Iron Base (i.e., Ferrous) Patents (Class 148/306)
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Publication number: 20090320961Abstract: A magnet core is required to be particularly dense, made of alloys produced in a rapid solidification process and have a minimal coercitive field strength. To achieve these aims, a coarse-grain powder fraction is first produced from an amorphous strip of a soft magnetic alloy. In addition, at least one fine-grain powder fraction is produced from a nanocrystalline strip of a soft magnetic alloy. The particle fractions are then mixed to produce a multi-modal powder, wherein the particles of the coarse-grain particle fraction have an amorphous structure and the particles of the fine-grain powder fraction have a nanocrystalline structure. The multi-modal powder is then pressed to produce a magnet core.Type: ApplicationFiled: July 11, 2007Publication date: December 31, 2009Applicant: VACUUMSHMELZE GMBH & CO.KGInventor: Markus Brunner
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Patent number: 7608154Abstract: A nonoriented electrical steel sheet excellent in core loss comprising copper sulfides with a sphere-equivalent radius of 100 nm or less, wherein the number density of the copper sulfides is less than 1×1010 [inclusions/mm3]. Preferably, the percentage of the number of copper sulfides with a (major axis)/(minor axis) ratio of more than 2 per total number of copper sulfides is 30% or less. The steel preferably further comprises Cu of 0.5 mass % or less and REM of 0.0005% or more and 0.03% or less, wherein the following expression (1) or expressions (1) and (2) are met: [REM]×[Cu]3?7.5×10?11??(1), ([REM]?0.003)0.1×[Cu]2?1.25×10?4??(2).Type: GrantFiled: September 9, 2005Date of Patent: October 27, 2009Assignee: Nippon Steel CorporationInventors: Wataru O-hashi, Masafumi Miyazaki, Yousuke Kurosaki, Takeshi Kubota
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Patent number: 7601229Abstract: A method for making soft magnetic material includes: a first heat treatment step applying a temperature of at least 400 deg C. and less than 900 deg C. to metal magnetic particles; a step for forming a plurality of compound magnetic particles in which said metal magnetic particles are surrounded by insulation film; and a step for forming a shaped body by compacting a plurality of compound magnetic particles. This provides a method for making soft magnetic material that provides desired magnetic properties.Type: GrantFiled: October 1, 2004Date of Patent: October 13, 2009Assignee: Sumitomo Electric Industries Ltd.Inventors: Haruhisa Toyoda, Hirokazu Kugai, Kazuhiro Hirose, Naoto Igarashi, Takao Nishioka
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Publication number: 20090252991Abstract: Provided is an iron nitride-based magnetic powder that comprises magnetic particles having a mean particle size of at most 20 nm. The magnetic particle has a core of a main phase of Fe16N2 and has, on the outer side of the core, an oxide phase derived from a metal Fe phase formed by reduction of iron nitride. In relation to the weatherability index ??s and the saturation magnetization as thereof, the magnetic powder satisfies ??s?0.8×?s?30. In this, ??s=(?s??s1)/?s×100. ?s1 means the saturation magnetization of the magnetic powder kept in an atmosphere of 60° C. and 90% RH for 1 week. The powder can be obtained by exposing powder particles having a main phase of Fe16N2 to a reducing gas to partly reduce the region of the surface of the particles into a metal Fe phase (gradual reduction) followed by exposing them to an oxidizing gas to oxidize a part of the surface of the metal Fe phase into an oxide phase (gradual oxidation).Type: ApplicationFiled: June 8, 2007Publication date: October 8, 2009Inventors: Yuzo Ishikawa, Kenji Masada
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Patent number: 7594972Abstract: The present invention is an alloy lump for R-T-B type sintered magnets, including an R2T14B columnar crystal and an R-rich phase (in which R is at least one rare earth element including Y, T is Fe or Fe with at least one transition metal element except for Fe, and B is boron or boron with carbon), in which in the as-cast state, R-rich phases nearly in the line-like or rod-like shape (the width direction of the line or rod is a short axis direction) are dispersed in the cross section, and the area percentage of the region where R2T14B columnar crystal grains have a length of 500 ?m or more in the long axis direction and a length of 50 ?m or more in the short axis direction is 10% or more of the entire alloy.Type: GrantFiled: April 7, 2005Date of Patent: September 29, 2009Assignee: Showda Denko K.K.Inventors: Hiroshi Hasegawa, Shiro Sasaki, Uremu Hosono, Masaaki Yui
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Patent number: 7588648Abstract: The present invention provides a soft magnetic material and a powder magnetic core having desired magnetic characteristics. A soft magnetic material contains a metal magnetic powder 10. The metal magnetic powder 10 is formed from crystals 1 with an average size, as determined from X-ray diffraction, of at least 30 nm. It would be preferable, in the metal magnetic particles 10, for crystal grains 2 to have an average size of at least 10 microns.Type: GrantFiled: October 7, 2004Date of Patent: September 15, 2009Assignee: Sumitomo Electric Industries, Inc.Inventors: Haruhisa Toyoda, Hirokazu Kugai, Kazuhiro Hirose, Naoto Igarashi, Takao Nishioka
