With Special Compositions Patents (Class 148/122)
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Publication number: 20020011278Abstract: An electromagnetic steel sheet having a low iron loss and a high magnetic flux density, with silicon, nitrogen and an added element bismuth or germanium prior to secondary recrystallization, to accelerate precipitation of fine BN and silicon nitride, improving the texture of the primary recrystallized grains of the steel sheet immediately before subjecting it to secondary recrystallization annealing, and combining the primary recrystallization annealing, cold rolling and further the texture improving treatment. Addition of bismuth or germanium or both to the steel prior to secondary recrystallization is combined with primary recrystallization annealing and warm rolling in the presence of limited aluminum and vanadium impurities limited to 0.002 wt % Al or less and 0.010 wt % V or less.Type: ApplicationFiled: August 9, 2001Publication date: January 31, 2002Applicant: Kawasaki Steel CorporationInventors: Michiro Komatsubara, Kazuaki Tamura, Mitsumasa Kurosawa
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Patent number: 6338761Abstract: With the intention of establishing fabrication methods for cheaply produced (Fe,Co)—Cr—B—R-type bonded magnets or (Fe,Co)—Cr—B—R—M-type bonded magnets containing few rare earth elements and having a coercive force iHc above 5 kOe and a residual magnetic flux density Br above 5.Type: GrantFiled: February 1, 2000Date of Patent: January 15, 2002Assignee: Sumitomo Special Metals Co., Ltd.Inventors: Hirokazu Kanekiyo, Satoshi Hirosawa
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Publication number: 20020000262Abstract: An anisotropic exchange spring magnet powder complexing a hard magnetic material and a soft magnetic material, wherein a rare earth metal element, a transition metal element, boron and carbon and the like are contained, and the hard magnetic material and soft magnetic material have crystal particle diameters of 150 nm or less. A method of producing an anisotropic exchange spring magnet powder comprises treating a crystalline mother material containing a hard magnetic material and soft magnetic material or the crystalline mother material having amorphous parts, in a continuous process composed of an amorphousating process and the following crystallizing process, repeated once or more times. An anisotropic exchange spring magnet is obtained by treatment, in an anisotropy-imparting molding process and a solidification process, of an anisotropic exchange spring magnet powder.Type: ApplicationFiled: June 29, 2001Publication date: January 3, 2002Applicant: NISSAN MOTOR CO., LTD.Inventors: Hideaki Ono, Norihisa Waki, Munekatsu Shimada
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Publication number: 20010054453Abstract: A magnetic material essentially consists of a composition represented by general formula: R1XR2YBZNUHVM100-X-Y-Z-C-V (in the formula, R1 denotes at least one kind element selected from rare earth elements, R2 denotes at least one kind element selected from Zr, Hf and Sc, M denotes at least one kind element selected from Fe and Co, X, Y, Z, U and V are numbers satisfying 2 at. %≦X, 0.01 at. %≦Y, 4≦X+Y≦20 at. %, 0≦Z≦10 at. %, 0.1≦U≦18 at. %, 0.01≦V≦10 at. %, respectively), and comprises a TbCu7 type crystal phase as a principal phase. A nitriding treatment to a mother alloy is carried out in a mixed gas of ammonia gas and hydrogen gas of which partial pressure ratio is set in the range of 3<Py/Px when partial pressure of ammonia gas is PX, that of the hydrogen gas is Py.Type: ApplicationFiled: July 13, 2001Publication date: December 27, 2001Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Shinya Sakurada, Takahiro Hirai, Keisuke Hashimoto, Tomohisa Arai
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Patent number: 6245441Abstract: This is a composite magnetic member excellent in corrosion resistance having a chemical composition consisting essentially, by weight, of 0.30 to 0.80% C, more than 16.0% but not more than 25.0% Cr, 0.1 to 4.0% Ni, 0.1 to 0.06% N, at least one kind not more than 2.0% in total selected from the group consisting of Si, Mn and Al, and the balance Fe and impurities, and having a ferromagnetic portion and a non-magnetic portion.Type: GrantFiled: June 18, 1999Date of Patent: June 12, 2001Assignees: Hitachi Metals, Ltd., Denso CorporationInventors: Shin-ichiro Yokoyama, Tsutomu Inui, Yoshihiro Tanimura
