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Unstable Motion of an Edge Dislocation in a Solute Atom Atmosphere Studied by Kinetic Monte Carlo Simulations

Published online by Cambridge University Press:  21 March 2011

X. M. Gu
Affiliation:
Department of Materials Science and EngineeringUniversity of Illinois, Urbana, IL 61801, USA
Y. Q. Sun
Affiliation:
Department of Materials Science and EngineeringUniversity of Illinois, Urbana, IL 61801, USA
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Abstract

The discontinuous yielding of a model material, which contains an edge dislocation moving in the atmosphere of solute atoms, is studied by Kinetic Monte Carlo (KMC) simulations. The stress-strain curves for a constant strain rate were obtained at different temperatures. The dislocation moves discontinuously, producing three types of serrated yielding behavior at intermediate temperatures for different imposed strain rates. Positive dependence of flow stress on temperature and negative strain rate sensitivity were observed in the regime of discontinuous motion. The present model, though highly simplified and not taking into account the collective behaviors of dislocations in real materials, does exhibit some of the basic features observed in experiments.

Type
Research Article
Copyright
Copyright © Materials Research Society 2001

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