公开(公告)号：US10991492B2

公开(公告)日：2021-04-27

申请号：US16823487

申请日：2020-03-19

申请人： TDK CORPORATION

发明人： Mariko Fujiwara ,  Makoto Iwasaki

IPC分类号： C22C38/16 ,  C22C38/14 ,  C22C38/10 ,  C22C38/00 ,  C22C38/06 ,  H01F1/057 ,  B22F3/24

摘要： The present invention provides an R-T-B based permanent magnet capable of improving a coercive force HcJ while maintaining a residual magnetic flux density Br.
The R-T-B based permanent magnet includes Ga. R is one or more selected from rare earth elements, T is Fe or a combination of Fe and Co, and B is boron. The R-T-B based permanent magnet has main phase grains including a crystal grain having an R2T14B crystal structure and grain boundaries formed between adjacent two or more main phase grains, and 0.030≤[Ga]/[R]≤0.100 is satisfied in which [Ga] represents an atomic concentration of Ga and [R] represents an atomic concentration of R in the main phase grains.

公开(公告)号：US10242777B2

公开(公告)日：2019-03-26

申请号：US15420151

申请日：2017-01-31

申请人： TDK Corporation

发明人： Makoto Iwasaki ,  Tetsuya Hidaka ,  Takuma Hayakawa ,  Ayato Kakoki ,  Yoshinori Fujikawa ,  Syota Goto ,  Haruna Nakajima ,  Takeshi Masuda ,  Chikara Ishizaka

IPC分类号： H01F1/055 ,  B22F1/00 ,  B22F3/10 ,  B22F9/02 ,  C22C38/00 ,  C22C38/06 ,  C22C38/10 ,  C22C38/14 ,  C22C38/16 ,  H01F1/057 ,  H01F41/02 ,  B22F9/04 ,  C22C33/02

摘要： Provided is a sintered magnet that is an R-T-B based sintered magnet having a region having a concentration of at least one heavy rare earth element decreasing from the surface toward the inside, in which the at least one heavy rare earth element includes at least either of Tb or Dy, R includes Nd, T includes Fe, Co, and Cu, there is a grain boundary phase containing at least either of Tb or Dy and Nd between two main phase particles, and a value obtained by subtracting a half value width of a concentration distribution curve of Cu from a half value width of a concentration distribution curve of Tb or Dy in a part including the grain boundary phase is from 10 to 20 nm.

公开(公告)号：US10026532B2

公开(公告)日：2018-07-17

申请号：US15285113

申请日：2016-10-04

申请人： TDK CORPORATION

发明人： Tetsuya Hidaka ,  Takuma Hayakawa ,  Makoto Iwasaki ,  Ayato Kakoki

IPC分类号： H01F1/00 ,  H01F1/057 ,  C22C38/00 ,  C22C38/04 ,  C22C38/06 ,  C22C38/10 ,  C22C38/14 ,  C22C38/16 ,  H01F1/058 ,  H01F41/02

摘要： An R-T-B based sintered magnet includes “R”, “T”, and “B”. “R” represents a rare earth element. “T” represents a metal element other than rare earth elements including at least Fe, Cu, Mn, Al, Co, Ga, and Zr. “B” represents boron or boron and carbon. With respect to 100 mass % of a total mass of the R-T-B based sintered magnet, a content of “R” is 28.0 to 31.5 mass %, a content of Cu is 0.04 to 0.50 mass %, a content of Mn is 0.02 to 0.10 mass %, a content of Al is 0.15 to 0.30 mass %, a content of Co is 0.50 to 3.0 mass %, a content of Ga is 0.08 to 0.30 mass %, a content of Zr is 0.10 to 0.25 mass %, and a content of “B” is 0.85 to 1.0 mass %.

公开(公告)号：US11244778B2

公开(公告)日：2022-02-08

申请号：US16822772

申请日：2020-03-18

申请人： TDK CORPORATION

发明人： Makoto Iwasaki ,  Akihiro Harada

IPC分类号： H01F1/057 ,  C22C30/02

摘要： An R-T-B based permanent magnet wherein R is one or more rare earth elements, T is Fe and Co, and B is boron. The R-T-B based permanent magnet includes M, C and N, wherein M is two or more selected from Cu, Ga, Mn, Zr, and Al, and includes at least Cu and Ga. A total content of R is ≥29.0 and ≤33.5 mass %, Co content is ≥0.10 and ≤0.49 mass %, B content is ≥0.80 and ≤0.96 mass %, a total content of M is ≥0.63 and ≤4.00 mass %, Cu content is ≥0.51 and ≤0.97 mass %, Ga content is ≥0.12 and ≤1.07 mass %, C content is ≥0.065 and ≤0.200 mass %, N content is ≥0.023 and ≤0.323 mass %, and Fe is a substantial balance.

