Extraordinary mechanical properties and successive caloric effects with ultrahigh cyclic stability in directionally solidified Ni36.6Co12.8Mn34.7Ti15.9 alloy

Abstract

Caloric effects based on multiferroic phase transformation have attracted extensive attention for their great potential to replace the conventional vapor-compression technique. However, most multiferroic phase transforming materials are inherently brittle and their caloric effects exhibit poor cyclic stability. Here, the Ni36.6Co12.8Mn34.7Ti15.9 alloy was manufactured by the directional solidification technique. The alloy can reach maximum compressive strength and strain of 2823 MPa and 17.7% at room temperature, respectively. Under magnetic field changes of 7 T, the maximum magnetic entropy change induced by a magnetic field is 28.1 J·kg−1·K−1. A large adiabatic temperature change of 20.1 K can be obtained by applying a stress field. Besides, the adiabatic temperature change between loading and unloading cycles can be maintained at ∼11.3 K for more than 10,000 cycles. A broad refrigeration temperature range of over 80 K can be realized by combining magnetocaloric and elastocaloric effects. With the simultaneously achieved extraordinary mechanical properties and large successive caloric effects with excellent cyclic stability, the present alloy has a great prospect for solid-state refrigeration applications.