公开(公告)号：US20170076846A1

公开(公告)日：2017-03-16

申请号：US15258589

申请日：2016-09-07

Applicant: TDK CORPORATION

Inventor： Naoto TSUKAMOTO ,  Hiroshi MIYASAKA ,  Makoto IWASAKI ,  Takahiro KAWASHIMA ,  Chikara ISHIZAKA

IPC: H01F7/02 ,  H02K1/02

Abstract: An R-T-B based sintered magnet includes a first main surface and a first side surface. The first main surface has a coercivity that is higher than that of the first side surface. ΔHcjM≦60 kA/m is satisfied, where ΔHcjM is a difference in coercivity between a portion having a highest coercivity on the first main surface and a portion having a lowest coercivity on the first main surface. ΔHcjG≦60 kA/m is satisfied, where ΔHcjG is a difference in coercivity between a portion having a highest coercivity on a first cross section and a portion having a lowest coercivity on the first cross section and the first cross section is a cross section parallel to the first main surface and spaced from the first main surface at a predetermined length or more.

Abstract translation: R-T-B系烧结磁体包括第一主表面和第一侧表面。 第一主表面的矫顽力高于第一侧表面的矫顽力。 ΔHcjM≤60kA/ m，其中ΔHcjM是第一主表面具有最高矫顽力的部分与第一主表面具有最低矫顽力的部分之间的矫顽力差。 ΔHcjG≤60kA/ m，其中ΔHcjG是在第一横截面上具有最高矫顽力的部分与第一横截面具有最低矫顽力的部分之间的矫顽力的差异与第一横截面是横截面平行 到第一主表面并且以预定长度或更长的距离与第一主表面间隔开。

公开(公告)号：US20190255618A1

公开(公告)日：2019-08-22

申请号：US16278876

申请日：2019-02-19

Applicant: TDK Corporation

Inventor： Takeshi MASUDA ,  Taeko TSUBOKURA ,  Hiroshi MIYASAKA ,  Yutaka HATAKEYAMA ,  Toshihiro KUROSHIMA

IPC: B22F3/24 ,  H01F41/02 ,  H01F1/08 ,  C22C30/02 ,  B22F3/16

Abstract: A method of processing a rare earth magnet comprises: a step of irradiating an R-T-B-based rare earth magnet with laser light to process; and a step of performing heat treatment on the magnet after the irradiating. The heat treatment includes: a step A of bringing the temperature of the magnet to 400° C. or less, a step B of holding the magnet at a temperature T1 in a range of 400 to 700° C. after the step A, and a step C of bringing the temperature of the magnet to less than 400° C. after the step B. The temperature of the magnet is made not to exceed 700° C. between the step A and the step B. The temperature of the magnet is made not to exceed 700° C. between the step B and the step C. A step of setting the magnet at a temperature higher than 700° C. after the step C is not included.