Effects of aging on the microstructure and phase transformation behavior of cu-al-mn shape memory alloy

Abstract

In the present study, the effects of artificial aging heat treatment on the transformation temperatures and hardness of Cu-Al-Mn shape memory alloy have been investigated. The aging processes have been performed on the one-time re-melted and 90% rolled samples. Differential scanning calorimetry reveals that reverse transformation is present for the re-melted sample which is aged at 400°C. However, in 90% rolled condition, this transformation takes place at 200°C and 300°C. Hardness examination shows that the aged specimens possess higher values in hardness in comparison to un-aged samples at all studied temperatures. Although, the peak-aged condition was demonstrated at 300°C for the re-melted sample, the rolled sample displayed increased hardness levels up to 500o C. Based on the DSC measurements and microstructural observations, it can be asserted that the thermo-mechanical processing including rolling plus aging at 300o C provides favorable transformation characteristics for shape memory behavior.