Shape memory characteristics of (TiZrHf)50Ni25Co10Cu15 high entropy shape memory alloy

A homogenized (TiZrHf)50Ni25Co10Cu15 high entropy shape memory alloy (HESMA) was studied to investigate its transformation behavior and shape memory effect. After solution treatment at 1000 °C, the (TiZrHf)50Ni25Co10Cu15 HESMA still contained Ti2Ni-like second phase and (Ti, Zr, Hf) carbide, and thus was not a single solid solution. It exhibited a broad transformation temperature range with Ms = 36.0 °C and Mf = −80.4 °C. In a three-point bending test, the (TiZrHf)50Ni25Co10Cu15 HESMA showed a reversible strain of 4.8% under 650 MPa, which is similar to the performance of Ti50Ni50 alloy but with a much higher output work density.