Patents by Inventor Hiroyuki Tomizawa

Hiroyuki Tomizawa 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: 8092619
    Abstract: An R-T-Cu—Mn—B based sintered magnet includes: 12.0 at % to 15.0 at % of R, which is at least one of the rare-earth elements that include Y and of which at least 50 at % is Pr and/or Nd; 5.5 at % to 6.5 at % of B; 0.08 at % to 0.35 at % of Cu; 0.04 at % to less than 0.2 at % of Mn; at most 2 at % (including 0 at %) of M, which is one, two, or more elements that are selected from the group consisting of Al, Ti, V, Cr, Ni, Zn, Ga, Zr, Nb, Mo, Ag, In, Sn, Hf, Ta, W, Au, Pb and Bi; and T as the balance, which is either Fe alone or Fe and Co and of which at most 20 at % is Co if T includes both Fe and Co.
    Type: Grant
    Filed: June 11, 2009
    Date of Patent: January 10, 2012
    Assignee: Hitachi Metals, Ltd.
    Inventors: Futoshi Kuniyoshi, Rintaro Ishii, Hiroyuki Tomizawa
  • Publication number: 20110095855
    Abstract: An R-T-Cu—Mn—B based sintered magnet includes: 12.0 at % to 15.0 at % of R, which is at least one of the rare-earth elements that include Y and of which at least 50 at % is Pr and/or Nd; 5.5 at % to 6.5 at % of B; 0.08 at % to 0.35 at % of Cu; 0.04 at % to less than 0.2 at % of Mn; at most 2 at % (including 0 at %) of M, which is one, two, or more elements that are selected from the group consisting of Al, Ti, V, Cr, Ni, Zn, Ga, Zr, Nb, Mo, Ag, In, Sn, Hf, Ta, W, Au, Pb and Bi; and T as the balance, which is either Fe alone or Fe and Co and of which at most 20 at % is Co if T includes both Fe and Co.
    Type: Application
    Filed: June 11, 2009
    Publication date: April 28, 2011
    Applicant: HITACHI METALS, LTD.
    Inventors: Futoshi Kuniyoshi, Rintaro Ishii, Hiroyuki Tomizawa
  • Patent number: 7892365
    Abstract: A method of making a magnetically anisotropic magnet powder according to the present invention includes the steps of preparing a master alloy by cooling a rare-earth-iron-boron based molten alloy and subjecting the master alloy to an HDDR process. The step of preparing the master alloy includes the step of forming a solidified alloy layer, including a plurality of R2Fe14B-type crystals (where R is at least one element selected from the group consisting of the rare-earth elements and yttrium) in which rare-earth-rich phases are dispersed, by cooling the molten alloy through contact with a cooling member.
    Type: Grant
    Filed: December 5, 2007
    Date of Patent: February 22, 2011
    Assignee: Hitachi Metals, Ltd.
    Inventors: Hiroyuki Tomizawa, Yuji Kaneko
  • Patent number: 7867343
    Abstract: In a rare earth magnet, an added heavy rare earth element RH such as Dy is effectively used without any waste, so as to effectively improve the coercive force. First, a molten alloy of a material alloy for an R-T-Q rare earth magnet (R is a rare earth element, T is a transition metal element, and Q is at least one element selected from the group consisting of B, C, N, Al, Si, and P), the rare earth element R containing at least one kind of element RL selected from the group consisting of Nd and Pr and at least one kind of element RH selected from the group consisting of Dy Tb, and Ho is prepared. The molten alloy is quenched, so as to produce a solidified alloy. Thereafter, a thermal treatment in which the rapidly solidified alloy is held in a temperature range of 400° C. or higher and lower than 800° C. for a period of not shorter than 5 minutes nor longer than 12 hours is performed.
    Type: Grant
    Filed: June 26, 2007
    Date of Patent: January 11, 2011
    Assignee: Hitachi Metals, Ltd.
    Inventors: Hiroyuki Tomizawa, Yuji Kaneko
  • Patent number: 7789933
    Abstract: An R-T-B based sintered magnet according to the present invention comprises: 12 at % to 15 at % of a rare-earth element R; 5.0 at % to 8.0 at % of boron B; 0.02 at % to 0.2 at % of Mn; and a transition metal T as the balance. The rare-earth element R is at least one element selected from the rare-earth elements, including Y (yttrium), and includes 0.2 at % to 8 at % of Pr. And the transition element T includes Fe as its main element.
