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Title: A Study of Microstructural Length Scale Effects on the Behaviour of FCC Polycrystals Using Strain Gradient Concepts

Abstract

Grain size is a critically important aspect of polycrystalline materials and experimental observations on Cu and Al polycrystals have shown that a Hall-Petchtype phenomenon does exist at the onset of plastic deformation. In this work, a parametric study is conducted to investigate the effect of microstructural and deformation-related length scales on the behavior of such FCC polycrystals. It relies on a recently proposed non-local dislocation-mechanics based crystallographic theory to describe the evolution of dislocation mean spacings within each grain, and on finite element techniques to incorporate explicitly grain interaction effects. Polycrystals are modeled as representative volume elements (RVEs) containing up to 64 randomly oriented grains. Predictions obtained from RVEs of Cu polycrystals with different grain sizes are shown to be consistent with experimental data. Furthermore, mesh sensitivity studies revealed that, when there is a predominance of geometrically necessary dislocations (GNDs) relative to statistically-stored dislocations (SSDs), the polycrystal response becomes increasingly mesh sensitive. This was found to occur specially during the early stages of deformation in polycrystals with small grains.

Authors:
; ;
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
894352
Report Number(s):
UCRL-JRNL-204073
TRN: US200701%%410
DOE Contract Number:  
W-7405-ENG-48
Resource Type:
Journal Article
Journal Name:
International Journal of Plasticity, vol. 21, no. 9, September 1, 2005, pp. 1797-1814
Additional Journal Information:
Journal Name: International Journal of Plasticity, vol. 21, no. 9, September 1, 2005, pp. 1797-1814
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 42 ENGINEERING; DEFORMATION; DISLOCATIONS; GRAIN SIZE; PLASTICS; POLYCRYSTALS; SENSITIVITY; STRAINS

Citation Formats

Cheong, K S, Busso, E P, and Arsenlis, A. A Study of Microstructural Length Scale Effects on the Behaviour of FCC Polycrystals Using Strain Gradient Concepts. United States: N. p., 2004. Web.
Cheong, K S, Busso, E P, & Arsenlis, A. A Study of Microstructural Length Scale Effects on the Behaviour of FCC Polycrystals Using Strain Gradient Concepts. United States.
Cheong, K S, Busso, E P, and Arsenlis, A. Fri . "A Study of Microstructural Length Scale Effects on the Behaviour of FCC Polycrystals Using Strain Gradient Concepts". United States. https://www.osti.gov/servlets/purl/894352.
@article{osti_894352,
title = {A Study of Microstructural Length Scale Effects on the Behaviour of FCC Polycrystals Using Strain Gradient Concepts},
author = {Cheong, K S and Busso, E P and Arsenlis, A},
abstractNote = {Grain size is a critically important aspect of polycrystalline materials and experimental observations on Cu and Al polycrystals have shown that a Hall-Petchtype phenomenon does exist at the onset of plastic deformation. In this work, a parametric study is conducted to investigate the effect of microstructural and deformation-related length scales on the behavior of such FCC polycrystals. It relies on a recently proposed non-local dislocation-mechanics based crystallographic theory to describe the evolution of dislocation mean spacings within each grain, and on finite element techniques to incorporate explicitly grain interaction effects. Polycrystals are modeled as representative volume elements (RVEs) containing up to 64 randomly oriented grains. Predictions obtained from RVEs of Cu polycrystals with different grain sizes are shown to be consistent with experimental data. Furthermore, mesh sensitivity studies revealed that, when there is a predominance of geometrically necessary dislocations (GNDs) relative to statistically-stored dislocations (SSDs), the polycrystal response becomes increasingly mesh sensitive. This was found to occur specially during the early stages of deformation in polycrystals with small grains.},
doi = {},
url = {https://www.osti.gov/biblio/894352}, journal = {International Journal of Plasticity, vol. 21, no. 9, September 1, 2005, pp. 1797-1814},
number = ,
volume = ,
place = {United States},
year = {2004},
month = {5}
}