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Patent number: 6183568Abstract: 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: GrantFiled: January 6, 1994Date of Patent: February 6, 2001Assignee: Fuji Photo Film Co., Ltd.Inventors: Kanji Nakanishi, Osamu Shimizu, Satoshi Yoshida, Masaaki Katayama, Tatsuya Isomura
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Patent number: 6176944Abstract: The present invention provides a high purity cobalt sputter target having a single phase h.c.p. structure and a magnetic permeability less than the intrinsic magnetic permeability of the material. Substantially pure cobalt is cast and slowly cooled, such as at a rate of 15° C./min. Or less, to form a cast target of single phase h.c.p. crystallographic structure. This cast target is hot worked at a temperature of at least about 1000° C. to impart a strain of about 65% or greater into the cobalt material, followed by a slow, controlled cooling to room temperature, such as at a rate of 15° C./min. or less, to maintain the single phase h.c.p. crystallographic structure. The cooled target is then cold worked at substantially room temperature to impart a strain of about 5-20%. The sputter target of the present invention processed by this method has a magnetic permeability of less than about 9, grain sizes in the size range of about 70-160 &mgr;m, and average grain size of about 130 &mgr;m.Type: GrantFiled: November 1, 1999Date of Patent: January 23, 2001Assignee: Praxair S.T. Technology, Inc.Inventors: Alfred Snowman, Holger Koenigsmann, Andre Desert, Thomas J. Hunt
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Patent number: 6168673Abstract: An object of this invention is to provide a thin-film magnet having a residual magnetic flux density Br of not less than 10 kG, a cost performance equal to that of a hard ferrite magnet, and a thickness of 70-300 &mgr;m contributing to the miniaturization and thinning of a magnetic circuit, and a method of manufacturing the same. When a molten alloy of a predetermined structure having a small content of a rare earth element is subjected to continuous casting using a cooling roll in an inert gas atmosphere with reduced pressures of not more than 30 kPa at a predetermined peripheral speed of the roll, it turns into a crystalline structure substantially not less than 90% of which comprises a Fe3B type compound and a compound phase having &agr; —Fe and Nd2Fe14B type crystalline structures compatible with the former.Type: GrantFiled: May 20, 1999Date of Patent: January 2, 2001Assignee: Sumitomo Special Metals Co., Ltd.Inventors: Hirokazu Kanekiyo, Satoshi Hirosawa
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Patent number: 6149736Abstract: A magnetostrictive material includes a rare earth element and a transition metal element, and has a plurality of spherical voids dispersed in the entire area thereof. The void content Vc is set in a range of 10%.ltoreq.Vc.ltoreq.40%. Thus, it is possible to provide a magnetostrictive material having a practical mechanical strength and a substantially increased magnetostriction amount.Type: GrantFiled: March 6, 1998Date of Patent: November 21, 2000Assignee: Honda Giken Kogyo Kabushiki KaishaInventors: Tooru Sukigara, Jun Takizawa, Hitoshi Itami
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Patent number: 6143094Abstract: 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: April 18, 1997Date of Patent: November 7, 2000Assignee: Denso CorporationInventors: Satoshi Sugiyama, Yoshihiro Tanimura, Masaki Shimizu, Yoshitada Katayama, Hidehito Kito, Suehisa Sugisaka
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Patent number: 6056830Abstract: A rare earth permanent magnet powder having high anisotropy, that means Br/Bs of more than 0.65, is produced by applying present invented hydrogen heat treatment. The rare earth permanent magnet powder consists essentially of rare earth element including yttrium, iron, and boron. It is subjected to hydrogen heat treatment accompanied with phase transformations. The treatment is carried out at the relative reaction rate within the range of 0.25-0.50 at 830.degree. C. and hydrogen pressure of 0.1 MPa. Here the relative reaction rate is defined as the ratio of actual reaction rate to the standard reaction rate which measured at the temperature of 830.degree. C. and hydrogen pressure of 0.1 MPa.Type: GrantFiled: October 8, 1997Date of Patent: May 2, 2000Assignee: Aichi Steel Works, Ltd.Inventors: Yoshinobu Honkura, Chisato Mishima, Hironari Mitarai
