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Title: Statistical behavior and strain localization patterns in the Portevin-Le Chatelier effect

Statistics of the stress drops associated with the Portevin-Le Chatelier effect in an Al-Mg alloy were studied both experimentally and theoretically. It was shown that the character of the statistics changes from a peaked distribution of the stress drop magnitudes to a monotonically decreasing one as the imposed strain rate or the temperature are increased. A discrete model based on a micromechanically founded local constitutive equation combined with spatial coupling between the elements of the system was shown to reproduce the observed statistical behavior. The mechanism of spatial coupling is connected with elastic stresses due to local plastic incompatibilities. The model was further applied to simulate spatial deformation patterns including propagative deformation bands. The systematics of the bands reported in the literature as well as the observed dependence of the band velocity on the imposed deformation rate were recovered. It was concluded that the model proposed provides an adequate description of both the statistics of stress discontinuities and the spatial features of the Portevin-Le Chatelier effect.
Authors:
 [1] ;  [2] ;  [3] ;  [4]
  1. Russian Academy of Sciences, Chernogolovka (Russian Federation). Inst. of Solid State Physics
  2. Inst. National Polytechnique de Grenoble, Saint Martin d`Heres (France). Lab. de Thermodynamique et Phisico-Chimie Metallurgiques
  3. Univ. of Western Australia, Nedlands, Western Australia (Australia). Dept. of Mechanical and Materials Engineering
  4. CNRS/ONERA, Chatillon (France). Lab. d`Etudes des Microstructures
Publication Date:
OSTI Identifier:
415438
Resource Type:
Journal Article
Resource Relation:
Journal Name: Acta Materialia; Journal Volume: 44; Journal Issue: 11; Other Information: PBD: Nov 1996
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ALUMINIUM ALLOYS; DEFORMATION; MAGNESIUM ALLOYS; STRESSES; STRAINS; STRAIN RATE; TEMPERATURE DEPENDENCE; MATHEMATICAL MODELS; COUPLING; ELASTICITY; PLASTICITY; SIMULATION; CORRELATIONS