A systematic investigation of the compressive behaviour of near equi-atomic NiTi over a range of strain rates and temperatures

Abstract
An investigation of the compressive stress-strain behaviour of a 50.4% Ni by weight NiTi shape memory alloy when subjected to both quasi-static and high strain rate deformation across a range of temperatures is reported. Testing was carried out using a Hounsfield universal testing machine and a split Hopkinson pressure bar system. Transformation stress dependence on both increasing strain rate and temperature is presented, together with observed values of strain rate sensitivity and derived entropy of transformation per unit volume.