Effect of Cu addition on the physical and mechanical properties of a Ni–Mn–In–Co polycrystalline shape memory alloy

The martensite transformation (MT), magnetocaloric effect (MCE), and mechanical properties of the polycrystalline Ni46Mn36In14Co4 (Co4) alloys with doping of 4 at.% Cu were examined. A large magnetization change (ΔM, 92 emu/g), large magnetic entropy change (ΔSM, 37.3 J kg−1K−1), high refrigerant capacity (RC, 261 J kg−1), relatively high sensitivity to magnetic fields (2.8 K/T), and two-way magnetic-field-induced MT were attained at approximately room temperature. Moreover, the compressive fracture strength and strain of the alloy reached 335 MPa and 7.4 %, respectively. Finally, the mechanism of the excellent combination properties of the Ni42Mn36In14Co4Cu4 (Co4Cu4) alloy was discussed. This study can aid in the development of high-performance magnetic refrigeration and intelligent actuator materials.