Patents by Inventor Futoshi Kuniyoshi

Futoshi Kuniyoshi 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: 20240363272
    Abstract: Provided is a sintered R-T-B based magnet having high Br and high HcJ. A sintered R-T-B based magnet containing: R: 26.8 mass % or more and 31.5 mass % or less (R is a rare earth element, and necessarily contains Pr); M: 0.05 mass % or more and 2.00 mass % or less (M is at least one selected from the group consisting of Ga, Cu, Zn, Al, and Si, and necessarily contains Cu); B: 0.84 mass % or more and 0.94 mass % or less; and T: 61.5 mass % or more (T is Fe and Co, and 90% or more of T is Fe in mass ratio), and having an internal structure, wherein the internal structure includes: crystal grains; a first phase between adjacent two crystal grains; and a second phase with Cu and Pr concentrations higher than those of the first phase between the first phase and one or each of the two crystal grains and, wherein the second phase contains Pr of 20 mass % or more 65 mass % or less.
    Type: Application
    Filed: April 25, 2024
    Publication date: October 31, 2024
    Applicant: Proterial, Ltd.
    Inventor: Futoshi KUNIYOSHI
  • Publication number: 20240212895
    Abstract: Provided is a sintered R-T-B based magnet having high Br and high HcJ. A sintered R-T-B based magnet containing: R: 26.8 to 31.5 mass % (R is a rare earth element, and contains one or two selected from the group consisting of Nd and Pr); M: 0.05 to 2.00 mass % (M is at least one selected from the group consisting of Ga, Cu, Zn, Al, and Si, and necessarily contains Cu); B: 0.84 to 0.94 mass %; and T: 61.5 mass % or more (T is Fe and Co, and 90% or more of T is Fe in mass ratio), and having an internal structure, wherein the internal structure includes: crystal grains; a first phase between adjacent two crystal grains; and a second phase with a Cu concentration higher than that of the first phase between at least any one of the two crystal grains and the first phase, wherein the second phase contains F in a range of 2 to 20 mass % and has a higher F concentration than the first phase.
    Type: Application
    Filed: December 21, 2023
    Publication date: June 27, 2024
    Applicant: Proterial, Ltd.
    Inventor: Futoshi KUNIYOSHI
  • Publication number: 20240170206
    Abstract: A method for producing an R-T-B-based sintered magnet comprises a sintering step for sintering a shaped product of R-T-B-based alloy powder. This sintering step includes: a first step for heating the shaped product at a first sintering temperature T1 to prepare a first sintered body; a cooling step for lowering the temperature of the first sintered body to a cooling temperature T0; and a second step for heating the first sintered body at a second sintering temperature T2 to prepare a second sintered body. The first sintering temperature T1 and the second sintering temperature T2 are higher than 900° C., and the cooling temperature T0 is 900° C. or lower. A first sintering time t1 for which the first sintering temperature T1 is maintained in the first step is shorter than a second sintering time t2 for which the second sintering temperature T2 is maintained in the second step.
    Type: Application
    Filed: February 24, 2022
    Publication date: May 23, 2024
    Inventors: Kouta SAITOU, Futoshi KUNIYOSHI
  • Publication number: 20240112854
    Abstract: A method for recycling a rare earth element-containing powder, including: disintegrating a molded body for a rare earth sintered magnet including a rare earth element-containing powder in oil such that a 149 mesh-pass, 500 mesh-on powder is included; and separating and collecting a 149 mesh-pass powder obtained after the disintegrating to obtain a recycles powder.
    Type: Application
    Filed: September 28, 2023
    Publication date: April 4, 2024
    Applicant: PROTERIAL, LTD.
    Inventors: Takahiro YOMOGITA, Futoshi KUNIYOSHI
  • Patent number: 11823824
    Abstract: The present disclosure includes a main phase comprising an R2T14B compound, and a grain boundary phase. The atom number ratio of B to T in this R-T-B sintered magnet is less than the atom number ratio of B to T in the stoichiometric composition of the R2T14B compound, and the relationships 26.0 mass %?([Nd]+[Pr]+[Ce]+[Dy]+[Tb])?(9×[O]+12×[C])?27.5 mass %, 0.15 mass %?[O]?0.30 mass %, and 0.05 mass %<[Tb]?0.35 mass % are satisfied, where [Nd] is the Nd content (mass %), [Pr] is the Pr content (mass %), [Ce] is the Ce content (mass %), [Dy] is the Dy content (mass %), [O] is the O content (mass %), and [C] is the C content (mass %). Tb concentration and/or the Dy concentration gradually decreases from the magnet surface toward the magnet interior, at least in part.
    Type: Grant
    Filed: September 17, 2021
    Date of Patent: November 21, 2023
    Assignee: PROTERIAL, LTD.