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Patent number: 6053989Abstract: The present invention provides an amorphous or amorphous/microcrystalline metal alloy comprising Fe.sub.a Cr.sub.b V.sub.c P.sub.d Si.sub.e C.sub.f M.sub.g X.sub.h wherein M is selected from the group consisting of Cu, Ni, and mixtures thereof; X is selected from the group consisting of Mo, W, and mixtures thereof; a is about 66 to about 80; b is about 0.5 to about 5.0; c is about 0.5 to about 5.0; d is about 7.0 to about 13.0; e is about 0.2 to about 3.0; f is about 4.5 to about 8.0; g is about 0.1 to about 0.9; h is about 0.1 to about 3.0; and a, b, c, d, e, f, g, and h represent atomic percent where the total is nominally equal to 100 atomic percent. Such metal alloys have desirable magnetic properties such as high saturation induction, low coercivity and high normal permeability. Significantly cost-effective methods of producing such alloys using by-product ferrophosphorus from phosphorus production and impure sources of alloying elements are also provided.Type: GrantFiled: February 12, 1998Date of Patent: April 25, 2000Assignee: FMC CorporationInventors: Michael Orillion, Johan Pfeiffer, Yulig K. Kovneristy
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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: 5932032Abstract: A process by which solid magnet bodies can be efficiently produced from mrials with soft magnetic properties using the die casting process is disclosed. The process is characterized in that an alloy comprising the alloy constituents of the soft magnetic material in addition to one or more elements lowering the melting point is used as a starting material, and in that the additional elements are at least partially extracted from the magnet bodies that are produced from this alloy by the die casting method subsequently by a heat treatment in a reactive atmosphere. The process is applicable for the production of soft magnetic magnet bodies for relays, transformers, magnet valves, actuators, and other electromagnetic products.Type: GrantFiled: October 16, 1997Date of Patent: August 3, 1999Assignee: Institut fuer Festkoerper-und Werkstofforschung Dresden e.V.Inventor: Stefan Roth
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Patent number: 5916376Abstract: An object of the invention is to provide an inexpensive magnet having a high coercivity, high squareness ratio and high maximum energy product. According to the invention, a magnet containing R, T, N, and M wherein R is at least one rare earth element with essential samarium, T is iron or iron and cobalt, and M is at least one element of Ti, V, Cr, Nb, Hf, Ta, Mo, W, Al, C, and P, with essential zirconium, in amounts of 4-8 at % of R, 10-20 at % of N, 2-10 at % of M, and having a hard magnetic phase (TbCu.sub.7 type crystalline phase) and a soft magnetic phase (which is a bcc structured T phase, has an average grain diameter of 5-60 nm, and accounts for 10 to 60% by volume of the entirety), the atomic ratio (R+M)/(R+T+M) in the hard magnetic phase being in excess of 12.5%, is prepared utilizing a single roll technique. In the single roll technique, the peripheral speed of a chill roll is at least 50 m/s, and the discharge pressure of the molten alloy is 0.3-2 kgf/cm.sup.2.Type: GrantFiled: December 4, 1997Date of Patent: June 29, 1999Assignee: TDK CorporationInventors: Akira Fukuno, Tomomi Yamamoto, Tetsuhito Yoneyama, Tetsuya Hidaka
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Patent number: 5876797Abstract: A method of producing doped and undoped silicon layers on a substrate by chemical vapor deposition at elevated pressures of from about 10 to about 350 Torr whereby deposition occurs at practicable rates. A substrate is loaded in a vacuum chamber, the temperature adjusted to obtain a silicon deposit of predetermined crystallinity, and the silicon precursor gases fed to the chamber to a preselected high pressure. Both undoped and doped silicon can be deposited at high rates up to about 3000 angstroms per minute.Type: GrantFiled: October 8, 1997Date of Patent: March 2, 1999Assignee: Applied Materials, Inc.Inventors: Israel Beinglass, David K. Carlson
