公开(公告)号：US20240047103A1

公开(公告)日：2024-02-08

申请号：US18266080

申请日：2021-11-10

Applicant: TDK CORPORATION

Inventor： Hikaru KUDO ,  Atsushi KODA ,  Takahiro SUWA

IPC: H01F1/057 ,  H01F1/053 ,  H01F41/02

CPC classification number: H01F1/0577 ,  H01F1/0536 ,  H01F41/0266

Abstract: An R-T-B-based permanent magnet including: R (rare earth element); T (Fe and Co); B (boron); and one or more selected from Al, Cu, Ga, and Zr. R includes Ce. The total R content is 31.3-34.0 mass % (inclusive), the Co content is 1.85-3.00 mass % (inclusive), the B content is 0.80-0.90 mass % (inclusive), the Al content is 0.03-0.90 mass % (inclusive), the Cu content is 0-0.25 mass % (inclusive), the Ga content is 0-0.10 mass % (inclusive), the Zr content is 0-0.60 mass % (inclusive), and the Fe content is substantially the remainder. The Ce content relative to R is 15-25 mass % (inclusive).

公开(公告)号：US20240038420A1

公开(公告)日：2024-02-01

申请号：US18266168

申请日：2021-11-10

Applicant: TDK CORPORATION

Inventor： Atsushi KODA ,  Takahiro SUWA ,  Hikaru KUDO

IPC: H01F1/057 ,  C22C38/16 ,  C22C38/14 ,  C22C38/10 ,  C22C38/06 ,  C22C38/00 ,  B22F9/02 ,  B22F9/04 ,  B22F3/24 ,  B22F3/16

CPC classification number: H01F1/0577 ,  C22C38/16 ,  C22C38/14 ,  C22C38/10 ,  C22C38/06 ,  C22C38/005 ,  C22C38/002 ,  B22F9/023 ,  B22F9/04 ,  B22F3/24 ,  B22F3/16 ,  B22F2999/00 ,  B22F2998/10 ,  B22F2301/355 ,  B22F2201/11 ,  B22F2201/02 ,  B22F2009/044 ,  B22F2202/05 ,  B22F2201/20 ,  B22F2003/248 ,  C22C2202/02

Abstract: An R-T-B permanent magnet that contains: main-phase grains composed of an R2T14B compound (where R is a rare earth element, T is a transition metal element, and B is boron); and grain boundaries. R includes Ce. The R-T-B permanent magnet has a Ce content of 15-35 mass % with respect to the total R content. The grain boundaries include an R-rich phase and an R-T phase. In a cross section of the R-T-B permanent magnet, the surface area ratio S(R-T) of the R-T phases with respect to the grain boundaries is 0.60-0.85.

公开(公告)号：US20240212896A1

公开(公告)日：2024-06-27

申请号：US18394227

申请日：2023-12-22

Applicant: TDK CORPORATION

Inventor： Atsushi KODA

IPC: H01F1/057 ,  H01F7/02

CPC classification number: H01F1/0577 ,  H01F7/02

Abstract: An R-T-B based permanent magnet includes rare earth elements, transition metal elements, boron, and M. An amount of boron is within a range between 0.90 mass % or more and 1.00 mass % or less. An amount of carbon is within a range between 0 mass % or more and 0.10 mass % or less, an amount of oxygen is within a range between 0 mass % or more and 0.15 mass % or less, an amount of nitrogen is within a range between 0 mass % or more and 0.15 mass % or less, an amount of M is within a range between 0.30 mass % or more and 1.50 mass % or less, an amount of the rare earth elements based on mass represented by TRE is within a range between 29.00 mass % or more and 31.00 mass % or less, and a value represented by Pr/TRE is within a range between 0.30 or larger and 0.50 or smaller.

公开(公告)号：US20240105368A1

公开(公告)日：2024-03-28

申请号：US18266007

申请日：2021-11-10

Applicant: TDK CORPORATION

Inventor： Atsushi KODA ,  Takahiro SUWA ,  Hikaru KUDO

IPC: H01F1/057 ,  B22F3/16 ,  B22F3/24 ,  B22F9/02 ,  B22F9/04 ,  C22C38/00 ,  C22C38/06 ,  C22C38/10 ,  C22C38/14 ,  C22C38/16

CPC classification number: H01F1/0571 ,  B22F3/16 ,  B22F3/24 ,  B22F9/023 ,  B22F9/04 ,  C22C38/002 ,  C22C38/005 ,  C22C38/06 ,  C22C38/10 ,  C22C38/14 ,  C22C38/16 ,  B22F2003/248 ,  B22F2009/044 ,  B22F2201/02 ,  B22F2202/05 ,  B22F2301/355 ,  B22F2304/10 ,  B22F2998/10 ,  B22F2999/00

Abstract: An R-T-B permanent magnet that contains: main-phase grains composed of an R2T14B compound (where R is a rare earth element, T is a transition metal element, and B is boron); and grain boundaries. R includes Ce. The grain boundaries include multi-grain grain boundaries that are adjacent to three or more main-phase grains. The multi-grain grain boundaries include an R-rich phase, and lamellar or acicular R-T precipitates are present in the R-rich phase.

公开(公告)号：US20230025223A1

公开(公告)日：2023-01-26

申请号：US17779619

申请日：2020-11-26

Applicant: TDK CORPORATION

Inventor： Yoshinori FUJIKAWA ,  Atsushi KODA ,  Mika JINGU ,  Takashi WATANABE

IPC: H01F1/057 ,  C22C38/00

Abstract: An R-T-B based permanent magnet including R2T14B main phase crystal grains and a grain boundary. R represents one or more rare earth elements, T represents one or more iron group elements essentially including Fe or Fe and Co, and B represents boron. In a cross-section parallel to the alignment direction of the R-T-B based permanent magnet, the coverage of the R2T14B main phase crystal grains is 50.0% or more, and the area ratio of the R2T14B main phase crystal grains is 92.0% or more.