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公开(公告)号：US20210304934A1
公开(公告)日：2021-09-30
申请号：US17198517
申请日：2021-03-11
Applicant: TDK CORPORATION
Inventor： Shogo MUROYA , Yoshitaka MURAKAWA , Hiroyuki MORITA , Masanori IKEDA
Abstract: To provide a ferrite sintered magnet having a high residual magnetic flux density (Br) and a high coercive force (HcJ), and also able to produce at a low cost. The ferrite sintered magnet includes a hexagonal M-type ferrite including A, R, Fe, and Co in an atomic ratio of A1-xRx(Fe12-yCoy)zO19. A is at least one selected from Sr, Ba, and Pb. R is La only or La and at least one selected from rare earth elements. 0.13≤x≤0.23, 10.80≤(12−y)z≤12.10, and 0.13≤yz≤0.20 are satisfied.
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公开(公告)号：US20210118598A1
公开(公告)日：2021-04-22
申请号：US17070469
申请日：2020-10-14
Applicant: TDK Corporation
Inventor： Yoshitaka MURAKAWA , Hiroyuki MORITA , Masanori IKEDA , Shogo MUROYA , Tomokazu ISHIKURA
Abstract: A ferrite sintered magnet 100 comprises M-type ferrite crystal grains 4 and multiple-crystal grain boundaries 6b surrounded by three or more of the M-type ferrite crystal grains 4. The ferrite sintered magnet 100 contains at least Fe, Ca, B, and Si, and contains 0.005 to 0.9 mass % of B in terms of B2O3. The multiple-crystal grain boundaries 6b contain Si and Ca, and in a case where the molar ratio of Ca to Si in the multiple-crystal grain boundaries 6b is represented by (Ca/Si)G, the following formula is satisfied. 0.1
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公开(公告)号：US20190304643A1
公开(公告)日：2019-10-03
申请号：US16295156
申请日：2019-03-07
Applicant: TDK Corporation
Inventor： Hiroyuki MORITA , Masanori IKEDA , Yoshitaka MURAKAWA , Hiroyuki ONO , Taku MURASE
IPC: H01F1/11
Abstract: The present invention provides a ferrite sintered magnet comprising (1) main phase grains containing a ferrite having a hexagonal structure, (2) two-grain boundaries formed between two of the main phase grains, and (3) multi-grain boundaries surrounded by three or more of the main phase grains. The above ferrite sintered magnet comprises Ca, R, Sr, Fe and Co, with R being at least one element selected from the group consisting of rare earth elements and Bi, and comprising at least La. The number Nm of the above main phase grains and the number Ng of the above multi-grain boundaries in the cross section including the direction of the easy magnetization axis of the above ferrite sintered magnet satisfy the formula (1A): 50%≤Nm/(Nm+Ng)≤65% (1A).
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公开(公告)号：US20190304642A1
公开(公告)日：2019-10-03
申请号：US16269612
申请日：2019-02-07
Applicant: TDK Corporation
Inventor： Masanori IKEDA , Hiroyuki MORITA , Yoshitaka MURAKAWA , Taku MURASE
Abstract: A ferrite sintered magnet comprising ferrite particles having a hexagonal structure is provided. The ferrite sintered magnet comprises metallic elements at an atomic ratio represented by formula (1). In formula (1), R is at least one element selected from the group consisting of rare-earth elements and Bi, and comprises at least La. In formula (1), w, x, z and m satisfy formulae (2) to (5). The above-mentioned ferrite sintered magnet comprises 0.037 to 0.181% by mass of B in terms of H3BO3. Ca1−w−xRwSrxFezCom (1) 0.360≤w≤0.420 (2) 0.110≤x≤0.173 (3) 8.51≤z≤9.71 (4) 0.208≤m≤0.269 (5)
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公开(公告)号：US20190304641A1
公开(公告)日：2019-10-03
申请号：US16267400
申请日：2019-02-05
Applicant: TDK Corporation
Inventor： Hiroyuki MORITA , Masanori IKEDA , Yoshitaka MURAKAWA , Taku MURASE
Abstract: There is provided a ferrite sintered magnet having a high residual magnetic flux density.A ferrite sintered magnet 2 includes a plurality of main phase particles 5 including ferrite having a hexagonal structure, the number of core-shell structured particles 5A having a core 7 and a shell 9 covering the core 7, among the main phase particles 5, is smaller than the number of the main phase particles 5 other than the core-shell structured particles 5A.
