Recovery of A1Mg alloys: flow stress and strain-hardening properties

M. Verdier, Y. Brechet, P. Guyot

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135 Citations (Scopus)

Abstract

The recovery of Al-2.5 wt% Mg alloys cold-rolled to several strains between 0.1 and 3 has been studied essentially using tensile tests. The yield stress and strain-hardening properties are studied as a function of the initial prestrain, and of the temperature and the duration of annealing treatments. A theoretical model based on the dislocation structure is proposed. The kinetic evolution of the yield stress is related to the variation of the total dislocation density as a single structural parameter. The pseudo-logarithmic time decay is explained on the basis of a relaxation of the internal stresses by thermally activated dislocation motion. A strain-hardening model is proposed based on Kocks' constitutive law of plasticity, where the dislocation storage and dislocation annihilation parameters are adapted to a heterogeneous cell/subgrain dislocation structure. The adjustment of the model to the work-hardening behaviour is in agreement with TEM observations.

Original languageEnglish
Pages (from-to)127-134
Number of pages8
JournalActa Materialia
Volume47
Issue number1
DOIs
Publication statusPublished - 11 Dec 1998
Externally publishedYes

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