Graded transitions in Ni-Ti shape memory alloys processed by severe plastic deformation

NiTi shape memory alloys were subjected to a single step severe plastic deformation via the equal channel angular pressing (ECAP). The properties were analyzed by comparing the transformation characteristics for sections across the thickness of the deformed sample, with focus on the deformation gradient in the outer layers of the materials and the front surface that gradually engages in the deformation. A gradient related to the crystallinity and the state of stress was observed across the thickness of the deformed sample.