Patents by Inventor Hidefumi Kishimoto

Hidefumi Kishimoto 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).

  • Publication number: 20180308633
    Abstract: A method for producing a rare earth magnet, including preparing a melt of a first alloy having a composition represented by (R1vR2wR3x)yTzBsM1t (wherein R1 is a light rare earth element, R2 is an intermediate rare earth element, R3 is a heavy rare earth element, T is an iron group element, and M1 is an impurity element, etc.), cooling the melt of the first alloy at a rate of from 100 to 102 K/sec to obtain a first alloy ingot, pulverizing the first alloy ingot to obtain a first alloy powder having a particle diameter of 1 to 20 ?m, preparing a melt of a second alloy having a composition represented by (R4pR5q)100-uM2u (wherein R4 is a light rare earth element, R5 is an intermediate or heavy rare earth element, M2 is an alloy element, etc.), and putting the first alloy powder into contact with the melt of the second alloy.
    Type: Application
    Filed: April 13, 2018
    Publication date: October 25, 2018
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Masaaki ITO, Noritsugu SAKUMA, Masao YANO, Hidefumi KISHIMOTO, Tetsuya SHOJI
  • Patent number: 10090090
    Abstract: The invention provides a nanocomposite magnet, which has achieved high coercive force and high residual magnetization. The magnet is a non-ferromagnetic phase that is intercalated between a hard magnetic phase with a rare-earth magnet composition and a soft magnetic phase, wherein the non-ferromagnetic phase reacts with neither the hard nor soft magnetic phase. A hard magnetic phase contains Nd2Fe14B, a soft magnetic phase contains Fe or Fe2Co, and a non-ferromagnetic phase contains Ta. The thickness of the non-ferromagnetic phase containing Ta is 5 nm or less, and the thickness of the soft magnetic phase containing Fe or Fe2Co is 20 nm or less. Nd, or Pr, or an alloy of Nd and any one of Cu, Ag, Al, Ga, and Pr, or an alloy of Pr and any one of Cu, Ag, Al, and Ga is diffused into a grain boundary phase of the hard magnetic phase of Nd2Fe14B.
    Type: Grant
    Filed: October 16, 2017
    Date of Patent: October 2, 2018
    Assignees: TOYOTA JIDOSHA KABUSHIKI KAISHA, NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Hidefumi Kishimoto, Noritsugu Sakuma, Masao Yano, Weibin Cui, Yukiko Takahashi, Kazuhiro Hono
  • Publication number: 20180182515
    Abstract: A rare earth magnet comprising a main phase, a grain boundary phase present around the main phase, and an intermediate phase sandwiched between the main phase and the grain boundary phase, and having a total composition of the rare earth magnet represented by the formula: CepR1qT(100-p-q-r-s)BrM1s.(R21-xM2x)t R1 and R2 are a rare earth element except for Ce, T is one or more members selected from Fe, Ni, and Co, M1 is a minor element, and M2 is an alloy element that makes, the melting point of R21-xM2x to be lower than the melting point of R2 the concentration of Ce is higher in the main phase than in the intermediate phase, and the concentration of R2 is higher in the intermediate phase than in the main phase, and a production method thereof.
    Type: Application
    Filed: December 19, 2017
    Publication date: June 28, 2018
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Masaaki ITO, Noritsugu SAKUMA, Masao YANO, Hidefumi KISHIMOTO, Tetsuya SHOJI
  • Publication number: 20180182516
    Abstract: To provide an R—Fe—B-based rare earth magnet where R is mainly Ce, ensuring that even when a rare earth element R1 except for Ce is very small in amount or is not present, the coercive force can be enhanced. A rare earth magnet wherein the rare earth magnet has a total composition represented by the formula: CepR1qT(100-p-q-r-s)BrM1s (wherein R1 is a rare earth element except for Ce, T is one or more members selected from Fe, Ni and Co, M1 is one or more members selected from Ti, Ga, Zn, Si, Al, Nb, Zr, Mn, V, W, Ta, Ge, Cu, Cr, Hf, Mo, P, C, Mg, Hg, Ag, and Au, and an unavoidable impurity, and p, q, r, and s are 11.80?p?12.90, 0?q?3.00, 5.00?r?20.00, and 0?s?3.00), and wherein the rear earth magnet comprises a magnetic phase and a (Ce,R1)-rich phase present around the magnetic phase.
