Tensile twin evolution of Mg–3Al–1Zn magnesium alloy during high-strain rate deformation

Abstract

In order to investigate the evolution of $\{10\overline{1}2\}$ tensile twin in Mg–3Al–1Zn (AZ31) magnesium alloy under high-strain rate impaction, the cylindrical specimens were compressed along the rolling direction under the strain rate of 1600 s⁻¹ by use of split Hopkinson pressure bars equipped with stop rings with different thicknesses. The microstructure was observed by electron back-scatter diffraction. The results show that $\{10\overline{1}2\}$ tensile twinning dominates the early plastic deformation and the area fraction of $\{10\overline{1}2\}$ tensile twins is increased with the increase of deformation strain. Furthermore, when the deformation strain is beyond ∼10%, plastic deformation is mainly dominated by dislocation slips. In addition, most of $\{10\overline{1}2\}$ tensile twins activated in a single grain belong to a variant or a variant pair, which has the highest Schmid factor among all the variants.

KEYWORDS:

• Magnesium alloy
• high-strain rate deformation
• $\{10\overline{1}2\}$ tensile twinning
• twin variant
• Schmid factor

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Project of Liaoning Education Department: [Grant Number LZGD2020003] and High Level Innovation Team of Liaoning Province: [Grant Number XLYC1908006].