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Patent number: 7582171Abstract: A high-strength, soft-magnetic iron-cobalt-vanadium alloy selection is proposed, consisting of 35.0?Co?55.0% by weight, 0.75?V?2.5% by weight, O?Ta+2×Nb?0.8% by weight, 0.3<Zr?1.5% by weight, remainder Fe and melting-related and/or incidental impurities. This zirconium-containing alloy selection has excellent mechanical properties, in particular a very high yield strength, high inductances and particularly low coercive forces. It is eminently suitable for use as a material for magnetic bearings used in the aircraft industry.Type: GrantFiled: May 7, 2004Date of Patent: September 1, 2009Assignee: Vacuumschmelze GmbH & Co. KGInventors: Joachim Gerster, Johannes Tenbrink
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Patent number: 7569115Abstract: Assemblages of particles of a magnetic alloy that are suited to magnetic recording are represented by the formula [TXM1-X] containing T and M in a composition ratio where X in the formula is in the range from 0.3 or greater to 0.7 or less, where T is one or two members of the group consisting of Fe and Co and M is one or two members of the group consisting of Pt and Pd, and metallic elements other than T and M that constitute no more than 30 at. % (including 0 at. %) of (T+M) as a percentage of atoms, and the remainder consists of impurities that are unavoidable from a production standpoint, wherein: the face-centered tetragonal fraction is 10-100%, the average grain size as measured by TEM observation (DTEM) is in the range from 5-30 nm, the x-ray crystal grain size derived by x-ray diffraction (DX) is no less than 4 nm, the particles of are dispersed from each other at a distance, and the dispersion on the composition of the individual particles is kept within a stipulated range.Type: GrantFiled: July 30, 2004Date of Patent: August 4, 2009Assignee: Dowa Electronics Materials Co., Ltd.Inventor: Kimitaka Sato
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Publication number: 20090145526Abstract: An object of the present invention is to provide a grain-oriented electrical steel sheet with low core loss and low magnetostriction and a method for producing the same. The grain-oriented electrical steel sheet is excellent in reduced core loss and magnetostriction while under a high flux density of 1.9 T, comprises a refined magnetic domain comprising a laser irradiated portion which has melted and resolidified to form a solidified layer, wherein the thickness of the solidified layer is 4 ?m or less. The grain-oriented electrical steel sheet may further comprise a laser irradiated portion where a surface roughness Rz is small and a cross section viewed from a transverse direction has a concave portion having a width of 200 ?m or less and a depth of 10 ?m or less for further improvement.Type: ApplicationFiled: April 26, 2006Publication date: June 11, 2009Inventors: Satoshi Arai, Hideyuki Hamamura, Tatsuhiko Sakai, Kaoru Sato, Hideyuki Kobayashi
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Patent number: 7540927Abstract: A soft magnetic steel has, on the mass basis, a carbon content of 0.0015% to 0.02%, a manganese content of 0.15% to 0.5%, and a sulfur content of 0.015% to 0.1%, has a ratio Mn/S of 5.7 or more, and contains a single-phase ferrite microstructure as its metallographic structure, in which the density of precipitated FeS grains having a major axis of 0.1 ?m or more is 5000 grains/mm2 or less. This steel ensures excellent magnetic properties with less variation after magnetic annealing, exhibits excellent machinability and cold forgeability during production processes, and can thereby yield a steel part even having a complicated shape and a large size in a high yield.Type: GrantFiled: July 10, 2006Date of Patent: June 2, 2009Assignee: Kobe Steel, Ltd.Inventor: Masamichi Chiba
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Patent number: 7513959Abstract: When a non-oriented electrical steel sheet is manufactured, simultaneously having superior magnetic properties and high strengths, a composition containing 0.02% or less of C, 4.5% or less of Si, 5.0% or less (including 0) of Ni, and 0.2% to 4.0% of Cu is used, and a solute Cu is allowed to appropriately remain in finish annealing. In the steel sheet thus obtained, finely shaped Cu is precipitated by aging treatment, and while the magnetic properties are not degraded, the yield stress is increased to not less than CYS (MPa) represented by the following formula: note CYS=180+5,600[% C]+95[% Si]+50[% Mn]+37[% Al]+435[% P]+25[% Ni]+22d?1/2 where d is an average grain diameter (mm) of crystal grains.Type: GrantFiled: December 3, 2003Date of Patent: April 7, 2009Assignee: JFE Steel CorporationInventors: Minoru Takashima, Masaaki Kohno, Katsumi Yamada, Masaki Kawano, Kaoru Sato
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Patent number: 7501028Abstract: The invention relates to non-grain oriented magnetic steel sheets which can be produced as final annealed and as a non-final annealed types in such a way that they have improved magnetic polarisation and reduced magnetic reversal losses compared with the previously achieved values. This is achieved in that a suitably composed steel, during its cooling starting from a maximum initial temperature of 1,300° C., passes through a temperature range with substantially complete exclusion of a purely austenitic structure (? phase), in which range it comprises an austenite/ferrite dual phase multi-structure (?, ? multi-phases), so the magnetic steel sheet, after hot rolling, etching, cold rolling and annealing of the hot strip obtained after hot rolling, has a magnetic polarisation J2500?1.74 T, measured in the longitudinal direction of the strip or sheet and at a magnetic field strength of 2,500 A/m and a value P1.5(50) of the magnetic losses of <4.5 W/kg, measured in the longitudinal direction of the strip at J=1.Type: GrantFiled: May 15, 2003Date of Patent: March 10, 2009Assignee: ThyssenKrupp Stahl AGInventors: Brigitte Hammer, Karl Ernst Friedrich, Olaf Fischer, Jürgen Schneider, Carl-Dieter Wuppermann