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Patent number: 5863356Abstract: The invention comprises a method for producing electric sheets, in particular grain-oriented electric sheets, with an evenly well-adhering glass film and with improved magnetic properties, in which the hot rolled strip which is produced at first and is optionally annealed is cold-rolled up to an end thickness in one or several steps, thereafter an annealing separator is applied to the strip which is rolled up to the end thickness, and is dried, and therafter the cold strip thus coated is subjected to high-temperature annealing, with an important component of the annealing separator being a hydrous magnesium oxide (MgO) dispersion and the annealing separator being additionally provided with at least one additive. The characterizing feature of the invention is that a finely dispersed water-soluble sodium phosphate compound is used as at least one additive.Type: GrantFiled: October 3, 1996Date of Patent: January 26, 1999Assignee: EBG Gesellschaft fur Elektromagnetische Werkstoffe mbHInventors: Fritz Bolling, Brigitte Hammer, Thomas Dolle, Klaus Gehnen, Heiner Schrapers
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Patent number: 5851312Abstract: In HDDR (hydrogenation, disproportionation, desorption and recombination) treatment, a mass production method and its apparatus for anisotropic rare earth magnet powder had not been established because it is difficult to keep a constant temperature of material due to an exothermic/endothermic reaction with hydrogen. The present invention compensates for the heat accompanied with the exothermic/endothermic reaction by a counter reaction by the use of dummy material. The apparatus includes sets of a processing vessel and a heat compensating vessel in contact and in control of their temperature. The apparatus enables the temperature control of HDDR treatment within a desired range and constantly brings out the maximum property from the material. The controlability of the method is independent of the production scale so that mass production by HDDR treatment can be set into practice.Type: GrantFiled: July 11, 1997Date of Patent: December 22, 1998Assignee: Aichi Steel Works, Ltd.Inventors: Yoshinobu Honkura, Hironari Mitarai, Takenobu Yoshimatsu
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Patent number: 5849109Abstract: Methods of producing a rare earth alloy magnet powder having superior magnetic anisotropy and an aggregate of fine recrystallized structure of a R.sub.2 T.sub.14 M type intermetallic compound phase. In the methods, a R--T--M--A--Mg alloy material containing Mg is subjected to the following steps: elevating the temperature of the R--T--M--A--Mg alloy material from room temperature to a temperature up to 500.degree. C. in a vacuum or inert gas atmosphere; hydrogen-occluding treatment in which hydrogen is occluded in the R.ltoreq.T--M--A--Mg alloy material to promote phase transformation by elevating the temperature from room temperature to a predetermined temperature ranging from 500.degree. to 1,000.degree. C.Type: GrantFiled: March 10, 1997Date of Patent: December 15, 1998Assignee: Mitsubishi Materials CorporationInventor: Hiroshi Ikeda
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Patent number: 5840131Abstract: A process for producing a grain-oriented electrical steel sheet excellent in the glass film and the magnetic properties by coating a steel sheet with an annealing separator, finish annealing the steel sheet, and baking an insulating coating agent, which comprises coating the steel sheet having been decarburization annealed with an annealing separator prepared by allowing 100 parts by weight of MgO to contain, in the course from the step of producing MgO to the stage of preparing a slurry in the step of coating the steel sheet with MgO, halogens selected from F, Cl, Br and I or compounds of the halogens in an amount of 0.015 to 0.120 part by weight in terms of F, Cl, Br and I, and finish annealing the steel sheet.Type: GrantFiled: May 17, 1997Date of Patent: November 24, 1998Assignee: Nippon Steel CorporationInventors: Kenichi Yakashiro, Hotaka Honma, Maremizu Ishibashi, Akira Sakaida, Tomoji Kumano, Koji Yamasaki, Katsuro Kuroki, Osamu Tanaka
