Structure and mobility of martensite variant interfaces in a Cu-Zn-AI shape memory alloy

Abstract
The structure and mobility of martensite variant interfaces have been investigated using TEM and HREM observations, and then the relations of interface structure to its mobility are revealed. It is shown that the A/C interface is straight, well-defined and perfectly coherent. The A/B interface is irrational, coherent and gradually curved. The A/D interface is stepped and the interface steps are the basal planes of the two variants. The intervariant-group interfaces are curved and blurred and some variants are tapered at the intervariant-group interface. The A/C and A/B interface have obvious mobility and may move smoothly and remain straight during moving. The mobility is not effective for A/D interface, and even worse for intervariant-group interfaces. The morphology, structure and mobility of interplate boundary are all related to the degree of self-accommodation and the misorientation of the twin boundary.