Patents by Inventor Hirokazu Kanekiyo

Hirokazu Kanekiyo 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: 20020017339
    Abstract: An iron-based rare earth alloy magnet has a composition represented by the general formula: (Fe1-mTm)100-x-y-zQxRyMz, where T is at least one element selected from the group consisting of Co and Ni; Q is at least one element selected from the group consisting of B and C; R is at least one rare earth element substantially excluding La and Ce; and M is at least one metal element selected from the group consisting of Ti, Zr and Hf and always includes Ti. In this formula, the mole fractions x, y, z and m meet the inequalities of: 10 at %<x≦20 at %; 6 at %≦y<10 at %; 0.1 at %≦z≦12 at %; and 0≦m≦0.5, respectively.
    Type: Application
    Filed: May 24, 2001
    Publication date: February 14, 2002
    Inventors: Hirokazu Kanekiyo, Toshio Miyoshi, Satoshi Hirosawa, Yasutaka Shigemoto, Yusuke Shioya
  • Patent number: 6338761
    Abstract: With the intention of establishing fabrication methods for cheaply produced (Fe,Co)—Cr—B—R-type bonded magnets or (Fe,Co)—Cr—B—R—M-type bonded magnets containing few rare earth elements and having a coercive force iHc above 5 kOe and a residual magnetic flux density Br above 5.
    Type: Grant
    Filed: February 1, 2000
    Date of Patent: January 15, 2002
    Assignee: Sumitomo Special Metals Co., Ltd.
    Inventors: Hirokazu Kanekiyo, Satoshi Hirosawa
  • Patent number: 6329894
    Abstract: The purpose of the present invention is to present a thin-plate magnet with a fine crystalline structure that is 70 &mgr;m to 500 &mgr;m thick, making miniature, thin magnetic circuits possible, and has, as cast, an inherent coercive force iHc of 2.5 kOe or higher and residual magnetic flux density of 9 kG or higher and a performance-to-cost ratio rivaling that of hard ferrite magnets when Nd—Fe—B fine crystalline permanent magnets with a low rare earth content that are a mixture of a soft magnetic phase and a hard magnetic phase are produced. iHc can be increased to 2.
    Type: Grant
    Filed: August 10, 1999
    Date of Patent: December 11, 2001
    Assignee: Sumitomo Special Metals Co., Ltd.
    Inventors: Hirokazu Kanekiyo, Satoshi Hirosawa
  • Patent number: 6302972
    Abstract: An inventive material alloy for a nanocomposite magnet is represented by a general formula Fe100−x−yRxBy, Fe100−x−y−zRxByCoz, Fe100−x−y−uRxByMu or Fe100−x−y−z−uRxByCozMu. R is a rare-earth element. 90 atomic percent or more of R is Pr and/or Nd, while equal to or larger than 0 atomic percent and less than 10 atomic percent of R is another lanthanoid and/or Y. M is at least one element selected from the group consisting of Al, Si, Ti, V, Cr, Mn, Ni, Cu, Ga, Zr, Nb, Mo, Hf, Ta, W, Pt, Pb, Au and Ag. The molar fractions x, y, z and u meet the inequalities of 2≦x≦6, 16≦y≦20, 0.2≦z≦7 and 0.01≦u≦7, respectively. The alloy includes a metastable phase Z represented by at least one of a plurality of Bragg reflection peaks observable by X-ray diffraction analysis. The at least one peak corresponds to a lattice spacing of 0.179 nm±0.005 nm.
    Type: Grant
    Filed: December 6, 1999
    Date of Patent: October 16, 2001
    Assignee: Sumitomo Special Metals Co., LTD
    Inventors: Satoshi Hirosawa, Hirokazu Kanekiyo, Yasutaka Shigemoto
  • Patent number: 6287391
    Abstract: A method for manufacturing a permanent magnet by fabricating rapidly cooled alloy thin strip of amorphous composition which has good tenacity, simple working properties and an average thickness of 10 &mgr;m˜200 &mgr;m, from a molten alloy of a specific composition containing 6 at % or less of rare-earth element and 15 at %˜30 at % of boron, by means of specific rapid cooling conditions, and then subjecting this rapidly cooled alloy thin strip, after cutting or punching to a prescribed shape, to crystallization heat treatment such that the average crystal grain size thereof becomes 10 nm˜50 nm, and by layering together two or more of these thin permanent magnets and bonding and uniting the layered thin strips by means of an inorganic adhesive material or a resin, it is possible readily to provide a high-performance layered permanent magnet having a desired thickness and a prescribed shape, without using a method involving crushing and bonded magnet forming processes and without needing to car
    Type: Grant
    Filed: February 24, 1999
    Date of Patent: September 11, 2001
    Assignee: Sumitomo Special Metals Co., Ltd.
