Method for producing raw material powder for rare earth sintered magnet, method for producing rare earth sintered magnet, granule and sintered body
AssigneeTDK Corporation
InventorsYasushi Enokido, Fumitaka Baba, Chikara Ishizaka, Takeshi Masuda
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Abstract
A method for producing a rare earth sintered magnet uses granules having an excellent fluidity to improve the dimensional accuracy and production of a compact formed of the granules without significant property losses. The granules are formed by adding an organic liquid to primary alloy particles having a predetermined composition to produce granules having the primary alloy particles adhered together by the organic liquid. Preferably, from 1.5 to 15.0% by weight of the organic liquid is added to the primary alloy particles.
Claims25
A method for producing a rare earth sintered magnet comprising the steps of:
- charging into a die cavity granules of primary alloy particles having a predetermined composition adhered together by an organic liquid free of polymer and comprising at least one member selected from the group consisting of ethanol, toluene, methyl isobutyl ketone, diethylene glycol monoethyl ether, terpene compounds, diethylene glycol monobutyl ether, diethylene glycol monobutyl ether acetate, n-butyl acetate, ethylene glycol monobutyl ether, cyclohexanol, terpineol, pinene, dibutyl ether, xylene, cyclohexanone, propionic anhydride, and menthane;
- obtaining a compacted body by applying a magnetic field to the granules and compressing the granules;
- and
- sintering the compacted body.
A method for producing a rare earth sintered magnet, comprising the steps of:
- charging a rare earth sintered magnet raw material powder and a granulation aid into a chamber, said granulation aid being free of polymer and comprising at least one member selected from the group consisting of ethanol, toluene, methyl isobutyl ketone, diethylene glycol monoethyl ether, terpene compounds, diethylene glycol monobutyl ether, diethylene glycol monobutyl ether acetate, n-butyl acetate, ethylene glycol monobutyl ether, cyclohexanol, terpineol, pinene, dibutyl ether, xylene, cyclohexanone, propionic anhydride, and menthane;
- agglomerating the raw material powder through contact with the granulation aid by rotating a main blade provided in the chamber relative to the chamber, and loosening the resulting agglomerate by contact with an auxiliary blade provided in the chamber for producing the granules;
- charging the granules into a die cavity;
- obtaining a compacted body by applying a magnetic field to the granules and compressing the granules;
- and
- sintering the compacted body.
Dependencies are inferred from the claim text.