Iron Base (i.e., Ferrous) Patents (Class 148/306)
  • Publication number: 20020014181
    Abstract: 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: Application
    Filed: October 30, 1998
    Publication date: February 7, 2002
    Inventors: DAVID S. LASHMORE, GLENN L. BEANE, LEV DERESH, ZONGLU HUA
  • Publication number: 20020011282
    Abstract: A steel sheet for heat shrink band of the present invention has anhysteretic magnetic permeability of 15,000 or higher at 0.35 Oe and yield stress of 24 kgf/mm2 or more. The steel sheet can be manufactured by a method comprising the steps of: hot rolling and/or cold rolling a steel containing 0.01 to 0.15% C by weight; annealing the rolled steel sheet at a temperature ranging from 650 to 900° C.; and temper rolling the annealed steel sheet at a rolling reduction rate of 1.5% or less. A CRT made of the steel sheet causes very little color deviation and practically no deformation of the panel surface.
    Type: Application
    Filed: March 9, 2001
    Publication date: January 31, 2002
    Inventors: Tatsuhiko Hiratani, Hideki Matsuoka, Yasushi Tanaka, Reiko Sugihara
  • Patent number: 6342108
    Abstract: 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: Grant
    Filed: February 9, 1999
    Date of Patent: January 29, 2002
    Assignee: Materials Innovation, Inc.
    Inventors: David S. Lashmore, Glenn L. Beane, Lev Deresh, Zonglu Hua
  • Patent number: 6338900
    Abstract: A soft magnetic composite material obtained by dispersing a powdered magnetic material (A) composed of soft ferrite in a polymer (B), wherein the powdered magnetic material (A) is a powdered magnetic material of a random form obtained by grinding a sintered magnetic material, and the average particle size (d2) of the powdered magnetic material (A) is greater than the average crystal grain size (d1) of the sintered magnetic material by at least twice.
    Type: Grant
    Filed: August 24, 1999
    Date of Patent: January 15, 2002
    Assignee: Kureha Kagaku Kogyo K.K.
    Inventors: Masahito Tada, Keiichiro Suzuki
  • Patent number: 6322639
    Abstract: A magnetic steel sheet used for an alternating current core, and having excellent magnetic properties in both a rolling direction, and the direction perpendicular thereto, and a method of producing the magnetic steel sheet. The magnetic steel sheet in a recrystallized cold-rolled condition is characterized in that the intensity ratio of {100}<001> orientation to random orientation is 2.0 or more, the intensity ratio of {011}<100> orientation to random orientation thereof is 2.0 to 10.0, and the intensity ratio of <001>//ND orientation to random orientation is preferably 2.0 or less. The method of producing a magnetic steel sheet includes hot-rolling a silicon steel slab so that the intensity ratio of (015)[100] orientation to random orientation of the recrystallized hot-rolled sheet is 3.0 or more.
    Type: Grant
    Filed: January 4, 2000
    Date of Patent: November 27, 2001
    Assignee: Kawasaki Steel Corporation
    Inventors: Akihiro Matsuzaki, Osamu Kondo, Takako Yamashita, Shigeaki Takajo
  • Patent number: 6319485
    Abstract: A magnetic material made up of an assembly of particles substantially consisting of an &agr;″-Fe16N2 crystal having a body-centered tetragonal system (bct). The magnetic material has a high saturated magnetic flux density and is directly synthesized by reacting fine particles of &agr;-Fe and a nitrogen-containing gas at a temperature of 200° C. or lower. By the synthesis of this invention, &agr;″-Fe16N2, which is a metastable compound conventionally deposited accompanied with phase transformation of crystallization from a martensite phase of &agr;′-Fe(N), is obtained as an isolated bulk substance in a single phase.
    Type: Grant
    Filed: January 19, 1999
    Date of Patent: November 20, 2001
    Assignee: Dowa Mining Co., Ltd.
