Achieving higher dynamic mechanical response by adjusting texture through twinning in a ZK61 Mg alloy

In this study, texture c-axis//ND of ZK61-T6 Mg alloy was reoriented towards c-axis//ED, TD and tilted in between ED and TD in a ZK61-PC Mg alloy through cross pre-compression. Subsequently, quasi-static and dynamic mechanical behaviour was examined. The results showed that compressive yield strength, ulti-mate compressive strength and elongation to fracture were considerably increased from 140 to 220 MPa, 374-437 MPa and 0.15-0.16, respectively. This increase was the synergistic effect of texture, grain refine-ment through twin boundaries and pre-induced dislocation hardening effect. In addition, an exceptional increase of ultimate compressive strength (531 MPa) was obtained under dynamic loading. The micro-structure evolution of deformed specimens revealed that the propensity and width of the adiabatic shear band were increased with an increase in strain rate in ZK61-PC Mg alloy. In addition, twinning, de-twin-ning, < a > and < c+a > dislocation inside the twin and the matrix absorbed the high-stress energy and provided a higher mechanical response in ZK61-PC Mg alloy. The twinning induce rotational dynamic re-crystallization mechanism was responsible for the development of fine grains. Based on the results, it is recommended that pre-compression is a practical way to increase the efficiency of the ZK61 Mg alloy. (c) 2022 Elsevier B.V. All rights reserved.