Cobalt Containing Patents (Class 148/311)
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Patent number: 6685882Abstract: A high strength soft magnetic Fe−Co−V alloy, comprising, in weight %, (Fe+Co)≧88%, (Fe−Co)≧2% or (Co−Fe)≧2%, at least 30% Co, and satisfying one of the following three conditions: (1) 0.05 to 4% Mo and 1.5 to 10% V, or (2) (Fe−Co) or (C0−Fe)≦13 and at least 4% V, or (3) at least 7% V. Additional alloying constituents, including B, C, Nb, Ti, W and Ni can be present.Type: GrantFiled: January 11, 2001Date of Patent: February 3, 2004Assignee: Chrysalis Technologies IncorporatedInventors: Seetharama C. Deevi, Rangaraj S. Sundar, Dwadasi H. Sastry
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Patent number: 6676772Abstract: The magnetic material for magnetic refrigeration of the present invention is characterized by exhibiting, in a certain temperature region, preferably, only in part of a temperature region from 200 K to 350 K, an inflection point at which a second order differential coefficient of a magnetization curve changes from positive to negative with respect to a magnetic field, within the range of this magnetic field formed using a permanent magnet unit. This magnetic material of the present invention can generate a low temperature by using a relatively low magnetic field, by transferring the entropy between the electron spin system and the lattice system near the temperature at which an inflection point appears on the magnetization curve. Examples of the magnetic material meeting this condition are La(Fe,Si)13, (Hf,Ta)Fe2, (Ti,Sc)Fe2, and (Nb,Mo)Fe2, each containing 50 to 60 atomic % of transition metals such as Fe.Type: GrantFiled: March 18, 2002Date of Patent: January 13, 2004Assignee: Kabushiki Kaisha ToshibaInventors: Akiko Saito, Tadahiko Kobayashi, Takao Sawa, Masashi Sahashi
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Patent number: 6663981Abstract: A marker for use in a magnetic anti-theft security system has an amorphous ferromagnetic alloy alarm strip and at least one activation strip. The semi-hard magnetic alloy for the activation strip contains 8 to 25 weight % Ni, 1.5 to 4.5 weight % Al, 0.5 to 3 weight % Ti and balance of iron. The alloy is distinguished over known, employed alloys by excellent magnetic properties and a high resistance to corrosion. Further, the alloy can be excellently cold-worked before the annealing.Type: GrantFiled: June 8, 1999Date of Patent: December 16, 2003Assignee: Vacuumschmelze GmbHInventors: Hartwin Weber, Gernot Hausch, Ottmar Roth
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Publication number: 20030209295Abstract: A cobalt-iron alloy film having saturation magnetization of at least about 2.30 Telsa. The film alloy includes about 55 wt % to about 75 wt. % iron and the remainder cobalt. The film is made by a process in which the film is electrodeposited from an aqueous medium which includes one or more ferrous salts, one or more cobaltous salts, a buffer having a pKa of about 6 to about 8, at least one carboxylic acid having a pKa of between about 3.5 and about 5.5, an aromatic sulfinic acid or its salt and optionally, a halide salt and/or a surfactant. The alloy film is useful as a write head in magnetic recording.Type: ApplicationFiled: June 9, 2003Publication date: November 13, 2003Applicant: International Business Machines CorporationInventors: Emanuel Israel Cooper, Thomas Edward Dinan, Lubomyr Taras Romankiw, Hong Xu
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Patent number: 6627313Abstract: Spindle-shaped magnetic metal particles containing iron as a main component of the present invention, have an average major axis diameter (L) of 0.05 to 0.15 &mgr;m; a coercive force of 111.4 to 143.2 kA/m; a Co content of from 0.5 to less than 5 atm % based on whole Fe; a crystallite size of from 150 to less than 170 Å; a ratio of Al to Co from 1.0:1 to less than 2.0:1; a specific surface area (S) represented by the formula: S≦−160×L+65; an oxidation stability (&Dgr;&sgr;s) of saturation magnetization of not more than 5.0%; and an ignition temperature of not less than 140° C. The spindle-shaped magnetic metal particles containing iron as a main component, exhibit an adequate coercive force, and are excellent in dispersibility, oxidation stability and coercive force distribution despite fine particles, especially notwithstanding the particles have an average major axis diameter as small as 0.05 to 0.15 &mgr;m.Type: GrantFiled: October 4, 2001Date of Patent: September 30, 2003Assignee: Toda Kogyo CorporationInventors: Kenji Okinaka, Masayuki Uegami
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Publication number: 20030172996Abstract: 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: ApplicationFiled: March 5, 2003Publication date: September 18, 2003Inventors: Kazuyuki Matsumoto, Kimitaka Sato, Takatoshi Fujino, Kenichi Inoue
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Patent number: 6599375Abstract: A composite magnetic body 1, comprising a soft magnetic powder (2) and a binding agent (3), in which the specific surface area of the soft magnetic powder (2) is 0.1-3 m2/g. The surface state of the soft magnetic powder contained in the composite magnetic body is defined in terms of specific surface area, and self-extinguishing properties, i.e. fire resistance properties, are obtained. An electromagnetic interference suppressing body is obtained using this composite magnetic body.Type: GrantFiled: June 13, 2001Date of Patent: July 29, 2003Assignee: NEC Tokin CorporationInventor: Yoshio Awakura
