Patents by Inventor Kenta Takagi

Kenta Takagi has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11798739
    Abstract: One embodiment of the present invention includes, in a samarium-iron-nitrogen based magnet powder, a main phase containing samarium and iron, and a sub-phase containing samarium, iron, and at least one or more elements selected from the group consisting of zirconium, molybdenum, vanadium, tungsten, and titanium, wherein an atomic ratio of a rare earth element to an iron group element is greater than an atomic ratio of the rare earth element to the iron group element of the main phase, wherein at least a part of a surface of the main phase is coated with the sub-phase.
    Type: Grant
    Filed: March 27, 2019
    Date of Patent: October 24, 2023
    Assignee: TDK Corporation
    Inventors: Ryuji Hashimoto, Yasushi Enokido, Shusuke Okada, Kenta Takagi
  • Publication number: 20230144902
    Abstract: A samarium-iron-nitrogen based magnet, wherein a samarium oxide phase is formed on at least a part of a surface of a crystal grain, and wherein an atomic ratio of calcium to a total amount of iron group elements, rare earth elements, and calcium is 0.4% or less.
    Type: Application
    Filed: March 29, 2021
    Publication date: May 11, 2023
    Applicant: TDK Corporation
    Inventors: Ryuji HASHIMOTO, Yasushi ENOKIDO, Shusuke OKADA, Kenta TAKAGI
  • Patent number: 11594353
    Abstract: A sintered magnet contains Sm—Fe—N-based crystal grains and has high coercivity; and a magnetic powder is capable of forming a sintered magnet without lowering the coercivity even if heat is generated in association with the sintering. A sintered magnet comprises a crystal phase composed of a plurality of Sm—Fe—N-based crystal grains and a nonmagnetic metal phase present between the Sm—Fe—N crystal grains adjacent to each other, wherein a ratio of Fe peak intensity IFe to SmFeN peak intensity ISmFeN measured by an X-ray diffraction method is 0.2 or less. A magnetic powder comprises Sm—Fe—N-based crystal particles and a nonmagnetic metal layer covering surfaces of the Sm—Fe—N crystal particles.
    Type: Grant
    Filed: July 8, 2019
    Date of Patent: February 28, 2023
    Assignees: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY, Murata Manufacturing Co., Ltd.
    Inventors: Kenta Takagi, Wataru Yamaguchi, Takaaki Yokoyama, Kenji Sakaguchi, Kazuhiro Yoshii, Yuji Yokoyama
  • Publication number: 20230039058
    Abstract: A Sm—Fe—N magnet includes Sm—Fe—N particles, wherein an inter-particle metal phase is present between at least two of the Sm—Fe—N particles, an average particle diameter of the Sm—Fe—N particles is less than 2.0 ?m, and a percentage of the Sm—Fe—N particles having an aspect ratio of 2.0 or more is 10% or less, the inter-particle metal phase includes a Fe3Zn10 phase and an ?-Fe phase in a particle form, and in the inter-particle metal phase, an area ratio of the Fe3Zn10 phase is 80% or more.
    Type: Application
    Filed: July 27, 2022
    Publication date: February 9, 2023
    Applicants: TDK Corporation, National Institute of Advanced Industrial Science and Technology
    Inventors: Hirotaka YOKOTA, Eiichiro Fukuchi, Shusuke Okada, Kenta Takagi
  • Publication number: 20230043317
    Abstract: A Sm—Fe—N magnet includes Sm—Fe—N particles each having a surface, a coating layer being provided on at least a portion of the surface or on at least a portion of an interface between at least two of the Sm—Fe—N particles, or being provided on both, wherein the coating layer includes a first layer and a second layer, the first layer being situated closer to the surface or the interface than is the second layer, he first layer includes ?-Fe, the second layer includes a Sm—Fe—Zn alloy, and a Zn content contained in the second layer is 1 at % or more and 20 at % or less.