    Inventors: Akira Nagatomi, Fumikazu Kanamaru, Shinichi Kikkawa
  • Publication number: 20010037841
    Abstract: The present invention provides a non-oriented electrical steel sheet having crystal grains of small diameter and excellent workability before stress relief annealing and having crystal grains of largely grown diameter and excellent iron loss property after stress relief annealing and a method for producing the same, and relates to a low iron loss non-oriented electrical steel sheet excellent in workability, containing, in weight %, 0.010% or less of C, 0.1 to 1.5% of Mn, 0.1 to 4% of Si, 0.1 to 4% of Al, wherein the latter three elements satisfy the formula Si+Mn+Al≦5.0%, and 0.0005 to 0.0200% of Mg, or further containing 0.005% or more of Ca, wherein the total amount of Mg and Ca is 0.0200% or less, or further containing 0.005% or more of REM, wherein the total amount of Mg and REM is 0.0200% or less, or further containing 0.005% or more of Ca and REM, wherein the total amount of Mg, Ca and REM is 0.0200% or less, and containing the remainder consisting of Fe and unavoidable impurities.
    Type: Application
    Filed: April 6, 2001
    Publication date: November 8, 2001
    Inventors: Ken-ichi Murakami, Takashi Morohoshi, Tomoji Kumano, Ryutaro Kawamata, Takeshi Kubota, Masafumi Zeze, Hidekuni Murakami, Shinichi Kanao
  • Patent number: 6312531
    Abstract: Soft magnetic powder of Fe—Al—Si system of which magnetostrictive constant &lgr; takes a positive value at the room temperature is employed to produce a magnetic composite article so that a temperature characteristic of core-loss of the article takes a negative value at the room temperature. Excellent magnetic characteristics such as a low core-loss and a high permeability can be obtained at a high frequency band.
    Type: Grant
    Filed: December 22, 1998
    Date of Patent: November 6, 2001
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Nobuya Matsutani, Yuji Mido, Kazuaki Onishi
  • Publication number: 20010032685
    Abstract: A magnetic core for use in a saturable reactor made of an Fe-based soft-magnetic alloy comprising as essential alloying elements Fe, Cu and M, wherein M is at least one element selected from the group consisting of Nb, W, Ta, Zr, Hf, Ti and Mo, and having an alloy structure at least 50% in area ratio of which being fine crystalline particles having an average particle size of 100 nm or less. The magnetic core has control magnetizing properties of a residual operating magnetic flux density &Dgr;Bb of 0.12 T or less, a total control operating magnetic flux density &Dgr;Br of 2.0 T or more, and a total control gain Gr of 0.10-0.20 T/(A/m) calculated by the equation: Gr=0.8×(&Dgr;Br−&Dgr;Bb)/Hr, wherein Hr is a total control magnetizing force defined as a control magnetizing force corresponding to 0.8×(&Dgr;Br−&Dgr;Bb)+&Dgr;Bb.
    Type: Application
    Filed: June 8, 2001
    Publication date: October 25, 2001
    Inventors: Shin Nakajima, Hirohiko Miki, Sadami Kubota, Mutsuhito Sakaguchi
  • Patent number: 6303240
    Abstract: A soft magnetic thin film having a compositional formula FeaBbNc, wherein a, b and c each denote atomic percent and B denotes at least one of Co, Ni and Ru, and wherein the compositional range is given by 0<b≦5, and 0<c≦5. The film may exhibit uniaxial anisotropy with a uniaxial anisotropy field strength of 1-5 Oe. The film has a coercivity 2.5-4 Oe or less and a saturated magnetic flux density B25 of at least 16 kG measured at a magnetic field of 25 Oe. The film is produced by subjecting a deposited thin film of the compositional formula to heat treatment at a temperature of 220 to 450° C., within or without magnetic field and, has an average crystal grain size of not more than 50 nm.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: October 16, 2001
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Osamu Shimizu, Kanji Nakanishi
  • Publication number: 20010020497
    Abstract: Electromagnetic steel sheet having excellent magnetic properties and a texture gratly integrated in the {100}<001> orientation, and an uncomplicated and low cost production method; with about a 15 &mgr;&OHgr;·cm or more specific resistivity, about a 2.0 or more {100}<001> integration degree/{111}<uvw> integration degree and about a 10 &mgr;m to 500 &mgr;m grain diameter; when about 0.1 to 3.5% by weight of Si is present, the {100}<001> integration degree is about 10 or more; when about 0.2 to 1.2% by weight of P is present, the{100}<001> integration degree is about 3 or more; by applying a large reduction ratio to a steel slab in the vicinity of the final stage of hot rolling, with the hot rolling finishing temperature controlled at about 750 to 1150° C., hot rolled steel having a texture highly integrated in the {100}<001> orientation is economically produced.
