Patents by Inventor Yoshihito Yoshizawa

Yoshihito Yoshizawa 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: 10546674
    Abstract: Conventional Fe-based soft magnetic alloy ribbons each containing Co and Ni have a problem that magnetic anisotropy that is neatly arranged in one direction cannot be induced easily even by a magnetic field annealing treatment and, therefore, a wound magnetic cores, a problem that a residual magnetic flux density Br is high, a problem that the hysteresis of the B—H curve becomes large (coercivity Hc becomes large), a problem that the change in incremental permeability relative to superimposed magnetic field becomes large, and others. In order to solve the problems, provided is an Fe-based soft magnetic alloy ribbon including a Cu-concentrated region present directly below a surface of the ribbon, and a Co-concentrated region present directly below the Cu-concentrated region. Also provided is a magnetic core including the Fe-based soft magnetic alloy ribbon.
    Type: Grant
    Filed: November 19, 2015
    Date of Patent: January 28, 2020
    Assignee: HITACHI METALS, LTD.
    Inventor: Yoshihito Yoshizawa
  • Patent number: 10468182
    Abstract: A rapidly quenched Fe-based soft-magnetic alloy ribbon having wave-like undulations on a free surface, the wave-like undulations having transverse troughs arranged at substantially constant intervals in a longitudinal direction, and the troughs having an average amplitude D of 20 mm or less, is produced by a method comprising (a) keeping a transverse temperature distribution in a melt nozzle within ±15° C. to have as small a temperature distribution as possible in a melt paddle of the alloy, and (b) forming numerous fine linear scratches on a cooling roll surface by a wire brush, thereby providing a ground surface of the cooling roll with an arithmetical mean (average) roughness Ra of 0.1-1 ?m and a maximum roughness depth Rmax of 0.5-10 ?m.
    Type: Grant
    Filed: March 3, 2017
    Date of Patent: November 5, 2019
    Assignee: HITACHI METALS, LTD.
    Inventors: Yoshihito Yoshizawa, Motoki Ohta, Naoki Ito
  • Patent number: 10115509
    Abstract: An ultrafine-crystalline alloy ribbon having a composition represented by the general formula of Fe100-x-y-zAxByXz, wherein A is Cu and/or Au, X is at least one element selected from the group consisting of Si, S, C, P, Al, Ge, Ga and Be, and x, y and z are numbers meeting the conditions of 0<x?5, 8?y?22, 0?z?10, and x+y+z?25 by atomic %, and a structure in which ultrafine crystal grains having an average particle size of 30 nm or less being dispersed in a proportion of more than 0% and less than 30% by volume in an amorphous matrix; an ultrafine crystal grains-depleted region comprising ultrafine crystal grains at a number density of less than 500/?m2 being formed in a region of 0.2 mm in width from each side of the ribbon.
    Type: Grant
    Filed: September 10, 2013
    Date of Patent: October 30, 2018
    Assignee: HITACHI METALS, LTD.
    Inventors: Motoki Ohta, Yoshihito Yoshizawa
  • Publication number: 20180015574
    Abstract: Provided is a brazing alloy powder with which the development of defect in a brazed portion is suppressed and which enables an increase in the joint strength of the portion to be joined. Also provided is a brazed joined component having a high joint strength of the portion to be joined. The brazing alloy powder includes particles which include 55 mass % or more of at least one element selected from Ni, Fe, and Co. The alloy powder includes not less than 10% alloy particles having an amorphous phase. In addition, d90?60 ?m, where d90 is the grain diameter indicating 90% in an integral volume distribution curve according to a laser diffraction scattering method. The joined component includes a plurality of members joined with a brazing material including the brazing alloy powder.
    Type: Application
    Filed: December 7, 2015
    Publication date: January 18, 2018
    Applicant: HITACHI METALS, LTD.