    Inventors: Hirokazu Kanekiyo, Satoshi Hirosawa
  • Publication number: 20010015239
    Abstract: The method for producing iron-base alloy permanent magnet powder of the present invention includes the steps of: chilling an Fe—R—B molten alloy by melt quenching, thereby forming a rapidly solidified alloy having a thickness in a range of 80 &mgr;m to 300 &mgr;m; crystallizing the rapidly solidified alloy by heat treatment, thereby producing an alloy having permanent magnet properties; and pulverizing the alloy to produce powder having an average particle size in a range of 50 &mgr;m to 300 &mgr;m or less and a ratio of minor axis size to major axis size of powder particles in a range of 0.3 to 1.0.
    Type: Application
    Filed: December 13, 2000
    Publication date: August 23, 2001
    Inventor: Hirokazu Kanekiyo
  • Patent number: 6168673
    Abstract: An object of this invention is to provide a thin-film magnet having a residual magnetic flux density Br of not less than 10 kG, a cost performance equal to that of a hard ferrite magnet, and a thickness of 70-300 &mgr;m contributing to the miniaturization and thinning of a magnetic circuit, and a method of manufacturing the same. When a molten alloy of a predetermined structure having a small content of a rare earth element is subjected to continuous casting using a cooling roll in an inert gas atmosphere with reduced pressures of not more than 30 kPa at a predetermined peripheral speed of the roll, it turns into a crystalline structure substantially not less than 90% of which comprises a Fe3B type compound and a compound phase having &agr; —Fe and Nd2Fe14B type crystalline structures compatible with the former.
    Type: Grant
    Filed: May 20, 1999
    Date of Patent: January 2, 2001
    Assignee: Sumitomo Special Metals Co., Ltd.
    Inventors: Hirokazu Kanekiyo, Satoshi Hirosawa
  • Patent number: 6019859
    Abstract: With the intention of establishing fabrication methods for cheaply produced (Fe,Co)--Cr--B--R-type bonded magnets or (Fe,Co)--Cr--B--R--M-type bonded magnets containing few rare earth elements and having a coercive force iHc above 5 kOe and a residual magnetic flux density Br above 5.5 kG matching the cost performance of hard ferrite magnets, we have obtained iron-based permanent magnets consisting of microcrystal clusters where the average crystal size of each component phase is in the range 1 nm .about.30 nm and where both a soft magnetic phase consisting of a ferromagnetic alloy whose main components are .alpha.-Fe and a ferromagnetic alloy having iron, and a hard magnetic phase having a Nd.sub.2 Fe.sub.
    Type: Grant
    Filed: June 5, 1996
    Date of Patent: February 1, 2000
    Assignee: Sumitomo Special Metals Co., Ltd.
    Inventors: Hirokazu Kanekiyo, Satoshi Hirosawa
  • Patent number: 5545266
    Abstract: For the purpose of establishing the manufacturing method to obtain the Fe.sub.3 B type Fe--Co--B--R--M system high performance resin bonded magnet which possesses improved iHc and (BH)max and can be reliably mass produced, the specific composition of Fe--Co--B--R (Pr, Nd)--M(Ag, Al, Si, Ga, Cu, Au) type molten alloy was rapidly solidified by the melt-quenching or atomization methods, or a combination of the two methods to obtain more than 90% of the solid in an essentially amorphous structure. After the temperature was raised at the rate of 1.degree..about.15.degree. C./min., the alloy was heat treated at 550.degree..about.730.degree. C. for 5 minutes.about.6 hours to obtain Fe-rich the boron compound phase, which crystallizes the body centered tetragonal Fe.sub.3 P type crystalline structure, and the Nd.sub.2 Fe.sub.14 B type crystalline structure phase both coexisting as fine crystalline clusters of the average crystalline diameter of 5 nm.about.100 nm.
    Type: Grant
    Filed: November 30, 1994
    Date of Patent: August 13, 1996
    Assignee: Sumitomo Special Metals Co., Ltd.
    Inventors: Satoshi Hirosawa, Hirokazu Kanekiyo