公开(公告)号：US20190080827A1

公开(公告)日：2019-03-14

申请号：US16123534

申请日：2018-09-06

Applicant: TDK CORPORATION

Inventor： Tetsuya Hidaka ,  Hidetake Kitaoka ,  Eiji Kato

IPC: H01F1/057 ,  H01F7/02

Abstract: Provided is an R-T-B based permanent magnet including main phase grains including an R2T14B compound and a grain boundary. R is one or more rare earth elements essentially including Nd, T is Fe or Fe and Co and B is boron. the R-T-B based permanent magnet further includes X, Z and M. X is one or more selected from Ti, V, Zr, Nb, Hf and Ta, Z is one or more selected from C and N, M essentially includes Ga and further includes one or more selected from Al, Si, Ge, Cu, Bi and Sn. The grain boundary includes an XZ phase having a face-centered cubic structure.

公开(公告)号：US09514869B2

公开(公告)日：2016-12-06

申请号：US14378432

申请日：2013-02-13

Applicant: TDK CORPORATION

Inventor： Masashi Miwa ,  Haruna Nakajima ,  Ken-ichi Nishikawa ,  Tetsuya Hidaka ,  Jun Hagiwara ,  Chikara Ishizaka

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

CPC classification number: H01F1/057 ,  B22F3/10 ,  C22C38/00 ,  C22C38/002 ,  C22C38/005 ,  C22C38/06 ,  C22C38/10 ,  C22C38/14 ,  C22C38/16 ,  H01F1/0577 ,  H01F7/02

Abstract: The present invention provides an R-T-B based sintered magnet including R2T14B crystal grains wherein; a grain boundary is formed by two or more adjacent R2T14B crystal grains, an R—O—C concentrated part, in which concentrations of R, O and C are higher than those in the R2T14B crystal grains respectively, is in the grain boundary, and an area of the R—O—C concentrated part occupying in that of the grain boundary on a cut surface of the R-T-B based sintered magnet is within a range of 10% or more to 75% or less.

Abstract translation: 本发明提供一种包含R2T14B晶粒的R-T-B系烧结磁体，其中： 晶界由两个或更多个相邻的R2T14B晶粒形成，其中R，O和C的浓度分别高于R2T14B晶粒中的R-O-C浓缩部分在晶界中，并且 在RTB型烧结磁体的切断面上占据晶界边界的R-O-C浓缩部分的面积在10％以上至75％以下的范围。

公开(公告)号：US10964463B2

公开(公告)日：2021-03-30

申请号：US15936752

申请日：2018-03-27

Applicant: TDK CORPORATION

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

IPC: H01F1/057 ,  H01F41/02 ,  B22F3/16 ,  B22F9/04 ,  C22C38/00

Abstract: Provided is an alloy for R-T-B based rare earth magnet. “R” is one or more of a rare earth element, ‘T’ is one or more of a transition metal element essentially including Fe or Fe and Co, and “B” is boron. The alloy includes a single or a plural number of main phase (A), having a minimum length of 10 μm or more and a maximum length of 30 μm or more and 300 μm or less, in a cross section cut along a thickness direction of the alloy. The main phase (A) includes an R2T14B phase, and an area ratio of the main phase (A) to an entire cross section is 2% or more and 60% or less.

公开(公告)号：US20150235750A1

公开(公告)日：2015-08-20

申请号：US14378428

申请日：2013-02-13

Applicant: TDK CORPORATION

Inventor： Masashi Miwa ,  Haruna Nakajima ,  Ken-ichi Nishikawa ,  Tetsuya Hidaka ,  Jun Hagiwara ,  Chikara Ishizaka

IPC: H01F7/02

CPC classification number: H01F7/021 ,  B22F1/0007 ,  B22F3/02 ,  B22F3/24 ,  B22F2003/248 ,  B22F2202/05 ,  B22F2999/00 ,  C22C33/0278 ,  C22C38/002 ,  C22C38/005 ,  C22C38/06 ,  C22C38/10 ,  C22C38/14 ,  C22C38/16 ,  H01F1/0577

Abstract: The present invention provides an R-T-B based sintered magnet including R2T14B crystal grains wherein; a grain boundary is formed by two or more adjacent R2T14B crystal grains, an R—O—C concentrated part, in which concentrations of R, O and C are higher than those in the R2T14B crystal grains respectively, is in the grain boundary, and a ratio (O/R) of O atom to R atom in the R—O—C concentrated part satisfies the following formula (1): 0.4

Abstract translation: 本发明提供一种包含R2T14B晶粒的R-T-B系烧结磁体，其中： 晶界由两个或更多个相邻的R2T14B晶粒形成，其中R，O和C的浓度分别高于R2T14B晶粒中的R-O-C浓缩部分在晶界中，并且 R-O-C浓缩部分中的O原子与R原子的比率（O / R）满足下式（1）：0.4 <（O / R）<0.7。