公开(公告)号：US20140290803A1

公开(公告)日：2014-10-02

申请号：US14228808

申请日：2014-03-28

Applicant: TDK CORPORATION

Inventor： Eiji KATO ,  Yoshinori FUJIKAWA ,  Taeko TSUBOKURA ,  Chikara ISHIZAKA ,  Katsuo SATO

IPC: H01F1/153 ,  H01F1/053

CPC classification number: H01F1/0577 ,  H01F41/0273

Abstract: The present invention provides a rare earth based magnet including R2T14B main-phase crystal grains, and two-grain boundary phases between adjacent two R2T14B main-phase crystal grains, the two-grain boundary phases are controlled such that the thickness thereof is 5 nm or more and 500 nm or less, and it is composed of a phase with a magnetism different from that of a ferromagnet.

Abstract translation: 本发明提供一种包含R2T14B主相晶粒和相邻的两个R2T14B主相晶粒之间的双晶界相的稀土类磁体，控制两晶界相的厚度为5nm， 多于500nm或更小，并且由具有与铁磁体不同的磁性的相组成。

公开(公告)号：US20170346432A1

公开(公告)日：2017-11-30

申请号：US15608067

申请日：2017-05-30

Applicant: TDK CORPORATION

Inventor： Makoto IWASAKI ,  Fumitaka BABA ,  Chikara ISHIZAKA

IPC: H02P21/22 ,  H02P6/08 ,  H02K41/03 ,  H02P27/04 ,  H02K1/27

Abstract: A motor includes a magnet and a coil. α2=[{(Br2−Br1)/Br1}/(T2−T1)]×100≧−0.10 and α3=[{(Br3−Br1)/Br1}/(T3−T1)]×100≦−0.12 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=23, T2=60, and T3=180.

公开(公告)号：US20170076846A1

公开(公告)日：2017-03-16

申请号：US15258589

申请日：2016-09-07

Applicant: TDK CORPORATION

Inventor： Naoto TSUKAMOTO ,  Hiroshi MIYASAKA ,  Makoto IWASAKI ,  Takahiro KAWASHIMA ,  Chikara ISHIZAKA

IPC: H01F7/02 ,  H02K1/02

Abstract: An R-T-B based sintered magnet includes a first main surface and a first side surface. The first main surface has a coercivity that is higher than that of the first side surface. ΔHcjM≦60 kA/m is satisfied, where ΔHcjM is a difference in coercivity between a portion having a highest coercivity on the first main surface and a portion having a lowest coercivity on the first main surface. ΔHcjG≦60 kA/m is satisfied, where ΔHcjG is a difference in coercivity between a portion having a highest coercivity on a first cross section and a portion having a lowest coercivity on the first cross section and the first cross section is a cross section parallel to the first main surface and spaced from the first main surface at a predetermined length or more.

Abstract translation: R-T-B系烧结磁体包括第一主表面和第一侧表面。 第一主表面的矫顽力高于第一侧表面的矫顽力。 ΔHcjM≤60kA/ m，其中ΔHcjM是第一主表面具有最高矫顽力的部分与第一主表面具有最低矫顽力的部分之间的矫顽力差。 ΔHcjG≤60kA/ m，其中ΔHcjG是在第一横截面上具有最高矫顽力的部分与第一横截面具有最低矫顽力的部分之间的矫顽力的差异与第一横截面是横截面平行 到第一主表面并且以预定长度或更长的距离与第一主表面间隔开。

公开(公告)号：US20140292454A1

公开(公告)日：2014-10-02

申请号：US14229296

申请日：2014-03-28

Applicant: TDK CORPORATION

Inventor： Eiji KATO ,  Yoshinori FUJIKAWA ,  Taeko TSUBOKURA ,  Chikara ISHIZAKA ,  Katsuo SATO

IPC: H01F1/057

CPC classification number: H01F1/0571 ,  H01F1/0577

Abstract: The present invention provides a rare earth based magnet having a microstructure in which in a section of the R2T14B main-phase crystal grains, the number density of the fine products in the interior of (inside) the crystal grains is larger than that in the periphery of (outside) the crystal grains. That is, the rare earth based magnet includes R2T14B main-phase crystal grains and grain boundary phases formed between the R2T14B main-phase crystal grains. The R2T14B main-phase crystal grains include a substance where fine products are formed in the crystal grains. In the section of the main-phase crystal grains, when the crystal grains are divided into the interior of the crystal grains and the periphery of the crystal grains with a specific ellipse, the fine products are formed such that the number density in the interior is larger than that in the periphery.

