On the microstructural and functional stability of Fe-Mn-Al-Ni at ambient and elevated temperatures

In the present study the effect of multiple aging treatments ranging from room temperature to 150 degrees C on the pseudoelastic behavior of previously aged bamboo-structured as well as single crystalline specimens of a Fe-34.8Mn-13.5Al-7.4Ni (at.%) shape memory alloy was investigated. No additional room temperature aging effects occurred in the initially aged bamboo-structured tensile specimen stored for two years, whereas small changes in the pseudoelastic response in single crystalline specimens stored for 96 h at elevated temperatures were seen. It appears that an average precipitate sizes of about 13 nm is sufficient to impede undesired aging effects at least at room temperature. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.