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Patent number: 5821000Abstract: A composite magnetic member formed of a single material having a ferromagnetic section with high soft magnetism and a non-magnetic or the like section with sufficiently low magnetic (feebly magnetized or non-magnetic) and sufficient low MS temperature and a process for producing the member are provided. A composite magnetic member made of a single material of martensitic stainless steel including Ni having two sections of a ferromagnetic section having maximum permeability not less than 200 and coercive force not more than 2000 A/m and a feebly magnetized section having permeability not more than 2 and MS temperature not more than -30.degree. C.Type: GrantFiled: December 6, 1996Date of Patent: October 13, 1998Assignee: Hitachi Metals, Ltd. and Denso CorporationInventors: Tsutomu Inui, Jun Sunakawa, Masaki Shimizu, Keizo Takeuchi, Shinya Sugiura
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Patent number: 5803988Abstract: The annealing conditions of a cold rolled steel sheet are properly controlled so as to form a dense surface oxide layer, thereby improving the adherence strength of the insulating layer on non-oriented electrical steel sheet. The method includes the following steps. A steel slab is prepared which is composed of in weight %: 0.05% or less of C, 3.5% or less of Si, 1.5% or less of Mn, 0.15% or less of P, 0.015% or less of S, 1.0% or less of Al, one or more elements selected from a group consisting of 0.03-0.30% of Sn, 0.03-0.3% of Sb, 0.03-1.0% of Ni and 0.03-0.50% of Cu, the balance of Fe and unavoidable impurities. The steel slab is reheated, hot rolled, pickled after annealing or without annealing and cold-rolled. A low temperature annealing is carried out on the cold rolled steel sheet at a temperature of 750.degree.-850.degree. C. for 30 seconds to 5 minutes under a humid atmosphere having a dew point of 25.degree.-65.degree. C.Type: GrantFiled: August 18, 1997Date of Patent: September 8, 1998Assignee: Pohang Iron & Steel Co., Ltd.Inventors: Byung Keun Bae, Sam Kyu Chang, Jong Soo Woo, Wun Gul Lee
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Patent number: 5801630Abstract: A harmonic-type EAS marker includes a wire segment formed of cobalt alloy. To form the wire segment, the cobalt alloy is cast as an amorphous wire, die-drawn to a smaller diameter, and then annealed with application of longitudinal tension. The annealed wire is cut to produce wire segments which have a magnetic hysteresis loop with a large Barkhausen discontinuity at a lower threshold level than has previously been achieved.Type: GrantFiled: November 8, 1996Date of Patent: September 1, 1998Assignee: Sensormatic Electronics CorporationInventors: Wing K. Ho, Jiro Yamasaki
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Patent number: 5788782Abstract: It is an object of the present invention to provide R-Fe-B permanent magnet materials having a good oxidation resistance and magnetic characteristics, and a process of producing the same capable of pulverizing efficiently, whereby an R-Fe-B molten alloy having a specific composition is casted into a cast piece having a specific plate thickness and a structure, in which an R-rich phase is finely separated below 5 .mu.m, by a strip casting process, the cast piece is subjected to a Hydrogenation for spontaneous decay, and thereafter, an alloy powder is dehydrogenated and stabilized for pulverization so as to fractionize crystal grains of a main phase constituting an alloy ingot, thereby the powder having a uniform grain distribution can be produced at an efficiency of about twice as much as the conventional process, and the R-rich phase and an R.sub.2 Fe.sub.Type: GrantFiled: August 9, 1995Date of Patent: August 4, 1998Assignee: Sumitomo Special Metals Co., Ltd.Inventors: Yuji Kaneko, Naoyuki Ishigaki, Koki Tokuhara
