Experimental and Finite Element Analysis of Asymmetric Rolling of 6061 Aluminum Alloy Using Two-Scale Elasto-Plastic Constitutive Relation

Abstract

The goal of this work was theoretical and experimental study of micro-and macroscopic mechanical fields of 6061 aluminum alloy induced by the asymmetric rolling process. Two-scale constitutive law was used by implementing an elasto-plastic selfconsistent scheme into the Finite Element code (ABAQUS/Explicit). The model was applied to study the asymmetric rolling. Such a deformation process induces heterogeneous mechanical fields that were reproduced by the model thanks to the crystallographic nature of constitutive law used. The studied material was processed, at room temperature, in one rolling pass to 36% reduction. The resulting material modifications were compared with predictions of the two-scale model. Namely, the calculated textures were compared with experimental ones determined by X-ray diffraction. Especially, detailed quantitative analysis of texture variation across the sample thickness was done. The influence of this texture variation on plastic anisotropy was studied. The advantages of asymmetric rolling process over symmetric one were identified. The main benefits are a nearly homogeneous crystallographic texture, reduced rolling normal forces and homogenization of plastic anisotropy through the sample thickness.

A Short Review on the Finite Element Method for Asymmetric Rolling Processes

“…Wro ński and coworkers [25][26][27] conducted three studies using two scales models to predict deformation textures caused by the asymmetric rolling process. Experimental textures measured by X-ray diffraction validated the computational models.…”

“…Wro ński and coworkers [25,27,55] also resorted to a two-scale procedure to model plastic deformation. At the macro-scale, they used the FEM.…”

Numerical and Experimental Analysis of the Anisotropy Evolution in Aluminium Alloys Processed by Asymmetric Rolling

“…Wronsky and co-workers [15] succeeded increased the anisotropy of AA6061 by ASR but the gain was diminished during recrystallization. They used the finite element commercial software ABAQUS coupled to the Leffers-Wierzbanowski (LW) model to predict deformation texture [16]. An increase of the normal anisotropy R-value (defined by R = (R 0 + R 90 + 2R 45 )/4) about 1.3 times and decrease the planar anisotropy DR (define by ∆R = (R 0 + R 90 − 2R 45 )/2) to 0.02 from 0.66 was achieved by Lee and co-works [17] in AA1050.…”

“…Figure16 Evolution of normal anisotropy (noted "Rbar" in the graph) and planar anisotropy (noted "deltaR" in the graph) in case of 30% reduction per pass.…”