Effects of Texture and Grain Size on the Yield Strength of ZK61 Alloy Rods Processed by Cyclic Extrusion and Compression.

Lixin Zhang,Wencong Zhang,Junpeng Duan,Wenzhen Chen,Biao Cao,Guorong Cui

doi:10.3390/ma10111234

Abstract

The ZK61 alloy rods with different grain sizes and crystallographic texture were successfully fabricated by cyclic extrusion and compression (CEC). Their room-temperature tension & compression yield strength displayed a significant dependence on grain size and texture, essentially attributed to {10-12} twinning. The texture variations were characterized by the angle θ between the c-axis of the grain and the extrusion direction (ED) during the process. The contour map of room-temperature yield strength as a function of grain size and the angle θ was obtained. It showed that both the tension yield strength and the compression yield strength of ZK61 alloy were fully consistent with the Hall-Patch relationship at a certain texture, but the change trends of the tension yield strength and the compression yield strength were completely opposite at the same grain size while texture altered. The friction stresses of different deformation modes calculated based on the texture confirmed the tension yield strength of the CECed ZK61 alloy rods, which was determined by both the basal slip and the tension twinning slip during the tension deformation at room temperature, while the compression yield strength was mainly determined by the basal slip during the compression deformation.

Highlights

In recent years, the ZK61 alloy has attracted more and more attention due to its high strength at room temperature (RT) as a kind of widely used commercial wrought magnesium alloy
In the previous literatures [5,6,7,8,9], the as-extruded ZK61 alloy rods exhibited an intense fiber texture with {0002} basal plane parallel to the extrusion direction (ED), which lead to an obvious tension/compression asymmetry along the ED
Our previous studies on the extruded extruded magnesium alloy rods showed that the reason caused this obvious tension/compression magnesium alloy rods showed that the reason caused this obvious tension/compression asymmetry asymmetry was usually related to the contribution of {10-12} tension twinning to deformation at was usually related to the contribution of {10-12} tension twinning to deformation at different stages

Summary

Introduction

The ZK61 alloy has attracted more and more attention due to its high strength at room temperature (RT) as a kind of widely used commercial wrought magnesium alloy. Most of the existing work has focused on the effects of texture and grain size on the mechanical properties of ZK61 alloy [1,2,3]. It is because of the hexagonal close-packed (hcp) crystallite structure of magnesium and its alloys that the preferred orientations of the grains caused by deformation are very common phenomena in wrought magnesium alloys [4]. The crystalline texture plays an important role in numerous mechanical and physical behaviors in magnesium alloy. In the previous literatures [5,6,7,8,9], the as-extruded ZK61 alloy rods exhibited an intense fiber texture with {0002} basal plane parallel to the extrusion direction (ED), which lead to an obvious tension/compression asymmetry along the ED.

Methods

Results

Conclusion