    Type: Application
    Filed: February 8, 2001
    Publication date: September 13, 2001
    Applicant: Kawasaki Steel Corporation
    Inventors: Osamu Kondo, Akihiro Matsuzaki, Shigeaki Takajo
  • Patent number: 6270592
    Abstract: A magnetic core for use in a saturable reactor made of an Fe-based soft-magnetic alloy comprising as essential alloying elements Fe, Cu and M, wherein M is at least one element selected from the group consisting of Nb, W, Ta, Zr, Hf, Ti and Mo, and having an alloy structure at least 50% in area ratio of which being fine crystalline particles having an average particle size of 100 nm or less. The magnetic core has control magnetizing properties of a residual operating magnetic flux density &Dgr;Bb of 0.12 T or less, a total control operating magnetic flux density &Dgr;Br of 2.0 T or more, and a total control gain Gr of 0.10-0.20 T/(A/m) calculated by the equation: Gr=0.8×(&Dgr;Br−&Dgr;Bb)/Hr, wherein Hr is a total control magnetizing force defined as a control magnetizing force corresponding to 0.8×(&Dgr;Br−&Dgr;Bb)+&Dgr;Bb.
    Type: Grant
    Filed: September 24, 1998
    Date of Patent: August 7, 2001
    Assignee: Hitachi Metals, Ltd.
    Inventors: Shin Nakajima, Hirohiko Miki, Sadami Kubota, Mutsuhito Sakaguchi
  • Patent number: 6248185
    Abstract: Electromagnetic steel sheet having excellent magnetic properties and a texture gratly integrated in the {100}<001> orientation, and an uncomplicated and low cost production method; with about a 15 &mgr;&OHgr;·cm or more specific resistivity, about a 2.0 or more {100}<001> integration degree /{111}<uvw> integration degree and about a 10 &mgr;m to 500 &mgr;m grain diameter; when about 0.1 to 3.5% by weight of Si is present, the {100}<001> integration degree is about 10 or more; when about 0.2 to 1.2% by weight of P is present, the {100}<001> integration degree is about 3 or more; by applying a large reduction ratio to a steel slab in the vicinity of the final stage of hot rolling, with the hot rolling finishing temperature controlled at about 750 to 1150° C., hot rolled steel having a texture highly integrated in the {100}<001> orientation is economically produced.
    Type: Grant
    Filed: August 14, 1998
    Date of Patent: June 19, 2001
    Assignee: Kawasaki Steel Corporation
    Inventors: Osamu Kondo, Akihiro Matsuzaki, Shigeaki Takajo
  • Patent number: 6238492
    Abstract: 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: Grant
    Filed: October 24, 1997
    Date of Patent: May 29, 2001
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Kanji Nakanishi, Osamu Shimizu, Satoshi Yoshida, Masaaki Katayama, Tatsuya Isomura
  • Patent number: 6232775
    Abstract: 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: Grant
    Filed: December 14, 1998
    Date of Patent: May 15, 2001
    Assignees: Alps Electric Co., LTD
    Inventors: Yutaka Naitoh, Teruo Bitoh, Takashi Hatanai, Akihiro Makino, Junichi Ouchi, Shinichi Sasaqawa, Akihisa Inoue, Tsuyoshi Masumoto
  • Patent number: 6190516
    Abstract: 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: Grant
    Filed: October 6, 1999
    Date of Patent: February 20, 2001
    Assignee: Praxair S.T. Technology, Inc.
    Inventors: Wei Xiong, Hung-Lee Hoo, Peter McDonald
  • Patent number: 6183568
    Abstract: A soft magnetic thin micro-crystalline film of FeaBbNc (at %) wherein B 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 temperature 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 higher frequency. It can also provide low magnetostriction around &lgr;s=0. Composite magnetic head is made using this thin film. Diffusion preventive SiO2 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: Grant
    Filed: January 6, 1994
    Date of Patent: February 6, 2001
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Kanji Nakanishi, Osamu Shimizu, Satoshi Yoshida, Masaaki Katayama, Tatsuya Isomura
  • Patent number: 6149704
    Abstract: A dust core ferromagnetic powder comprises a ferromagnetic metal powder, an insulating material, and a lubricant. The insulating material comprises a phenol resin and/or a silicone resin, and the lubricant comprises at least one compound selected from the group consisting of magnesium stearate, calcium stearate, strontium stearate, and barium stearate. It is possible to achieve a dust core having high saturation magnetic flux density, low losses, and satisfactory permeability with its dependence on frequency being improved.
