Microstructure and Texture Evolution of AZ31 Alloy Prepared by Cyclic Expansion Extrusion with Asymmetrical Extrusion Cavity at Different Temperatures.

Jie Zheng,Zhimin Zhang,Yong Xue,Zhaoming Yan,Qiang Wang

doi:10.3390/ma13173757

Abstract

This work is to study the microstructure and texture evolution of AZ31 alloy prepared by cyclic expansion extrusion with an asymmetrical extrusion cavity (CEE-AEC) at different deformation temperatures. The result shows AZ31 alloy undergoes continuous dynamic recrystallization (CDRX) and discontinuous dynamic recrystallization (DDRX) during CEE-AEC processing. At the initial stage of deformation, AZ31 alloys exhibit similar bimodal microstructure of coarse deformed grains surrounded by fine DRXed grains. As the passes increase, the cumulative strain increases, and the coarse grains of all samples are almost replaced by fine equiaxed grains. The average grain sizes and the basal texture intensities of the deformed samples increase as the deformation temperature increases. In addition, due to the existence of an asymmetrical cavity, as the passes increase, the basal textures of all samples are deflected with maximum intensities increase, and even an unusual bimodal texture is formed, resulting in a soft orientation that is easy to basal slip.

Highlights

In recent years, magnesium (Mg) and its alloys have received attention from the automotive industry and the aerospace field due to their high specific stiffness and excellent lightweight performance [1,2,3]
It is obvious that the microstructures of the deformed samples are effectively effectively refined after each pass of the cyclic expansion-extrusion (CEE)-AEC deformation
The evolution process of the microstructure and texture of the AZ31 alloy sample prepared by the asymmetric extrusion cavity cyclic expansion-extrusion at different temperatures was studied

Summary

Introduction

Magnesium (Mg) and its alloys have received attention from the automotive industry and the aerospace field due to their high specific stiffness and excellent lightweight performance [1,2,3]. Grain refinement and texture control are the most effective methods for preparing high-performance Mg alloys [9,10,11]. Wang et al [22] introduced shear deformation into the process by changing the cavity structure to form deflection basal texture, which effectively improved traditional extruded sheet process by changing the cavity structure to form deflection basal texture, the mechanical properties of AZ31 alloy sheets. Based on theabove above research research progress, that thethe shear deformation introduced by by changing thethe cavity structure cancan significantly refine the grains and improve the mechanical properties. We studied the microstructure and mechanical properties of Mg-Gd-Y-Zn-Zr alloy prepared by the CEE-AEC process [25,26].

Methods

Results

Conclusions