Multi-pass cold rolling and wire drawing process of gadolinium and its magnetocaloric effect

Abstract

Owing to low ductility of magnetocaloric material (MCM)s, the plastic deformation process is quite challenging, and information available on the deformation process of MCMs is limited. In this study, the cold rolling and wire drawing processes of Gd wire including heat treatment were conducted. Uniaxial compression test of as-cast and heat treated Gd rod was conducted to evaluate the material property. The magnetocaloric effect (MCE) of drawn Gd wire was indirectly measured using a vibrating sample magnetometer (VSM). Pass schedule of cold rolling and wire drawing process for the Gd wire of Ø1.0 was designed. Finite element (FE) simulation of drawing process was conducted to investigate the drawing force for each drawing pass and strain distribution. Friction coefficient between the drawing die and Gd wire was evaluated via FE simulation and drawing experiments using a lubricant. Magnetic properties of the deformed and annealed Gd wire were evaluated and compared. The evaluated magnetic properties have shown that the presented process schedule is reasonable for manufacturing magnetocaloric wire without diminishing the magnetocaloric effect.