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

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 lambda-interfaces and their nonclassical 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.