Superelastic deformation behavior of TiNi shape memory alloy subjected to various cyclic loading

TiNi shape memory alloys are used most commonly due to their excellent mechanical properties, corrosion resistance and biocompatibility. Superelasticity is one of the important mechanical properties of TiNi shape memory alloys (SMA). In the present paper, the superelastic deformation behavior of TiNi SMA subjected to various full and partial loading at different experimental temperatures and strain rates was investigated. The characteristics of transformation stress and the modulus of elasticity during cyclic deformation were analyzed. The research results show martensite transformation stress decreases with an increase in cycle due to the residual strain during full cyclic loading. The amount of decrease in martensite transformation stress, i.e. residual stress, was proportional to residual strain. After mechanical training with cyclic deformation, superelastic behavior of TiNi shape memory alloy subjected to partial loading was studied, the starting and completing conditions of the transformation were prescribed.