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Publication number: 20030136473Abstract: 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 &mgr;m, preferably from 0.02 to less than 0.05 &mgr;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 &Dgr;&sgr;s of usually not more than 10%.Type: ApplicationFiled: November 27, 2002Publication date: July 24, 2003Inventors: Akinori Yamamoto, Yasutaka Ota, Haruki Kurokawa, Masaaki Maekawa
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Patent number: 6547889Abstract: The invention discloses an iron-based alloy sheet as a material for preparing a magnetic yoke member to build up a magnetic circuit in a hard-disk voice-coil motor as well as a magnetic yoke member made from such a sheet material. With an object to improve the magnetic circuit in respect of compactness and flatness, the iron-based alloy forming the sheet material contains inherent side elements including C, Si, Mn, P, S, Al, O and N each in a specified amount and is characterized by specified values of saturated magnetic flux density, maximum magnetic permeability and coercive force. The iron-based alloy may further contain up to 10% by weight of cobalt and/or one or a combination of adjuvant elements selected from Ti, Zr, Nb, Mo, Cr, V, Ni, W, Ta and B.Type: GrantFiled: September 5, 2001Date of Patent: April 15, 2003Assignee: Shin-Etsu Chemical Co., Ltd.Inventors: Masanobu Shimao, Takehisa Minowa, Masaaki Nishino
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Patent number: 6521055Abstract: A method of stress inducing transformation from the austenite phase to the martensite phase by conducting cold working on material of austenite stainless steel in the temperature range from the point Ms to the point Md. The above cold working is a biaxial tensing. An intermediately formed hollow body is made, which includes a ferromagnetic portion and a non-magnetic portion contracting inward. Then, the intermediately formed body is subjected to a stress removing process in which residual tensile stress is removed from an intermediately formed body. In the stress removing process, it is preferable that a punch is press-fitted into the intermediately formed body so as to expand a non-magnetic portion and then the intermediately formed body is drawn with ironing while the punch is inserted so that the residual tensile stress can be changed into the residual compressive stress in the non-magnetic portion.Type: GrantFiled: February 3, 2000Date of Patent: February 18, 2003Assignee: Denso CorporationInventors: Satoshi Sugiyama, Yoshihiro Tanimura, Masaki Shimizu, Yoshitada Katayama, Hidehito Kito, Suehisa Sugisaka
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Patent number: 6514358Abstract: Magnetic materials for use in sputtering targets are hot rolled and stretched at ambient temperature or at a temperature not exceeding 1400° F. The magnetic material can be pure Co, pure Ni, or Co based alloys.Type: GrantFiled: April 5, 2001Date of Patent: February 4, 2003Assignee: Heraeus, Inc.Inventors: Michael Bartholomeusz, Michael Tsai
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Publication number: 20020127132Abstract: A high strength soft magnetic Fe−Co−V alloy is provided in which the weight percent of constituents are such that (Fe+Co)≧90, (Fe−Co)≧10, and 1.5 to 10% V. Additional alloying constituents, including B, C, Nb, Ti, W, Ni and Mo, can be present.Type: ApplicationFiled: January 11, 2001Publication date: September 12, 2002Inventors: Seetharama C. Deevi, Rangaraj S. Sundar, Dwadasi H. Sastry
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Patent number: 6423386Abstract: 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 &mgr;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 &mgr;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: April 6, 1999Date of Patent: July 23, 2002Assignee: Hitachi Metals, Ltd.Inventors: Katsunori Iwasaki, Kazunori Tabaru
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Patent number: 6407676Abstract: A first magnetostrictive member 1a is housed in a storage section 2f of a first frame 2a and a second magnetostrictive member 1b is housed in a storage section 2g of a second frame 2b. They are fixed by an adhesive, etc., so as to sandwich a belt-like magnetic member 3 between the frames 2a and 2b. A sealing plate 4a, 4b is fixed to the opposite side of the frame 2a, 2b, forming a magnetostrictive resonator 5. When an electromagnetic wave is applied from the long side direction of the magnetostrictive member 1a, 1b, a magnetic field is applied to the magnetostrictive members 1a and 1b. When the frequency matches the resonance frequency of the magnetostrictive member, the magnetostrictive resonator 5 vibrates with the maximum amplitude. An electromagnetic wave emitted from the magnetostrictive member 1a or 1b can be detected based on mechanical vibration continuing for a short time still after the magnetic field is stopped.Type: GrantFiled: August 27, 1998Date of Patent: June 18, 2002Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Yoshihiko Tanji, Toshihiro Yoshioka, Joji Kamata