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Publication number: 20090050240Abstract: A magnetic metal powder having fluidity is provided which is composed of FePt nanoparticles synthesized by the polyol synthesis method that possess fct (face-centered tetragonal) structure and exhibit crystal magnetic anisotropy from immediately after synthesis. Specifically, there is provided a magnetic metal powder having fluidity which is composed of magnetic metal particles whose main components and the contents thereof are represented by the following general formula (1): [TXM1?X]YZ1?Y??(1), where T is one or both of Fe and Co, M is one or both of Pt and Pd, Z is at least one member selected from the group composed of Ag, Cu, Bi, Sb, Pb and Sn, X represents 0.3˜0.7, and Y represents 0.7˜1.Type: ApplicationFiled: October 15, 2008Publication date: February 26, 2009Inventor: Kazuyuki Tohji
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Publication number: 20090042051Abstract: A process for the manufacture of soft magnetic composite components is provided comprising the steps of die compacting a powder composition comprising a mixture of soft magnetic, iron or iron-based powder, the core particles of which are surrounded by an electrically insulating, inorganic coating, and an organic lubricant in an amount of 0.05 to 1.5% by weight of the composition, the organic lubricant being free from metal and having a temperature of vaporisation less than the decomposition temperature of the coating; ejecting the compacted body from the die; heating the compacted body in a non-reducing atmosphere to a temperature above the vaporisation temperature of the lubricant and below the decomposition temperature of the inorganic coating for removing the lubricant from the compacted body, and subjecting the obtained body to heat treatment at a temperature between 3000 and 6000 in water vapour.Type: ApplicationFiled: June 15, 2006Publication date: February 12, 2009Applicant: HOGANAS ABInventors: Bjorn Skarman, Zhou Ye, Patricia Jansson
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Patent number: 7488369Abstract: A magnetostriction device is made such that an impregnated composition material, such as phenol resin, a resin in which an inorganic material such as silica is dispersed into a phenol resin, an epoxy based resin, or an acrylic resin is impregnated and caked into holes of a magnetostrictive sintered material manufactured by a powder metallurgy method. This magnetostriction device has improved mechanical strength against external force.Type: GrantFiled: May 30, 2006Date of Patent: February 10, 2009Assignee: Sony CorporationInventors: Yoshio Ohashi, Masaru Uryu
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Patent number: 7473325Abstract: A current transformer core made of an alloy having a composition represented by the general formula: Fe100-x-a-y-cMxCuaM?yX?c (by atomic %), wherein M is Co and/or Ni, M? is at least one element selected from the group consisting of V, Ti, Zr, Nb, Mo, Hf, Ta and W, X? is Si and/or B, and x, a, y and c are numbers satisfying 10?x?50, 0.1?a?3, 1?y?10, 2?c?30, and 7?y+c?31, respectively; at least part or all of the alloy structure being composed of crystal grains having an average particle size of 50 nm or less.Type: GrantFiled: December 16, 2005Date of Patent: January 6, 2009Assignee: Hitachi Metals, Ltd.Inventors: Yoshihito Yoshizawa, Masamu Naoe
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Patent number: 7470333Abstract: A non-oriented electrical steel sheet is characterized in that the number density of inclusions with an equivalent volume diameter of less than 100 nm contained in the steel sheet is 1×1010 [/mm3] or less, and that the steel sheet contains, by mass %, C: up to 0.01%, Si: 0.1% to 7.0%. Al: 0.1% to 3.0%. Mn: 0.1% to 2.0%, REM: 0.0003% to 0.05%. Ti: up to 0.02%. S: up to 0.005%. and N: up to 0.005%. the balance Fe and inevitable impurities and the mass % of Al represented by [Al] and the mass % of Ti represented by [Ti] satisfy the equation log([Ti]×[N])?1.19×log([Al]×[N])+1.84>0 . . . (1).Type: GrantFiled: April 28, 2004Date of Patent: December 30, 2008Assignee: Nippon Steel Corp.Inventors: Wataru Ohashi, Akihito Kiyose, Masafumi Miyazaki, Takeshi Kubota, Yousuke Kurosaki, Yoshihiro Arita, Ken-ichiro Miyamoto, Takashi Sawai
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Patent number: 7416795Abstract: A method for manufacturing magnetic metal powder is provided. In the method, a powdered magnetic metal oxide is supplied to a heat treatment furnace with a carrier gas composed of a reducing gas. The heat treatment furnace is maintained at temperatures above a reducing action starting temperature for the powdered magnetic metal oxide and above a melting point of the magnetic metal in the powder. The powdered magnetic metal oxide is subject to a reducing process, and then magnetic metal particles, the resultant reduced product, is melted to form a melt. The melt is re-crystallized in a succeeding cooling step, to obtain single crystal magnetic metal power in substantially spherical form.Type: GrantFiled: September 22, 2004Date of Patent: August 26, 2008Assignee: TDK CorporationInventors: Minoru Takaya, Yoshiaki Akachi, Hisashi Kobuke, Hiroyuki Uematsu
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Patent number: 7381239Abstract: Disclosed are alloy nano-particles having a fluctuation coefficient of particle size of 20% or less and a fluctuation coefficient of composition of 20% or less. The alloy nano-particles have a low transformation point and hardly aggregate and which can form a flat magnetic film having high coercive force.Type: GrantFiled: June 25, 2004Date of Patent: June 3, 2008Assignee: Fujifilm CorporationInventors: Koukichi Waki, Genichi Furusawa, Yasushi Hattori
