US 2018/0294095 A1Published application

Method for producing rare-earth magnets, and slurry application device

AssigneeShin-Etsu Chemical Co., Ltd.

InventorsYukihiro KURIBAYASHI, Shogo KAMIYA, Harukazu MAEGAWA, Shintaro TANAKA

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Abstract

A method for producing rare-earth magnets is provided in which, when a slurry 2 having a rare-earth-compound powder dispersed therein is applied to sintered magnet bodies 1 and dried to apply the powder thereto, the magnet bodies 1 are accommodated and conveyed in holding pockets 42 of a conveyance drum 4 which rotates in a state of being partially immersed in the slurry 2, and, as a result, the magnet bodies 1 are immersed in the slurry 2, withdrawn from the slurry 2, and dried to apply the powder to the sintered magnet bodies 1. According to this production method, the powder can be uniformly and efficiently applied, wastage of the rare-earth compound can be effectively suppressed, and a reduction in the surface area of equipment for performing an application step can also be achieved.

Claims14

Dependent claims

A method for producing rare earth permanent magnet comprising the steps of applying a slurry of a powder in a solvent to sintered magnet bodies of R1—Fe—B composition (wherein le is one or more elements selected from Y, Sc and rare earth elements), the powder containing one or more compounds selected from an oxide, fluoride, oxyfluoride, hydroxide and hydride of R2 (wherein R2 is one or more elements selected from Y, Sc and rare earth elements), drying the slurry to coat the sintered magnet bodies with the powder, and heat treating the coated bodies for causing R2 to be absorbed in the sintered magnet bodies, the method further comprising the steps of:

providing a conveyor drum having a plurality of holding pockets circumferentially arranged in its periphery,
rotating the conveyor drum while a portion of the drum is immersed in the slurry,
placing a sintered magnet body in one holding pocket at a predetermined position of the drum prior to entry into the slurry, so that the sintered magnet body is held in the holding pocket, the sintered magnet body being conveyed along the rotational track of the conveyor drum, immersed in the slurry, then withdrawn from the slurry, and conveyed further whereby the slurry is dried and the sintered magnet body is coated with the powder,
recovering the sintered magnet body from the pocket at a predetermined position after the drying treatment and prior to re-entry into the slurry, and
subjecting the sintered magnet body to the subsequent heat treatment.

2 more elements

A device for applying rare earth compound when rare earth permanent magnet is produced by applying a slurry of a powder in a solvent to sintered magnet bodies of R1—Fe—B composition (wherein le is one or more elements selected from Y, Sc and rare earth elements), the powder containing one or more compounds selected from an oxide, fluoride, oxyfluoride, hydroxide and hydride of R2 (wherein R2 is one or more elements selected from Y, Sc and rare earth elements), drying the slurry to coat the sintered magnet bodies with the powder, and heat treating the coated bodies for causing R2 to be absorbed in the sintered magnet bodies, the device comprising

an applicator tank for containing the slurry,
a conveyor drum which rotates while a portion of the drum is immersed in the slurry,
a plurality of holding pockets circumferentially arranged in the periphery of the conveyor drum, and
drying means for blowing air into the holding pocket for drying the sintered magnet body accommodated in the pocket,
wherein a sintered magnet body is supplied into one holding pocket at a predetermined position of the drum prior to entry into the slurry, the sintered magnet body held in the pocket is conveyed along the rotational track of the conveyor drum, immersed in the slurry, then withdrawn from the slurry, and dried by the drying means, and the sintered magnet body is recovered from the pocket at a predetermined position after the drying treatment and prior to re-entry into the slurry.

2 more elements

Dependencies are inferred from the claim text.