Study on stress relaxation characteristics of Fe based memory alloy based on strain constraint

Abstract

The characteristics of stress induced ε martensitic phase transformation and its stress relaxation during tensile stopped loading of Fe-17Mn-5Si-10Cr-5Ni alloy under constant strain constraint were studied by X-ray diffraction. The results showed that the amount of stress-induced martensite of the alloy could be increased effectively under the constant strain constraint condition when the constant strain stopped loading for 0~10 min. The stress relaxation ratio of Fe-Mn-Si memory alloy increased sharply when the constant strain stopped loading for 0~5 min, and the relaxation ratio increased slowly after 5 min, indicating that the stress-induced γ→ε phase transformation was mainly completed within 5 min. Thermo-mechanical training not only improved the shape memory effect of Fe-Mn-Si memory alloy, but also reduced the stress relaxation ratio of the alloy. The characteristics of Fe-Mn-Si memory alloy should be considered when it was applied in practical engineering.