    Type: Application
    Filed: December 19, 2017
    Publication date: June 28, 2018
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Masaaki ITO, Noritsugu SAKUMA, Masao YANO, Hidefumi KISHIMOTO, Tetsuya SHOJI
  • Publication number: 20180182519
    Abstract: A rare earth magnet includes a main phase, a grain boundary phase present around the main phase and an intermediate phase interposed between the main phase and the grain boundary phase, and has an overall composition that is represented by the formula ((Ce(1-x)Lax)(1-y)R1y)pT(100-p-q-r)BqM1r.(R21-zM2z)s (where, R1 and R2 are rare earth elements other than Ce and La, T is at least one selected from among Fe, Ni, and Co, M1 is an element having a small amount that does not influence magnetic characteristics, and M2 is an alloy element for which a melting point of R21-zM2z is lower than a melting point of R2). A total concentration of Ce and La is higher in the main phase than in the intermediate phase, and a concentration of R2 is higher in the intermediate phase than in the main phase.
    Type: Application
    Filed: December 5, 2017
    Publication date: June 28, 2018
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Masaaki Ito, Noritsugu Sakuma, Tetsuya Shoji, Hidefumi Kishimoto, Masao Yano
  • Publication number: 20180040404
    Abstract: The invention provides a nanocomposite magnet, which has achieved high coercive force and high residual magnetization. The magnet is a non-ferromagnetic phase that is intercalated between a hard magnetic phase with a rare-earth magnet composition and a soft magnetic phase, wherein the non-ferromagnetic phase reacts with neither the hard nor soft magnetic phase. A hard magnetic phase contains Nd2Fe14B, a soft magnetic phase contains Fe or Fe2Co, and a non-ferromagnetic phase contains Ta. The thickness of the non-ferromagnetic phase containing Ta is 5 nm or less, and the thickness of the soft magnetic phase containing Fe or Fe2Co is 20 nm or less. Nd, or Pr, or an alloy of Nd and any one of Cu, Ag, Al, Ga, and Pr, or an alloy of Pr and any one of Cu, Ag, Al, and Ga is diffused into a grain boundary phase of the hard magnetic phase of Nd2Fe14B.
    Type: Application
    Filed: October 16, 2017
    Publication date: February 8, 2018
    Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Hidefumi KISHIMOTO, Noritsugu SAKUMA, Masao YANO, Weibin CUI, Yukiko TAKAHASHI, Kazuhiro HONO
  • Patent number: 9818520
    Abstract: The invention provides a nanocomposite magnet, which has achieved high coercive force and high residual magnetization. The magnet is a non-ferromagnetic phase that is intercalated between a hard magnetic phase with a rare-earth magnet composition and a soft magnetic phase, wherein the non-ferromagnetic phase reacts with neither the hard nor soft magnetic phase. A hard magnetic phase contains Nd2Fe14B, a soft magnetic phase contains Fe or Fe2Co, and a non-ferromagnetic phase contains Ta. The thickness of the non-ferromagnetic phase containing Ta is 5 nm or less, and the thickness of the soft magnetic phase containing Fe or Fe2Co is 20 nm or less. Nd, or Pr, or an alloy of Nd and any one of Cu, Ag, Al, Ga, and Pr, or an alloy of Pr and any one of Cu, Ag, Al, and Ga is diffused into a grain boundary phase of the hard magnetic phase of Nd2Fe14B.
