公开(公告)号：US08907755B2

公开(公告)日：2014-12-09

申请号：US13835754

申请日：2013-03-15

Applicant: Toda Kogyo Corp.

Inventor： Nobuhiro Katayama ,  Hirofumi Kawasaki ,  Koichiro Morimoto

IPC: H01F7/02 ,  H01F1/00 ,  H01F1/057 ,  H01F1/01 ,  H01F41/00

CPC classification number: H01F7/02 ,  B22F1/0085 ,  B22F2999/00 ,  C22C33/02 ,  C22C38/002 ,  C22C38/005 ,  C22C38/06 ,  C22C38/10 ,  C22C38/14 ,  C22C2202/02 ,  H01F1/01 ,  H01F1/0573 ,  H01F1/0578 ,  H01F41/005 ,  B22F2201/013 ,  B22F2203/11

Abstract: R-T-B-based rare earth magnet particles are produced by an HDDR treatment which comprises a first stage HD step of heating particles of a raw material alloy having a composition of R, B and Co in an inert atmosphere or in a vacuum atmosphere and then replacing the atmosphere with a hydrogen-containing gas atmosphere in which the raw material alloy particles are held in the same temperature range and a second stage HD step of heating a material obtained in the first stage HD step in which the material is held in the hydrogen-containing gas atmosphere.

Abstract translation: 通过HDDR处理生产RTB型稀土磁体颗粒，其包括在惰性气氛或真空气氛中加热具有R，B和Co组成的原料合金的颗粒的第一阶段HD步骤，然后将 含有原料合金颗粒保持在相同温度范围的含氢气体气氛的气氛，以及第二阶段HD步骤，将在第一阶段HD步骤中获得的材料加热，其中所述材料保持在含氢气体 气体气氛。

公开(公告)号：US11120932B2

公开(公告)日：2021-09-14

申请号：US14205894

申请日：2014-03-12

Applicant: TODA KOGYO CORP.

Inventor： Nobuhiro Katayama ,  Hirofumi Kawasaki ,  Koichiro Morimoto

IPC: H01F1/057 ,  C21D6/00 ,  B22F9/04 ,  C22C38/06 ,  C22C33/02 ,  C22C38/00 ,  C22C38/10 ,  C22C38/14

Abstract: An object of the present invention is to enhance a coercive force of magnetic particles by promoting formation of a continuous R-rich grain boundary phase in a crystal grain boundary of a magnetic phase of the particles, and to thereby obtain R-T-B-based rare earth magnet particles further having a high residual magnetic flux density. The present invention relates to production of R-T-B-based rare earth magnet particles capable of exhibiting a high coercive force even when a content of Al therein is reduced, and a high residual magnetic flux density, in which formation of an R-rich grain boundary phase therein can be promoted by heat-treating Al-containing R-T-B-based rare earth magnet particles obtained by HDDR treatment in vacuum or in an Ar atmosphere at a temperature of not lower than 670° C. and not higher than 820° C. for a period of not less than 30 min and not more than 300 min.

公开(公告)号：US11688534B2

公开(公告)日：2023-06-27

申请号：US15010539

申请日：2016-01-29

Applicant: TODA KOGYO CORP.

Inventor： Shohei Kaneko ,  Kuniyoshi Shigeoka ,  Nobuhiro Katayama ,  Koichiro Morimoto

IPC: H01F1/08 ,  B22F9/02 ,  H01F1/053 ,  C22C38/14 ,  C22C38/10 ,  C22C38/06 ,  C22C38/00 ,  H01F1/057

CPC classification number: H01F1/083 ,  B22F9/023 ,  C22C38/002 ,  C22C38/005 ,  C22C38/06 ,  C22C38/10 ,  C22C38/14 ,  H01F1/0573 ,  B22F2201/013 ,  B22F2203/13 ,  B22F2301/355 ,  B22F2998/10 ,  C22C2202/02 ,  H01F1/0572 ,  H01F1/0578

Abstract: A process for producing R-T-B-based rare earth magnet powder having excellent coercive force and high remanent flux density. A process for producing R-T-B-based rare earth magnet powder by HDDR treatment, in which a raw material alloy for the R-T-B-based rare earth magnet powder includes R (wherein R represents at least one rare earth element including Y), T (wherein T represents Fe, or Fe and Co) and B (wherein B represents boron), and has a composition including R in an amount of between 12.0 atom % and 17.0 atom %, and B in an amount of between 4.5 atom % and 7.5 atom %; the HDDR treatment includes a DR step including a preliminary evacuation step and a complete evacuation step; and a rate of pressure reduction caused by evacuation in the preliminary evacuation step is not less than 1 kPa/min and not more than 30 kPa/min.