On twinning and anisotropy in rolled Mg alloy AZ31 under uniaxial tension

Xiaoqian Guo,Xianbiao Mao,Adrien Chapuis,Peidong Wu,Qing Liu,K Saanouni

doi:10.1051/matecconf/20168005001

Abstract

The Elastic Visco-Plastic Self-Consistent (EVPSC) model, with the recently developed Twinning and De-Twinning (TDT) description, is applied to study the mechanical behaviour of hot-rolled Mg alloy AZ31 under uniaxial tension. Numerical results are compared to the experimental uniaxial tensile tests reported earlier by Chapuis et al. [29] for the out-of-plane directions of a thick plate along angles of α = 0°, 30°, 45°, 60° and 90° between the normal direction and longitudinal specimen axis. It is shown that accounting for the initial texture and calibrating the EVPSC-TDT model by using uniaxial tension tests along the rolling direction and normal direction permits prediction of the strength anisotropy and strain hardening behavior along all five tensile directions, i.e. for cases in which the contribution of twinning is dominating, negligible or intermediate.

Highlights

It has been demonstrated that accounting for the initial texture and calibrating the Elastic Visco-Plastic Self-Consistent (EVPSC)-Twinning and DeTwinning (TDT) model using in-plane uniaxial tension and compression along the rolling direction (RD) permits prediction of the strength anisotropy and monotonic strain hardening behavior along any tilt angle with respect to the normal direction a Corresponding author: peidong@mcmaster.ca (ND)
Because it is rare that a grain can be fully twinned, a threshold twin volume fraction is defined in the model to terminate twinning
Not shown in the present paper, it was found that the EVPSC-TDT model predicts very well the measured texture evolution reported in Chapuis et al [29]

Summary

Introduction

The mechanical anisotropy of hotrolled Mg alloy AZ31 under uniaxial tension is investigated numerically, based on the EVPSC-TDT model. Numerical results are compared with the experimental results reported by Chapuis et al [29]. Five uniaxial tension tests along angles of α=0°, 30°, 45°, 60° and 90° between the ND and longitudinal specimen axis were performed to experimentally study the mechanical anisotropy.

Constitutive Model

Results and discussion

Conclusions