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Publication number: 20020069944Abstract: Preferred embodiments of the invention provide new nanostructured materials and methods for preparing nanostructured materials having increased tensile strength and ductility, increased hardness, and very fine grain sizes making such materials useful for a variety of applications such as rotors, electric generators, magnetic bearings, aerospace and many other structural and nonstructural applications. The preferred nanostructured materials have a tensile yield strength from at least about 1.9 to about 2.3 GPa and a tensile ductility from at least 1%. Preferred embodiments of the invention also provide a method of making a nanostructured material comprising melting a metallic material, solidifying the material, deforming the material, forming a plurality of dislocation cell structures, annealing the deformed material at a temperature from about 0.30 to about 0.70 of its absolute melting temperature, and cooling the material.Type: ApplicationFiled: October 3, 2001Publication date: June 13, 2002Inventors: Timothy P. Weihs, Robert Cammarata, Chia-Ling Chien, Changhe Shang
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Publication number: 20020062885Abstract: A soft magnetic steel alloy contains in weight percent, about 1.0-5.0% manganese, about 7-17% cobalt, and the balance is essentially iron. The disclosed alloy provides a highly acceptable level of magnetic saturation induction combined with good electrical resistivity with a substantially reduced amount cobalt relative to the known Co—Fe soft magnetic steel alloys.Type: ApplicationFiled: October 4, 2001Publication date: May 30, 2002Inventor: Lin Li
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Patent number: 6350324Abstract: Soft magnetic alloy of the iron-nickel type, the chemical composition of which comprises, in % by weight: 34%≦Ni≦40%; 7%≦Cr≦10%; 0.5%≦Co≦3%; 0.1%≦Mn≦1%; O≦0.007%; S≦0.002%; N≦0.004%; with N+S+O≦0.01%; iron and impurities 5 resulting from the production process. Use in motors especially suited for use in horology.Type: GrantFiled: March 27, 2000Date of Patent: February 26, 2002Assignee: Imphy Ugine PrecisionInventors: Thierry Waeckerle, Lucien Coutu, Laurent Chaput
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Patent number: 6350323Abstract: A high permeability metal glassy alloy for high frequencies contains at least one element of Fe, Co, and Ni as a main component, at least one element of Zr, Nb, Ta, Hf, Mo, Ti, V, Cr, and W, and B. In the metal glassy alloy, the temperature interval &Dgr;Tx of a super cooled liquid region, which is represented by the equation &Dgr;Tx=Tx−Tg (wherein Tx represents the crystallization temperature, and Tg represents the glass transition temperature) is 20° C. or more, and resistivity is 200 &mgr;&OHgr;·cm or more.Type: GrantFiled: September 2, 1999Date of Patent: February 26, 2002Assignees: Alps Electronic Co., Ltd.Inventors: Akihisa Inoue, Tao Zhang
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Publication number: 20020014181Abstract: A ferromagnetic powder comprising ferromagnetic particles coated with a material that does not degrade at temperatures above 150° C. and permits adjacent particles to strongly bind together after compaction such that parts made from the ferromagnetic powder have a transverse rupture strength of about 8,000 to about 20,000 pounds/square inch before sintering. The coating includes from 2 to 4 parts of an oxide and one part of a chromate, molybdate, oxalate, phosphate, or tungstate. The coating may be substantially free of organic materials. The invention also includes a method of making the ferromagnetic powder, a method of making soft magnetic parts from the ferromagnetic powder, and soft magnetic parts made from the ferromagnetic powder.Type: ApplicationFiled: October 30, 1998Publication date: February 7, 2002Inventors: DAVID S. LASHMORE, GLENN L. BEANE, LEV DERESH, ZONGLU HUA
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Patent number: 6342108Abstract: A ferromagnetic powder comprising ferromagnetic particles coated with a material that does not degrade at temperatures above 150° C and permits adjacent particles to strongly bind together after compaction such that parts made from the ferromagnetic powder have a transverse rupture strength of about 8,000 to about 20,000 pounds/square inch before sintering. The coating includes from 2 to 4 parts of an oxide and one part of a chromate, molybdate, oxalate, phosphate, or tungstate. The coating may be substantially free of organic materials. The invention also includes a method of making the ferromagnetic powder, a method of making soft magnetic parts from the ferromagnetic powder, and soft magnetic parts made from the ferromagnetic powder.Type: GrantFiled: February 9, 1999Date of Patent: January 29, 2002Assignee: Materials Innovation, Inc.Inventors: David S. Lashmore, Glenn L. Beane, Lev Deresh, Zonglu Hua
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Patent number: 6309479Abstract: Spindle-shaped metal particles and a process for producing magnetic spindle-shaped metal particle containing iron as a main component, which contains cobalt of 8 to 45 atm % calculated as Co, aluminum of 5 to 20 atm %, calculated as Al, and a rare earth element of 1 to 15 atm %, calculated as rare earth element, wherein the particles have an average major axial diameter of 0.05 to 0.15 &mgr;m, an average minor axial diameter of 0.010 to 0.022 &mgr;m, an aspect ratio of 4:1 to 8:1, a particle size distribution of not more than 0.20, and an X-ray crystallite size D110 of 12.0 to 17.0 nm. The spindle-shaped metal particles have a high coercive force, an excellent particle coercive force distribution, a large saturation magnetization and an excellent oxidation stability, and are excellent in a squareness (Br/Bm) of the sheet due to a good dispersibility in a binder resin.Type: GrantFiled: March 2, 1999Date of Patent: October 30, 2001Assignee: Toda Kogyo CorporationInventors: Kenji Okinaka, Masaaki Maekawa
