Martensitic reorientation and shape-memory effect in initially textured polycrystalline Ti-Ni sheet

In this work we modify the crystal-mechanics-based constitutive model of Thamburaja [J. Mech. Phys. Solids, 53 (2005) 825] for martensitic reorientation in shape-memory alloys to include austenite-martensite phase transformation. Texture effects on martensitic reorientation in a polycrystalline Ti-Ni sheet in the fully martensitic state were investigated by conducting tensile experiments along different directions. By fitting the constitutive model to the stress-strain response for the experiment conducted along the 45° direction the constitutive model is shown to predict the experimental tensile stress-strain response in the rolling and transverse direction to good accord. Shapememory effect experiments were conducted by raising the temperature of the post-deformed tensile specimens. Austenite-martensite phase transformation material parameters were first determined by fitting the model to a superelastic experiment. With the model calibrated, the experimental shape-memory effect stress-straintemperature responses were reasonably well predicted by the constitutive model.