    Inventor: Futoshi Kuniyoshi
  • Publication number: 20230307158
    Abstract: A sintered R-T-B based magnet includes a main phase formed of an R2T14B compound and a grain boundary phase at grain boundaries of the main phase. The grain boundary phase contains an R-T-M compound (M is at least one selected from the group consisting of Ga, Cu, Zn, Al and Si) and an R-M compound. In any cross-section of the sintered R-T-B based magnet, a sum of an area ratio of the R-T-M compound and an area ratio of the R-M compound is not lower than 1.5% and not higher than 3.5%, the area ratio of the R-T-M compound is not lower than 0.4% and not higher than 2.5%, and the area ratio of the R-M compound is not lower than 0.4% and not higher than 2.5%.
    Type: Application
    Filed: February 23, 2023
    Publication date: September 28, 2023
    Inventors: Daisuke FURUSAWA, Futoshi KUNIYOSHI
  • Patent number: 11738390
    Abstract: An application step of applying an adhesive agent to an application area of a surface of a sintered R-T-B based magnet work, an adhesion step of allowing a particle size-adjusted powder that is composed of a powder of an alloy or a compound of a Pr—Ga alloy which is at least one of Dy and Tb to the application area of the surface of the sintered R-T-B based magnet work, and a diffusing step of heating it at a temperature which is equal to or lower than a sintering temperature of the sintered R-T-B based magnet work to allow the Pr—Ga alloy contained in the particle size-adjusted powder to diffuse from the surface into the interior of the sintered R-T-B based magnet work are included.
    Type: Grant
    Filed: September 26, 2017
    Date of Patent: August 29, 2023
    Assignee: PROTERIAL, LTD.
    Inventors: Futoshi Kuniyoshi, Shuji Mino
  • Publication number: 20230260684
    Abstract: The present disclosure includes a main phase comprising an R2T14B compound, and a grain boundary phase. The atom number ratio of B to T in this R—T—B sintered magnet is less than the atom number ratio of B to T in the stoichiometric composition of the R2T14B compound, and the relationships 26.0 mass %?([Nd]+[Pr]+[Ce]+[Dy]+[Tb])?(9×[O]+12×[C])?27.5 mass %, 0.15 mass %?[O]?0.30 mass %, and 0.05 mass %<[Tb]?0.35 mass % are satisfied, where [Nd] is the Nd content (mass %), [Pr] is the Pr content (mass %), [Ce] is the Ce content (mass %), [Dy] is the Dy content (mass %), [O] is the O content (mass %), and [C] is the C content (mass %). Tb concentration and/or the Dy concentration gradually decreases from the magnet surface toward the magnet interior, at least in part.
    Type: Application
    Filed: September 17, 2021
    Publication date: August 17, 2023
    Inventor: Futoshi KUNIYOSHI
  • Publication number: 20230040720
    Abstract: A method for manufacturing an R-T-B based sintered magnet according the present disclosure comprises: a step for preparing a coarse ground powder which is made from an alloy for R-T-B based sintered magnets and which has an average particle size of 10-500 ?m; a step for obtaining a fine powder having an average particle size of 2.0-4.5 ?m, by feeding the coarse ground powder to a jet mill device that has a grinding chamber filled with inert gas and grinding the coarse ground powder; and a step for producing a sintered body of the fine powder, wherein the inert gas has been humidified, and the oxygen content of the R-T-B based sintered magnet is 1000-3500 ppm by mass.
    Type: Application
    Filed: December 24, 2020
    Publication date: February 9, 2023
    Inventors: Nobuhiko FUJIMORI, Tohru OBATA, Kazuhiro SONODA, Futoshi KUNIYOSHI, Daisuke FURUSAWA, Tomohito MAKI, Shuji MINO, Kouta SAITOU
  • Patent number: 11239011
    Abstract: A sintered R-T-B based magnet has remanence (Br) of 1.47 T or greater and coercivity (HcJ) of 1900 kA/m or greater and contains Tb at a content of 0.35 mass % or lower.
    Type: Grant
    Filed: March 23, 2020
    Date of Patent: February 1, 2022
    Assignee: HITACHI METALS, LTD.
    Inventor: Futoshi Kuniyoshi
  • Patent number: 11177069
    Abstract: A sintered R-T-B based magnet work contains R: 27.5 to 35.0 mass % (R is at least one rare-earth element which always includes Nd), B: 0.80 to 0.99 mass %, Ga: 0 to 0.8 mass %, M: 0 to 2 mass % (M is at least one of Cu, Al, Nb and Zr), and a balance T (T is at least one transition metal element which always includes Fe, with 10% or less of Fe replaceable by Co). [T]/55.85>14[B]/10.8 is satisfied where [T] is the T content (mass %) and [B] is the B content (mass %). At least a portion of a Pr—Ga alloy is in contact with a portion of the sintered magnet work surface, and a first heat treatment is performed at a temperature between 600° C. and 950° C. A second heat treatment is performed at a temperature lower than the temperature of the first heat treatment and between 450° C. and 750° C.
