Enhanced mechanical properties in fully recrystallized ultrafine grained ZKX600 Mg alloy

Ruixiao Zheng,Wu Gong,Tilak Bhattacharjee,Akinobu Shibata,Kazuhiro Hono,Taisuke Sasaki,Nobuhiro Tsuji,Si Gao

doi:10.1088/1757-899x/219/1/012055

Abstract

Mg-Zn-Zr-Ca (ZKX600) alloy specimens with various fully recrystallized grain sizes ranging from 0.77 μm to 23.3 μm were fabricated by high pressure torsion (HPT) followed by subsequent annealing. Tensile tests carried out at room temperature revealed that ultrafine grained (UFG) specimens exhibited enhanced combinations of strength and ductility compared to their coarse-grained counterparts. Observation of deformation microstructures suggested that basal slip and {10-12} extension twinning were the dominant mechanisms during deformation of coarse grained specimens, while deformation twinning was significantly inhibited in the UFG specimens. Based on the observations it is proposed that non-basal slip activity is responsible for the enhanced mechanical properties, and should be the focus of further investigations.

Highlights

Due to their ultra-low density, and high specific strength, magnesium (Mg) alloys have been increasingly used as structural components in the automotive and aerospace industries to achieve weight reduction and fuel economy improvements [1,2,3]
The areas at a distance of 3.0 mm from the center on sections perpendicular to the rotation axis of the annealed discs were characterized by field emission scanning electron microscopy (FE-SEM) using a JSM 7100F scanning electron microscope equipped with an electron backscatter diffraction (EBSD) system
The EBSDIPF map reveals that the as-solution treated (ST) specimen has a coarse grained structure with a mean grain size of about

Summary

Introduction

Due to their ultra-low density, and high specific strength, magnesium (Mg) alloys have been increasingly used as structural components in the automotive and aerospace industries to achieve weight reduction and fuel economy improvements [1,2,3]. Severe plastic deformation (SPD) processes, such as equal channel angular pressing (ECAP), accumulative roll bonding (ARB) and high pressure torsion (HPT), have already been proven as effective approaches for realizing ultra-grain refinement in various metallic materials [6]. It is, quite challenging to refine the grain size of Mg alloys by using. It is expected that these nano-precipitates should be effective for controlling the grain size during thermomechanical processes

Experimental Procedures

Results and Discussion

Conclusion