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Patent number: 6238492Abstract: A soft magnetic thin micro-crystalline film of FeaTbNc (at %) wherein T is at least one of Zr, Hf, Ti, Nb, Ta, V, Mo, and W and 0<b≦20, and 0<c≦22 except the range of b≦7.5 and c≦5, shows low coercivity Hc of 80-400 Am−1 (1-5 Oe) which is stable upon heating at elevated temperatures for glass bonding. This film is produced by crystallizing an amorphous alloy film of the similar composition at 350-650° C. to a crystal grain size up to 30 nm to provide uniaxial anisotropy and increased magnetic permeability at a higher frequency. It can also provide low magnetostriction around &lgr;s=0. A composite magnetic head is made using this thin film. A diffusion preventive SiO2 layer is disposed between ferrite cores, and this thin film in the magnetic head prevents an interdiffusion layer and suppresses beat in the output signal.Type: GrantFiled: October 24, 1997Date of Patent: May 29, 2001Assignee: Fuji Photo Film Co., Ltd.Inventors: Kanji Nakanishi, Osamu Shimizu, Satoshi Yoshida, Masaaki Katayama, Tatsuya Isomura
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Patent number: 6232775Abstract: A magneto-impedance element comprises an alloy composed of at least one of Fe, Co and Ni. The alloy has a mixed texture of an amorphous phase and a fine crystalline phase having an average crystal grain size of 50 nm or less. The magneto-impedance element shows a change in impedance in response to an external magnetic field by applying an alternating current. The magneto-impedance element is applied to an azimuth sensor, an autocanceler, or a magnetic head.Type: GrantFiled: December 14, 1998Date of Patent: May 15, 2001Assignees: Alps Electric Co., LTDInventors: Yutaka Naitoh, Teruo Bitoh, Takashi Hatanai, Akihiro Makino, Junichi Ouchi, Shinichi Sasaqawa, Akihisa Inoue, Tsuyoshi Masumoto
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Patent number: 6190516Abstract: A planar ferromagnetic sputter target is provided for use as cathode in the magnetron sputtering of magnetic thin films, wherein the ferromagnetic material has localized regions of differing magnetic permeability. A solid, unitary, planar sputter target is formed from a ferromagnetic material, such as cobalt, nickel, iron or an alloy thereof, and this planar target is subjected to mechanical deformation, heat treatment, and/or thermal-mechanical treatment to create regions within the sputter target having different permeability than adjacent regions. The permeability differences in the ferromagnetic sputter target guides the path of the magnetic flux flow through the target to thereby increase the magnetic leakage flux at the target sputtering surface.Type: GrantFiled: October 6, 1999Date of Patent: February 20, 2001Assignee: Praxair S.T. Technology, Inc.Inventors: Wei Xiong, Hung-Lee Hoo, Peter McDonald
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Patent number: 6190465Abstract: Soft magnetic alloy of the iron-nickel type, the chemical composition of which comprises, by weight: 40%≦Ni+Co≦65%; 0%≦Co≦7%; 2%≦Cr≦5%; 1%≦Ti≦3%; 0%≦Al≦0.5%; 0%≦Mn+Si≦2%; optionally, up to 3% Mo, 2% W, 2% V, 1.5% Nb, 1% Ta and 3% Cu, the sum of the Cr, Mo, W, V, Nb, Ta and Cu contents being less than 7% and the sum of the Mo, W, V, Nb, Ta and Cu contents being less than 4%; the balance being iron and impurities, such as carbon, sulfur and phosphorus, resulting from the smelting process, the chemical composition furthermore satisfying the relationships: Cr<5−0.015×(Ni+Co−52.5)2, if: Ni+Co≦52.5; Cr<5−0.040×(Ni+Co−52.5)2, if: Ni+Co≧52.5; the alloy having a saturation induction Bs of greater than 0.9 tesla, a coercive field of less than 10 A/m, an electrical resistivity p of greater than 60 &mgr;&OHgr;.cm and a hardness of greater than 200 HV. Process for manufacturing the alloy and uses.Type: GrantFiled: July 2, 1998Date of Patent: February 20, 2001Assignee: Imphy Ugine PrecisionInventors: Lucien Coutu, Laurent Chaput, Thierry Waeckerle
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Patent number: 6183868Abstract: The present invention relates to spindle-shaped goethite particles and spindle-shaped hematite particles, which have a narrow particle size distribution, include no dendrites, and have an appropriate particle shape and a large aspect ratio (major axial diameter/minor axial diameter); and spindle-shaped magnetic iron based alloy particles which are obtained from the spindle-shaped goethite particle or spindle-shaped hematite particles as a beginning material and which have a high coercive force and an excellent coercive force distribution. Such spindle-shaped goethite particles comprises: goethite seed containing 0.5 to 25 atm % of Co based on the total Fe in the spindle-shaped goethite particles, and goethite surface layer containing 0.5 to 15 atm % of Al based on the total Fe in the spindle-shaped goethite particles; and having an average major axial diameter of 0.05 to 1.0 &mgr;m.Type: GrantFiled: September 13, 1999Date of Patent: February 6, 2001Assignee: Toda Kogyo CorporationInventors: Haruki Kurokawa, Kohji Mori
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Patent number: 6146474Abstract: An iron--cobalt alloy the chemical composition of which comprises, by weight: 35%.ltoreq.Co.ltoreq.55%; 0.5%.ltoreq.V.ltoreq.2.5%; 0.02%.ltoreq.Ta+2.times.Nb.ltoreq.0.2%; 0.0007%.ltoreq.B.ltoreq.0.007%; C.ltoreq.0.05%; the balance being iron and impurities resulting from the smelting operation.Type: GrantFiled: January 15, 1999Date of Patent: November 14, 2000Assignee: Imphy Ugine PrecisionInventors: Lucien Coutu, Laurent Chaput