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Patent number: 7371271Abstract: An object of the present invention is to provide a composite soft magnetic sintered material that has high density, high mechanical strength and high relative magnetic permeability at high frequencies and, in order to achieve this object, the present invention provides a method of producing the composite soft magnetic sintered material, which comprises mixing a composite soft magnetic powder, that consists of iron powder, Fe—Si based soft magnetic iron alloy powder, Fe—Al based soft magnetic iron alloy powder, Fe—Si—Al based soft magnetic iron alloy powder, Fe—Cr based soft magnetic iron alloy powder or nickel-based soft magnetic alloy powder (hereinafter these powders are referred to as soft magnetic metal powder) of which particles arc coated with a ferrite layer which has a spinel structure, with 0.05 to 1.Type: GrantFiled: March 29, 2002Date of Patent: May 13, 2008Assignee: Mitsubishi Materials PMG CorporationInventors: Kazunori Igarashi, Ryoji Nakayama, Koichiro Morimoto, Muneaki Watanabe
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Publication number: 20080011390Abstract: A magnetostrictive alloy containing iron and gallium comprising: Fe100?(x+y+z)GaxAlyCz; where x is of from about 5 at. % to about 30 at. %; where x+y is of from about 5 at. % to about 30 at. %; and where z is of from about 0.005 at. % to about 4.1 at. %. The alloys can also contain B and N.Type: ApplicationFiled: July 10, 2007Publication date: January 17, 2008Inventors: Arthur E. Clark, Marily Wun-Fogle, Thomas A. Lograsso
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Publication number: 20070227302Abstract: A metal magnetic powder for a magnetic recording medium is provided whose particles have a metal magnetic phase, composed mainly of Fe or Fe plus Co, and an oxide layer, wherein the average major axis length of the powder particles is 10-50 nm, the average particle volume including the oxide layer is 5,000 nm3 or less, the atomic ratio (R+Al+Si)/(Fe+Co) calculated using the content values (at. %) of the elements contained in the powder particles is 20% or less, where R is rare earth element (Y being treated as a rare earth element). The metal magnetic powder is obtained by using a complexing agent and a reducing agent to elute nonmagnetic constituents after firing. The metal magnetic powder exhibits a large saturation magnetization ?s for its particle volume while maintaining weatherability comparable to the conventional level and is suitable for a coated-type magnetic recording medium.Type: ApplicationFiled: March 27, 2007Publication date: October 4, 2007Inventors: Takayuki Yoshida, Masatoshi Nakayama, Ryota Igarashi
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Patent number: 7267729Abstract: A soft magnetic low-carbon steel has a chemical composition having a C content of 0.05% by mass or below, Si content of 0.1% or below, a Mn content in the range of 0.10 to 0.50% by mass, a P content of 0.030% by mass or below, a S content in the range of 0.010 to 0.15% by mass, an Al content of 0.01% by mass or below, a N content of 0.005% by mass or below, and an 0 content of 0.02% by mass or below. In the soft magnetic low-carbon steel, Mn/S mass ratio is 3.0 or above, ferrite grain size is 100 ?m or above, ferrite grains contain precipitated MnS grains of grain sizes of 0.2 ?m or above in a density in the density range of 0.02 to 0.5 grains/?2m and the precipitated MnS grains have a mean grain size in the range of 0.05 to 4 ?m. The soft magnetic low-carbon steel is excellent in cold-rollability and machinability. Steel parts of the soft magnetic low-carbon steel having complicated shapes can be produced at a high yield.Type: GrantFiled: December 18, 2003Date of Patent: September 11, 2007Assignee: Kobe Steel, Ltd.Inventors: Masamichi Chiba, Masato Kaiso
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Patent number: 7195680Abstract: The invention relates to a soft magnetic alloy with the following composition in wt. %: 28%?Ni?34%, 0%?Co?4%, 0%?Cu?4%, 1%?Cr, 0%?Mo?8%, 0%?Nb?1%, 0%?Mn?2%, 0%?V?5%, 0%?W?5%, 0%?Si?4%, 0%?Al?4%, 0%?C?0.4%, optionally one or several elements selected from magnesium and calcium the content of which is such as to remain below 0.1%, the rest being iron and impurities from production. The chemical composition furthermore satisfies the following relationships: 180.5?6×Ni2.5×(Cr+Mo+V+W+Si+Al)+4×(Co+Cu)?197.5 et Co+Cu?4%. The invention relates to the use thereof for production of a stator for use in a motor for clock-making.Type: GrantFiled: February 14, 2003Date of Patent: March 27, 2007Assignee: Imphy AlloysInventors: Thierry Waeckerle, Hervë Fraisse, Bruno Boulogne
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Patent number: 7192491Abstract: In order to dampen magnetization changes in magnetic devices, such as magnetic tunnel junctions (MTJ) used in high speed Magnetic Random Access Memory (MRAM), a transition metal selected from the 4d transition metals and 5d transition metals is alloyed into the magnetic layer to be dampened. In a preferred form, a magnetic permalloy layer is alloyed with osmium (Os) in an atomic concentration of between 4% and 15% of the alloy.Type: GrantFiled: July 15, 2002Date of Patent: March 20, 2007Assignee: International Business Machines CorporationInventors: Snorri T. Ingvarsson, Roger H. Koch, Stuart S. Parkin, Gang Xiao