    Inventors: Yoshihito YOSHIZAWA, Seishin UEDA
  • Publication number: 20170323712
    Abstract: Conventional Fe-based soft magnetic alloy ribbons each containing Co and Ni have a problem that magnetic anisotropy that is neatly arranged in one direction cannot be induced easily even by a magnetic field annealing treatment and, therefore, a wound magnetic cores, a problem that a residual magnetic flux density Br is high, a problem that the hysteresis of the B—H curve becomes large (coercivity Hc becomes large), a problem that the change in incremental permeability relative to superimposed magnetic field becomes large, and others. In order to solve the problems, provided is an Fe-based soft magnetic alloy ribbon including a Cu-concentrated region present directly below a surface of the ribbon, and a Co-concentrated region present directly below the Cu-concentrated region. Also provided is a magnetic core including the Fe-based soft magnetic alloy ribbon.
    Type: Application
    Filed: November 19, 2015
    Publication date: November 9, 2017
    Applicant: HITACHI METALS, LTD.
    Inventor: Yoshihito YOSHIZAWA
  • Publication number: 20170178805
    Abstract: A rapidly quenched Fe-based soft-magnetic alloy ribbon having wave-like undulations on a free surface, the wave-like undulations having transverse troughs arranged at substantially constant intervals in a longitudinal direction, and the troughs having an average amplitude D of 20 mm or less, is produced by a method comprising (a) keeping a transverse temperature distribution in a melt nozzle within ±15° C. to have as small a temperature distribution as possible in a melt paddle of the alloy, and (b) forming numerous fine linear scratches on a cooling roll surface by a wire brush, thereby providing a ground surface of the cooling roll with an arithmetical mean (average) roughness Ra of 0.1-1 ?m and a maximum roughness depth Rmax of 0.5-10 ?m.
    Type: Application
    Filed: March 3, 2017
    Publication date: June 22, 2017
    Applicant: HITACHI METALS, LTD.
    Inventors: Yoshihito YOSHIZAWA, Motoki OHTA, Naoki ITO
  • Publication number: 20170151639
    Abstract: The present invention is intended to modify a composition of a typical brazing Ni-base amorphous alloy ribbon to reduce clogging of a casting nozzle and embrittlement in manufacturing of the ribbon, thereby improving workability and improving corrosion resistance and bonding strength of a stainless steel bonded body used for a heat exchanger etc. Provided are a brazing Ni-base amorphous alloy ribbon having a composition represented by a composition formula: Ni100-d-x-y-z-f-gCrdPxSiyBzCfNg (in units of mass %, 22.00?d?29.00, 4.00?x?8.00, 1.00?y?7.00, 0<z?0.20, 0.005?f?0.100, 0.001?g?0.050, and 7.00?x+y?13.00) and a stainless steel bonded body formed by braze-bonding using the brazing Ni-base amorphous alloy ribbon.
    Type: Application
    Filed: May 28, 2015
    Publication date: June 1, 2017
    Inventors: Yoshihito YOSHIZAWA, Seishin UEDA
  • Patent number: 9290831
    Abstract: A soft-magnetic, amorphous alloy ribbon produced by a rapid quenching method, having transverse lines of recesses formed on its surface by laser beams with predetermined longitudinal intervals, with a doughnut-shaped projection formed around each recess; doughnut-shaped projections having smooth surfaces substantially free from splashes of the alloy melted by the irradiation of laser beams, and a height t2 of 2 ?m or less; and a ratio t1/T of the depth t1 of the recesses to the thickness T of the ribbon being in a range of 0.025-0.18, thereby having low iron loss and low apparent power.
    Type: Grant
    Filed: September 14, 2010
    Date of Patent: March 22, 2016
    Assignee: HITACHI METALS, LTD.
