Effects of thermo-mechanical treatment on a Fe-30Mn-6Si shape memory alloy
Journal
Materials Science and Engineering A
Journal Volume
497
Journal Issue
1-2
Pages
445-450
Date Issued
2008
Author(s)
Abstract
Effects of thermo-mechanical treatment on a Fe-30Mn-6Si shape memory alloy were investigated, including the microstructure, precipitation behavior and shape memory performance. Experimental results show that the as-cold-rolled specimen exhibits a worse shape recovery, and its Ms temperature and transformational enthalpy (ΔH) are much lower than those of as-annealed one. Specimens with 10% cold-rolling and subsequent 550-650 °C aging have lots of (Fe, Mn)3Si precipitates within the grain interior. These precipitates exhibit a D03 structure with lattice constant of 5.66 Å, and show a near orientation relationship with γ austenite as [ over(1, ̄) 1 1 ]D 03 / / [ 0 1 1 ]γ, (over(2, ̄) 0 over(2, ̄))D 03 / / (over(1, ̄) over(1, ̄) 1)γ . The 550-650 °C aged specimen can exhibit high shape recovery ratios, due to the contributions of effective nuclei and well-aligned precipitates within the grain interior. If the aging temperature is higher than 750 °C, the recrystallization occurs and the disappearance of both effective nuclei and well-aligned precipitates within the grain interior will obviously reduce the specimen's shape memory performance. © 2008 Elsevier B.V. All rights reserved.
SDGs
Type
journal article