Abstract translation: 本发明提供一种稀土类磁体，其具有微结构，其中在R2T14B主相晶粒的截面中，晶粒内部（内部）的细微产物的数量密度大于周边 （外）晶粒。 也就是说，稀土类磁体包括在R2T14B主相晶粒之间形成的R2T14B主相晶粒和晶界相。 R2T14B主相晶粒包括在晶粒中形成细小产物的物质。 在主相晶粒的截面中，当晶粒分为晶粒内部和具有特定椭圆的晶粒周边时，形成精细产物，使得内部的数量密度为 大于周边的。

公开(公告)号：US20190074114A1

公开(公告)日：2019-03-07

申请号：US16181811

申请日：2018-11-06

Applicant: TDK Corporation

Inventor： Makoto IWASAKI ,  Tetsuya HIDAKA ,  Takuma HAYAKAWA ,  Ayato KAKOKI ,  Yoshinori FUJIKAWA ,  Syota GOTO ,  Haruna NAKAJIMA ,  Takeshi MASUDA ,  Chikara ISHIZAKA

IPC: H01F1/055 ,  H01F41/02 ,  H01F1/057

Abstract: 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：US20170221616A1

公开(公告)日：2017-08-03

申请号：US15420151

申请日：2017-01-31

Applicant: TDK Corporation

Inventor： Makoto IWASAKI ,  Tetsuya HIDAKA ,  Takuma HAYAKAWA ,  Ayato KAKOKI ,  Yoshinori FUJIKAWA ,  Syota GOTO ,  Haruna NAKAJIMA ,  Takeshi MASUDA ,  Chikara ISHIZAKA

IPC: H01F1/055 ,  C22C38/14 ,  C22C38/10 ,  B22F3/10 ,  C22C38/00 ,  B22F1/00 ,  B22F9/02 ,  C22C38/16 ,  C22C38/06

CPC classification number: H01F1/0557 ,  B22F1/0059 ,  B22F3/1017 ,  B22F9/026 ,  B22F2009/044 ,  B22F2202/05 ,  B22F2301/35 ,  B22F2998/10 ,  B22F2999/00 ,  C22C33/02 ,  C22C38/002 ,  C22C38/005 ,  C22C38/06 ,  C22C38/10 ,  C22C38/14 ,  C22C38/16 ,  C22C2202/02 ,  H01F1/0577 ,  H01F41/0293 ,  B22F9/023 ,  B22F9/04 ,  B22F3/02 ,  B22F3/10

Abstract: 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：US20150270041A1

公开(公告)日：2015-09-24

申请号：US14332808

申请日：2014-07-16

Applicant: TDK CORPORATION

Inventor： Eiji KATO ,  Yoshinori FUJIKAWA ,  Taeko TSUBOKURA ,  Chikara ISHIZAKA ,  Katsuo SATO

IPC: H01F1/057 ,  C22C38/06 ,  C22C38/16 ,  C22C38/02 ,  H01F1/055 ,  C22C38/00

CPC classification number: H01F1/0577 ,  C22C38/002 ,  C22C38/005 ,  C22C38/008 ,  C22C38/02 ,  C22C38/06 ,  C22C38/16 ,  H01F1/0557

Abstract: The present invention provides a rare earth based magnet that inhibits the high temperature demagnetization rate even when less or no heavy rare earth elements such as Dy, Tb and the like than before are used. The rare earth based magnet according to the present invention is a sintered magnet which includes R2T14B crystal grains as main phase and grain boundary phases between the R2T14B crystal grains. When the grain boundary phase surrounded by three or more main phase crystal grains is regarded as the grain boundary multi-point, the microstructure of the sintered body is controlled so that the ratio of the grain boundary triple-point surrounded by three main phase crystal grains in all grain boundary multi-points to be specified value or less.

Abstract translation: 本发明提供一种稀土类磁体，即使使用比以前少的或不存在稀土类元素如Dy，Tb等，也能够抑制高温退磁率。 根据本发明的稀土类磁体是包含R2T14B晶粒作为主相和R2T14B晶粒之间的晶界相的烧结磁体。 当由三个或更多个主相晶粒包围的晶界相被认为是晶界多点时，控制烧结体的微观结构，使得由三个主相晶粒包围的晶界三重点的比例 在所有晶界多点中指定值或更小。

