Elastocaloric Effect and Magnetic Properties of Cu–Al–Mn Shape Memory Alloy

Herein, the magnetic properties and elastocaloric effects of Cu70Al19 + 0.5xMn11−0.5x (x = 0, 1, 2, 3) alloys are investigated. The resistance versus temperature curves indicate that the phase transition temperature increases as the Mn content decreases. In particular, the Cu70Al20.5Mn9.5 alloy exhibits a phase transition temperature close to room temperature. Therefore, the elastocaloric effects of this alloy are examined under stresses ranging from 200 to 500 MPa. The results show that the adiabatic temperature change of the alloy under a stress of 500 MPa reaches 9.8 K. Furthermore, the magnetization curves at 300 K reveal that the magnetic properties of the alloy significantly improve after undergoing low-temperature aging treatment. The X-ray diffraction patterns show that this improvement can be attributed to the transformation of the β1 phase to the ferromagnetic phase β3. Overall, the Cu70Al20.5Mn9.5 alloy demonstrates elastocaloric and magnetic properties comparable to those observed in certain Ni–Mn-based alloys.