Atomic-scale comparison between (1101) and (1102) twin growth mechanisms in magnesium

Abstract

The two most frequently observed twins in hexagonal close-packed (HCP) Mg, (1101) and (1102) twins, have surprisingly different properties and morphologies, with (1101) twins appearing under higher stresses and being much thinner than (1102) twins. By considering the atomic-scale elementary properties of the twin interfaces and their disconnections, we show that (1) the transverse propagation of (1101) twins is hindered by the absence of low-energy mobile interfaces, whereas (1102) twins benefit from prismatic-basal interfaces and (2) the thickening of (1101) twins is slowed by higher energy barriers against both the nucleation and propagation of disconnections along their interfaces. © 2014 The Author(s). Published by Taylor & Francis.