Severe Plastic Deformation of Melt-Spun Shape Memory Ti₂NiCu and Ni₂MnGa Alloys

Abstract

This paper describes the influence of severe plastic deformation (SPD) on the structure, phase transformations, and physical properties of melt-spun Ti₂NiCu-based and Ni₂MnGa-based shape memory intermetallic alloys. It was found that the SPD by high pressure torsion (HPT) at room temperature can be effectively used for the synthesis of bulk nanostructured states in these initially submicro-grained or amorphized alloys obtained by melt-spinning method in the form of a ribbon. The subsequent low-temperature annealing of HPT-processed alloys leads to formation of homogeneous ultrafine nano-grained structure. This is connected with a very high degree and high homogeneity of deformation at SPD in the whole volume of deformed samples.