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Patent number: 7179338Abstract: Magnetostrictive devices and methods involving a magnetostrictive alloy having; (1) one or more of Pd, and Pt, and (2) one or more of Ni, Co, Fe, where the alloy comprises one or more of PdxNi1?x, PdxFe1?x, PdxCo1?x, PtxNi1?x, PtxFe1?x, PtxCo1?x, where x is less than 1, where magnetostrictive properties and diffusion, and solubility properties than variable in response to variations to a magnetic field to which the alloy is subjected. Devices and methods are used in hydrogen storage, isotopic separation, catalytic systems, actuator/sensor, and other magnetostrictive applications.Type: GrantFiled: March 24, 2005Date of Patent: February 20, 2007Assignee: University of Utah Research FoundationInventors: Sivaraman Guruswamy, Kevin Nguyen, Pinai Mungsantisuk, Rob Corson
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Patent number: 7172642Abstract: Magnetic metal particles containing iron as a main component, comprising cobalt in an amount of usually 20 to 50 atm %, calculated as Co, based on whole Fe, aluminum in an amount of usually 3 to 15 atm %, calculated as Al, based on whole Fe and a rare earth element in an amount of usually 3 to 20 atm %, calculated as rare earth element, based on whole Fe, and having an average major axis diameter of usually 0.02 to 0.065 ?m, preferably from 0.02 to less than 0.05 ?m, a coercive force of usually 159.2 to 222.9 kA/m (2,000 to 2,800 Oe), a soluble Na content of usually not more than 30 ppm, a soluble Ca content of usually not more than 100 ppm, and an oxidation stability ??s of usually not more than 10%.Type: GrantFiled: November 27, 2002Date of Patent: February 6, 2007Assignee: Toda Kogyo CorporationInventors: Akinori Yamamoto, Yasutaka Ota, Haruki Kurokawa, Masaaki Maekawa
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Patent number: 7163592Abstract: A steel sheet for a tension mask excellent in the shielding properties from geomagnetism consists essentially of lower than 0.1% by weight of C, lower than 0.2% by weight of Si, 0.4 to 2% by weight of Mn, not higher than 0.1% by weight of P, not higher than 0.03% by weight of S, not higher than 0.01% by weight of sol. Al, 0.003 to 0.02% by weight of N and the balance of Fe, and has an anhysteretic magnetic permeability of 5,000 or higher.Type: GrantFiled: July 2, 2003Date of Patent: January 16, 2007Assignee: JFE Steel CorporationInventors: Hideki Matsuoka, Yasushi Tanaka, Reiko Sugihara, Tatsuhiko Hiratani, Kenichiro Takayanagi, Masamichi Okada, Hiroaki Kato
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Patent number: 7063754Abstract: The magnetic material for magnetic refrigeration according to the present invention has an NaZn13-type crystalline structure and comprises iron (Fe) as a principal element (more specifically, Fe is substituted for the position of “Zn”) and hydrogen (H) in an amount of 2 to 18 atomic % based on all constitutional elements. Preferably, the magnetic material for magnetic refrigeration preferably contains 61 to 87 atomic % of Fe, 4 to 18 atomic % of a total amount of Si and Al, 5 to 7 atomic % of La. The magnetic material for magnetic refrigeration exhibits a large entropy change in a room temperature region and no thermal hysteresis in a magnetic phase transition. Therefore, when a magnetic refrigeration cycle is configured using the magnetic material for magnetic refrigeration, a stable operation can be performed.Type: GrantFiled: April 1, 2003Date of Patent: June 20, 2006Assignee: Kabushiki Kaisha ToshibaInventors: Kazuaki Fukamichi, Asaya Fujita, Yoshiaki Iijima, Akiko Saito, Tadahiko Kobayashi, Masashi Sahashi
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Patent number: 7048809Abstract: Magnetic powder having a large coercivity, Hc, is consolidated with a non-magnetic binder to form a magnetic implement having desired dimension and shape. The magnetic implement exhibits a linear B-H loop and low magnetic loss. It is capable of operating under a wide magnetic field range, and finds use current and pulse transformers, inductors carrying large electrical current, stable bandpass filters, and the like.Type: GrantFiled: January 21, 2003Date of Patent: May 23, 2006Assignee: Metglas, Inc.Inventors: Ryusuke Hasegawa, Vincent H. Hammond, James M. O'Reilly
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Patent number: 7045025Abstract: A low core loss grain-oriented electrical steel sheet that does not have a significant deterioration in a magnetic flux density and a decrease of a space factor, and which may withstand stress-relieving annealing is provided. Melted and re-solidified layers can be formed on either or both of the surfaces of the grain-oriented electrical steel sheet that extend in a direction that is perpendicular to the rolling direction (e.g., in the direction of the width thereof), at a cyclic interval of not less than approximately 2 mm to less than approximately 5 mm in the rolling direction. The melted and re-solidified layers may be provided on each surface of the grain-oriented electrical steel sheet, and can have an aspect ratio that is a ratio of the depth to the width of the melted and re-solidified layer of not less than approximately 0.20 and a depth of not less than approximately 15 ?m. In addition, the melted and re-solidified layers can be formed by using a laser.Type: GrantFiled: May 30, 2003Date of Patent: May 16, 2006Assignee: Nippon Steel CorporationInventors: Hideyuki Hamamura, Tatsuhiko Sakai, Naoya Hamada
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Patent number: 7041148Abstract: High-permeability, low-core-loss soft magnetic composite materials, compositions containing the same, and methods for making the same are described. These magnetic materials are made by forming fiber or flake shaped particles from a ferromagnetic material, annealing the particles, and then coating an insulating material on the particles. These particles can then be compacted to form an article that has high permeability, high saturation, low core loss, and is a suitable replacement for laminations in various applications, such as motors.Type: GrantFiled: March 3, 2003Date of Patent: May 9, 2006Assignee: General Electric CompanyInventors: Luana Emiliana Iorio, Paul Alfred Siemers, Gerald Burt Kliman, Krishnamurthy Anand, Amitabh Verma