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Patent number: 6132524Abstract: A semiconductor magneto-optical material includes a semiconductor dispersed with fine magnetic material particles and is characterized by exhibiting magneto-optical effect at ordinary room temperature.Type: GrantFiled: January 15, 1998Date of Patent: October 17, 2000Assignees: Agency of Industrial Science & Technology, Ministry of International Trade & Industry, Tokin CorporationInventors: Hiroyuki Akinaga, Koichi Onodera
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Patent number: 6132891Abstract: There is disclosed an amorphous soft magnetic material represented by a composition formula:Co.sub.x Zr.sub.y Pd.sub.z M.sub.a wherein M denotes at least one element selected from a group consisting of niobium, chromium, vanadium, tantalum, tungsten, molybdenum; and0.82.ltoreq.x.ltoreq.0.940.04.ltoreq.y.ltoreq.0.100.01.ltoreq.z.ltoreq.0.080.01.ltoreq.a.ltoreq.0.10.The amorphous soft magnetic material, which has a high saturated magnetic flux density, a low coercive force, a high magnetic permeability and excellent wear and corrosion resistances, can be obtained by adding at least one or more of the elements of the Va and VIa groups to a Co--Zr--Pd amorphous soft magnetic material.Type: GrantFiled: July 6, 1992Date of Patent: October 17, 2000Assignee: Sony CorporationInventors: Tatsuo Kumura, Yukari Utsumi, Hideaki Karamon
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Patent number: 6129790Abstract: A ferromagnetic powder comprising ferromagnetic particles coated with a material that does not degrade at temperatures above 150.degree. C. and permits adjacent particles to strongly bind together after compaction such that parts made from the ferromagnetic powder have a transverse rupture strength of about 8,000 to about 20,000 pounds/square inch before sintering. The coating includes from 2 to 4 parts of an oxide and one part of a chromate, molybdate, oxalate, phosphate, or tungstate. The coating may be substantially free of organic materials. The invention also includes a method of making the ferromagnetic powder, a method of making soft magnetic parts from the ferromagnetic powder, and soft magnetic parts made from the ferromagnetic powder.Type: GrantFiled: February 11, 1999Date of Patent: October 10, 2000Assignee: Materials Innovation, Inc.Inventors: David S. Lashmore, Glenn L. Beane, Lev Deresh, Zonglu Hua
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Patent number: 6048412Abstract: The present invention relates to spindle-shaped goethite particles and spindle-shaped hematite particles, which have a narrow particle size distribution, include no dendrites, and have an appropriate particle shape and a large aspect ratio (major axial diameter/minor axial diameter); and spindle-shaped magnetic iron based alloy particles which are obtained from the spindle-shaped goethite particle or spindle-shaped hematite particles as a beginning material and which have a high coercive force and an excellent coercive force distribution. Such spindle-shaped goethite particles comprises: goethite seed containing 0.5 to 25 atm % of Co based on the total Fe in the spindle-shaped goethite particles, and goethite surface layer containing 0.5 to 15 atm % of Al based on the total Fe in the spindle-shaped goethite particles; and having an average major axial diameter of 0.05 to 1.0 .mu.m.Type: GrantFiled: April 25, 1997Date of Patent: April 11, 2000Assignee: Toda Kogyo CorporationInventors: Haruki Kurokawa, Kohji Mori
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Patent number: 6018296Abstract: A resonator for use in a marker in a magnetomechanical electronic article surveillance system is formed by a planar strip of an amorphous magnetostrictive alloy having a composition Fe.sub.a Co.sub.b Ni.sub.c Si.sub.x B.sub.y M.sub.z wherein a, b, c, x, y, and z are at % and a+b+c+x+y+z=100, a+b+c>75, a>15, b<20, c>5 and z<3, wherein M is at least one element selected from the group consisting of C, P, Ge, Nb, Mo, Cr and Mn, the amorphous magnetostrictive alloy having a resonant frequency f.sub.r which is a minimum at a field strength H.sub.min and having a linear B-H loop up to at least a field strength which is about 0.8 H.sub.min and a uniaxial anisotropy perpendicular to the plane of the strip with an anisotropy field strength H.sub.k which is at least as large as H.sub.min and, when driven by an alternating signal burst in the presence of a bias field H.sub.Type: GrantFiled: July 9, 1997Date of Patent: January 25, 2000Assignee: Vacuumschmelze GmbHInventor: Giselher Herzer
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Patent number: 5993939Abstract: A permanent magnet material is prepared by cooling with a chill roll a molten alloy containing R wherein R is at least one rare earth element inclusive of Y, Fe or Fe and Co, and B. The chill roll has a plurality of circumferentially extending grooves in a circumferential surface, the distance between two adjacent ones of the grooves at least in a region with which the molten alloy comes in contact being 100 to 300 .mu.m on average in an arbitrary cross section containing a roll axis. Permanent magnet material of stable performance is obtained since the variation of cooling rate caused by a change in the circumferential speed of the chill roll is small. The variation of cooling rate is small even when it is desired to change the thickness of the magnet by altering the circumferential speed. The equalized groove pitch results in a minimized variation in crystal grain diameter.Type: GrantFiled: April 16, 1997Date of Patent: November 30, 1999Assignee: TDK CorporationInventors: Akira Fukuno, Hideki Nakamura, Tetsuhito Yoneyama