    Type: Grant
    Filed: July 29, 1999
    Date of Patent: November 21, 2000
    Assignee: TDK Corporation
    Inventors: Hideharu Moro, Takeo Tsukada, Katsuhiko Wakayama
  • Patent number: 6139650
    Abstract: A non-oriented electromagnetic steel sheet contains 0.005 wt. % or less C, 0.2 wt. % or less P, 0.005 wt. % or less N, 4.5 wt. % or less Si, 0.05 to 1.5 wt. % Mn, 1.5 wt. % or less Al and 0.001 wt. % or less S, at least one element selected from the group of 0.001 to 0.05 wt. % Sb, 0.002 to 0.1 wt. % Sn, 0.0005 to 0.01 wt. % Se and 0.0005 to 0.01 wt. % Te; and the balance being Fe and inevitable impurities. The non-oriented electromagnetic steel sheet is produced by the steps of: hot-rolling a slab to form a hot-rolled steel sheet, cold-rolling the hot-rolled steel sheet to form a cold-rolled steel sheet; and finish annealing the cold-rolled steel sheet.
    Type: Grant
    Filed: March 12, 1998
    Date of Patent: October 31, 2000
    Assignee: NKK Corporation
    Inventors: Yoshihiko Oda, Nobuo Yamagami, Akira Hiura, Yasushi Tanaka, Noritaka Takahashi, Hideki Matsuoka, Atsushi Chino, Katsumi Yamada, Shunji Iizuka
  • Patent number: 6132524
    Abstract: 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: Grant
    Filed: January 15, 1998
    Date of Patent: October 17, 2000
    Assignees: Agency of Industrial Science & Technology, Ministry of International Trade & Industry, Tokin Corporation
    Inventors: Hiroyuki Akinaga, Koichi Onodera
  • Patent number: 6120617
    Abstract: For manufacturing a pulse generator wherein a voltage pulse dependent on the change in magnetic field can be achieved by sudden magnetic reversal (Barkhausen skip) given an applied magnetic field, an iron alloy is employed for one of the materials of the composite member, the additional alloy constituents of this iron alloy being selected such that a structural conversion with volume change respectively occurs at different temperatures. For producing the stressed condition, a thermal treatment is then implemented, which includes heating above the upper transition temperature and a cooling below the lower transition temperature. As a result, substantially greater stresses between the materials of the composite member arise, causing a pulse behavior significantly improved in comparison to known pulse generators of the type capable of recognizing constant or alternating magnetic fields.
    Type: Grant
    Filed: April 7, 1994
    Date of Patent: September 19, 2000
    Assignee: Vacuumschmelze GmbH
    Inventors: Gernot Hausch, Christian Radeloff, Gerd Rauscher
  • Patent number: 6117205
    Abstract: Corrosion-resistant, soft magnetic metal components manufactured by powder metallurgy and infiltration processes are disclosed. The magnetic components are manufactured by a powder metallurgy process using acicular metal particles to form a skeleton, and thermally infiltrating the skeleton.
    Type: Grant
    Filed: November 20, 1998
    Date of Patent: September 12, 2000
    Assignee: Magnetics International, Inc.
    Inventors: Robert F. Krause, Harold R. Kokal, Joseph H. Bularzik
  • Patent number: 6102980
    Abstract: A ferromagnetic powder composition for dust cores contains a ferromagnetic metal powder and 0.1-15% by volume based on the powder of titania sol and/or zirconia sol. The composition is pressure molded and desirably annealed into a dust core which exhibits a high magnetic flux density, low coercivity, low loss and high mechanical strength.
    Type: Grant
    Filed: March 26, 1998
    Date of Patent: August 15, 2000
    Assignee: TDK Corporation
    Inventors: Masami Endo, Takeo Tsukada, Masaaki Kanasugi, Kazuhiro Okada, Hideharu Moro, Norishige Yamaguchi, Toshiaki Yamada, Hideki Kitashima
  • Patent number: 6103405
    Abstract: A planar inductance element is provided which has good high-frequency magnetic properties and which can be manufactured at high yield. The element has at least one ferromagnetic film which, whose high-frequency properties change only a little when thermal, magnetic and mechanical stresses are applied to them during the manufacture of the element. The film has high process immunity. The film has been formed by applying a stress in a plane of a ferromagnetic film having uniaxial magnetic anisotropy or forming an antiferromagnetic film on such a ferromagnetic film, and by heat-treating the resultant structure in a magnetic field, thereby inducing inplane unidirectional magnetic anisotropy in a prescribed direction. The ferromagnetic film thus formed has its high-frequency permeability improved and its high-frequency loss reduced. In forming the ferromagnetic film, the inplane unidirectional magnetic anisotropy may be induced at an angle of about 30.degree. or about 60.degree.