    Type: Grant
    Filed: July 20, 2016
    Date of Patent: November 16, 2021
    Assignee: HITACHI METALS, LTD.
    Inventor: Futoshi Kuniyoshi
  • Patent number: 11174537
    Abstract: A sintered R-T-B based magnet includes a main phase crystal grain and a grain boundary phase, in which R: not less than 27.5 mass % and not more than 35.0 mass % (R always includes at least Nd and Pr); B: not less than 0.80 mass % and not more than 1.05 mass %; Ga: not less than 0.05 mass % and not more than 1.0 mass %; M: not more than 2 mass % (where M is at least one of Cu, Al, Nb, and Zr); and a balance T (where T is Fe, or Fe and Co) and impurities. At 300-?m depth from the magnet surface, a Pr/Nd ratio in a central portion of a main phase crystal grain is lower than 1, and a Pr/Nd ratio in an intergranular grain boundary is higher than 1. The Ga concentration gradually decreases in a portion of the magnet from the surface toward the interior.
    Type: Grant
    Filed: August 14, 2017
    Date of Patent: November 16, 2021
    Assignee: HITACHI METALS, LTD.
    Inventor: Futoshi Kuniyoshi
  • Patent number: 11062844
    Abstract: A method for producing a sintered R-T-B based magnet includes applying an adhesive agent to an application area of the magnet, adhering a particle size-adjusted powder of a heavy rare-earth element RH which is at least one of Dy and Tb to the application area, and heating at a temperature which is equal to or lower than a sintering temperature of the magnet to allow the element RH in the particle size-adjusted powder to diffuse from the surface into the interior of the magnet. The particle size of the particle size-adjusted powder is set so that, when powder particles are placed on the entire surface of the magnet to form a single particle layer, the amount of element RH in the particle size-adjusted powder is in a range from 0.6 to 1.5% with respect to the magnet by mass ratio.
    Type: Grant
    Filed: July 28, 2017
    Date of Patent: July 13, 2021
    Assignee: HITACHI METALS, LTD.
    Inventors: Futoshi Kuniyoshi, Shuji Mino
  • Patent number: 11062843
    Abstract: A method for producing a sintered R-T-B based magnet includes the steps of: providing a sintered R1-T-B based magnet work (where R1 is a rare-earth element; T is Fe, or Fe and Co); providing a powder of an alloy in which a rare-earth element R2 accounts for 40 mass % or more of the entire alloy, the rare-earth element R2 always including Dy and/or Tb; subjecting the powder to a heat treatment to obtain a diffusion source; and heating the sintered R1-T-B based magnet work with the diffusion source to allow the at least one of Dy and Tb contained in the diffusion source to diffuse from the surface into the interior of the sintered R1-T-B based magnet work. The alloy powder is a powder produced by atomization.
    Type: Grant
    Filed: September 27, 2018
    Date of Patent: July 13, 2021
    Assignee: HITACHI METALS, LTD.
    Inventor: Futoshi Kuniyoshi
  • Patent number: 11037724
    Abstract: A method of producing a sintered R-T-B based magnet includes providing a sintered R-T-B based magnet work, an RH compound (at least one selected from RH fluorides, RH oxides, and RH oxyfluorides), and an RL-Ga alloy, where the sintered magnet work contains R: 27.5 to 35.0 mass %, B: 0.80 to 0.99 mass %, Ga: 0 to 0.8 mass %, M: 0 to 2 mass % (where M is at least one of Cu, Al, Nb and Zr), and T: 60 mass % or more; a diffusion step of, while keeping the RH compound and the RL-Ga alloy in contact with a surface of the sintered magnet work, performing a first heat treatment between 700° C. and 950° C. to increase the RH amount contained in the sintered magnet work by between 0.05 mass % and 0.40 mass %; and performing a second heat treatment between 450° C. and 750° C. but which is lower than the first heat treatment.
    Type: Grant
    Filed: January 31, 2018
    Date of Patent: June 15, 2021
    Assignee: HITACHI METALS, LTD.