    Inventors: Yoshihito Yoshizawa, Naoki Ito, Shinichi Kazui, Makoto Sasaki
  • Publication number: 20160027566
    Abstract: A primary ultrafine-crystalline alloy having a composition represented by the general formula: Fe100-x-y-zAxByXz, wherein A is Cu and/or Au, X is at least one element selected from the group consisting of Si, S, C, P, Al, Ge, Ga and Be, and x, y and z are numbers (by atomic %) meeting the conditions of 0<x?5, 10?y?22, 0?z?10, and x+y+z?25, and a structure in which 5-30% by volume of primary ultrafine crystal grains having an average particle size of 30 nm or less are dispersed in an amorphous matrix; its differential scanning calorimetry (DSC) curve having a first exothermic peak and a second exothermic peak lower than the first exothermic peak between a crystallization initiation temperature TX1 and a compound precipitation temperature TX3; and a ratio of the heat quantity of the second exothermic peak to the total heat quantity of the first and second exothermic peaks being 3% or less.
    Type: Application
    Filed: October 2, 2015
    Publication date: January 28, 2016
    Applicant: HITACHI METALS, LTD.
    Inventors: Motoki OHTA, Yoshihito YOSHIZAWA, Taku MIYAMOTO, Toshio MIHARA
  • Patent number: 9224527
    Abstract: A method for producing an ultrafine-crystalline alloy ribbon having a structure in which crystal grains having an average grain size of 1-30 nm are dispersed at a ratio of 5-30% by volume in an amorphous matrix ultrafine, comprising the steps of ejecting an alloy melt onto a rotating cooling roll to quench it; forming an easily windable ribbon having such toughness that it is not fractured when bent to a bending radius of 1 mm or less, before the start of winding around a reel; and changing the forming conditions of the ribbon after the start of winding around a reel, to obtain a structure in which ultrafine crystal grains having an average grain size of 1-30 nm are dispersed at a ratio of 5-30% by volume in an amorphous matrix.
    Type: Grant
    Filed: December 20, 2012
    Date of Patent: December 29, 2015
    Assignee: HITACHI METALS, LTD.
    Inventors: Motoki Ohta, Yoshihito Yoshizawa
  • Patent number: 9222145
    Abstract: A method for producing a soft magnetic alloy ribbon having a composition represented by Fe100-x-y-zAxByXz, wherein A is Cu and/or Au, X is at least one element selected from the group consisting of Si, S, C, P, Al, Ge, Ga and Be, and x, y and z are numbers (by atomic %) meeting the conditions of 0<x?5, 10?y?22, 1?z?10, and x+y+z?25, and comprising a matrix phase in which fine crystal grains having an average diameter of 60 nm or less are dispersed at a volume fraction of 50% or more, part of an oxide film formed on the surface being a layer having a lower B concentration than the average B concentration of the matrix phase; comprising the steps of (1) ejecting an alloy melt having the above composition onto a rotating cooling roll for quenching, to form a primary fine-crystalline alloy ribbon having a matrix phase, in which fine crystal nuclei having an average diameter of 30 nm or less are dispersed at a volume fraction of more than 0% and less than 30% in an amorphous phase; and then (2) annealing the pr
    Type: Grant
    Filed: January 20, 2010
    Date of Patent: December 29, 2015
    Assignee: HITACHI METALS, LTD.
    Inventors: Motoki Ohta, Yoshihito Yoshizawa
  • Patent number: 9177706
    Abstract: This method of producing an amorphous transformer for electric power supply comprises forming and shaping an iron core by laminating amorphous alloy thin bands and forming a winding, subjecting the iron core, after forming and shaping, to an annealing treatment in which a temperature of a center portion of the iron core during annealing is 300 to 340° C. and a holding time is not less than 0.5 hr, and applying a magnetic field having a strength of not less than 800 A/m to the iron core while subjecting the iron core, after forming and shaping, to the annealing treatment.
    Type: Grant
    Filed: May 5, 2011
    Date of Patent: November 3, 2015
    Assignee: HITACHI INDUSTRIAL EQUIPMENT SYSTEMS CO., LTD.