    Type: Grant
    Filed: December 27, 2012
    Date of Patent: November 14, 2017
    Assignees: TOYOTA JIDOSHA KABUSHIKI KAISHA, NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Hidefumi Kishimoto, Noritsugu Sakuma, Masao Yano, Weibin Cui, Yukiko Takahashi, Kazuhiro Hono
  • Patent number: 9761358
    Abstract: A method for producing a nanocrystalline rare earth magnet having a grain and a grain boundary phase includes: quenching a melt of a rare earth magnet composition to form a quenched thin ribbon having a nanocrystalline structure; sintering the quenched thin ribbon to obtain a sintered body; heat treating the sintered body at a temperature which is higher than a lowest temperature in a first temperature range where the grain boundary phase diffuses or flows, and which is lower than a lowest temperature in a second temperature range where the grain becomes coarse; and quenching the heat treated sintered body to 200° C. or less at a cooling speed of 50° C./min or more.
    Type: Grant
    Filed: August 22, 2012
    Date of Patent: September 12, 2017
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Noritsugu Sakuma, Hidefumi Kishimoto
  • Patent number: 9640305
    Abstract: A method for producing a sintered rare-earth magnet characterized by sintering a raw material that includes a ribbon-shaped polycrystalline phase with an average grain size of 10 to 200 nm fabricated by rapid solidification of an alloy melt having a rare-earth magnet composition, and a low-melting point phase formed on the surface of the polycrystalline phase and having a melting point lower than the polycrystalline phase.
    Type: Grant
    Filed: November 18, 2010
    Date of Patent: May 2, 2017
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Tetsuya Shoji, Noritsugu Sakuma, Hidefumi Kishimoto
  • Patent number: 9520230
    Abstract: A rare earth magnet, which is represented by a neodymium magnet (Nd2Fe14B) and neodymium magnet films with applications in micro-systems. A method for producing a rare earth magnet, comprising: (a) quenching a molten metal having a rare earth magnet composition to form quenched flakes of nanocrystalline structure; sintering the quenched flakes; subjecting the sintered body obtained to an orientation treatment; and applying a heat treatment with pressurization at a temperature sufficiently high to enable diffusion or fluidization of a grain boundary phase and at the same time, low enough to prevent coarsening of the crystal grains, (b) thick films deposited on a substrate, applying an annealing to crystallize with pressurization at a temperature sufficiently high to enable diffusion or fluidization of a grain boundary phase and, at the same time, low enough to prevent coarsening of the crystal grains.
    Type: Grant
    Filed: May 13, 2011
    Date of Patent: December 13, 2016
    Assignees: TOYOTA JIDOSHA KABUSHIKI KAISHA, CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE, LEIBNIZ INSTITUTE FOR SOLID STATE AND MATERIALS RESEARCH DRESDEN, UNIVERSITY OF SHEFFIELD
    Inventors: Noritsugu Sakuma, Hidefumi Kishimoto, Akira Kato, Tetsuya Shoji, Dominique Givord, Nora Dempsey, Thomas George Woodcock, Oliver Gutfleisch, Gino Hrkac, Thomas Schrefl
  • Publication number: 20160141083
    Abstract: To provide a rare earth magnet ensuring excellent magnetic anisotropy while reducing the amount of Nd, etc., and a manufacturing method thereof. A rare earth magnet comprising a crystal grain having an overall composition of (R2(1-x)R1x)yFe100-y-w-z-vCowBzTMv (wherein R2 is at least one of Nd, Pr, Dy and Tb, R1 is an alloy of at least one or two or more of Ce, La, Gd, Y and Sc, TM is at least one of Ga, Al, Cu, Au, Ag, Zn, In and Mn, 0<x<1, y=12 to 20, z=5.6 to 6.5, w=0 to 8, and v=0 to 2), wherein the average grain size of the crystal grain is 1,000 nm or less, the crystal grain consists of a core and an outer shell, the core has a composition of R1 that is richer than R2, and the outer shell has a composition of R2 that is richer than R1.
    Type: Application
    Filed: June 5, 2014
    Publication date: May 19, 2016
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Masaaki ITO, Masao YANO, Hidefumi KISHIMOTO, Noritsugu SAKUMA, Tetsuya SHOJI, Akira MANABE
  • Publication number: 20160074936
    Abstract: A method for producing a raw material powder of a permanent magnet, includes: preparing a material powder of a permanent magnet, measuring magnetic characteristics of the material powder, and judging the quality of the material powder as the raw material powder based on a preliminarily determined relation between magnetic characteristics and the structure of the material powder. A method for producing a permanent magnet includes integrating material powders judged as good in the step of judging the quality as raw material powders by the method for producing a raw material powder of a permanent magnet. A method for inspecting a permanent magnet material powder includes transmitting a magnetic field to a material powder of a permanent magnet, receiving the magnetic field from the material powder, and measuring a magnetic field difference between the transmitted magnetic field and the received magnetic field as magnetic characteristics of the material powder.