    Type: Application
    Filed: July 27, 2022
    Publication date: February 9, 2023
    Applicants: TDK Corporation, National Institute of Advanced Industrial Science and Technology
    Inventors: Hirotaka YOKOTA, Shusuke Okada, Kenta Takagi
  • Patent number: 11453057
    Abstract: A samarium-iron-nitrogen alloy powder according to one embodiment of the present invention is characterized in that a value obtained by dividing the hydrogen content of the samarium-iron-nitrogen alloy powder by the BET specific surface area of the samarium-iron-nitrogen alloy powder is less than or equal to 400 ppm/(m2/g), and a value obtained by dividing the oxygen content of the samarium-iron-nitrogen alloy powder by the BET specific surface area of the samarium-iron-nitrogen alloy powder is less than or equal to 11,000 ppm/(m2/g).
    Type: Grant
    Filed: February 28, 2017
    Date of Patent: September 27, 2022
    Assignees: National Institute of Advanced Industrial Science and Technology, TDK Corporation
    Inventors: Shusuke Okada, Kazuyuki Suzuki, Kenta Takagi, Kimihiro Ozaki, Yasushi Enokido
  • Publication number: 20220189669
    Abstract: One embodiment of the present invention includes single-crystal particles of a TbCu7 type samarium-iron-nitrogen based alloy in an anisotropic magnet powder.
    Type: Application
    Filed: January 10, 2020
    Publication date: June 16, 2022
    Applicants: TDK Corporation, National Institute of Advanced Industrial Science and Technology
    Inventors: Suguru SATOH, Yasushi ENOKIDO, Shusuke OKADA, Kenta TAKAGI
  • Patent number: 11361888
    Abstract: One embodiment of the present invention is that in samarium-iron-nitrogen magnet powder, a non-magnetic phase is formed on a surface of the samarium-iron-nitrogen magnet phase, and an arithmetic mean roughness Ra of the surface is 3.5 nm or less.
    Type: Grant
    Filed: May 29, 2018
    Date of Patent: June 14, 2022
    Assignees: National Institute of Advanced Industrial Science and Technology, TDK Corporation
    Inventors: Shusuke Okada, Kenta Takagi, Yasushi Enokido, Yoshinori Fujikawa, Ryuji Hashimoto
  • Publication number: 20220148771
    Abstract: A single crystal particle powder having a crystal structure of TbCu7-type of the present invention is represented by the general formula: [Chemical Formula 1] (R1-zMz)Tx??(1) or the general formula: [Chemical Formula 2] (R1-zMz)TxNy??(2) and has a crystal structure of TbCu7-type, wherein R is at least one element selected from the group consisting of Sm and Nd, T is at least one element selected from the group consisting of Fe and Co, x is 7.0?x?10.0, y is 1.0?y?2.0, and z is 0.0?z?0.3.
    Type: Application
    Filed: March 13, 2020
    Publication date: May 12, 2022
    Applicant: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY
    Inventors: Yusuke HIRAYAMA, Akihide HOSOKAWA, Kenta TAKAGI
  • Publication number: 20220037065
    Abstract: A Sm—Fe—N-based magnet powder that includes a Sm—Fe—N-based magnetic material powder, wherein an average particle size of the Sm—Fe—N-based magnetic material powder is not larger than 5 ?m, and a full width at half maximum of a diffraction peak of a (220) plane in an X-ray diffraction profile of the Sm—Fe—N-based magnetic material powder is not larger than 0.0033 ?. Also disclosed is a Sm—Fe—N-based sintered magnet that includes a sintered body of a Sm—Fe—N-based magnetic material, wherein an average grain size of crystal grains of the Sm—Fe—N-based magnetic material is not larger than 5 ?m, and a full width at half maximum of a diffraction peak of a (220) plane in an X-ray diffraction profile of the Sm—Fe—N-based magnetic material is not larger than 0.0033 ?.
