Study on the Effect of Solid Solution Treatment on the Bending Fatigue Property of Fe-Mn-Si Shape Memory Alloys

Abstract

Fe-Mn-Si shape memory alloys have excellent low-cycle fatigue performance and broad application prospects in the field of civil engineering and construction. It is necessary to conduct comprehensive and in-depth research on the mechanical properties of Fe-Mn-Si shape memory alloys. This study takes the Fe17Mn5Si10Cr5Ni shape memory alloy as the research object. After solid solution treatment at different temperatures and times, the effect of solid solution treatment on the bending fatigue performance of Fe-Mn-Si shape memory alloys was studied using bending cycle tests. The phase composition and fracture morphology of the sample were analyzed. The results showed that solid solution treatment can significantly improve the bending fatigue performance of Fe-Mn-Si shape memory alloys, reaching the optimal value at 850 °C for 1 h. The number of bending cycles until fracture increased by 131% compared to untreated specimens. Stress induction γ → ε martensitic transformation occurred in Fe-Mn-Si shape memory alloy specimens during bending cyclic testing, which is reversible. The fracture area of Fe-Mn-Si shape memory alloy specimens is mainly characterized by ductile fracture, with some areas exhibiting quasi-quasi-cleavage fracture characteristics.