Spontaneous Athermal Cross-Slip Nucleation at Screw Dislocation Intersections in FCC Metals and L1(2) Intermetallics Investigated via Atomistic Simulations

Abstract

In this manuscript, we extend on our prior work to show that under certain conditions cross-slip nucleation is athermal and spontaneous with zero activation energy in FCC elemental metals such as Ni and Cu, and L12 intermetallic compounds such as Ni3Al. Using atomistic simulations (molecular statics), we show that spontaneous cross-slip occurs at mildly repulsive intersections. Further, the local Shockley partial dislocation interactions at such repulsive intersections are found to be attractive leading to junction formation. The line orientation of the intersecting dislocation determines whether the spontaneous cross-slip nucleation occurs from either the glide plane to the cross-slip plane or vice versa. Collectively, these results suggest that cross-slip should be preferentially observed at selected screw dislocation intersections in FCC-derviative metals and alloys.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 2013
Accession Number
ADA613120

Entities

People

  • Christopher F. Woodward
  • Dennis M. Dimiduk
  • J. A. El-awady
  • 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 Research Laboratories
  • Crystal Structure
  • Crystals
  • Dislocations
  • Heat Of Activation
  • Low Temperature
  • Materials
  • Molecular Dynamics
  • Nucleation
  • Simulations
  • Strain Hardening
  • Three Dimensional
  • Two Dimensional

Readers

  • Materials Science and Engineering.