Thermal treatments and transformation behavior of Cu-Al-Be shape memory alloys

Among the different Cu-based shape memory alloys, the Cu-Al-Be family exhibits a particular technological interest for intermediate and low temperature applications. In this work we studied the martensitic transformation behavior of Cu-Al-Be single crystalline shape memory alloys with three different concentrations. The influence of four specific thermal treatments of quenching and aging on the transformation temperatures has been studied by differential scanning calorimetry and compared with similar studies by mechanical spectroscopy. The analysis of the influence of thermal treatments on the martensitic transformation behavior allows optimize a treatment useful for all the alloys transforming between 200 K and 400 K, avoiding both stabilization and precipitation. In addition, an anomalous jerky behavior has been reported for the alloy with low transformation temperatures, which is discussed in terms of the possible mechanisms. (C) 2012 Elsevier B.V. All rights reserved.