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Patent number: 5783145Abstract: An iron-nickel alloy, the chemical composition of which includes by weight:30%.ltoreq.Ni+Co.ltoreq.85%;0%.ltoreq.Co+Cu+Mn.ltoreq.10%;0%.ltoreq.Mo+W+Cr.ltoreq.4%;0%.ltoreq.V+Si.ltoreq.2%;0%.ltoreq.Nb+Ta.ltoreq.1%;0.003%.ltoreq.C.ltoreq.0.05% 0.003%.ltoreq.Ti.ltoreq.0.15%;0.003%.ltoreq.Ti+Zr+Hf.ltoreq.0.15%;0.001%<S+Se+Te<0.015%;and the remainder, iron and impurities resulting from production; in addition, the chemical composition satisfies the relationship:0.ltoreq.Nb+Ta+Ti+Al.ltoreq.1%.A cold-rolled strip with a cubic texture and its uses.Type: GrantFiled: February 27, 1997Date of Patent: July 21, 1998Assignee: Imphy S.A.Inventors: Lucien Coutu, Pierre Louis Reydet
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Patent number: 5776263Abstract: Homogenizing heat-treatment is conducted for changing an ingot containing R (R: Sm or a substance obtained by replacing a part of Sm with one or more kinds of rare earth elements) and T (T: Fe or a substance obtained by replacing a part of Fe with one or more kinds of transition elements) as main component into an alloy ingot mainly containing a R.sub.2 T.sub.17 phase. Next, the above-described alloy ingot is allowed to absorb hydrogen in hydrogen gas in the temperature range of 70.degree. C. to 300.degree. C. and at pressures of 5kgf/cm.sup.2 or more, thus conducting coarse crushing treatment.Type: GrantFiled: November 19, 1996Date of Patent: July 7, 1998Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Kiyoshi Kojima, Takeshi Takahashi
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Patent number: 5769965Abstract: A method for treating soft magnetic parts by annealing and producing a wear guard layer, in which the soft magnetic parts are either successively annealed and provided with a wear guard layer in a reaction chamber of a treatment apparatus, or the annealing and production of a wear guard layer are done simultaneously in the reaction chamber. This avoids intermediate transportation and temporary storage as well as contamination of the parts and reduces the costs of the method. The method is especially suitable for treating soft magnetic parts of electromagnetic fuel injection valves.Type: GrantFiled: April 19, 1996Date of Patent: June 23, 1998Assignee: Robert Bosch GmbHInventors: Dieter Liedtke, Juergen Graner, Norbert Keim, Joerg Illing
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Patent number: 5753051Abstract: Low core loss oriented electrical steel sheet having a surface coating that has a Young's modulus that is not less than 100 GPa and a differential of thermal expansion coefficient relative to the sheet base metal that is not less than 2.times.10.sup.-6 /K and which contains not less than 10 percent, by weight, of crystallites with an average size of not less than 10 nm and an average crystal grain diameter that does not exceed 1000 nm, and a method of manufacturing same.Type: GrantFiled: January 28, 1997Date of Patent: May 19, 1998Assignee: Nippon Steel CorporationInventors: Takao Kanai, Kei Tanemoto, Shuichi Yamazaki, Takeo Nagashima
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Patent number: 5741982Abstract: A structure of a magnetostrictive shaft applicable to a magnetostriction-type torque sensor and a method for manufacturing the same can achieve a high torque sensitivity. A shaft parent material is made of a non-magnetic austenitic series metallic material (YHD50) and a magnetic thin film is made of a magnetostriction material such as Iron-Aluminium series alloy plasma spray coated on the whole outer peripheral surface of the shaft parent material. In a second embodiment, a mechanical working is carried out for the shaft material on the surface of which the magnetostriction material thin film is coated, the worked shaft material is heated under an inert gas atmosphere, and the heated shaft material is immersed into oil under the inert gas atmosphere to perform the oil quenching.Type: GrantFiled: August 13, 1996Date of Patent: April 21, 1998Assignee: Unisia JECS CorporationInventors: Nobuaki Kobayashi, Satoshi Kaise, Hideki Kano
