force Research Laboratories
  • Constrictions
  • Department Of Defense
  • Dislocations
  • Energy
  • Heat Of Activation
  • Military Research
  • Molecular Dynamics
  • Nucleation
  • Simulations
  • Stresses
  • United States

Readers

  • Materials Science and Engineering.