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Mechanics and Dislocation Structures at the Micro-Scale: Insights on Dislocation Multiplication Mechanisms from Discrete Dislocation Dynamics Simulations

Published online by Cambridge University Press:  04 April 2014

D. Weygand
D. Weygand*
Affiliation:
Institute for Applied Materials, Karlsruhe Institute of Technology, Kaiserstr. 12, 76131 Karlsruhe, Germany
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Abstract

The plasticity of micro-pillar deformation has widely been studied by discrete dislocation dynamics simulations to explain the so-called size effect. In this study the role of glissile junctions forming during plastic deformation under various loading scenarios is in the center of interest. The activity of these naturally forming dislocation sources is followed in detail. Surprisingly these junctions are rather active sources and not just another obstacle as often assumed. Their relative contribution to the overall dislocation density for the simulated specimens reaches often values of 20% or even more. The formation of such a glissile junction is often correlated to stress drops or the end of a stress drop. It is therefore suggested – at least for the sample sizes considered – that this dislocation multiplication mechanism should be take into account in continuum models such as crystal plasticity of higher order dislocation continuum theories.

Keywords

dislocationsstrengthsimulation

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Type
Articles
Information
MRS Online Proceedings Library (OPL) , Volume 1651: Symposium KK – Dislocation Plasticity , 2014 , mrsf13-1651-kk07-02
Copyright
Copyright © Materials Research Society 2014 

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References

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