Discrete dislocation plasticity analysis of the size dependence of the flow strength of polycrystals
File(s)
Accepted version
Author(s)
Balint, DS
Deshpande, VS
Needleman, A
Van der Giessen, E
Type
Journal Article
Abstract
The grain size dependence of the flow strength of polycrystals is analyzed using plane strain, discrete dislocation plasticity. Dislocations are modeled as line singularities in a linear elastic solid and plasticity occurs through the collective motion of large numbers of dislocations. Constitutive rules are used to model lattice resistance to dislocation motion, as well as dislocation nucleation, dislocation annihilation and the interaction with obstacles. The materials analyzed consist of micron scale grains having either one or three slip systems and two types of grain arrangements: either a checkerboard pattern or randomly dispersed with a specified volume fraction. Calculations are carried out for materials with either a high density of dislocation sources or a low density of dislocation sources. In all cases, the grain boundaries are taken to be impenetrable to dislocations. A Hall–Petch type relation is predicted with Hall–Petch exponents ranging from 0.3 to 1.6 depending on the number of slip systems, the grain arrangement, the dislocation source density and the range of grain sizes to which a Hall–Petch expression is fit. The grain size dependence of the flow strength is obtained even when no slip incompatibility exists between grains suggesting that slip blocking/transmission governs the Hall–Petch effect in the simulations.
Date Issued
2008-12
Citation
International Journal of Plasticity, 2008, 24 (12), pp.2149-2172
ISSN
0749-6419
Publisher
Elsevier
Start Page
2149
End Page
2172
Journal / Book Title
International Journal of Plasticity
Volume
24
Issue
12
Copyright Statement
Copyright © 2007 Elsevier Ltd. All rights reserved. NOTICE: this is the author’s version of a work that was accepted for publication in International Journal of Plasticity. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in International Journal of Plasticity, 24(12), 2008. DOI:10.1016/j.ijplas.2007.08.005
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=000261541900001&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Subjects
mechanical properties
PLASTICITY
Polycrystals
Size effects
Discrete dislocations
Publication Status
Published