Mobile Interfacial Microstructures in Single Crystals of Cu–Al–Ni Shape Memory Alloy

Abstract

This paper summarizes the main properties of the microstructures formed during reverse (austenite → martensite) transitions in single crystals of the Cu–Al–Ni shape memory alloy, and discusses the relation between these properties and the mechanical stabilization effect. It is shown that all experimentally observed interfacial microstructures (X- and λ-interfaces and their non-classical equivalents) are not local minimizers of the quasi-static energy, and their formation is probably governed by requirements on mobility and dissipation. This conclusion is supported by finite elements models, and acoustic emission measurements.