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Patent Agency Ranking
16.发明申请公开(公告)号：US20140097378A1
公开(公告)日：2014-04-10
申请号：US14070842
申请日：2013-11-04
Applicant: TDK CORPORATION
Inventor： Shigeki YANAGIDA , Takahiro MORI , Hiroyuki MORITA , Nobuhiro SUTO , Tatsuya KATOH , Yoshihiko MINACHI
IPC: H01F1/01
CPC classification number: H01F1/01 , C04B35/2633 , C04B35/2641 , C04B35/6261 , C04B35/62695 , C04B35/632 , C04B35/63408 , C04B35/63424 , C04B35/638 , C04B2235/32 , C04B2235/3201 , C04B2235/3203 , C04B2235/3206 , C04B2235/3208 , C04B2235/3213 , C04B2235/3215 , C04B2235/3217 , C04B2235/3227 , C04B2235/3232 , C04B2235/3239 , C04B2235/3241 , C04B2235/3244 , C04B2235/3251 , C04B2235/3256 , C04B2235/3258 , C04B2235/3262 , C04B2235/3277 , C04B2235/3279 , C04B2235/3281 , C04B2235/3284 , C04B2235/3286 , C04B2235/3287 , C04B2235/3293 , C04B2235/3294 , C04B2235/3409 , C04B2235/3418 , C04B2235/3427 , C04B2235/5409 , C04B2235/5436 , C04B2235/5445 , C04B2235/6022 , C04B2235/605 , C04B2235/6562 , C04B2235/6588 , C04B2235/767 , C04B2235/786 , C04B2235/787 , C04B2235/788 , H01F1/10 , H01F1/11
Abstract: A ferrite magnet and a ferrite sintered magnet including a ferrite magnetic material are provided. A main phase of the ferrite magnetic material includes a ferrite phase having a hexagonal crystal structure, and metal element composition expressed by Ca1-w-x-yR wSr xBayFezMm wherein 0.25
Abstract translation: 提供铁氧体磁铁和包括铁氧体磁性材料的铁氧体烧结磁体。 铁素体磁性材料的主相包括具有六方晶系结构的铁素体相和由Ca1-wx-yR wSr xBayFezMm表示的金属元素组成，其中0.25
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公开(公告)号：US20210296030A1
公开(公告)日：2021-09-23
申请号：US17198542
申请日：2021-03-11
Applicant: TDK CORPORATION
Inventor： Hiroyuki MORITA , Masanori IKEDA , Yoshitaka MURAKAWA , Shogo MUROYA
Abstract: A ferrite sintered magnet including 0.010 mass % or more and 0.090 mass % or less of Mg in terms of MgO.
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18.发明申请公开(公告)号：US20200312497A1
公开(公告)日：2020-10-01
申请号：US16825290
申请日：2020-03-20
Applicant: TDK Corporation
Inventor： Shogo MUROYA , Yoshitaka MURAKAWA , Hiroyuki MORITA , Masanori IKEDA
Abstract: This ferrite sintered magnet comprises ferrite phases having a magnetoplumbite type crystal structure. This magnet comprises an element R, an element M, Fe, Co, B, Mn and Cr, the element R is at least one element selected from rare earth elements including Y, the element M is at least one element selected from the group consisting of Ca, Sr and Ba, with Ca being an essential element, and when an atomic composition of metallic elements is represented by R1-xMxFem-yCoy, x, y and m satisfy formulae: 0.2≤x≤0.8 (1) 0.1≤y≤0.65 (2) 3≤m
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公开(公告)号：US20200312496A1
公开(公告)日：2020-10-01
申请号：US16826812
申请日：2020-03-23
Applicant: TDK Corporation
Inventor： Yoshitaka MURAKAWA , Shogo MUROYA , Hiroyuki MORITA , Masanori IKEDA
Abstract: A ferrite sintered magnet 100 comprises M-type ferrite crystal grains 4 having a hexagonal structure, two-crystal grain boundaries 6a formed between two of the M-type ferrite crystal grains 4, and multiple-crystal grain boundaries 6b surrounded by three or more of the M-type ferrite crystal grains 4. This ferrite sintered magnet 100 contains at least Fe, Ca, B, and Si, and contains B in an amount of 0.005 to 0.9 mass % in terms of B2O3, the two-crystal grain boundaries 6a and the multiple-crystal grain boundaries 6b contain Si and Ca, and in a cross-section parallel to a c-axis of the ferrite sintered magnet, when the number of multiple-crystal grain boundaries 6b having a maximum length of 0.49 to 5 μm per cross-sectional area of 76 μm2 is N, N is 7 or less.
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公开(公告)号：US20200312493A1
公开(公告)日：2020-10-01
申请号：US16823871
申请日：2020-03-19
Applicant: TDK Corporation
Inventor： Yoshitaka MURAKAWA , Shogo MUROYA , Hiroyuki MORITA , Masanori IKEDA
Abstract: A ferrite sintered magnet comprising an M type Sr ferrite having a hexagonal structure as a main phase, wherein the ferrite sintered magnet does not substantially comprise a rare earth element and Co, a content of B is 0.005 to 0.9% by mass in terms of B2O3, and a content of Zn is 0.01 to 1.2% by mass in terms of ZnO.
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