公开(公告)号：US20150179317A1

公开(公告)日：2015-06-25

申请号：US14578621

申请日：2014-12-22

Applicant: TDK CORPORATION

Inventor： Yoshinori FUJIKAWA ,  Yuki NAGAMINE ,  Wakako OKAWA ,  Chikara ISHIZAKA ,  Eiji KATO ,  Katsuo SATO

IPC: H01F1/057

CPC classification number: H01F1/057 ,  H01F1/0577

Abstract: The present invention provides a rare earth based magnet in which the demagnetization rate at a high temperature can be inhibited even if the amount of heavy rare earth element(s) such as Dy and Tb is evidently decreased compared to the past or no such heavy rare earth element is used. The rare earth based magnet of the present invention is a sintered magnet which comprises R2T14B crystal grains as the main phases and the crystal boundary phases among the R2T14B crystal grains. The microstructure of the sintered body is controlled by including crystal boundary phases containing at least R, T and M in the crystal boundary phases, wherein the relative atomic ratios of R, T and M are as follows, i.e., 25 to 35% for R, 60 to 70% for T and 2 to 10% for M.

Abstract translation: 本发明提供了一种稀土类磁体，其中即使Dy和Tb等重稀土元素的量与过去相比明显减少，也可以抑制高温下的退磁率，或者不存在这种重稀土 使用地球元素。 本发明的稀土类磁体是包含R2T14B晶粒作为主相和R2T14B晶粒中的晶界相的烧结磁体。 烧结体的微结构通过在晶界边界相中包含至少含有R，T和M的晶界相来控制，其中R，T和M的相对原子比如下，即R为25〜35％ ，T为60〜70％，M为2〜10％

公开(公告)号：US20160086701A1

公开(公告)日：2016-03-24

申请号：US14889069

申请日：2014-07-03

Applicant: TDK CORPORATION

Inventor： Masashi MIWA ,  Haruna NAKAJIMA ,  Koji MITAKE ,  Chikara ISHIZAKA

IPC: H01F1/01 ,  H02K1/02

CPC classification number: H01F1/01 ,  H01F1/0577 ,  H02K1/02 ,  H02K1/278

Abstract: An R-T-B based sintered magnet having R2T14B crystal grains and a grain boundary formed by two or more adjacent R2T14B crystal grains. An R—Co—Cu—N concentrated part whose concentrations of R, Co, Cu and N are respectively higher than those in the R2T14B crystal grains may be in the grain boundary. An R—O—C concentrated part or an R—O—C—N concentrated part may be further provided in the grain boundary.

Abstract translation: 具有R2T14B晶粒的R-T-B系烧结磁体和由两个以上相邻的R2T14B晶粒形成的晶界。 R，Co，Cu和N的浓度分别高于R2T14B晶粒中的R-Co-Cu-N浓缩部分可能在晶界。 可以在晶界中进一步提供R-O-C浓缩部分或R-O-C-N浓缩部分。

公开(公告)号：US20150310972A1

公开(公告)日：2015-10-29

申请号：US14332666

申请日：2014-07-16

Applicant: TDK CORPORATION

Inventor： Eiji KATO ,  Yoshinori FUJIKAWA ,  Taeko TSUBOKURA ,  Chikara ISHIZAKA ,  Katsuo SATO

IPC: H01F1/057 ,  H01F1/053 ,  C22C38/00 ,  H01F1/08

CPC classification number: H01F1/0577 ,  C22C38/002 ,  C22C38/005 ,  H01F1/0536 ,  H01F1/086

Abstract: The present invention provides a rare earth based magnet that inhibits the high temperature demagnetization rate even when less or no heavy rare earth elements such as Dy, Tb and the like than before are used. The rare earth based magnet according to the present invention is a sintered magnet which includes R2T14B crystal grains as main phase and grain boundary phases between the R2T14B crystal grains. when evaluating the cross-sectional area distribution of the main phase crystal grains by histogram in any cross-section of the rare earth based magnet, the crystal grains with large particle size and the crystal grains with small particle size are controlled so that the cross-sectional area distribution becomes the one which respectively has at least one peak at two sides of the average value of the cross-sectional area.

Abstract translation: 本发明提供一种稀土类磁体，即使使用比以前少的或不存在稀土类元素如Dy，Tb等，也能够抑制高温退磁率。 根据本发明的稀土类磁体是包含R2T14B晶粒作为主相和R2T14B晶粒之间的晶界相的烧结磁体。 当在稀土类磁体的任何截面中通过直方图评估主相晶粒的横截面积分布时，控制粒径大的晶粒和粒径小的晶粒， 截面积分布分别成为横截面积的平均值的两侧分别具有至少一个峰。