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Patent number: 5976715Abstract: The invention is embodied in a soft magnetic thin film article comprising an iron--chromium-nitrogen (Fe--Cr--N) based alloy and methods for making such article. The soft magnetic thin film article is formed using an iron--chromium--nitrogen based alloy with tantalum in one embodiment and with at least one of the elements titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), molybdenum (Mo), niobium (Nb) or tungsten (W) in another embodiment. The article is formed such that the alloy has a relatively high saturation magnetization (e.g., greater than approximately 15 kG) and a relatively low coercivity (e.g., less than approximately 2.0 oersteds) in an as-deposited condition or, alternatively, with a very low temperature treatment (e.g., below approximately 150.degree. C.). The inventive films are suitable for use in electromagnetic devices, for example, in microtransformer cores, inductor cores and in magnetic read-write heads.Type: GrantFiled: November 6, 1997Date of Patent: November 2, 1999Assignee: Lucent Techologies Inc.Inventors: Li-Han Chen, Sungho Jin, Wei Zhu, Robert Bruce van Dover
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Patent number: 5966064Abstract: A nanocrystalline alloy wherein at least 50 volume % of an alloy structure consists of a crystal grain mainly comprising bcc-phase having a grain size of 50 nm or less, a saturation magnetic flux density of the alloy is 1 T or more, a remanent flux density of the alloy is 0.4 T or less, and an Fe--B compound phase is partially formed in the alloy. The nanocrystalline alloy produced by heat treatment without applying any magnetic field shows pulse attenuation characteristics comparable to or more excellent than those of a nanocrystalline alloy obtained by heat treatment in a magnetic field.Type: GrantFiled: July 20, 1994Date of Patent: October 12, 1999Assignee: Hitachi Metals Ltd.Inventors: Yoshihito Yoshizawa, Yoshio Bizen, Shunsuke Arakawa
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Patent number: 5919319Abstract: An Iron-cobalt alloy, whose chemical composition contains, by weight:5%.ltoreq.Co.ltoreq.40%0%.ltoreq.Si.ltoreq.5%0.2%.ltoreq.Al.ltoreq.5%0.5%.ltoreq.Si+Al.ltoreq.5%the balance being iron and impurities resulting from the smelting. Process for manufacturing a strip and strip obtained.Type: GrantFiled: January 13, 1997Date of Patent: July 6, 1999Assignee: Imphy S.A.Inventor: Georges Couderchon
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Patent number: 5873955Abstract: A recording head for recording data onto a recording medium is provided with a thin film formed of the following compound Fe.sub.100-a-b-c X.sub.a Y.sub.b Z.sub.c, wherein X is at least one element selected from the group consisting of Nb, Ta, Hf and Zr, Y is one or two elements selected from the group consisting of Cr, Ru, Al, Si, Ti and Rh, and Z is at least one element selected from the group consisting of C and N, and wherein 5.ltoreq.a.ltoreq.20, 0.5.ltoreq.b.ltoreq.15, 1.ltoreq.c.ltoreq.20, and 0.5.ltoreq.a/c.ltoreq.0.7, the carbide or the nitride of the element X having an average grain size of not larger than 3 nm. This way, increased corrosion resistance is provided without substantially reducing magnetic characteristics such as saturation and coercive force. A recording apparatus, such as a VTR, including such a recording head is disclosed as well as a recording medium formed using this thin film.Type: GrantFiled: February 1, 1996Date of Patent: February 23, 1999Assignee: Hitachi, Ltd.Inventors: Fumiyoshi Kirino, Shigekazu Otomo, Nagatugu Koiso, Noriyuki Kumasaka, Takeshi Miura
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Patent number: 5830587Abstract: A process resulting in enhanced pole performance, relative to permalloy poles, in narrow track magnetic devices. A preferred process includes increasing the anisotropy field of the pole material while maintaining an acceptable coercivity level and near zero magnetostriction. One embodiment utilizes a NiCoFe alloy containing 22% cobalt by weight, heat treated in an easy axis magnetic field in a non-oxidizing atmosphere. This process achieves favorable domain structures at narrow pole tip widths.Type: GrantFiled: November 4, 1996Date of Patent: November 3, 1998Assignee: MKE-Quantum Components Colorado, LLCInventors: Harold B. Shukovsky, Michelle Martin, Michael Mallary, Alan Lee Sidman
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Patent number: 5825290Abstract: A self-biasing magnetostrictive element for use in a magnetomechanical EAS marker is a strip of amorphous alloy with crystalline particles of semi-hard or hard magnetic material distributed throughout the bulk of the amorphous alloy strip. The crystalline particles are magnetized to bias the amorphous alloy strip to resonate in response to an interrogation signal. The crystalline particles are formed by heat-treating the amorphous alloy strip at a temperature above the Curie temperature of the amorphous alloy in the presence of a longitudinal magnetic field. The alloy strip is then cross-field annealed at a temperature below the Curie temperature of the amorphous alloy to form a transverse anisotropy in the amorphous bulk of the alloy strip. A preferred alloy composition includes iron, cobalt, niobium, copper, boron and silicon.Type: GrantFiled: February 14, 1997Date of Patent: October 20, 1998Assignee: Sensormatic Electronics CorporationInventors: Ming-Ren Lian, Robert C. O'Handley
