Ageing study of Cu–Al–Be hypoeutectoid shape memory alloy

Thermal ageing at constant temperature (350 °C) and under systematically designed temperature-varying conditions were performed on the metastable austenitic phase of hypoeutectoid Cu–Al–Be shape memory alloy. Thermal precipitations and their effects on the alloy global microstructure were studied by DSC, XRD and SEM techniques. Precipitations of equilibrium phases (α + γ2) within the temperature range of 330–370 °C, and their generalization by a discontinuous mechanism for an ageing time of 864 ks (240 h), were identified and analyzed. The results of this study are expected to benefit the applications of copper-based shape memory alloys under various thermal conditions.