ANISOTROPIC ND-FE-CO-ZR-B POWDERS PREPARED BY THE HDDR PROCESS

Nd2Fe14B-type powders, where there has been partial substitution of Fe by Zr (up to 1 at.%) and by both Zr and Co, have been prepared by the hydrogenation, disproportionation, desorption, recombination (HDDR) process. Materials with good magnetic properties are obtained for Nd-rich compositions. Powders containing at least 0.3 at.% of Zr, e.g. Nd16Fe75.7Zr0.3B8, are anisotropic with an intrinsic coercivity of 971 kA m(-1). The addition of Co to the Zr containing alloy results in an increase in the remanence but a decrease in the coercivity. The powders are of potential use in the manufacture of polymer bonded magnets.