In-situ synchrotron X-ray diffraction study of stress-induced phase transformation in Ti50.1Ni40.8Cu9.1 thin films

Stress-induced martensitic transformation of as-sputtered and post-annealed Ti50.1Ni40.8Cu9.1 thin films was investigated using in-situ synchrotron X-ray diffraction (S-XRD) technique. For the as-deposited film, in-situ S-XRD analysis showed a martensitic transformation from parent phase to martensite during initial loading, followed by reorientation of martensite variants via detwinning. This detwinning process induced a strong 〈0 2 0〉 fiber texture along the loading direction and a strong 〈0 0 2〉 fiber texture perpendicular to the loading direction. For the 650 °C annealed film, there is only elastic deformation, followed by a martensitic transformation during deformation.