    Type: Application
    Filed: May 24, 2013
    Publication date: March 17, 2016
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Noritsugu SAKUMA, Hidefumi KISHIMOTO, Mikiya NOZAKI, Masao YANO, Tetsuya SHOJI, Akira MANABE
  • Publication number: 20160071635
    Abstract: Provided is a magnetic compound represented by the formula (R(1-x)Zrx)a(Fe(1-y)Coy)bTcMdAe (wherein R represents one or more rare earth elements, T represents one or more elements selected from the group consisting of Ti, V, Mo, and W, M represents one or more elements selected from the group consisting of unavoidable impurity elements, Al, Cr, Cu, Ga, Ag, and Au, A represents one or more elements selected from the group consisting of N, C, H, and P, 0?x?0.5, 0?y?0.6, 4?a?20, b=100?a?c?d, 0<c<7, 0?d?1, and 1?e?18), in which a main phase of the magnetic compound includes a ThMn12 type crystal structure, and a volume percentage of an ?-(Fe,Co) phase is 20% or lower.
    Type: Application
    Filed: September 3, 2015
    Publication date: March 10, 2016
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Noritsugu SAKUMA, Akira KATO, Kota WASHIO, Hidefumi KISHIMOTO, Masao YANO, Akira MANABE, Masaaki ITO, Shunji SUZUKI, Kurima KOBAYASHI
  • Publication number: 20150008998
    Abstract: The invention provides a nanocomposite magnet, which has achieved high coercive force and high residual magnetization. The magnet is a non-ferromagnetic phase that is intercalated between a hard magnetic phase with a rare-earth magnet composition and a soft magnetic phase, wherein the non-ferromagnetic phase reacts with neither the hard nor soft magnetic phase. A hard magnetic phase contains Nd2Fe14B, a soft magnetic phase contains Fe or Fe2Co, and a non-ferromagnetic phase contains Ta. The thickness of the non-ferromagnetic phase containing Ta is 5 nm or less, and the thickness of the soft magnetic phase containing Fe or Fe2Co is 20 nm or less. Nd, or Pr, or an alloy of Nd and any one of Cu, Ag, Al, Ga, and Pr, or an alloy of Pr and any one of Cu, Ag, Al, and Ga is diffused into a grain boundary phase of the hard magnetic phase of Nd2Fe14B.
    Type: Application
    Filed: December 27, 2012
    Publication date: January 8, 2015
    Applicants: NATIONAL INSTITUTE FOR MATERIALS SCIENCE, TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Hidefumi Kishimoto, Noritsugu Sakuma, Masao Yano, Weibin Cui, Yukiko Takahashi, Kazuhiro Hono
  • Publication number: 20140260800
    Abstract: A method for producing magnetic powder for forming a sintered body that is a precursor of a rare-earth magnet. Provided is a method for producing magnetic powder for forming a sintered body that is a precursor of a rare-earth magnet, which can produce magnetic powder with a structure containing optimal nanosized crystal grains by accurately and efficiently sorting out magnetic powder containing no coarse grains in the structure thereof.
    Type: Application
    Filed: October 9, 2012
    Publication date: September 18, 2014
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Noritsugu Sakuma, Hidefumi Kishimoto, Noritaka Miyamoto, Akira Kato, Akira Manabe, Daisuke Ichigozaki, Tetsuya Shoji, Shoichi Harakawa
  • Publication number: 20140238553
    Abstract: Provided are a sintered body for forming a rare-earth magnet with a high degree of orientation and high remanent magnetization, and a method for producing magnetic powder for forming the sintered body. A sintered body S that is a precursor of a rare-earth magnet, the sintered body S including crystal grains g2 of an Nd—Fe—B-based main phase with a nanocrystalline structure, and a grain boundary phase around the main phase, and the rare-earth magnet being adapted to be formed by applying hot deformation processing to the sintered body S for imparting anisotropy thereto and further diffusing an alloy for improving coercivity therein. Each crystal grain g2 that forms the sintered body S has a planar shape that is, when viewed from a direction perpendicular to an easy direction of magnetization (i.e., a c-axis direction), a rectangle having sides in the c-axis direction and sides in a direction (i.e., an a-axis direction) that is perpendicular to the c-axis direction, or a shape that is close to the rectangle.