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Patent number: 5817191Abstract: An iron-based, cobalt-containing soft magnetic alloy suitable for use as a core in a magnetic switch or other exciting circuits has a cobalt content of 6 through 30 weight percent, at least one of the elements chromium, molybdenum, vanadium and tungsten in range of 3 through 8 weight percent, and a remainder iron, possibly including inconsequential contaminants. The alloy has a coercive field strength of lower than or equal to 3.2 A/cm, and a saturation flux density of greater than 1.9 Tesla.Type: GrantFiled: August 26, 1997Date of Patent: October 6, 1998Assignee: Vacuumschmelze GmbHInventors: Kurt Emmerich, Hartwin Weber, Hermann Wegerle
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Patent number: 5772797Abstract: A soft magnetic thin micro-crystalline film of FeT.sub.b N.sub.c (at %) wherein T is at least one of Zr, Hf, Ti, Nb, Ta, V, Mo and W, and 0<b<20 and 0<c<22 except the range of b.ltoreq.7.5 and c.ltoreq.5, shows low coercivity Hc of 80-400 Am.sup.-1 (1-5 Oe) which is stable upon heating at elevated temperature for glass bonding.This film is produced by crystallizing an amorphous alloy film of the similar composition at 350.degree.-650.degree. C. to a crystal grain size up to 30 nm to provide uniaxial anisotropy and increased magnetic permeability at higher frequency. It can also provide low magnetostriction around .gamma.s=0.Composite magnetic head is made using this thin film. Diffusion preventive SiO.sub.2 layer disposed between ferrite core and this thin film in the magnetic head prevents an interdiffusion layer and suppress beat in the output signal.Type: GrantFiled: January 2, 1997Date of Patent: June 30, 1998Assignee: Fuji Photo Film Co., Ltd.Inventors: Kanji Nakanishi, Osamu Shimizu, Satoshi Yoshida, Masaaki Katayama, Tatsuya Isomura
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Patent number: 5741373Abstract: An Fe-based soft magnetic alloy having a high saturated magnetic flux density and having a composition represented by formula (I) below:(Fe.sub.1-a Q.sub.a).sub.b B.sub.x T.sub.y T'.sub.z (I)wherein Q represents at least one element selected from the group consisting of Co and Ni; T represents at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Mo and W, with Zr and/or Hf being always included; T' represents at least one element selected from the group consisting of Cu, Ag, Au, Ni, Pd and Pt; a, b, x, y and z are real numbers satisfying relationships below:0.ltoreq.a.ltoreq.0.05,0.ltoreq.b.ltoreq.93 atomic %,0.5.ltoreq.x.ltoreq.16 atomic %,4.ltoreq.y.ltoreq.10 atomic %,0.ltoreq.z.ltoreq.4.5 atomic %provided that when 0<z.ltoreq.4.5 atomic %, Q represents Co and 0<b.ltoreq.92 atomic %; and when z=0, 0.5.ltoreq.x.ltoreq.8 atomic % and 4.ltoreq.y.ltoreq.9 atomic %.Type: GrantFiled: April 14, 1995Date of Patent: April 21, 1998Assignees: Alps Electric Co., Ltd., Tsuyoshi MasumotoInventors: Kiyonori Suzuki, Akihiro Makino, Tsuyoshi Masumoto, Akihisa Inoue, Noriyuki Kataoka
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Patent number: 5741374Abstract: A magnetically soft, Co--Fe--C alloy is disclosed which contains in weight percent, about______________________________________ Carbon 0.05-0.50 Manganese 0.5 max. Silicon 0.5 max. Phosphorus 0.01 max. Sulfur 0.01 max. Chrominum 1.0 max. Nickel 1.0 max. Molybdenum 0.25 max. Cobalt 14-28 Vanadium 0.1 max. Niobium 0.1 max. Tungsten 0.1 max. ______________________________________and the balance is essentially iron. The alloy provides a yield strength of up to about 580 MPa (84 ksi) while maintaining ductility and magnetic induction comparable to the known 27Co--Fe soft magnetic alloy. Magnetic and mechanical properties are developed through an annealing heat treatment which is performed after the alloy has been mechanically worked and machined to final shape.Type: GrantFiled: May 14, 1997Date of Patent: April 21, 1998Assignee: CRS Holdings, Inc.Inventor: Lin Li
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Patent number: 5728237Abstract: Amorphous alloys having the formulaFe.sub.a Co.sub.b Ni.sub.c Si.sub.x B.sub.y M.sub.zare employed as monitoring strips for mechanically oscillating tags, for example for anti-theft protection, together with a source of a pre-magnetization field in which the strip is disposed so as to place the strip in an activated state. In the formula, M denotes one or more elements of groups IV through VII of the periodic table, including C, Ge and P, and the constituents in at % meet the following conditions: a lies between 20 and 74, b lies between 4 and 23, c lies between 5 and 50, with the criterion that b+c>14, x lies between 0 and 10, y lies between 10 and 20, and z lies between 0 and 5 with the sum x+y+z being between 12 and 21. These alloys have a resonant frequency associated therewith and when passed through an alternating field whose alternation frequency coincides with the resonant frequency, a pulse having a signal amplitude is produced.Type: GrantFiled: December 9, 1996Date of Patent: March 17, 1998Assignee: Vacuumschmelze GmbHInventor: Giselher Herzer
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Patent number: 5645652Abstract: The disclosure describes spindle-shaped magnetic iron-based alloy particles containing cobalt and iron as the main ingredients in which the Co content is 1.0 to 50.0 atm % (calculated as Co) based on the total Fe in the spindle-shaped magnetic iron-based alloy particles, and which the spindle-shaped magnetic iron-based alloy particles have an average major axis diameter of 0.05 to 0.18 .mu.m, a size distribution (standard deviation/major axis diameter) of not more than 0.25, an average minor axis diameter of 0.010 to 0.020 .mu.m, an aspect ratio (major axis diameter/minor axis diameter) of 4 to 15, an X-ray crystallite size D.sub.110 of 120 to 180 .ANG., a coercive force of 1720 to 2500 Oe, a saturation magnetization of not less than 110 emu/g, and a saturation magnetization decrement percentage of not more than 17%.Type: GrantFiled: May 1, 1995Date of Patent: July 8, 1997Assignee: Toda Kogyo CorporationInventors: Kenji Okinaka, Yasutaka Ota
