Low Hydrogen Pressure Induced High Anisotropy in HDDR-Treated Nd13Fe75Co4B8 Powders

Abstract

High anisotropic Nd13Fe75Co4B8 magnetic powders are obtained with low desorption H2-pressure of the hydrogenation disproportionation desorption recombination (HDDR) process. Scanning electron microscopy (SEM) indicates a lamella structure in the 20 kPa desorption H2-pressure HDDR products and may be related to the high anisotropy. The magnetic powders with a desorption H2-pressure of 20 kPa have the magnetic properties of Br =0.86 T and Mr/Ms =0.81.This shows that the H2-pressure has great effect on the formation of crystal texture in the HDDR Nd-Fe-B powders.