    Inventors: Kazuyuki Fukui, Koji Yamashita, Yuichi Ogawa, Masamu Naoe, Yoshihito Yoshizawa
  • Publication number: 20150243421
    Abstract: An ultrafine-crystalline alloy ribbon having a composition represented by the general formula of Fe100-x-y-zAxByXz, wherein A is Cu and/or Au, X is at least one element selected from the group consisting of Si, S, C, P, Al, Ge, Ga and Be, and x, y and z are numbers meeting the conditions of 0<x?5, 8?y?22, 0?z?10, and x+y+z?25 by atomic %, and a structure in which ultrafine crystal grains having an average particle size of 30 nm or less being dispersed in a proportion of more than 0% and less than 30% by volume in an amorphous matrix; an ultrafine crystal grains-depleted region comprising ultrafine crystal grains at a number density of less than 500/?m2 being formed in a region of 0.2 mm in width from each side of the ribbon.
    Type: Application
    Filed: September 10, 2013
    Publication date: August 27, 2015
    Applicant: HITACHI METALS, LTD.
    Inventors: Motoki Ohta, Yoshihito Yoshizawa
  • Publication number: 20150000862
    Abstract: A method for producing an ultrafine-crystalline alloy ribbon having a structure in which crystal grains having an average grain size of 1-30 nm are dispersed at a ratio of 5-30% by volume in an amorphous matrix ultrafine, comprising the steps of ejecting an alloy melt onto a rotating cooling roll to quench it; forming an easily windable ribbon having such toughness that it is not fractured when bent to a bending radius of 1 mm or less, before the start of winding around a reel; and changing the forming conditions of the ribbon after the start of winding around a reel, to obtain a structure in which ultrafine crystal grains having an average grain size of 1-30 nm are dispersed at a ratio of 5-30% by volume in an amorphous matrix.
    Type: Application
    Filed: December 20, 2012
    Publication date: January 1, 2015
    Applicant: HITACHI METALS, LTD.
    Inventors: Motoki Ohta, Yoshihito Yoshizawa
  • Patent number: 8895186
    Abstract: It is an objective of the present invention to provide a lithium-ion rechargeable battery anode which can control the volume change of a primary particle of a negative-electrode active material other than a carbon-based material and that can prevent cracks due to stress caused by the volume change from occurring and extending. There is provided an anode for a lithium-ion rechargeable battery including a primary particle of a negative-electrode active material, a conductive material, and a binder, the negative-electrode active material including at least one of silicon and tin, and at least one element selected from elements that do not chemically react with lithium, in which holes are present both in an inner core region in the central region of the primary particle of the negative-electrode active material and in a periphery region that covers the inner core region.
    Type: Grant
    Filed: May 27, 2011
    Date of Patent: November 25, 2014
    Assignee: Hitachi, Ltd.
    Inventors: Takashi Nakabayashi, Shin Takahashi, Motoki Ohta, Yoshihito Yoshizawa
  • Publication number: 20140191832
    Abstract: A method for cutting a primary ultrafine-crystalline alloy ribbon having a structure in which ultrafine crystal grains having an average grain size of 30 nm or less are dispersed in a proportion of 5-30% by volume in an amorphous matrix, comprising placing the ribbon on a soft base deformable to an acute angle by local pressing, bringing a cutter blade into horizontal contact with a surface of the ribbon, and pressing the cutter to the ribbon to apply uniform pressure thereto, thereby bending the ribbon along a cutter blade edge to brittly fracture-cut the ribbon.
    Type: Application
    Filed: September 11, 2012
    Publication date: July 10, 2014
    Applicant: HITACHI METALS, LTD.
    Inventors: Motoki Ohta, Yoshihito Yoshizawa
  • Patent number: 8663399
    Abstract: An iron-based amorphous alloy and magnetic core with an iron-based amorphous alloy having a chemical composition with a formula FeaBbSicCd, where 81<a?84, 10?b?18, 0<c?5 and 0<d<1.5, numbers being in atomic percent, with incidental impurities, simultaneously have a value of a saturation magnetic induction exceeding 1.6 tesla, a Curie temperature of at least 300° C. and a crystallization temperature of at least 400° C. When cast in a ribbon form, such an amorphous metal alloy is ductile and thermally stable, and is suitable for various electric devices because of high magnetic stability at such devices' operating temperatures.