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Patent number: 7029769Abstract: An insulation film whose requisite constituent elements are first elements and a second element. The first elements include B, P, O and Fe. The second element can generate cations whose hexa-coordinated ion radius, defined by Shannon, R. D., is 0.073 nm or more, and which are bivalent or more. Since the second element having a large ion radius is incorporated into network formers made from the first elements, it is possible to improve the heat resistance of the insulation film.Type: GrantFiled: March 18, 2003Date of Patent: April 18, 2006Assignees: Kabushiki Kaisha Toyota Chuo Kenkyusho, Toyota Jidosha Kabushiki Kaisha, Finesinter Co., Ltd.Inventors: Shin Tajima, Takeshi Hattori, Mikio Kondoh, Kiyoshi Higashiyama, Hidefumi Kishimoto, Masaki Sugiyama, Tadayoshi Kikko
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Patent number: 6942741Abstract: An iron alloy strip having a gage of 0.1 to 5 mm and a magnetic field strength variation within the strip of 0 to 10 Hz, made of an iron alloy consisting essentially of, in % by weight, 0.0001-0.02% of C, 0.0001-5% of Si, 0.001-0.2% of Mn, 0.0001-0.05% of P, 0.0001-0.05% of S, 0.0001-5% of Al, 0.001-0.1% of O, 0.0001-0.03% of N, 0-10% of Co, 0-10% of Cr, 0.01-5% in total of Ti, Zr, Nb, Mo, V, Ni, W, Ta and/or B, and the balance of Fe, and having a saturation magnetic flux density of 1.7-2.3 Tesla, a maximum relative permeability of 1,200-22,000 and a coercive force of 20-380 A/m is suited for use as yokes in voice coil motor magnetic circuits. The iron alloy strip is highly resistant to corrosion and eliminates a need for a corrosion resistant coating.Type: GrantFiled: August 7, 2002Date of Patent: September 13, 2005Assignee: Shin-Etsu Chemical Co., Ltd.Inventors: Masanobu Shimao, Masaaki Nishino, Takehisa Minowa
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Patent number: 6938324Abstract: A motor stator core for achieving improved magnetizing feature in lower magnetic fields and reduced iron loss, and improving motor power. The stator core fabriated out of non-oriented electrical steel sheets is annealed by applying a magnetic field to the heated stator core at least in the temperature range from a temperature immediately above a Curie point thereof to 300° C. in the process of cooling the stator core. The magnetic field has the same direction as the direction of exitation of a stator in the motor when used to drive a motor. This increases the magnetic induction in lower magnetic fields in particular and reduces the hysteresis loss, with a reduction in the total iron loss of the stator. A motor using this stator core increases in saturation induction under exciting currents of higher frequncies, allowing enhanced motor power.Type: GrantFiled: October 21, 2003Date of Patent: September 6, 2005Assignees: Toyo Tessin Kogyo Co., Ltd., Hi-Z Co., Ltd.Inventors: Hiromichi Koshiishi, Tomiya Ogata, Shigeki Eguchi, Hideo Hasegawa
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Patent number: 6940388Abstract: A dust core consists essentially of ferromagnetic powder; and an insulating binder, in which the ferromagnetic powder is dispersed; wherein the insulating binder is a silicone resin comprising a trifunctional alkyl-phenyl silicone resin and optionally containing an inorganic insulator such as an inorganic oxide, carbide or nitride. Preferably the alkyl-phenyl silicone resin is a methyl-phenyl silicone resin and comprises about 20 to 70 mol % of trifunctional groups. The dust core can be produced by pressure-molding a ferromagnetic powder, a lubricant and a trifunctional alkyl-phenyl silicone resin binder and heat treating the molded core at a temperature in the range of about 300 to about 800 ° C. for a time period in the range of about 20 minutes to about 2 hours in a non-oxidizing atmosphere. The dust core has high magnetic permeability representing the direct current superimposition characteristics, has reduced core loss and has increased mechanical strength.Type: GrantFiled: April 11, 2003Date of Patent: September 6, 2005Assignee: TDK CorporationInventor: Hideharu Moro
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Patent number: 6918966Abstract: The object of the present invention is to provide a low iron loss and low noise grain-oriented electrical steel sheet for securing both low core loss and low noise of a transformer at the same time. The present invention relates to a grain-oriented electrical steel sheet containing Si: 1.0-4.0 wt % produced by controlling, with regard to ?O, which is defined as a 0-p value when a grain-oriented electrical steel sheet is magnetized up to a saturated magnetic flux density, and ?17, which is defined as the value obtained by subtracting a 0-p value at the magnetization magnetic flux density of 1.7 T from a 0-p value at a saturated magnetic flux density, ?OC and ?17L, which are absolute values deviated by forming a tension film and a forsterite film, and ?OL and ?17L, which are absolute values deviated by irradiating laser after the film formation, in adequate ranges respectively, and further controlling ?17, which is a 0-p value at the magnetization magnetic flux density of 1.Type: GrantFiled: November 6, 2002Date of Patent: July 19, 2005Assignee: Nippon Steel CorporationInventors: Masahiro Fujikura, Satoshi Arai, Masato Mizokami, Hisashi Mogi, Takeshi Kubota
