PURPOSE: To stably produce an anisotropic rare-earth alloy powder having excellent magnetic characteristics at the time of hydrogenating the powder of an alloy consisting essentially of Fe, contg. rare-earth elements and having a specified composition by previously causing the natural collapse of a raw alloy due to hydrogen storage.
CONSTITUTION: An alloy consisting of 67-85 atomic % T (formed by replacing Fe or a part of it with ≤50% Co), 10-20% R (at least one kind of rare-earth element including Y and ≤50% of which is replaced by one or ≥2 kinds between Pr and Nd), 0.01-10% M (one or ≥2 kinds among Ga, Zr, Nb, Hf, Ta, Al, V and Si) and 4-10% B is crushed to obtain an Nd2Fe14B-type tetragonal compd., at least 80% of which has 3-50mm average particle size, the compd. is naturally collapsed in gaseous hydrogen by hydrogen storage and then hydrogenated in the same hydrogen atmospher. The hydrogenated compd. is then dehydrogenated in vacuum or in an inert gas atmosphere, and an anisotropic rare-earth alloy fine powder for a permanent magnet with the average bound particle diameter controlled to 0.05-1μm and having a high coercive force is produced.
TOMIZAWA HIROYUKI
HOSOKAWA SEIICHI
UEHARA MINORU
HIROZAWA SATORU
TOMITA TOSHIRO
SUMITOMO METAL IND