公开(公告)号：US20250037933A1

公开(公告)日：2025-01-30

申请号：US18717056

申请日：2022-11-04

Applicant: MINEBEA MITSUMI Inc.

Inventor： Yu OKAWARA ,  Haruhiro KOMURA ,  Yuki ITO ,  Heki NAKAYA

IPC: H01F41/02 ,  H01F1/057 ,  H01F13/00

Abstract: A method of producing a rare earth iron-based sintered magnet according to an embodiment includes a step of filling a mold with a rare earth iron-based magnet powder produced by a rapid quenching method, a step of setting the mold in a sintering apparatus, supplying a predetermined current from electrodes, and pressurizing and heating the rare earth iron-based magnet powder filled to produce a sintered magnet body, and a step of magnetizing the sintered magnet body with a magnetizing device. The mold includes dies having a hollow cylindrical form, punches to be inserted into the dies, and die supports made of a conductive material and respectively disposed at both ends of the dies in an axial direction. A cavity to be formed by the dies and the punches is filled with the rare earth iron-based magnet powder. The dies include an inner die made of a non-conductive material and an outer die made of a conductive material and disposed outside the inner die, inner peripheral surfaces of the die supports are in contact with an outer peripheral surface of the outer die, and the electrodes are in contact with the die supports.