    Type: Grant
    Filed: September 18, 2009
    Date of Patent: September 7, 2010
    Assignee: Hitachi Metals, Ltd.
    Inventor: Hiroyuki Tomizawa
  • Patent number: 7740715
    Abstract: An R-T-B based sintered magnet according to the present invention has a composition comprising: 12 at % to 15 at % of a rare-earth element R; 5.0 at % to 8.0 at % of boron B; 0.1 at % to at % of Al; 0.02 at % to less than 0.2 at % of Mn; and a transition metal T as the balance. The rare-earth element R is at least one element selected from the rare-earth elements, including Y (yttrium), and includes at least one of Nd and Pr. The transition element T includes Fe as its main element.
    Type: Grant
    Filed: September 16, 2009
    Date of Patent: June 22, 2010
    Assignee: Hitachi Metals, Ltd.
    Inventor: Hiroyuki Tomizawa
  • Publication number: 20100008814
    Abstract: An R-T-B based sintered magnet according to the present invention comprises: 12 at % to 15 at % of a rare-earth element R; at % to 8.0 at % of boron B; 0.02 at % to 0.2 at % of Mn; and a transition metal T as the balance. The rare-earth element R is at least one element selected from the rare-earth elements, including Y (yttrium), and includes 0.2 at % to 8 at % of Pr. And the transition element T includes Fe as its main element.
    Type: Application
    Filed: September 18, 2009
    Publication date: January 14, 2010
    Applicant: HITACHI METALS, LTD.
    Inventor: Hiroyuki TOMIZAWA
  • Publication number: 20100003160
    Abstract: An R-T-B based sintered magnet according to the present invention has a composition comprising: 12 at % to 15 at % of a rare-earth element R; 5.0 at % to 8.0 at % of boron B; 0.1 at % to at % of Al; 0.02 at % to less than 0.2 at % of Mn; and a transition metal T as the balance. The rare-earth element R is at least one element selected from the rare-earth elements, including Y (yttrium), and includes at least one of Nd and Pr. The transition element T includes Fe as its main element.
    Type: Application
    Filed: September 16, 2009
    Publication date: January 7, 2010
    Applicant: HITACHI METALS, LTD.
    Inventor: Hiroyuki TOMIZAWA
  • Patent number: 7578892
    Abstract: A magnetic alloy material according to the present invention has a composition represented by Fe100-a-b-cREaAbCoc, where RE is a rare-earth element always including La, A is either Si or Al, 6 at %?a?11 at %, 8 at %?b?18 at %, and 0 at %?c?9 at %, and has either a two phase structure consisting essentially of an ?-Fe phase and an (RE, Fe, A) phase including 30 at % to 90 at % of RE or a three phase structure consisting essentially of the ?-Fe phase, the (RE, Fe, A) phase including 30 at % to 90 at % of RE and an RE(Fe, A)13 compound phase with an NaZn13-type crystal structure. The respective phases have an average minor-axis size of 40 nm to 2 ?m.
    Type: Grant
    Filed: March 30, 2006
    Date of Patent: August 25, 2009
    Assignee: Hitachi Metals, Ltd.
    Inventors: Satoshi Hirosawa, Hiroyuki Tomizawa, Ryosuke Kogure
  • Patent number: 7550047
    Abstract: A method of making a magnetically anisotropic magnet powder according to the present invention includes the steps of preparing a master alloy by cooling a rare-earth-iron-boron based molten alloy and subjecting the master alloy to an HDDR process. The step of preparing the master alloy includes the step of forming a solidified alloy layer, including a plurality of R2Fe14B-type crystals (where R is at least one element selected from the group consisting of the rare-earth elements and yttrium) in which rare-earth-rich phases are dispersed, by cooling the molten alloy through contact with a cooling member.
    Type: Grant
    Filed: December 18, 2002
    Date of Patent: June 23, 2009
    Assignee: Hitachi Metals, Ltd.
    Inventors: Hiroyuki Tomizawa, Yuji Kaneko
  • Patent number: 7534311
    Abstract: A rare-earth sintered magnet according to the present invention, of which the main phase is an R2T14B type compound phase, includes: 27 mass % through 32 mass % of R, which is at least one rare-earth element that is selected from the group consisting of Nd, Pr, Tb, and Dy and that always includes at least one of Nd and Pr; 60 mass % through 73 mass % of T, which is either Fe alone or a mixture of Fe and Co; 0.85 mass % through 0.98 mass % of Q, which is either B alone or a mixture of B and C and which is converted-into B on a number of atoms basis when its mass percentage is calculated; more than 0 mass % through 0.3 mass % of Zr; at most 2.0 mass % of an additive element M, which is at least one element selected from the group consisting of Al, Cu, Ga, In and Sn; and inevitably contained impurities.