    Type: Grant
    Filed: December 30, 2005
    Date of Patent: March 4, 2014
    Assignees: Metglas, Inc., Hitachi Metals, Ltd.
    Inventors: Ryusuke Hasegawa, Daichi Azuma, Yoshihito Yoshizawa, Yuichi Ogawa
  • Publication number: 20130314198
    Abstract: A rapidly quenched Fe-based soft-magnetic alloy ribbon having wave-like undulations on a free surface, the wave-like undulations having transverse troughs arranged at substantially constant intervals in a longitudinal direction, and the troughs having an average amplitude D of 20 mm or less, is produced by a method comprising (a) keeping a transverse temperature distribution in a melt nozzle within ±15° C. to have as small a temperature distribution as possible in a melt paddle of the alloy, and (b) forming numerous fine linear scratches on a cooling roll surface by a wire brush, thereby providing a ground surface of the cooling roll with an arithmetical mean (average) roughness Ra of 0.1-1 ?m and a maximum roughness depth Rmax of 0.5-10 ?m.
    Type: Application
    Filed: January 27, 2012
    Publication date: November 28, 2013
    Applicant: HITACHI METALS, LTD.
    Inventors: Yoshihito Yoshizawa, Motoki Ohta, Naoki Ito
  • Patent number: 8414712
    Abstract: Disclosed are a thin strip of an amorphous alloy having excellent workability, a nanocrystalline soft magnetic alloy which can stably provide good magnetic properties, and a magnetic core using the nanocrystalline soft magnetic alloy. The thin strip of an amorphous alloy is characterized in that the thin strip is formed of an alloy having a composition represented by Fe100-a-b-c-dMaSibBcCud (atomic %), wherein 0?a?10, 0?b?20, 4?c?20, 0.1?d?3, and 9?a+b+c?35, and containing unavoidable impurities, and, in the composition, M represents at least one element selected from Ti, V, Zr, Nb, Mo, Hf, Ta, and W, a Cu segregated part is present, on the surface side of the thin strip of the amorphous alloy, in which Cu is segregated at a higher concentration than the Cu concentration in the outermost surface part of the thin strip of the amorphous alloy, and the highest Cu concentration in the Cu segregated part is not more than 4 atomic %.
    Type: Grant
    Filed: March 30, 2009
    Date of Patent: April 9, 2013
    Assignee: Hitachi Metals, Ltd.
    Inventors: Yoshihito Yoshizawa, Motoki Ohta
  • Publication number: 20120318412
    Abstract: A primary ultrafine-crystalline alloy having a composition represented by the general formula: Fe100-x-y-zAxByXz, wherein A is Cu and/or Au, X is at least one element selected from the group consisting of Si, S, C, P, Al, Ge, Ga and Be, and x, y and z are numbers (by atomic %) meeting the conditions of 0<x?5, 10?y?22, 0?z?10, and x+y+z?25, and a structure in which 5-30% by volume of primary ultrafine crystal grains having an average particle size of 30 nm or less are dispersed in an amorphous matrix; its differential scanning calorimetry (DSC) curve having a first exothermic peak and a second exothermic peak lower than the first exothermic peak between a crystallization initiation temperature TX1 and a compound precipitation temperature TX3; and a ratio of the heat quantity of the second exothermic peak to the total heat quantity of the first and second exothermic peaks being 3% or less.
    Type: Application
    Filed: March 28, 2011
    Publication date: December 20, 2012
    Applicant: HITACHI METALS, LTD.
    Inventors: Motoki Ohta, Yoshihito Yoshizawa, Taku Miyamoto, Toshio Mihara