Easy Axis Orientation of Nd-Fe-B Melt-spun Magnets Caused by Hot-rolling

Abstract

The c-axis orientation of Nd-Fe-B melt-spun ribbons caused by hot-rolling was investigated. A small roll is added on a steel wheel near a quartz tube in such a way that melt-spun ribbons are hot-rolled immediately after quenching. X-ray diffraction patterns measured on both surfaces of the ribbons indicate that the c-axis is oriented normal to the ribbon plane. A domain pattern at the surface of the ribbons was observed with a Kerr microscope. Most of the grains exhibit maze domain configurations indicating the c-axis orientation normal to the ribbon plane. This suggests that hot-rolling promotes the c-axis orientation of Nd-Fe-B melt-spun ribbons.