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).
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Patent number: 8092619Abstract: 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: GrantFiled: June 11, 2009Date of Patent: January 10, 2012Assignee: Hitachi Metals, Ltd.Inventors: Futoshi Kuniyoshi, Rintaro Ishii, Hiroyuki Tomizawa
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Publication number: 20110095855Abstract: 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: ApplicationFiled: June 11, 2009Publication date: April 28, 2011Applicant: HITACHI METALS, LTD.Inventors: Futoshi Kuniyoshi, Rintaro Ishii, Hiroyuki Tomizawa
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Patent number: 7892365Abstract: 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: GrantFiled: December 5, 2007Date of Patent: February 22, 2011Assignee: Hitachi Metals, Ltd.Inventors: Hiroyuki Tomizawa, Yuji Kaneko
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Patent number: 7867343Abstract: 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: GrantFiled: June 26, 2007Date of Patent: January 11, 2011Assignee: Hitachi Metals, Ltd.Inventors: Hiroyuki Tomizawa, Yuji Kaneko
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Patent number: 7789933Abstract: 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: GrantFiled: September 18, 2009Date of Patent: September 7, 2010Assignee: Hitachi Metals, Ltd.Inventor: Hiroyuki Tomizawa
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Patent number: 7740715Abstract: 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: GrantFiled: September 16, 2009Date of Patent: June 22, 2010Assignee: Hitachi Metals, Ltd.Inventor: Hiroyuki Tomizawa
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Publication number: 20100008814Abstract: 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: ApplicationFiled: September 18, 2009Publication date: January 14, 2010Applicant: HITACHI METALS, LTD.Inventor: Hiroyuki TOMIZAWA
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Publication number: 20100003160Abstract: 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: ApplicationFiled: September 16, 2009Publication date: January 7, 2010Applicant: HITACHI METALS, LTD.Inventor: Hiroyuki TOMIZAWA
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Patent number: 7578892Abstract: 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: GrantFiled: March 30, 2006Date of Patent: August 25, 2009Assignee: Hitachi Metals, Ltd.Inventors: Satoshi Hirosawa, Hiroyuki Tomizawa, Ryosuke Kogure
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Patent number: 7550047Abstract: 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: GrantFiled: December 18, 2002Date of Patent: June 23, 2009Assignee: Hitachi Metals, Ltd.Inventors: Hiroyuki Tomizawa, Yuji Kaneko
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Patent number: 7534311Abstract: 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: GrantFiled: August 10, 2004Date of Patent: May 19, 2009Assignee: Hitachi Metals, Ltd.Inventors: Hiroyuki Tomizawa, Yutaka Matsuura
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Publication number: 20080271821Abstract: 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: ApplicationFiled: June 4, 2008Publication date: November 6, 2008Applicant: HITACHI METALS, LTD.Inventor: Hiroyuki TOMIZAWA
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Publication number: 20080274009Abstract: 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: ApplicationFiled: June 4, 2008Publication date: November 6, 2008Applicant: HITACHI METALS, LTD.Inventor: Hiroyuki TOMIZAWA
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Publication number: 20080113210Abstract: 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: ApplicationFiled: December 5, 2007Publication date: May 15, 2008Applicant: NEOMAX CO., LTD.Inventors: Hiroyuki TOMIZAWA, Yuji KANEKO
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Patent number: 7316752Abstract: 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: GrantFiled: June 29, 2001Date of Patent: January 8, 2008Assignee: Neomax Co., Ltd.Inventors: Hiroyuki Tomizawa, Yuji Kaneko
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Publication number: 20070261766Abstract: 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: ApplicationFiled: June 26, 2007Publication date: November 15, 2007Inventors: Hiroyuki Tomizawa, Yuji Kaneko
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Patent number: 7258751Abstract: 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: GrantFiled: June 19, 2002Date of Patent: August 21, 2007Assignee: Neomax Co., Ltd.Inventors: Hiroyuki Tomizawa, Yuji Kaneko
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Patent number: 7172659Abstract: 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: GrantFiled: June 24, 2002Date of Patent: February 6, 2007Assignee: Neomax Co., Ltd.Inventors: Hiroyuki Tomizawa, Koji Nakahara, Yuji Kaneko
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Publication number: 20060231163Abstract: 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: ApplicationFiled: March 30, 2006Publication date: October 19, 2006Inventors: Satoshi HIROSAWA, Hiroyuki Tomizawa, Ryosuke Kogure
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Publication number: 20060201585Abstract: 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: ApplicationFiled: August 10, 2004Publication date: September 14, 2006Inventors: Hiroyuki Tomizawa, Yutaka Matsuura