公开(公告)号：US10825589B2

公开(公告)日：2020-11-03

申请号：US15928378

申请日：2018-03-22

申请人： TDK CORPORATION

发明人： Makoto Iwasaki ,  Tetsuya Hidaka ,  Eiji Kato ,  Takuma Hayakawa ,  Hidetake Kitaoka

IPC分类号： H01F1/057 ,  C22C38/16 ,  C22C38/14 ,  C22C38/10 ,  C22C38/06 ,  C22C38/04 ,  C22C38/00 ,  C22C30/02 ,  B22F9/04 ,  B22F9/02 ,  B22F3/26 ,  B22F1/00 ,  B22F3/24

摘要： Provided is an R-T-B based rare earth magnet. R is one or more rare earth elements, T is one or more transition metal elements essentially including Fe or Fe and Co, and B is boron. B content with respect to a total R-T-B based rare earth magnet is 0.80 mass % or more and 0.98 mass % or less. The R-T-B based rare earth magnet includes an R1T4B4 phase.

公开(公告)号：US20200321151A1

公开(公告)日：2020-10-08

申请号：US16909351

申请日：2020-06-23

申请人： TDK Corporation

发明人： Ayato Kakoki ,  Makoto Iwasaki ,  Tetsuya Hidaka ,  Takuma Hayakawa

IPC分类号： H01F1/057 ,  H01F41/02 ,  C22C38/00 ,  C22C38/06 ,  C22C38/16 ,  C22C38/14 ,  C22C38/10 ,  B22F3/16 ,  B22F9/04 ,  C22C28/00 ,  C22C30/02

摘要： An R-T-B based sintered magnet containing a first heavy rare earth element, in which R includes Nd, T includes Co and Fe, the first heavy rare earth element includes Tb or Dy, the R-T-B based sintered magnet has a region in which a concentration of the first heavy rare earth element decreases from the surface toward the inside, a first grain boundary phase which contains the first heavy rare earth element and Nd but does not contain Co is present in one cross section including the region, and an area occupied by the first grain boundary phase in one cross section including the region is 1.8% or less.

公开(公告)号：US10726983B2

公开(公告)日：2020-07-28

申请号：US15439975

申请日：2017-02-23

申请人： TDK Corporation

发明人： Jun Hagiwara ,  Fumitaka Baba ,  Makoto Iwasaki ,  Satoshi Koga

IPC分类号： H02K1/00 ,  H01F7/02 ,  H02K1/04

摘要： A rare earth magnet capable of reducing an eddy current loss by virtue of a low-cost, simple configuration, when mounted in a motor, is to be provided. The rare earth magnet can include a magnet body that includes a rare earth element and iron; and a resistive layer formed on at least one surface of the magnet body, the resistive layer comprising a rare earth element, iron, and oxygen and having an average volume resistivity of 103 Ωcm or more and a thickness of from 3 to 25 μm.

公开(公告)号：US10530232B2

公开(公告)日：2020-01-07

申请号：US15607993

申请日：2017-05-30

申请人： TDK CORPORATION

发明人： Eiji Kato ,  Makoto Iwasaki

IPC分类号： H02K41/03 ,  H02K1/02 ,  H02K1/27 ,  H02K1/16

摘要： A motor includes a magnet and a coil. α2=[{(Br2−Br1)/Br1}/(T2−T1)]×100≥0.11 and α3=[{(Br3−Br1)/Br1}/(T3−T1)]×100≤0.13 are satisfied. In the magnet, Br1 (mT) is a residual magnetic flux density at T1 (° C.), Br2 (mT) is a residual magnetic flux density at T2 (° C.), and Br3 (mT) is a residual magnetic flux density at T3 (° C.), and α2 (%/° C.) is a temperature coefficient at a target temperature of T2 (° C.) with respect to a reference temperature of T1 (° C.), and α3 (%/° C.) is a temperature coefficient at a target temperature of T3 (° C.) with respect to a reference temperature of T1 (° C.) in conditions of T1=20, T2=100, and T3=220.

公开(公告)号：US09991035B2

公开(公告)日：2018-06-05

申请号：US15285113

申请日：2016-10-04

申请人： TDK CORPORATION

发明人： Tetsuya Hidaka ,  Takuma Hayakawa ,  Makoto Iwasaki ,  Ayato Kakoki

IPC分类号： H01F1/00 ,  H01F1/057 ,  C22C38/00 ,  C22C38/04 ,  C22C38/06 ,  C22C38/10 ,  C22C38/14 ,  C22C38/16 ,  H01F1/058 ,  H01F41/02

摘要： An R-T-B based sintered magnet includes “R”, “T”, and “B”. “R” represents a rare earth element. “T” represents a metal element other than rare earth elements including at least Fe, Cu, Mn, Al, Co, Ga, and Zr. “B” represents boron or boron and carbon. With respect to 100 mass % of a total mass of the R-T-B based sintered magnet, a content of “R” is 28.0 to 31.5 mass %, a content of Cu is 0.04 to 0.50 mass %, a content of Mn is 0.02 to 0.10 mass %, a content of Al is 0.15 to 0.30 mass %, a content of Co is 0.50 to 3.0 mass %, a content of Ga is 0.08 to 0.30 mass %, a content of Zr is 0.10 to 0.25 mass %, and a content of “B” is 0.85 to 1.0 mass %.