2010 年 57 巻 1 号 p. 27-32
We applied Hydrogenation-Disproportionation-Desorption-Recombination (HDDR) treatment on compacts of fine powder of Nd-Fe-B-based alloys to obtain porous, submicron-grained bulk permanent magnets. The crystallographic orientation of the Nd2Fe14B particles was maintained in the porous magnets, which could be further densified to the full density by hot pressing. Significant improvements over conventional HDDR-processed magnets were observed in the squareness of demagnetization curves for the full-density bulk magnets.