    Type: Grant
    Filed: February 3, 1998
    Date of Patent: August 15, 2000
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Hiroshi Tomita
  • Patent number: 6103396
    Abstract: An amorphous metal strip having a sheet thickness ranging from about 50 to 75 .mu.m and a sheet width of at least 20 mm is produced by a casting process utilizing a single nozzle orifice and a high thermal conductivity, large diameter wheel as a casting substrate. The strip has a fracture strain of 0.01 or more, a lamination factor of 0.8 or more, and a core loss of less than 0.2 W/kg at 60 Hz and 1.4 T.
    Type: Grant
    Filed: August 29, 1997
    Date of Patent: August 15, 2000
    Assignee: AlliedSignal Inc.
    Inventors: Santosh K. Das, Richard L. Bye, Jeng S. Lin
  • Patent number: 6079480
    Abstract: A twin drum-type continuous casting process for casting thin cast strip by solidifying molten steel continuously fed between a pair of cooling drums placed parallel to each other, wherein the cooling drums are given an added degree of concave crown such that a solid fraction at the thickness center of the thin cast strip, when the distance from the edges toward the center of the thin cast strip at the closest position of the cooling drums is within 50 mm, is exhibited which is a value greater than the fluid critical solid fraction, or alternatively the cooling rate near the edges of the cooling drums is improved.
    Type: Grant
    Filed: June 11, 1997
    Date of Patent: June 27, 2000
    Assignee: Nippon Steel Corporation
    Inventors: Hideki Oka, Takashi Arai, Masafumi Miyazaki, Kazuto Yamamura, Mamoru Yamada
  • Patent number: 6039784
    Abstract: Metallurgical powder compositions are provided that contain a metal powder that is associated with a polymeric material in admixture with a solid, particulate polyether lubricant. The incorporation of the polyether lubricant enhances the green strength properties of compacted parts made from the powder compositions, and generally reduces the ejection forces required to remove the compacted part from the die cavity.
    Type: Grant
    Filed: March 12, 1997
    Date of Patent: March 21, 2000
    Assignee: Hoeganaes Corporation
    Inventor: Sydney Luk
  • Patent number: 6033792
    Abstract: 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: Grant
    Filed: October 19, 1998
    Date of Patent: March 7, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Fumiyoshi Kirino, Shigekazu Otomo, Nagatugu Koiso, Noriyuki Kumasaka, Takeshi Miura
  • Patent number: 6023397
    Abstract: A magnetic pole or magnetic shielding film is constructed of a soft magnetic thin film that has a composition represented by formula (Fe.sub.1-x M.sub.x).sub.1-y N.sub.y wherein M is at least one element selected from the group consisting of magnesium, calcium, yttrium, titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, and boron, and an atomic ratio x is 0.01.ltoreq.x.ltoreq.0.1 and an atomic ratio y is 0.01.ltoreq.y.ltoreq.0.1. This soft magnetic thin film has a I(200)/I(110) ratio of 0.1 inclusive to 1 exclusive with the proviso that I(200), and I(110) represents an intensity of a diffraction peak for an iron (200) plane, and an iron (110) plane, respectively, as found from an X-ray diffraction pattern, and is substantially free from a diffraction peak for a nitride of the element M, as found from the X-ray diffraction pattern.
    Type: Grant
    Filed: September 18, 1997
    Date of Patent: February 8, 2000
    Assignee: TDK Corporation
    Inventors: Tetsuya Mino, Yasufumi Uno
  • Patent number: 6016029
    Abstract: Magnetic shield materials having excellent inner magnetic shield characteristics and an excellent handling strength, method for producing thereof and color picture tubes produced by incorporating the materials are provided. The magnetic shield materials are produced by subjecting hot rolled low carbon steel strips essentially consisting of equal to or less than 0.006 weight % of C, equal to or less than 0.002 weight % of N, equal to or less than 0.5 weight % of Mn, 0.1-1.5 weight % of Cu, Fe as a balance and unavoidable impurities to a cold rolling and subsequently annealing the cold rolled steel strips at a temperature of 550-850.degree. C.
