Thermodynamically-Guided Improvement of Fe-Mn-Al-Ni Shape-Memory Alloys.

A microstructural informed thermodynamic model was utilized to tailor the pseudoelastic performance of a series of Fe-Mn-Al-Ni shape-memory alloys. Following this approach, the influence of the stability and the amount of the B2-ordered precipitates on the stability of the austenitic state and the pseudoelastic response was revealed. This was assessed by a combination of complementary nanoindentation measurements and incremental-strain tests under compressive loading. Based on these investigations, the applicability of the proposed models for the prediction of shape-memory capabilities of Fe-Mn-Al-Ni alloys was confirmed. Eventually, these thermodynamic considerations enable the guided enhancement of functional properties in this alloy system through the direct design of alloy compositions. The procedure proposed renders a significant advancement in the field of shape-memory alloys. This article is protected by copyright. All rights reserved.