On the temperature dependence of the superelastic strength and the prediction of the theoretical uniaxial transformation strain in Nitinol

Abstract This paper describes an alternative method for applying the Clausius-Clapeyron equation in a study of the effect of temperature on the superelastic stress in the shape memory alloy Nitinol—a candidate material for many medical devices. including, in particular, endovascular stents. This new analysis will provide some clarification on the controversy regarding estimation of the thermodynamic equilibrium temperature. The theoretical uniaxial transformation strain has been calculated by means of the Clausius–Clapeyron equation. The calculated value of strain, 5.0%, corresponded closely to the experimentally measured value of 4.7%.