    Type: Grant
    Filed: February 6, 1998
    Date of Patent: January 18, 2000
    Assignee: Toyo Kohan Co., Ltd.
    Inventors: Hironao Okayama, Akira Ikeda
  • Patent number: 6002211
    Abstract: The invention relates to a sintered moulding of Li(Ni)Zn ferrite material, a transformer core and an inductor core of this material as well as several applications of these cores. In accordance with the invention, the majority of the grains of the sintered material have a monodomain structure. This leads to a substantial reduction of the loss factor and the overall losses when these mouldings are subjected to high-frequency applications and power applications. The ferrite material preferably comprises 59-65 mol % Fe.sub.2 O.sub.3, 7-11 mol % Li.sub.2 CO.sub.3, 4-8 mol % MnO and 20-28 mol % ZnO. This also provides the material with a high saturation magnetization.
    Type: Grant
    Filed: September 13, 1995
    Date of Patent: December 14, 1999
    Assignee: U.S. Philips Corporation
    Inventors: Pieter J. Van Der Zaag, Pieter J. Van Der Valk
  • Patent number: 6001194
    Abstract: A bias material for magnetic markers is produced by plastic working to provide a strip form, which has a metal structure consisting of the iron-base matrix and a non-magnetic copper group metal phase in an amount of not less than a solubility limit thereof in an equilibrium state at a room temperature. The non-magnetic copper group metal phase is dispersed in the matrix so as to form a microstructural rod pattern. The bias material comprises preferably 3 to 35% wt % of a copper group metal. The magnetic marker is produced by combining the bias material and a magnetostriction element.
    Type: Grant
    Filed: April 29, 1998
    Date of Patent: December 14, 1999
    Assignee: Hitachi Metals, Ltd.
    Inventors: Noriyuki Nakaoka, Tsutomu Inui, Akira Kawakami
  • Patent number: 5993939
    Abstract: 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: Grant
    Filed: April 16, 1997
    Date of Patent: November 30, 1999
    Assignee: TDK Corporation
    Inventors: Akira Fukuno, Hideki Nakamura, Tetsuhito Yoneyama
  • Patent number: 5993569
    Abstract: The invention relates to a method for preparing silicon-containing iron powders by thermal decomposition of a gas mixture comprising iron pentacarbonyl and, as a volatile silicon compound, a silane or a halogen-free organosilane in which the gas mixture flows through a heated reaction chamber and heating of the gas mixture is effected by thermal conduction. The silicon-containing iron powders obtained are distinguished by a particularly low impurity element content. The silicon-containing iron powders can be used for the fabrication of cores, magnets and radar-absorbing materials.
    Type: Grant
    Filed: April 15, 1998
    Date of Patent: November 30, 1999
    Assignee: BASF Aktiengesellschaft
    Inventors: Joachim Simon, Reinhold Schlegel, Bernd Leutner
  • Patent number: 5976715
    Abstract: 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: Grant
    Filed: November 6, 1997
    Date of Patent: November 2, 1999
    Assignee: Lucent Techologies Inc.
    Inventors: Li-Han Chen, Sungho Jin, Wei Zhu, Robert Bruce van Dover
  • Patent number: 5966064
    Abstract: 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: Grant
    Filed: July 20, 1994
    Date of Patent: October 12, 1999
    Assignee: Hitachi Metals Ltd.
    Inventors: Yoshihito Yoshizawa, Yoshio Bizen, Shunsuke Arakawa
  • Patent number: 5896078
    Abstract: A soft magnetic alloy thin film includes a fine crystalline phase and an amorphous phase. The fine crystalline phase includes an average crystalline grain size of 10 nm or less in diameter and has body-centered cubic structure mainly composed of Fe. The amorphous phase has a nitrogen (N) compound as the main composition and occupies at least 50% of the structure of the thin film. An element M is incorporated at least in the amorphous phase, and includes at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, W, and rare earth metal elements. A plane-type magnetic device is made using this thin film.
    Type: Grant
    Filed: October 19, 1995
    Date of Patent: April 20, 1999
    Assignee: Alps Electric Co., Ltd.
