Thermomagnetic Characteristics of Martensitic Transformation in the Ni50Mn18.5Ga25Cu6.5 Alloy with the As-Cast and Recrystallized Equiaxed Structures

The thermal and thermomagnetic properties of the Ni50Mn18.5Ga25Cu6.5 alloy were studied in the as-cast state and after recrystallization annealing of the strain-hardened structure. It was shown that annealing of the pre-strain-hardened structure at 1123 K for 2 h leads to the formation of an equiaxed grain structure with an average crystallite size of approximately 200 µm. Combined thermal and thermomagnetic analysis demonstrated a simultaneous martensitic and magnetic phase transition. The transformation of the as-cast structure resulted in no significant changes in the thermal and thermomagnetic properties of the martensitic transition.