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Patent number: 6852174Abstract: There is disclosed a powder magnetic core in which a permeability does not easily drop even when an applied magnetic field intensifies, comprising: a bulk body containing a main component of a powder of an Fe-base alloy having a soft magnetic property, and the balance substantially including a heat-treated insulation binder and a void, wherein an aspect ratio of the powder is in a range of 1 to 1.5, and a volume ratio of the powder in the bulk body is in a range of 40 to 60 volume %, and an initial permeability (?0) has a value which satisfies 6??0?20, and a relation of ?/?0?0.5 is established between K and A, when the permeability is ? with an applied magnetic field of 24 kA/m.Type: GrantFiled: August 12, 2002Date of Patent: February 8, 2005Assignee: Daido Tokushuko Kabushiki KaishaInventors: Satoshi Takemoto, Takanobu Saito
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Patent number: 6841271Abstract: A ferromagnetic iron alloy powder for a magnetic recording medium is composed of acicular iron-base particles of an average major axis length (X) of not less than 20 nm and not greater than 80 nm and have oxygen content of not less than 15 wt % and coercive force (Hc) of not less than [0.0036 X3?1.1 X2+110 X?1390 (Oe)] (where X is average major axis length expressed in nm). The ferromagnetic iron alloy powder is obtained by reacting metal powder composed of acicular iron-base particles having an average major axis length of not less than 20 nm and not greater than 80 nm with pure water in substantial absence of oxygen to form a metal oxide film on the particle surfaces. Optionally, the particles can be reacted with a weak oxidizing gas by a wet or dry method.Type: GrantFiled: March 5, 2003Date of Patent: January 11, 2005Assignee: Dowa Mining Co., Ltd.Inventors: Kazuyuki Matsumoto, Kimitaka Sato, Takatoshi Fujino, Kenichi Inoue
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Patent number: 6822831Abstract: An object of the present invention is to provide a recording head having a magnetic pole simultaneously possessing a high saturation magnetic flux density, a high permeability and a high electric resistivity, and the magnetic pole of the recording head is a polycrystalline film comprising Fe whose content is not less than 57.5 atomic % and not more than 94.5 atomic %; one or more kinds of elements selected from the element group of Al, B, Ga, Si, Ge, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W and Rh, whose whole content is not less than 1 atomic % and not more than 15 atomic %; N whose content is not less than 0.5 atomic % and not more than 10 atomic %; and O whose content is not less than 1.5 atomic % and not more than 22.5 atomic %.Type: GrantFiled: February 12, 2002Date of Patent: November 23, 2004Assignee: Fujitsu LimitedInventors: Shoji Ikeda, Yuji Uehara, Ikuya Tagawa, Naoki Takeguchi, Masahiro Kakehi
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Patent number: 6805980Abstract: Refractory metal layers 2, 4, 6, 8, and 10, and rare earth alloy magnetic layers 3, 5, 7, 9, 11, and 12 are alternately deposited, so as to form a multilayer structure including four or more layers on a substrate. The refractory metal layers 2, 4, 6, 8, and 10 are formed from at least one kind of material selected from a group consisting of Ti, V, Cr, Zr, Nb, Mo, Hf, Ta, and W, and each has a thickness of not less than 5 nm nor more than 50 nm. The rare earth alloy magnetic layers 3, 5, 7, 9, 11, and 12 have tetragonal R2Fe14B (R is Nd and/or Pr) as a primary constituent phase, and each has a thickness of not less than 50 nm nor more than 500 nm.Type: GrantFiled: October 22, 2001Date of Patent: October 19, 2004Assignee: Neomax Co., Ltd.Inventor: Minoru Uehara
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Patent number: 6800146Abstract: A magnetic circuit member contains a matrix portion including iron and silicon; and graphite particles in the matrix. Each of the graphite particles has either a spherical shape or a compact vermicular shape. The inclusion of graphite particles having a relatively low conductivity in the matrix portion having a good magnetic property prevents eddy currents from forming in the magnetic circuit member in an alternating magnetic field, thus preserving the original magnetic property found in the absence of the alternating magnetic field. Each of the graphite particles has a spherical or compact vermicular shape that does not intercept magnetic flux passing through the material forming the magnetic circuit member. The graphite contained in the material improves liquidity of the melted material in casting, thus the magnetic circuit member can be manufactured by casting.Type: GrantFiled: March 19, 2002Date of Patent: October 5, 2004Assignee: Aisin Seiki Kabushiki KaishaInventors: Akikazu Matsumoto, Wataru Yagi
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Patent number: 6797410Abstract: A steel composition, in which, Si content is regulated to a given range and Nb and Cu or Ni, Mo are compositively added, and a recrystallization annealing is carried out to form an internal oxide layer just beneath a surface of a steel sheet and a surface oxide simultaneously formed on the surface of the steel sheet is removed by pickling. As a result, the formation of oxides of Si, Mn and the like is considerably decreased on the surface of the steel sheet in a subsequent heating before plating because the above internal oxide layer acts as a diffusion barrier. Thus, there can be obtained high tensile strength hot-dipped steel sheets having a considerably excellent plating property.Type: GrantFiled: May 13, 2002Date of Patent: September 28, 2004Assignee: JFE Steel CorporationInventors: Kazuhide Ishii, Kazuaki Kyono, Chiaki Kato, Kazuo Mochizuki
