Enhanced elastocaloric effect and mechanical properties of Fe-doped Ni–Mn–Al ferromagnetic shape memory alloys

Abstract The influence of Fe substitution for Ni on mechanical properties and elastocaloric effect (eCE) in Ni50-xFexMn32Al18 (x = 2, 3 and 4) ferromagnetic shape memory alloys (FSMAs) has been investigated. These alloys undergo a first-order martensitic transformation from B2 (austenite) to L10 (martensite) on the cooling process. As the Fe content increases, the martensitic transformation temperature shifts toward lower temperature region, and the amount of γ phase increases gradually in Ni50-xFexMn32Al18 (x = 2, 3 and 4) alloys. Moreover, the maximum compressive strength (1147 MPa) is obtained in Ni46Fe4Mn32Al18 alloy. The application and removal stress of 300 MPa can produce a large adiabatic temperature change of about 5.1 K and no significant degradation of eCE after 30 stress cycles in Ni46Fe4Mn32Al18 alloy. These results show that Ni50-xFexMn32Al18 alloys would be the promising candidates for new multifunctional materials.