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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。
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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
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。
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公开(公告)号：US20140292453A1
公开(公告)日：2014-10-02
申请号：US14229253
申请日：2014-03-28
Applicant: TDK CORPORATION
Inventor： Eiji KATO , Yoshinori FUJIKAWA , Taeko TSUBOKURA , Chikara ISHIZAKA , Katsuo SATO
IPC: H01F1/057
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 are used. The rare earth based magnet according to the present invention includes R2T14B main phase crystal grains and grain boundary phases between adjacent main phase crystal grains. In any cross-section of the rare earth based magnet, when evaluating the circular degree of the main phase crystal grains with Wadell's Roundenss A, the shape of the main phase crystal grains is controlled such that the Roundness A becomes 0.24 or more.
Abstract translation: 本发明提供一种稀土类磁体，即使在使用Dy或Tb等稀土元素较少的情况下也能够抑制高温退磁率。 根据本发明的稀土类磁体包括相邻的主相晶粒之间的R2T14B主相晶粒和晶界相。 在稀土类磁体的任何截面中，当用Wadell's Roundens A评估主相晶粒的圆度时，控制主相晶粒的形状，使得圆度A变为0.24以上。
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公开(公告)号：US20190255618A1
公开(公告)日：2019-08-22
申请号：US16278876
申请日：2019-02-19
Applicant: TDK Corporation
Inventor： Takeshi MASUDA , Taeko TSUBOKURA , Hiroshi MIYASAKA , Yutaka HATAKEYAMA , Toshihiro KUROSHIMA
Abstract: A method of processing a rare earth magnet comprises: a step of irradiating an R-T-B-based rare earth magnet with laser light to process; and a step of performing heat treatment on the magnet after the irradiating. The heat treatment includes: a step A of bringing the temperature of the magnet to 400° C. or less, a step B of holding the magnet at a temperature T1 in a range of 400 to 700° C. after the step A, and a step C of bringing the temperature of the magnet to less than 400° C. after the step B. The temperature of the magnet is made not to exceed 700° C. between the step A and the step B. The temperature of the magnet is made not to exceed 700° C. between the step B and the step C. A step of setting the magnet at a temperature higher than 700° C. after the step C is not included.
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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
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。
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Patent Agency Ranking
公开(公告)号：US20210304929A1
公开(公告)日：2021-09-30
申请号：US17202424
申请日：2021-03-16
Applicant: TDK Corporation
Inventor： Masashi MIWA , Yoshitomo TANAKA , Koji MIURA , Taeko TSUBOKURA
Abstract: Provided is a permanent magnet including a rare-earth element R (such as Nd), a transition metal element T (such as Fe), B, Zr, and Cu. The permanent magnet contains a plurality of main phase grains including Nd, T, and B, and grain boundary multiple junctions, the one grain boundary multiple junction is a grain boundary surrounded by three or more of the main phase grains, one of the grain boundary multiple junctions contains a ZrB2 crystal and an R—Cu-rich phase including R and Cu, Fe is contained in the ZrB2 crystal, a total concentration of Nd and Pr in the one grain boundary multiple junction containing both the ZrB2 crystal and the R—Cu-rich phase is higher than a total concentration of Nd and Pr in the main phase grain, a concentration of Cu in the one grain boundary multiple junction containing both the ZrB2 crystal and the R—Cu-rich phase is higher than a concentration of Cu in the main phase grain, and a unit of the concentration of each of Nd, Pr, and Cu is atomic %.
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公开(公告)号：US20210280345A1
公开(公告)日：2021-09-09
申请号：US17186770
申请日：2021-02-26
Applicant: TDK Corporation
Inventor： Taeko TSUBOKURA , Toshihiro KUROSHIMA , Koji MITAKE , Takeshi MASUDA
Abstract: A magnet structure includes a first sintered magnet, a second sintered magnet, and an intermediate layer disposed between the first sintered magnet and the second sintered magnet. Each of the first sintered magnet and the second sintered magnet independently includes crystal grains containing a rare earth element, a transition metal element, and boron. The intermediate layer contains rare earth element oxide phases and crystal grains containing a rare earth element, transition metal element, and boron. Each of the transition metal elements independently includes Fe or a combination of Fe and Co. An average coverage factor of the rare earth element oxide phases measured on the basis of a cross section perpendicular to the intermediate layer of the magnet structure is within a range of 10% to 69%.
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公开(公告)号：US20200176155A1
公开(公告)日：2020-06-04
申请号：US16698019
申请日：2019-11-27
Applicant: TDK Corporation
Inventor： Takeshi MASUDA , Taeko TSUBOKURA , Taku MURASE
Abstract: An R-T-B permanent magnet comprises rare-earth elements R, transition metal elements T, and boron B; wherein at least some of the rare-earth elements R is Nd and at least one of Tb and Dy; at least some of the transition metal elements T are Fe; the R-T-B permanent magnet comprises a plurality of main phase grains and grain boundary triple points each surrounded by the main phase grains; the grain boundary triple points comprise at least one of Nd and Pr, at least one of Tb and Dy, at least one of Fe and Co, and copper; the average contents of Nd, Pr, Tb, Dy, Fe, Co and Cu each (unit: atom %) are represented by [Nd], [Pr], [Tb], [Dy], [Fe], [Co] and [Cu]; ([Fe]+[Co])/([Nd]+[Pr]) is 2 or more and 5 or less; and [Cu]/([Tb]+[Dy]) is 1 or more and 4 or less.
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公开(公告)号：US20210313099A1
公开(公告)日：2021-10-07
申请号：US17202410
申请日：2021-03-16
Applicant: TDK Corporation
Inventor： Masashi MIWA , Koji MIURA , Taeko TSUBOKURA
Abstract: Provided is a permanent magnet including a rare-earth element R (such as Nd), a transition metal element T (such as Fe), B, Zr, and Cu. The permanent magnet contains a plurality of main phase grains including Nd, T, and B, and grain boundary multiple junctions, the one grain boundary multiple junction is a grain boundary surrounded by three or more of the main phase grains, one of the grain boundary multiple junctions contains a ZrB2 crystal and an R—Cu-rich phase including R and Cu, a concentration of B in the one grain boundary multiple junction containing both the ZrB2 crystal and the R—Cu-rich phase is from 5 to 20 atomic %, a concentration of Cu in the one grain boundary multiple junction containing both the ZrB2 crystal and the R—Cu-rich phase is from 5 to 25 atomic %, and a surface layer part of the main phase grain includes at least one kind of heavy rare-earth element among Tb and Dy.
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公开(公告)号：US20200176184A1
公开(公告)日：2020-06-04
申请号：US16698083
申请日：2019-11-27
Applicant: TDK Corporation
Inventor： Taeko TSUBOKURA , Takeshi Masuda , Taku Murase
Abstract: A method for manufacturing an R-T-B permanent magnet comprises a diffusion step of adhering a diffusing material to the surface of a magnet base material and heating the magnet base material with the diffusing material adhered thereto, wherein the magnet base material comprises rare-earth elements R, transition metal elements T and boron B; at least some of R are Nd; at least some of T are Fe; the diffusing material comprises a first component, a second component and a third component; the first component is at least one of a simple substance of Tb and a simple substance of Dy; the second component comprises a metal comprising at least one of Nd and Pr and not comprising Tb and Dy; and the third component is at least one selected from the group consisting of a simple substance of Cu, an alloy comprising Cu, and a compound of Cu.
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