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Patent number: 5620535Abstract: An alloy sheet for making a shadow mask consists essentially of 34 to 38 wt. % Ni, 0.07 wt. % or less Si, 0.002 wt. % or less B, 0.002 wt. % or less O, less than 0.002 wt. % N and the balance being Fe and inevitable impurities;said alloy sheet after annealing before press-forming having 0.2% proof stress of 28 kgf/mm.sup.2 or less; anda gathering degree of {211} plane being 16% or less.A method for manufacturing an alloy sheet comprises:a finish cold-rolling step of cold-rolling the cold-rolled sheet at a cold-rolling reduction ratio in response to an average austenite grain size D (.mu.m), the reduction ratio of final cold-rolling R (%) satisfying the equations below;16.ltoreq.R.ltoreq.75,6.38D-133.9.ltoreq.R.ltoreq.6.38D-51.0a softening annealing step of annealing said cold rolled sheet in a temperature range of 720.degree. to 790.degree. C. for 2 to 40 min. before press-forming and on conditions satisfying the equation below;T.gtoreq.-53.8 log t+806,where T(.degree. C.) is the temperature and t (min.Type: GrantFiled: December 1, 1993Date of Patent: April 15, 1997Assignee: NKK CorporationInventors: Tadashi Inoue, Kiyoshi Tsuru, Michihito Hiasa, Tomoyoshi Okita
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Patent number: 5580399Abstract: In a magnetic recording medium of the coating type using a metal magnetic powder, for the purpose of improving switching field distribution (SFD) and electromagnetic properties, there is used a metal magnetic powder based on iron and containing Al and/or Si and a rare earth element, the content of Al and/or Si being 0.5 to 8% by weight based on the iron and the content of rare earth element (inclusive of Y) being 1 to 10% by weight based on the iron, and optionally 6 to 30% by weight of Co, preferably having a length of 0.06 to 0.30 .mu.m and an aspect ratio of from 4 to 15.Type: GrantFiled: January 29, 1996Date of Patent: December 3, 1996Assignee: TDK CorporationInventors: Kiminori Tamai, Yoichi Yoshimura
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Patent number: 5576098Abstract: A thin film magnetic head includes an upper magnetic core film and a lower magnetic core film laminated one on another through a magnetic gap layer. The upper and lower magnetic core films are multilayer thin films, respectively, each of which is composed of a plurality of magnetic thin film layers and a plurality of non-magnetic thin film layers, alternately laminated one on another. The magnetic core films and have single domain structures, respectively, and the use of such magnetic core films realizes a thin film magnetic head having high permeability at high frequencies and improved high frequency characteristics and attains high recording density.Type: GrantFiled: July 6, 1993Date of Patent: November 19, 1996Assignee: Fuji Electric Co., Ltd.Inventors: Yuko Arimoto, Takabumi Fumoto, Keiji Okubo, Osamu Saito, Toyoji Ataka, Hisashi Yamasaki
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Patent number: 5501747Abstract: A soft magnetic article is disclosed which is formed of an alloy consisting essentially of, in weight percent, about______________________________________ C 0.003-0.02 Mn 0.10 max. Si 0.10 max. P 0.01 max. S 0.003 max. Cr 0.1 max. Ni 0.2 max. Mo 0.1 max. Co 48-50 V 1.8-2.2 Nb 0.15-0.5 N 0.004 max. O 0.006 max. ______________________________________with the balance essentially iron. The article is annealed at a temperature of not more than 740.degree. C. (1364.degree. F.) for not more than about 4 hours and provides a room temperature yield strength of at least about 620 MPa (90 ksi) in the annealed condition. Among the disclosed embodiments of the annealed article according to this invention are a rotor and a stator for a rotating electrical machine such as a motor, generator, alternator or a magnetic bearing.Type: GrantFiled: May 12, 1995Date of Patent: March 26, 1996Assignee: CRS Holdings, Inc.Inventors: Millard S. Masteller, Douglas W. Dietrich
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Patent number: RE38098Abstract: Amorphous alloys having the formula Fea Cob Nic Six By Mz are employed as monitoring strips for mechanically oscillating tags, for example for anti-theft protection, together with a source of a pre-magnetization field in which the strip is disposed so as to place the strip in an activated state. In the formula, M denotes one or more elements of groups IV through VII of the periodic table, including C, Ge and P, and the constituents in at % meet the following conditions: a lies between 20 and 74, b lies between 4 and 23, c lies between 5 and 50, with the criterion that b+c>14, x lies between 0 and 10, y lies between 10 and 20, and z lies between 0 and 5 with the sum x+y+z being between 12 and 21. These alloys have a resonant frequency associated therewith and when passed through an alternating field whose alternation frequency coincides with the resonant frequency, a pulse having a signal amplitude is produced.Type: GrantFiled: December 15, 1998Date of Patent: April 29, 2003Assignee: Vacuumschmelze GmbHInventor: Giselher Herzer