公开(公告)号：US11043320B2

公开(公告)日：2021-06-22

申请号：US15915901

申请日：2018-03-08

申请人： TDK CORPORATION

发明人： Masahiro Kamiya ,  Yasuhide Yamashita ,  Chiomi Sato ,  Yousuke Futamata ,  Ryoma Nakazawa ,  Takeshi Takahashi ,  Hiroyuki Ono

IPC分类号： H01F1/24 ,  H01F1/33 ,  H01F3/08 ,  B22F1/02 ,  H01F41/02 ,  C22C38/02 ,  H01F1/26

摘要： A dust core includes a metal magnetic material, a resin, and an insulation film. The insulation film contacts with a surface of the metal magnetic material and covers the metal magnetic material. The insulation film includes a first film and a second film. The first film contacts with the surface of the metal magnetic material. The second film contacts with a surface of the first film. A density of the first film is higher than a density of the second film.

公开(公告)号：US10109403B2

公开(公告)日：2018-10-23

申请号：US14909563

申请日：2014-08-08

申请人： TDK CORPORATION

发明人： Isao Kanada ,  Hiroyuki Ono ,  Eiji Kato ,  Masashi Miwa

IPC分类号： H01F1/057 ,  H01F1/055 ,  C22C38/00 ,  C22C38/06 ,  C22C38/10 ,  C22C38/16 ,  H02K1/02 ,  H01F41/02

摘要： The present invention provides an R-T-B based sintered magnet that inhibits the demagnetization rate at high temperature even when less or no heavy rare earth elements such as Dy, Tb and the like are used. The R-T-B based sintered magnet comprises R2T14B crystal grains and two-grain boundary parts between the R2T14B crystal grains. Two-grain boundary parts formed by a phase containing R, Cu, Co, Ga and Fe with a ratio of 40≤R≤70, 1≤Co≤10, 5≤Cu≤50, 1≤Ga≤15, and 1≤Fe≤40 (wherein, R+Cu+Co+Ga+Fe=100, and R is at least one selected from rare earth elements) exists in the magnet.

公开(公告)号：US11996220B2

公开(公告)日：2024-05-28

申请号：US17879862

申请日：2022-08-03

申请人： TDK CORPORATION

发明人： Katsushi Yasuhara ,  Ryoma Nakazawa ,  Yusuke Taniguchi ,  Hiroyuki Ono

IPC分类号： H01F1/147 ,  B22F1/052 ,  C22C38/02 ,  H01F1/20 ,  H01F3/08 ,  H01F5/00 ,  H01F27/255 ,  H01F27/28

CPC分类号： H01F1/14766 ,  B22F1/052 ,  C22C38/02 ,  H01F1/20 ,  H01F3/08 ,  H01F5/00 ,  H01F27/255 ,  H01F27/28 ,  C22C2202/02

摘要： A soft magnetic alloy powder contains soft magnetic alloy particles. The soft magnetic alloy particles contain Fe and Si. The soft magnetic alloy particles each include crystal grains and crystal grain boundary between the crystal grains. At least one of the crystal grains has a Si segregation part.

公开(公告)号：US11450458B2

公开(公告)日：2022-09-20

申请号：US16282619

申请日：2019-02-22

申请人： TDK Corporation

发明人： Junnichi Nagaoka ,  Hiroyuki Ono ,  Yuichi Sugawara

IPC分类号： H01F1/11 ,  C04B35/26 ,  C04B35/64 ,  H01F1/10 ,  H02K1/02

摘要： Provided is a ferrite sintered magnet including a main phase formed of ferrite having a hexagonal magnetoplumbite type crystalline structure, in which the main phase contains Fe and Co, and the ferrite sintered magnet contains CaB2O4. CaB2O4 is contained in a heterophase that is a crystalline phase different from the main phase, and an area ratio of CaB2O4 to the entire cross-sectional surface of a sintered magnet, is less than or equal to 2%.

公开(公告)号：US11380466B2

公开(公告)日：2022-07-05

申请号：US16295156

申请日：2019-03-07

申请人： TDK Corporation

发明人： Hiroyuki Morita ,  Masanori Ikeda ,  Yoshitaka Murakawa ,  Hiroyuki Ono ,  Taku Murase

IPC分类号： H01F1/11 ,  H01F1/03 ,  H01F1/053 ,  C04B35/26 ,  H01F1/10

摘要： The present invention provides a ferrite sintered magnet comprising (1) main phase grains containing a ferrite having a hexagonal structure, (2) two-grain boundaries formed between two of the main phase grains, and (3) multi-grain boundaries surrounded by three or more of the main phase grains. The above ferrite sintered magnet comprises Ca, R, Sr, Fe and Co, with R being at least one element selected from the group consisting of rare earth elements and Bi, and comprising at least La. The number Nm of the above main phase grains and the number Ng of the above multi-grain boundaries in the cross section including the direction of the easy magnetization axis of the above ferrite sintered magnet satisfy the formula (1A): 50%≤Nm/(Nm+Ng)≤65%  (1A).

公开(公告)号：US11205533B2

公开(公告)日：2021-12-21

申请号：US16282466

申请日：2019-02-22

申请人： TDK Corporation

发明人： Junnichi Nagaoka ,  Hiroyuki Ono ,  Yuichi Sugawara

IPC分类号： H01F1/11 ,  H01F41/02 ,  C04B35/26 ,  H01F3/08 ,  H02K1/17 ,  H02K1/02

摘要： A ferrite sintered magnet contains a main phase formed of ferrite having a hexagonal magnetoplumbite type crystalline structure; a first subphase containing La, Ca, and Fe, in which an atomic ratio of La is higher than that of the main phase, and the atomic ratio of La is higher than an atomic ratio of Ca; and a second subphase containing La, Ca, Si, B, and Fe, in which an atomic ratio of Ca is higher than an atomic ratio of La, an atomic ratio of B is higher than an atomic ratio of Fe, and the atomic ratio of Fe is lower than that of the main phase. An area ratio of the second subphase on a cross-sectional surface of the ferrite sintered magnet is greater than or equal to 1%.

公开(公告)号：US10388441B2

公开(公告)日：2019-08-20

申请号：US14909606

申请日：2014-08-08

申请人： TDK CORPORATION

发明人： Isao Kanada ,  Hiroyuki Ono ,  Eiji Kato ,  Masashi Miwa

IPC分类号： H01F1/055 ,  C22C38/00 ,  C22C38/02 ,  C22C38/06 ,  C22C38/10 ,  C22C38/14 ,  C22C38/16 ,  H01F1/057

摘要： The present invention provides an R-T-B based sintered magnet that inhibits the demagnetization rate at high temperature even when less or no heavy rare earth elements such as Dy, Tb and the like are used. The R-T-B based sintered magnet includes R2T14B crystal grains and two-grain boundary parts between the R2T14B crystal grains. Two-grain boundary parts formed by R—Co—Cu-M-Fe phase exist, and M is at least one selected from the group consisting of Ga, Si, Sn, Ge and Bi.