    Inventors: Yasuo Hayakawa, Akihiro Makino
  • Patent number: 5876520
    Abstract: The present invention relates to a semiprocessed nonoriented magnetic steel sheet which is used in iron cores of motors and transformers, finished to a final product by rolling having a reduction rate of 2 to 18% after final annealing by a manufacturer, and assures desired magnetic characteristics due to coarsening of crystal grains during strain-relief annealing after processing by a user. The excellent magnetic characteristics can be achieved by increasing lubrication during second cold rolling so as to satisfy the equation: e.sub.c .ltoreq.e.sub.s .ltoreq.1.18e.sub.c wherein e.sub.s represents a strain value at the surface layer of the steel sheet and e.sub.c represents a strain value at the central layer.
    Type: Grant
    Filed: September 30, 1997
    Date of Patent: March 2, 1999
    Assignee: Kawasaki Steel Corporation
    Inventors: Minoru Takashima, Akio Fujita, Keiji Sato, Masaki Kawano
  • Patent number: 5873955
    Abstract: 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: Grant
    Filed: February 1, 1996
    Date of Patent: February 23, 1999
    Assignee: Hitachi, Ltd.
    Inventors: Fumiyoshi Kirino, Shigekazu Otomo, Nagatugu Koiso, Noriyuki Kumasaka, Takeshi Miura
  • Patent number: 5858125
    Abstract: A magnetoresistive material of the present invention has a structure in which many clusters are surrounded by a crystal phase of Cu and/or Ag, where each cluster has a grain size of 20 nm or less and composed of an amorphous phase containing at least one ferromagnetic metal element T as a main component selected from Fe, Co and Ni, and at least one element M selected from Ti, Zr, Hf, V, Nb, Ta, Mo and W.
    Type: Grant
    Filed: October 15, 1996
    Date of Patent: January 12, 1999
    Assignee: Alps Electric Co., Ltd.
    Inventor: Naoya Hasegawa
  • Patent number: 5858548
    Abstract: Corrosion resistance of a magnetic film composed mainly of Fe is maintained while keeping its magnetic properties. A magnetic head having a magnetic core is formed in part of the magnetic thin film, which contains not only an alloy of Fe-metalloid series but also (Al, Ru) or (Al, Rh) and which is thermally treated at a constant temperature to develop the soft magnetic properties. The deterioration of the saturation magnetization and the soft magnetic properties is suppressed by adding (Al, Ru) or (Al, Rh) together. The magnetic film has a high saturation magnetization and excellent soft magnetic properties and is excellent in corrosion resistance and hardness.
    Type: Grant
    Filed: July 31, 1995
    Date of Patent: January 12, 1999
    Assignee: Hitachi, Ltd.
    Inventors: Fumiyoshi Kirino, Shigeharu Otomo, Nagatugu Koiso, Noriyuki Kumasaka, Takeshi Miura
  • Patent number: 5849400
    Abstract: A magnetic thin film having excellent soft magnetic properties formed by alternately laminating a main magnetic layer and an intermediate layer, in which the main magnetic layer includes magnetic crystal grains substantially having a columnar structure which have an average height dl and an average diameter ds forming a shape ratio of 0.3.ltoreq.ds/dl.ltoreq.90.9, and the intermediate layer has saturation magnetic flux density of at least 0.1 tesla less than the main magnetic layer. The main magnetic layer and the intermediate layer having saturation magnetic flux density of at least 0.1 tesla less than the main magnetic layer are alternately laminated. It is preferable that the main magnetic layer has a thickness of 3 to 100 nm, and the intermediate layer has a thickness of 0.1 to 10 nm. In addition, it is preferable that a thickness of the entire laminated structure is in the range of about 100 nm to 10 .mu.m.
    Type: Grant
    Filed: January 30, 1996
    Date of Patent: December 15, 1998
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masayoshi Hiramoto, Osamu Inoue, Koichi Kugimiya, Kenji Iijima
  • Patent number: 5800636
    Abstract: A dust core is prepared from an iron powder with a particle size of 75-200 .mu.m having added thereto 0.015-0.15 wt % of silica sol, 0.05-0.5 wt % of a silicone resin, and 10-50 wt % based on the silicone resin of an organic titanium compound. By subjecting the iron powder to a curing treatment at 50.degree.-250.degree. C., compacting the powder, and annealing in an inert atmosphere at 550.degree.-650.degree. C., there is obtained a dust core consisting essentially of iron powder particles with a particle size of 75-200 .mu.m, 0.03-0.1% by weight of Si, 15-210 ppm of Ti, and 300-2,500 ppm of oxygen.
