Shape Memory and Mechanical Properties of Cold Rolled and Annealed Fe-17Mn-5Si-5Cr-4Ni-1Ti-0.3C Alloy

Abstract

In the present study, the shape, memory, and mechanical properties of cold-rolled and annealed Fe-17Mn-5Si-5Cr-4Ni-1Ti-0.3C (wt.%) alloy were investigated. The cold-rolled alloy was annealing heat-treated at different temperatures in the range of 500–900 °C for 30 min. The shape recovery behavior of the alloy was investigated using strip bending test followed by recovery heating. The microstructural evolution and the stress-strain response of the alloy heat-treated at different temperatures revealed that the recovery took place at a heat-treatment temperature higher than 600 °C. Recrystallization occurred when the heat-treatment temperature was higher than 800 °C. Meaningful shape recovery was observed only when the alloy was annealed at temperatures higher than 600 °C. The highest recovery strain of up to 2.56% was achieved with a pre-strain of 5.26% and recovery heating temperature of 400 °C, when the alloy was heat-treated at 700 °C. Conversely, the yield strength reduced significantly with increasing annealing heat-treatment temperature. The experimental observations presented in this paper provide a guideline for post-annealing heat-treatment when a good compromise between mechanical property and shape recovery performance is required.

Physical Factors Controlling Large Shape Memory Effect in FCC ↔ HCP Martensitic Transformation in CrMnFeCoNi High-Entropy-Alloy Single Crystals

“…Secondly, the FCC-HCP transition is characterized by a large shift of 0.35, which is much larger than the shift for other types of MTs [1,4]. With the reversible FCC ↔ HCP MT, the SME was less than 2% in non-textured polycrystals of Fe-Mn-Si alloys under tension [12]. When casting-annealing Fe-Mn-Ni-Cr-Si polycrystals with a grain size of up to 400 µm, the SME was 7.6% [7].…”