Martensitic reorientation and shape-memory effect in initially textured polycrystalline Ti–Ni sheet Original Research Article

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. Shape-memory 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–strain–temperature responses were reasonably well predicted by the constitutive model.