    Type: Application
    Filed: September 29, 2021
    Publication date: February 3, 2022
    Inventors: Kenta Takagi, Wataru Yamaguchi, Takaaki Yokoyama, Ryoichi Yamagata, Yosuke Sato
  • Publication number: 20210082605
    Abstract: One embodiment of the present invention includes, in a samarium-iron-nitrogen based magnet powder, a main phase containing samarium and iron, and a sub-phase containing samarium, iron, and at least one or more elements selected from the group consisting of zirconium, molybdenum, vanadium, tungsten, and titanium, wherein an atomic ratio of a rare earth element to an iron group element is greater than an atomic ratio of the rare earth element to the iron group element of the main phase, wherein at least a part of a surface of the main phase is coated with the sub-phase.
    Type: Application
    Filed: March 27, 2019
    Publication date: March 18, 2021
    Applicant: TDK Corporation
    Inventors: Ryuji HASHIMOTO, Yasushi ENOKIDO, Shusuke OKADA, Kenta TAKAGI
  • Patent number: 10632533
    Abstract: A raw material for a magnet, which comprises Sm and Fe. A magnet is obtained by nitriding this raw material for a magnet. In particular, a raw material for a magnet comprises an Sm—Fe binary alloy as a main component. An intensity ratio of an Sm2Fe17 (024) peak to an SmFe7 (110) peak is less than 0.001 as measured by an X-ray diffraction method.
    Type: Grant
    Filed: July 10, 2018
    Date of Patent: April 28, 2020
    Assignees: Murata Manufacturing Co., Ltd., NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY
    Inventors: Satoshi Oga, Kenta Takagi, Kimihiro Ozaki
  • Publication number: 20200118722
    Abstract: One embodiment of the present invention is that in samarium-iron-nitrogen magnet powder, a non-magnetic phase is formed on a surface of the samarium-iron-nitrogen magnet phase, and an arithmetic mean roughness Ra of the surface is 3.5 nm or less.
    Type: Application
    Filed: May 29, 2018
    Publication date: April 16, 2020
    Applicants: National Institute of Advanced Industrial Science and Technology, TDK Corporation
    Inventors: Shusuke OKADA, Kenta TAKAGI, Yasushi ENOKIDO, Yoshinori FUJIKAWA, Ryuji HASHIMOTO
  • Publication number: 20200105446
    Abstract: A samarium-iron-bismuth-nitrogen-based magnet powder includes: a main phase including samarium, iron, and bismuth, wherein a ratio of bismuth to a total amount of samarium, iron, and bismuth is less than or equal to 3.0 at %.
    Type: Application
    Filed: September 25, 2019
    Publication date: April 2, 2020
    Applicants: TDK Corporation, National Institute of Advanced Industrial Science and Technology
    Inventors: Ryuji HASHIMOTO, Yasushi Enokido, Shusuke Okada, Kenta Takagi
  • Publication number: 20200016663
    Abstract: A samarium-iron-nitrogen alloy powder according to one embodiment of the present invention is characterized in that a value obtained by dividing the hydrogen content of the samarium-iron-nitrogen alloy powder by the BET specific surface area of the samarium-iron-nitrogen alloy powder is less than or equal to 400 ppm/(m2/g), and a value obtained by dividing the oxygen content of the samarium-iron-nitrogen alloy powder by the BET specific surface area of the samarium-iron-nitrogen alloy powder is less than or equal to 11,000 ppm/(m2/g).
    Type: Application
    Filed: February 28, 2017
    Publication date: January 16, 2020
    Applicants: National Institute of Advanced Industrial Science and Technology, TDK Corporation
    Inventors: Shusuke OKADA, Kazuyuki SUZUKI, Kenta TAKAGI, Kimihiro OZAKI, Yasushi ENOKIDO
  • Publication number: 20190333661
    Abstract: A sintered magnet contains Sm—Fe—N-based crystal grains and has high coercivity; and a magnetic powder is capable of forming a sintered magnet without lowering the coercivity even if heat is generated in association with the sintering. A sintered magnet comprises a crystal phase composed of a plurality of Sm—Fe—N-based crystal grains and a nonmagnetic metal phase present between the Sm—Fe—N crystal grains adjacent to each other, wherein a ratio of Fe peak intensity IFe to SmFeN peak intensity ISmFeN measured by an X-ray diffraction method is 0.2 or less. A magnetic powder comprises Sm—Fe—N-based crystal particles and a nonmagnetic metal layer covering surfaces of the Sm—Fe—N crystal particles.