    Type: Grant
    Filed: August 10, 2004
    Date of Patent: May 19, 2009
    Assignee: Hitachi Metals, Ltd.
    Inventors: Hiroyuki Tomizawa, Yutaka Matsuura
  • Publication number: 20080271821
    Abstract: An R-T-B based sintered magnet according to the present invention has a composition comprising: 12 at % to 17 at % of a rare-earth element R; 5.0 at % to 8.0 at % of boron B; 0.1 at % to 1.0 at % of Al; 0.02 at % to less than 0.2 at % of Mn; and a transition metal T as the balance. The rare-earth element R is at least one element selected from the rare-earth elements, including Y (yttrium), and includes at least one of Nd and Pr. The transition element T includes Fe as its main element.
    Type: Application
    Filed: June 4, 2008
    Publication date: November 6, 2008
    Applicant: HITACHI METALS, LTD.
    Inventor: Hiroyuki TOMIZAWA
  • Publication number: 20080274009
    Abstract: An R-T-B based sintered magnet according to the present invention comprises: 12 at % to 17 at % of a rare-earth element R; 5.0 at % to 8.0 at % of boron B; 0.02 at % to 0.2 at % of Mn; and a transition metal T as the balance. The rare-earth element R is at least one element selected from the rare-earth elements, including Y (yttrium), and includes 0.2 at % to 8 at % of Pr. And the transition element T includes Fe as its main element.
    Type: Application
    Filed: June 4, 2008
    Publication date: November 6, 2008
    Applicant: HITACHI METALS, LTD.
    Inventor: Hiroyuki TOMIZAWA
  • Publication number: 20080113210
    Abstract: A method of making a magnetically anisotropic magnet powder according to the present invention includes the steps of preparing a master alloy by cooling a rare-earth-iron-boron based molten alloy and subjecting the master alloy to an HDDR process. The step of preparing the master alloy includes the step of forming a solidified alloy layer, including a plurality of R2Fe14B-type crystals (where R is at least one element selected from the group consisting of the rare-earth elements and yttrium) in which rare-earth-rich phases are dispersed, by cooling the molten alloy through contact with a cooling member.
    Type: Application
    Filed: December 5, 2007
    Publication date: May 15, 2008
    Applicant: NEOMAX CO., LTD.
    Inventors: Hiroyuki TOMIZAWA, Yuji KANEKO
  • Patent number: 7316752
    Abstract: The step of preparing a rapidly solidified alloy by rapidly quenching a melt of an R-T-B-C based rare-earth alloy (where R is at least one of the rare-earth elements including Y, T is a transition metal including iron as its main ingredient, B is boron, and C is carbon) and the step of thermally treating and crystallizing the rapidly solidified alloy are included. The step of thermally treating results in producing a first compound phase with an R2Fe14B type crystal structure and a second compound phase having a diffraction peak at a site with an interplanar spacing d of 0.295 nm to 0.300 nm (i.e., where 2?=30 degrees). An intensity ratio of the diffraction peak of the second compound phase to that of R2Fe14B type crystals representing a (410) plane is at least 10%. The present invention provides an R-T-B-C based rare-earth alloy magnetic material, including carbon (C) as an indispensable element but exhibiting excellent magnetic properties, and makes it possible to recycle rare-earth magnets.
    Type: Grant
    Filed: June 29, 2001
    Date of Patent: January 8, 2008
    Assignee: Neomax Co., Ltd.
    Inventors: Hiroyuki Tomizawa, Yuji Kaneko
  • Publication number: 20070261766
    Abstract: In a rare earth magnet, an added heavy rare earth element RH such as Dy is effectively used without any waste, so as to effectively improve the coercive force. First, a molten alloy of a material alloy for an R-T-Q rare earth magnet (R is a rare earth element, T is a transition metal element, and Q is at least one element selected from the group consisting of B, C, N, Al, Si, and P), the rare earth element R containing at least one kind of element RL selected from the group consisting of Nd and Pr and at least one kind of element RH selected from the group consisting of Dy Tb, and Ho is prepared. The molten alloy is quenched, so as to produce a solidified alloy. Thereafter, a thermal treatment in which the rapidly solidified alloy is held in a temperature range of 400° C. or higher and lower than 800° C. for a period of not shorter than 5 minutes nor longer than 12 hours is performed.
