Atomic motion in Mg–3Al–1Zn during twinning deformation

We demonstrate that the origin of twinning in the Mg alloy Mg–3Al–1Zn can be understood and technologically manipulated from the atomic viewpoint. By using electron backscattered diffraction, we identify the species of twins in the compressed alloy. A theoretical analysis based on quadrangular prism-shaped atomic group unit model attributes the atomic motion during twinning to the rotation of units. Moreover, we find that the degree of difficulty for twinning in Mg alloy is governed by the magnitude of the relative motion between adjacent units.