    Type: Application
    Filed: July 8, 2019
    Publication date: October 31, 2019
    Applicants: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY, Murata Manufacturing Co., Ltd.
    Inventors: Kenta TAKAGI, Wataru YAMAGUCHI, Takaaki YOKOYAMA, Kenji SAKAGUCHI, Kazuhiro YOSHII, Yuji YOKOYAMA
  • Publication number: 20180318923
    Abstract: A raw material for a magnet, which comprises Sm and Fe. A magnet is obtained by nitriding this raw material for a magnet. In particular, a raw material for a magnet comprises an Sm—Fe binary alloy as a main component. An intensity ratio of an Sm2Fe17 (024) peak to an SmFe7 (110) peak is less than 0.001 as measured by an X-ray diffraction method.
    Type: Application
    Filed: July 10, 2018
    Publication date: November 8, 2018
    Applicants: Murata Manufacturing Co., Ltd., NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY
    Inventors: Satoshi OGA, Kenta TAKAGI, Kimihiro OZAKI
  • Patent number: 9455389
    Abstract: In a thermoelectric conversion module, each of a p-type element and an n-type element is configured by aligning a plurality of particles in series and connecting the particles to each other. Around a connection part in which the particles are connected to each other, a protrusion is protruded. The protrusion has a shape of continuously extending around the entire periphery of the connection part. The protrusion may be partly interrupted, but in such a case, a circumferential length of one interrupted portion is less than one half of the periphery of the connection part.
    Type: Grant
    Filed: November 16, 2012
    Date of Patent: September 27, 2016
    Assignees: National Institute of Advanced Industrial Science and Technology, KITAGAWA INDUSTRIES CO., LTD.
    Inventors: Yasuhiro Kawaguchi, Hideo Yumi, Hiroki Kitano, Kenta Takagi, Kimihiro Ozaki
  • Publication number: 20140261605
    Abstract: A thermoelectric conversion module according to one aspect of embodiments of the present invention as disclosed herein includes a plurality of layered planar bodies. Each of the plurality of layered planar bodies includes a base material having a planar shape, a plurality of p-type granular bodies made of a p-type thermoelectric material, and a plurality of n-type granular bodies made of an n-type thermoelectric material. The plurality of p-type granular bodies and the plurality of n-type granular bodies are held by the base material in such a manner as to be spaced apart from each other in a direction along a face of the base material crossing a layered direction of the plurality of layered planar bodies.
    Type: Application
    Filed: March 12, 2014
    Publication date: September 18, 2014
    Applicants: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY, KITAGAWA INDUSTRIES CO., LTD.
    Inventors: HIROKI KITANO, HIDEO YUMI, YASUHIRO KAWAGUCHI, KENTA TAKAGI, KIMIHIRO OZAKI
  • Publication number: 20130125948
    Abstract: In a thermoelectric conversion module, each of a p-type element and an n-type element is configured by aligning a plurality of particles in series and connecting the particles to each other. Around a connection part in which the particles are connected to each other, a protrusion is protruded. The protrusion has a shape of continuously extending around the entire periphery of the connection part. The protrusion may be partly interrupted, but in such a case, a circumferential length of one interrupted portion is less than one half of the periphery of the connection part.
    Type: Application
    Filed: November 16, 2012
    Publication date: May 23, 2013
    Applicants: National Institute of Advanced Industrial Science and Technology
    Inventors: Yasuhiro KAWAGUCHI, Hideo YUMI, Hiroki KITANO, Kenta TAKAGI, Kimihiro OZAKI