    Type: Application
    Filed: October 9, 2012
    Publication date: August 28, 2014
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Noritsugu Sakuma, Hidefumi Kishimoto, Masao Yano
  • Publication number: 20140191833
    Abstract: A method for producing a nanocrystalline rare earth magnet having a grain and a grain boundary phase includes: quenching a melt of a rare earth magnet composition to form a quenched thin ribbon having a nanocrystalline structure; sintering the quenched thin ribbon to obtain a sintered body; heat treating the sintered body at a temperature which is higher than a lowest temperature in a first temperature range where the grain boundary phase diffuses or flows, and which is lower than a lowest temperature in a second temperature range where the grain becomes coarse; and quenching the heat treated sintered body to 200° C. or less at a cooling speed of 50° C./min or more.
    Type: Application
    Filed: August 22, 2012
    Publication date: July 10, 2014
    Inventors: Noritsugu Sakuma, Hidefumi Kishimoto
  • Publication number: 20140116577
    Abstract: Method of producing a rare earth magnetic alloy ribbon by rapid solidification using a rotary roll comprising: a step of preparing a rare earth magnetic alloy melt inside of a nozzle which faces said rotary roll, a step of applying a discharge pressure to said rare earth magnetic alloy melt in said nozzle, and a step of causing the discharge pressure to fall from a value at the time of start of discharge to a value which is required for sustained discharge at the instant that said rare earth magnetic alloy melt starts to be discharged from said nozzle. Preferably, the discharge pressure which is loaded on the melt surface inside the nozzle is made to increase from the sustained discharge pressure in accordance with the decrease in the amount of melt in the nozzle.
    Type: Application
    Filed: October 28, 2013
    Publication date: May 1, 2014
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Noritsugu SAKUMA, Hidefumi KISHIMOTO, Mikiya NOZAKI
  • Publication number: 20130248754
    Abstract: The method of the present invention produces a rare earth magnet, which is represented by a neodymium magnet (Nd2Fe14B) and neodymium magnet films with applications in micro-systems, by using a heat treatment method capable of enhancing the magnetic characteristics, particularly the magnetic coercive force. A method for producing a rare earth magnet, comprising: (a) quenching a molten metal having a rare earth magnet composition to form quenched flakes of nanocrystalline structure; sintering the quenched flakes; subjecting the sintered body obtained to an orientation treatment; and applying a heat treatment with pressurization at a temperature sufficiently high to enable diffusion or fluidization of a grain boundary phase and at the same time, low enough to prevent coarsening of the crystal grains.
    Type: Application
    Filed: May 13, 2011
    Publication date: September 26, 2013
    Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, UNIVERSITY OF SHEFFIELD, CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE
    Inventors: Noritsugu Sakuma, Hidefumi Kishimoto, Akira Kato, Tetsuya Shoji, Dominique Givord, Nora Dempsey, Thomas George Woodcock, Oliver Gutfleisch, Gino Hrkac, Thomas Schrefl
  • Publication number: 20130092867
    Abstract: A method for producing a sintered rare-earth magnet characterized by sintering a raw material that includes a ribbon-shaped polycrystalline phase with an average grain size of 10 to 200 nm fabricated by rapid solidification of an alloy melt having a rare-earth magnet composition, and a low-melting point phase formed on the surface of the polycrystalline phase and having a melting point lower than the polycrystalline phase.
    Type: Application
    Filed: November 18, 2010
    Publication date: April 18, 2013
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Tetsuya Shoji, Noritsugu Sakuma, Hidefumi Kishimoto