    Inventor: Futoshi Kuniyoshi
  • Patent number: 10984930
    Abstract: A method for producing a sintered R-T-B based magnet includes the steps of: providing a sintered R-T-B based magnet work; providing a Pr—Ga alloy powder produced through atomization; subjecting the Pr—Ga alloy powder to a heat treatment at a temperature which is not lower than a temperature that is 250° C. below a melting point of the Pr—Ga alloy powder and which is not higher than the melting point, to obtain a diffusion source from the Pr—Ga alloy powder; and placing the sintered R-T-B based magnet work and the diffusion source in a process chamber, and heating the sintered R-T-B based magnet work and the diffusion source in a vacuum or an inert gas ambient, thereby allowing Pr and Ga to diffuse from the diffusion source into the interior of sintered R-T-B based magnet work.
    Type: Grant
    Filed: September 27, 2018
    Date of Patent: April 20, 2021
    Assignee: HITACHI METALS, LTD.
    Inventor: Futoshi Kuniyoshi
  • Patent number: 10923256
    Abstract: To provide an R-T-B based sintered magnet including R: 27.5 to 34.0% by mass, RH: 2 to 10% by mass, B: 0.89 to 0.95% by mass, Ti: 0.1 to 0.2% by mass, Ga: 0.3 to 0.7% by mass, Cu: 0.07 to 0.50% by mass, Al: 0.05 to 0.50% by mass, M (M is Nb and/or Zr): 0 to 0.3% by mass, balance T, and inevitable impurities, the following inequality expressions (1), (2), and (3) being satisfied: [T]?72.3([B]?0.45[Ti])>0??(1) ([T]?72.3([B]?0.45[Ti]))/55.85<13[Ga]/69.72??(2) [Ga]?[Cu]??(3).
    Type: Grant
    Filed: June 17, 2016
    Date of Patent: February 16, 2021
    Assignee: HITACHI METALS, LTD.
    Inventors: Teppei Satoh, Futoshi Kuniyoshi, Rintaro Ishii, Takeshi Nishiuchi, Noriyuki Nozawa
  • Publication number: 20200411236
    Abstract: A sintered R-T-B based magnet work, an RH compound (at least one selected from RH fluorides, RH oxides, and RH oxyfluorides), and an RL-Ga alloy are provided. The sintered magnet work contains R: 27.5 to 35.0 mass %, B: 0.80 to 0.99 mass %, Ga: 0 to 0.8 mass %, M: 0 to 2 mass % (where M is at least one of Cu, Al, Nb and Zr), and T: 60 mass % or more. A diffusion step of, while keeping at least a portion of the RH compound and at least a portion of the RL-Ga alloy in contact with at least a portion of a surface of the sintered magnet work, performing a first heat treatment at a temperature which is not lower than 700° C. and not higher than 950° C. to increase the RH amount contained in the sintered magnet work by not less than 0.05 mass % and not more than 0.40 mass %, is performed; and a second heat treatment is performed at a temperature which is not lower than 450° C. and not higher than 750° C. but which is lower than the temperature of the first heat treatment.
    Type: Application
    Filed: January 31, 2018
    Publication date: December 31, 2020
    Inventor: Futoshi KUNIYOSHI
  • Patent number: 10847290
    Abstract: To provide an R-T-B based sintered magnet having high Br and high HcJ while suppressing the content of Dy. Disclosed is an R-T-B based sintered magnet represented by the formula: uRwBxGayCuzAlqM(balance)T, where R is composed of light rare-earth element(s) RL and heavy rare-earth element(s) RH, RL is Nd and/or Pr, RH is Dy and/or Tb, T is Fe, and 10% by mass or less of Fe is capable of being replaced with Co, M is Nb and/or Zr, inevitable impurities being included, and u, w, x, y, z and q are expressed in terms of % by mass; RH accounts for 5% by mass or less of the R-T-B based sintered magnet, 0.4?x?1.0, 0.07?y?1.0, 0.05?z?0.5, 0?q?0.1, and 0.100?y/(x+y)?0.340; v=u?(6?+10?+8?), where the amount of oxygen (% by mass) is ?, the amount of nitrogen (% by mass) is ?, and the amount of carbon (% by mass) is ?; and v and w satisfy the following inequality expressions: v?32.0, 0.84?w?0.93, and ?12.5w+38.75?v??62.5w+86.125.
    Type: Grant
    Filed: August 11, 2014
    Date of Patent: November 24, 2020
    Assignee: HITACHI METALS, LTD.
    Inventors: Takeshi Nishiuchi, Takayuki Kanda, Rintaro Ishii, Futoshi Kuniyoshi, Teppei Satoh
  • Publication number: 20200312492
    Abstract: A sintered R-T-B based magnet has remanence (Br) of 1.47 T or greater and coercivity (HcJ) of 1900 kA/m or greater and contains Tb at a content of 0.35 mass % or lower.
    Type: Application
    Filed: March 23, 2020
    Publication date: October 1, 2020
    Inventor: Futoshi KUNIYOSHI