    Type: Application
    Filed: June 26, 2007
    Publication date: November 15, 2007
    Inventors: Hiroyuki Tomizawa, Yuji Kaneko
  • Patent number: 7258751
    Abstract: In a rare earth magnet, an added heavy rare earth element RH such as Dy is effectively used without any waste, so as to effectively improve the coercive force. First, a molten alloy of a material alloy for an R-T-Q rare earth magnet (R is a rare earth element, T is a transition metal element, and Q is at least one element selected from the group consisting of B, C, N, Al, Si, and P), the rare earth element R containing at least one kind of element RL selected from the group consisting of Nd and Pr and at least one kind of element RH selected from the group consisting of Dy Tb, and Ho is prepared. The molten alloy is quenched, so as to produce a solidified alloy. Thereafter, a thermal treatment in which the rapidly solidified alloy is held in a temperature range of 400° C. or higher and lower than 800° C. for a period of not shorter than 5 minutes nor longer than 12 hours is performed.
    Type: Grant
    Filed: June 19, 2002
    Date of Patent: August 21, 2007
    Assignee: Neomax Co., Ltd.
    Inventors: Hiroyuki Tomizawa, Yuji Kaneko
  • Patent number: 7172659
    Abstract: The present invention is a production method of an R-T-B—C rare earth alloy (R is at least one element selected from the group consisting of rare earth elements and yttrium, T is a transition metal including iron as a main component, B is boron, and C is carbon). An R-T-B bonded magnet containing a resin component, or an R-T-B sintered magnet with a resin film formed on the surface thereof is prepared, and a solvent alloy containing a rare earth element R and a transition metal element T is prepared. Thereafter, the R-T-B bonded magnet is molten together with the solvent alloy. In this way, a rare earth alloy can be recovered from a spent bonded magnet or a defective one generated in a production process stage, and a rapidly quenched alloy magnet can be obtained. As a result, magnet powder is recovered from the R-T-B magnet, and the recycling of a magnet including a resin component can be realized.
    Type: Grant
    Filed: June 24, 2002
    Date of Patent: February 6, 2007
    Assignee: Neomax Co., Ltd.
    Inventors: Hiroyuki Tomizawa, Koji Nakahara, Yuji Kaneko
  • Publication number: 20060231163
    Abstract: A magnetic alloy material according to the present invention has a composition represented by Fe100-a-b-cREaAbCoc, where RE is a rare-earth element always including La, A is either Si or Al, 6 at %?a?11 at %, 8 at %?b?18 at %, and 0 at %?c?9 at %, and has either a two phase structure consisting essentially of an ?-Fe phase and an (RE, Fe, A) phase including 30 at % to 90 at % of RE or a three phase structure consisting essentially of the ?-Fe phase, the (RE, Fe, A) phase including 30 at % to 90 at % of RE and an RE(Fe, A)13 compound phase with an NaZn13-type crystal structure. The respective phases have an average minor-axis size of 40 nm to 2 ?m.
    Type: Application
    Filed: March 30, 2006
    Publication date: October 19, 2006
    Inventors: Satoshi HIROSAWA, Hiroyuki Tomizawa, Ryosuke Kogure
  • Publication number: 20060201585
    Abstract: A rare-earth sintered magnet according to the present invention, of which the main phase is an R2T14B type compound phase, includes: 27 mass % through 32 mass % of R, which is at least one rare-earth element that is selected from the group consisting of Nd, Pr, Tb, and Dy and that always includes at least one of Nd and Pr; 60 mass % through 73 mass % of T, which is either Fe alone or a mixture of Fe and Co; 0.85 mass % through 0.98 mass % of Q, which is either B alone or a mixture of B and C and which is converted-into B on a number of atoms basis when its mass percentage is calculated; more than 0 mass % through 0.3 mass % of Zr; at most 2.0 mass % of an additive element M, which is at least one element selected from the group consisting of Al, Cu, Ga, In and Sn; and inevitably contained impurities.
    Type: Application
    Filed: August 10, 2004
    Publication date: September 14, 2006
    Inventors: Hiroyuki Tomizawa, Yutaka Matsuura