A phase field - Finite element approach to model the interaction between phase transformations and plasticity in shape memory alloys

The coupling between phase transformations and plasticity in shape memory alloys (SMAs) is studied by developing a finite element framework in which the constitutive relation captures both phase transformations at the martensite correspondence variant (CV) scale and rate-dependent crystal plasticity in austenite. Load-free and load-biased thermal cycling simulations involving a model cubic-to-tetragonal transformation system are carried out to study how slip in austenite can affect the resulting martensite microstructure. Three key questions are answered. First, where does austenite slip predominantly occur during phase transformation? Second, at what stage during a thermal cycle is plastic deformation most pronounced? Third, what is the effect of plastic deformation on measurable parameters like transformation temperature and subsequent transformation microstructure? The model can also be generalized to study the coupling between phase transformations, twining, and slip. (C) 2015 Elsevier Ltd. All rights reserved.