Experimental verification of a micromechanical model for polycrystalline shape memory alloys in dependence of martensite orientation distributions

We make use of a micromechanical model for polycrystalline shape memory alloys, whose main focus is the orientation distribution of the martensitic low symmetry variant. By energy minimization, the internal reorientation of martensite can be predicted. Hysteresis effects are included via the hypothesis that changes in the orientation distribution are connected to energy dissipation. From these considerations, we obtain evolution equations for the orientation distribution in terms of the thermomechanical driving forces. Comparing our model to results from synchrotron diffraction experiments, good agreement is found between experimentally observed and analytically predicted orientations of austenite and stress-induced martensite. (C) 2007 Elsevier B.V. All rights reserved.