Enhancement of coercivity in high remanence HDDR Nd-Fe-B powders

A new type of HDDR (Hydrogenation, Disproportionation, Desorption, Recombination) processing route, in which alloys are heated up under a low pressure of H/sub 2/ for the disproportionation stage, was found to be an effective way of obtaining high remanence Nd-Fe-B ternary powders, with no large decrease in coercivity (which was the problem with the previous HDDR processing route, in which the alloys were heated under vacuum), The alloys with 0.5% Ga addition exhibited high coercivities of 1.0 MAm/sup -1/ with no degradation in remanence (Br=1.4 T),.