Texture and Lattice Strain Evolution during Tensile Loading of Mg–Zn Alloys Measured by Synchrotron Diffraction

Xiaohua Zhou,Changwan Ha,Mingyi Zheng,Norbert Schell,Yuanqing Chi,Jan Bohlen,Heinz-Günter Brokmeier,Sangbong Yi

doi:10.3390/met10010124

Abstract

To explore the effect of neodymium (Nd) on the deformation mechanisms of Mg–Zn alloys, texture and lattice strain developments of hot-rolled Mg–Zn (Z1) and Mg–Zn–Nd (ZN10) alloys were investigated using in situ synchrotron diffraction and compared with elasto-viscoplastic self-consistent simulation under tensile loading. The Nd-containing ZN10 alloys show much weaker texture after hot rolling than the Nd-free Z1 alloy. To investigate the influence of the initial texture on the texture and lattice strain evolution, the tensile tests were carried out in the rolling and transverse direction. During tension, the {002}<100> texture components develop fast in Z1, which was not seen for ZN10. On the other hand, <100> fiber // loading direction (LD) developed in both alloys, although it was faster in ZN10 than in Z1. Lattice strain investigation showed that <101> // LD-oriented grains experienced plastic deformation first during tension, which can be related to basal slip activity. This was more apparent for ZN10 than for Z1. The simulation results show that the prismatic slip plays a vital role in the plastic deformation of Z1 directly from the beginning. In contrast, ZN10 plastic deformation starts with dominant basal slip but during deformation prismatic slip becomes increasingly important.

Highlights

Magnesium (Mg) and its alloys have been manufactured in large quantities for the automobile industry and as aeronautic and 3C products [1] due to its low density of 1.74 g/cm3
The elasto-viscoplastic self-consistent (EVPSC) model was originally developed by Molinari et al [30] and was recently implemented by Wang et al [31] to be applicable to large strain and to arbitrary crystal structure
The average grain sizes of Z1 and ZN10 are comparable at 27 μm and 23 μm, respectively (Figure 2)

Summary

Introduction

Magnesium (Mg) and its alloys have been manufactured in large quantities for the automobile industry and as aeronautic and 3C products [1] due to its low density of 1.74 g/cm. The pronounced plastic anisotropy has limited the wide applications of Mg and its alloys in the automotive industry [2,3,4,5,6,7,8,9]. The most common deformation modes include basal slip, prismatic slip, pyramidal slip, and tension twinning. To overcome this anisotropy problem, one must modify the microstructure to have less preferred orientation, optimized grain size, and balanced nano-defects. Many researchers have investigated the effect of texture [10,11,12], grain size [5,11,13,14], precipitation [15,16,17,18], and solutes [19,20,21] on the deformation behavior of Mg

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