    Type: Grant
    Filed: January 3, 1997
    Date of Patent: September 1, 1998
    Assignee: TDK Corporation
    Inventors: Takeo Tsukada, Masaaki Kanasugi, Masataka Miyashita, Kazuhiro Okada, Norishige Yamaguchi
  • Patent number: 5798176
    Abstract: The present invention is a magnetic recording medium comprising a substrate and a magnetic layer including a binder resin and a plate-like magnetic powder of which easy axis of magnetization exists in a plane, and this magnetic recording medium is excellent in recording and regeneration characteristics.
    Type: Grant
    Filed: September 12, 1994
    Date of Patent: August 25, 1998
    Assignee: Kao Corporation
    Inventors: Noriyuki Kitaori, Osamu Yoshida, Hirohide Mizunoya, Akira Shiga
  • Patent number: 5777828
    Abstract: A magnetically soft thin-film is prepared either to be of a composition wherein Fe is used as a principal component, and 0.5 to 20 atomic % of Al, 2 to 25 atomic % of at least one of Zr, Hf, Nb, Ta, Mo and W, 0.05 to 5 atomic % of at lease one of Ag and Cu, 0.5 to 25 atomic % of C and 0.2 to 8 atomic % of O are added as additional elements to the principal component, or to be of a composition wherein 0.1 to 5 atomic % of at least one of rare earth elements such as Ce, Sm and Dy is added further to the above-stated composition. These compositions enable the magnetically soft thin-film to have excellent properties as desired for a magnetic head.
    Type: Grant
    Filed: April 4, 1996
    Date of Patent: July 7, 1998
    Assignee: Canon Kabushiki Kaisha
    Inventors: Makoto Kameyama, Masaaki Matsushima, Michio Yanagi
  • Patent number: 5772797
    Abstract: 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: Grant
    Filed: January 2, 1997
    Date of Patent: June 30, 1998
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Kanji Nakanishi, Osamu Shimizu, Satoshi Yoshida, Masaaki Katayama, Tatsuya Isomura
  • Patent number: 5741373
    Abstract: 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: Grant
    Filed: April 14, 1995
    Date of Patent: April 21, 1998
    Assignees: Alps Electric Co., Ltd., Tsuyoshi Masumoto
    Inventors: Kiyonori Suzuki, Akihiro Makino, Tsuyoshi Masumoto, Akihisa Inoue, Noriyuki Kataoka
  • Patent number: 5725685
    Abstract: A soft magnetic alloy thin film includes a fine crystalline phase and an amorphous phase. The fine crystalline phase includes an average crystalline grain size of 10 nm or less in diameter and has body-centered cubic structure mainly composed of Fe. The amorphous phase has a nitrogen (N) compound as the main composition and occupies at least 50% of the structure of the thin film. An element M is incorporated at least in the amorphous phase, and includes at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, W, and rare earth metal elements. A plane-type magnetic device is made using this thin film.
    Type: Grant
    Filed: October 29, 1996
    Date of Patent: March 10, 1998
    Assignee: Alps Electric Co., Ltd.
    Inventors: Yasuo Hayakawa, Akihiro Makino
  • Patent number: 5693250
    Abstract: A soft magnetic structure substantially comprised of a plurality of magnetic field carrying particles molded and retained in a predetermined shape, bonded in that shape by an insulating binding agent, wherein said particles have grain alignment substantially parallel to a preferred direction, and wherein said preferred direction is parallel to a direct axis providing the structure with a high direct axis to quadrature axis reactance ratio.
    Type: Grant
    Filed: November 18, 1993
    Date of Patent: December 2, 1997
    Assignee: General Motors Corporation
    Inventors: Ahmed Mostafa El-Antably, Robert Walter Ward
  • Patent number: 5676770
    Abstract: This invention relates to a non-oriented electromagnetic steel sheet with low leakage flux for a compact transformer and a method for making the same. After stress relief annealing, the magnetic permeability .mu..sub.C of the sheet in the direction transverse to the sheet rolling direction is.mu..sub.C .gtoreq.about 2.5.times.10.sup.-3 (H/m)and magnetic permeability .mu..sub.D of the sheet in the direction 45.degree. to the sheet rolling direction is.mu..sub.D .gtoreq.about 1.5.times.10.sup.-3 (H/m).
    Type: Grant
    Filed: December 11, 1995
    Date of Patent: October 14, 1997
    Assignee: Kawasaki Steel Corporation
    Inventors: Keiji Sato, Kouji Yano, Minoru Takashima, Masaki Kawano, Takashi Obara