公开(公告)号：US09997284B2

公开(公告)日：2018-06-12

申请号：US14409186

申请日：2013-06-21

Applicant: TDK Corporation

Inventor： Masashi Miwa ,  Atsushi Fujiwara ,  Eiji Kato ,  Taeko Tsubokura ,  Koji Mitake ,  Chikara Ishizaka

IPC: H01F1/057 ,  C22C38/00 ,  C22C38/06 ,  C22C38/10 ,  C22C38/14 ,  C22C38/16 ,  B22F3/10 ,  H01F7/02

CPC classification number: H01F1/0577 ,  B22F3/10 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/06 ,  C22C38/10 ,  C22C38/14 ,  C22C38/16 ,  H01F7/02

Abstract: A sintered magnet of a preferred embodiment has a composition comprising: R (R is a rare earth element that must contain any one of Nd and Pr.): 29.5 to 33.0 mass %; B: 0.7 to 0.95 mass %; Al: 0.03 to 0.6 mass %; Cu: 0.01 to 1.5 mass %; Co: 3.0 mass % or less (provided that 0 mass % is not included.); Ga: 0.1 to 1.0 mass %; C: 0.05 to 0.3 mass %; O: 0.03 to 0.4 mass %; and Fe and other elements: a balance, and wherein a content of heavy rare earth elements in total is 1.0 mass % or less, and wherein the following relations are satisfied: 0.29

公开(公告)号：US09607742B2

公开(公告)日：2017-03-28

申请号：US14351119

申请日：2012-10-11

Applicant: TDK CORPORATION

Inventor： Tamotsu Ishiyama ,  Taeko Tsubokura ,  Eiji Kato ,  Nobuhiro Jingu ,  Chikara Ishizaka

IPC: C22C33/02 ,  C22C38/10 ,  B22D11/06 ,  H01F1/053 ,  H01F1/057 ,  H01F1/08 ,  H01F41/02 ,  C22C38/00 ,  C22C38/06 ,  C22C38/14 ,  C22C38/16

CPC classification number: H01F1/053 ,  B22D11/0611 ,  C22C33/02 ,  C22C38/002 ,  C22C38/005 ,  C22C38/06 ,  C22C38/10 ,  C22C38/14 ,  C22C38/16 ,  C22C2202/02 ,  H01F1/0536 ,  H01F1/0571 ,  H01F1/0577 ,  H01F1/086 ,  H01F41/0266

Abstract: An R-T-B based alloy strip containing dendritic crystals including a R2T14B phase, wherein on at least one surface, the average value for the widths of the dendritic crystals is no greater than 60 μm, and the number of crystal nuclei in the dendritic crystals is at least 500 per 1 mm square area.