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Patent number: 6783608Abstract: Secondary agglomerates of magnetic metal particles for magnetic recording, have a sodium content of not more than 20 ppm and a calcium content of not more than 40 ppm, an average particle diameter of 300 to 800 &mgr;m and an upper limit of particle diameters of 2,000 &mgr;m, and comprise magnetic metal primary particles having an average major axis diameter of 0.05 to 0.25 &mgr;m.Type: GrantFiled: April 24, 2002Date of Patent: August 31, 2004Assignee: Toda Kogyo CorporationInventors: Kenji Okinaka, Kohji Mori, Masayuki Uegami
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Publication number: 20040129345Abstract: A steel sheet for an inner magnetic shield has a ratio of the anhysteretic magnetic permeability in the rolling direction to the anhysteretic magnetic permeability in the transversal direction, which is not higher than 0.7 or not lower than 1.4, preferably not higher than 0.5 or not lower than 2.0. A higher value of the two anhysteretic magnetic permeability values in the rolling direction and in the transversal direction is not lower than 18000. The inner magnetic shield formed of the particular steel sheet has a substantially truncated pyramid body which has a pair of short side members of a screen and a pair of long side members of a screen. The short side members are joined to the long side members at edge portions of the truncated pyramidal inner magnetic shield. The direction, in which the anhysteretic magnetic permeability of the steel sheet is the higher value, corresponds to the horizontal plane direction of the short side member.Type: ApplicationFiled: October 28, 2003Publication date: July 8, 2004Applicants: JFE STEEL CORPORATION, SONY CORPORATIONInventors: Hideki Matsuoka, Reiko Sugihara, Kenji Tahara, Noriko Kubo, Keisuke Fukumizu, Teruo Takeuchi, Hiroaki Kato
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Patent number: 6758915Abstract: The invention is a grain-oriented magnetic steel sheet having extremely low iron loss, suitable for use as an iron core material for transformers and power generators, and a method for producing the same. The method includes forming a coating layer on a surface of a steel sheet having a thickness of 0.27 mm or less by vapor deposition in a low oxidizing atmosphere with an oxygen partial pressure (Po2) of less than 0.1 atm and a total pressure of 0.1 atm or more. The steel sheet has extremely low iron loss with a thickness of 0.27 mm or less and includes a coating layer formed by vapor deposition on a matrix surface.Type: GrantFiled: December 5, 2002Date of Patent: July 6, 2004Assignee: JFE Steel CorporationInventors: Minoru Takashima, Mineo Muraki, Hiroi Yamaguchi, Mitsumasa Kurosawa, Michiro Komatsubara
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Patent number: 6743304Abstract: The present invention provides a non-oriented electrical steel sheet having ultra-high magnetic flux density and low core loss, characterized by: comprising a steel containing, in terms of wt %, Si: 0.4% or less, Ni: 2.0% to 6.0%, and Mn: 0.5% or less, with the balance consisting of Fe and unavoidable impurities; and having B25, the magnetic flux density under the magnetic field strength of 2500 A/m, of 1.70T or higher and B50, the magnetic flux density under the magnetic field strength of 5000 A/m, of 1.80T or higher.Type: GrantFiled: December 10, 2001Date of Patent: June 1, 2004Assignee: Nippon Steel CorporationInventors: Ryutaro Kawamata, Takeshi Kubota
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Patent number: 6723179Abstract: A soft magnetism metal powder having a majority of particles, each of which, when cross-sectioned, has no greater than ten crystal particles on average, may be coated on an outer surface of each of the particles with a resistive material having a higher resistivity than the underlying parent phase. The soft magnetism metal powder may be prepared by heating a soft magnetism metal powder to a high temperature in a high temperature atmosphere, thereby reducing the number of crystal particles in each of the soft magnetism metal powder particles. A soft magnetism metal formed body may be prepared by pressing the soft magnetism metal particles at a sufficient temperature and pressure.Type: GrantFiled: October 16, 2001Date of Patent: April 20, 2004Assignee: Aisin Seiki Kabushiki KaishaInventors: Wataru Yagi, Kota Maruyama, Yoshiharu Iyoda, Aiko Nakashima, Toshihisa Terazawa, Naoki Kamiya
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Publication number: 20040040627Abstract: The present invention is related to a magnesium oxide particle aggregate with the requirement of a first inflection point diameter is more than 0.30×10−6 to 0.60×10−6 m, a particle void volume is 0.50×10−3 to 0.90×10−3 m3·kg−1, and a micropore volume is 0.04×10−3 to 0.11×10−3 m3·kg−1 in the cumulative intrusion volume curve of said particle by having controlled particle aggregation structure so that the solid phase-solid phase reaction between magnesium oxide and the SiO2 film on the surface can be appropriately controlled.Type: ApplicationFiled: April 24, 2003Publication date: March 4, 2004Inventors: Atsuo Toutsuka, Yutaka Hiratsu
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Patent number: RE40524Abstract: The magnet powder-resin compound particles substantially composed of rare earth magnet powder and a binder resin are in such a round shape that a ratio of the longitudinal size a to the transverse size b (a/b) is more than 1.00 and 3 or less, and that an average particle size defined by (a/b)/2 is 50-300 ?m. They are produced by charging a mixture of rare earth magnet powder and a binder resin into an extruder equipped with nozzle orifices each having a diameter of 300 ?m or less; extruding the mixture while blending under pressure though the nozzle orifices to form substantially cylindrical, fine pellets; and rounding the pellets by rotation.Type: GrantFiled: July 20, 2004Date of Patent: September 30, 2008Assignee: Hitachi Metals, Ltd.Inventors: Katsunori Iwasaki, Kazunori Tabaru