Cyclic ageing of Ti–50.8 at.% Ni alloy

This study investigated the effects of cyclic ageing on the transformation behaviour of Ti–50.8 at.% Ni by means of differential scanning calorimetric analysis. It is found that cyclic ageing between two different temperatures causes reversible changes of the transformation behaviour and alternating increases and decreases of transformation temperatures. This is attributed to the temperature dependence of the phase equilibria between the B2 matrix and Ni-rich precipitates. Based on the experimental evidences, the solvus of the precipitates (Ti3Ni4) in B2–NiTi is estimated.