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Patent number: 5725681Abstract: Producing a grain oriented silicon steel sheet by controlling physical properties of the oxides layer, formed in decarburization annealing, in the surface layer of a steel sheet. A silicon compound is adhered to the surface of steel sheet before the decarburization annealing in an amount ranging from about 0.5 to 7.0 mg per square meter, expressed as Si, and the atmosphere of an earlier portion of the temperature holding process is adjusted to a ratio of steam partial pressure to the hydrogen partial pressure of less than about 0.7, and the atmosphere of the temperature rising process up to the temperature holding process is adjusted to an atmospheric composition lower than the atmospheric composition of the earlier portion of the temperature holding process, and the atmosphere of a later part of the temperature holding process is adjusted to an atmospheric composition lower than the atmospheric composition of the earlier part of the temperature holding process and in a range from about 0.005 to 0.2.Type: GrantFiled: September 3, 1996Date of Patent: March 10, 1998Assignee: Kawasaki Steel CorporationInventors: Hirotake Ishitobi, Takafumi Suzuki, Michiro Komatsubara, Hiroi Yamaguchi
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Patent number: 5720828Abstract: Magnetic materials containing a rare earth metal, and iron or a similar metal, as well as nitrogen and carbon, are produced by gas absorbing nitrogen and carbon sequentially into a parent intermetallic compound; the resulting magnetic materials have high T.sub.c, .mu..sub.o M.sub.s and .mu..sub.o H.sub.A, are essentially free of .alpha.-Fe, and have a coercivity at 300.degree. K. of at least 1.5 T. Anisotropic magnetic materials are produced by pretreating the intermetallic compound, which contains carbon, by powder sintering or oriented hot shaping, followed by nitriding and/or carbiding.Type: GrantFiled: February 15, 1995Date of Patent: February 24, 1998Assignee: Martinex R&D Inc.Inventors: John Olaf Strom-Olsen, Xinhe Chen, Le Xiang Liao, Zaven Altounian, Dominic Hugh Ryan
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Patent number: 5716461Abstract: A functionally gradient permanent magnet is formed as a slab of alloy comprised of a rare earth-transition metal-boron, and areas of a diffused transition metal positioned at points along the length of at least one surface of the slab of alloy.Type: GrantFiled: September 30, 1996Date of Patent: February 10, 1998Assignee: Eastman Kodak CompanyInventors: Edward Paul Furlani, Syamal Kumar Ghosh, Dilip Kumar Chatterjee
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Patent number: 5679177Abstract: Low core loss oriented electrical steel sheet having a surface coating that has a Young's modulus that is not less than 100 GPa and a differential of thermal expansion coefficient relative to the sheet base metal that is not less than 2.times.10.sup.-6 /K and which contains not less than 10 percent, by weight, of crystallites with an average size of not less than 10 nm and an average crystal grain diameter that does not exceed 1000 nm, and a method of manufacturing same.Type: GrantFiled: January 30, 1995Date of Patent: October 21, 1997Assignee: Nippon Steel CorporationInventors: Takao Kanai, Kei Tanemoto, Shuichi Yamazaki, Takeo Nagashima
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Patent number: 5660927Abstract: The present invention provides acicular fine particles made up of iron and carbon, and these acicular metal iron fine particles can be prepared by contacting acicular iron carbide fine particles with a reducing agent containing no carbon atom. Further, the present invention provides a magnetic coating composition and magnetic recording medium containing the above acicular metal iron fine particles.Type: GrantFiled: July 28, 1994Date of Patent: August 26, 1997Assignee: Daikin Industries Ltd.Inventors: Takuya Arase, Yoshiyuki Shibuya, Ikuo Kitamura, Shigeo Daimon
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Patent number: 5658398Abstract: There is provided an alloy with ultrafine crystal grains excellent in corrosion resistance, at least 50% of the alloy structure being occupied by ultrafine crystal grains, the alloy having a surface layer containing hydroxide components in a total proportion of 65% or more based on oxide components.Type: GrantFiled: April 5, 1996Date of Patent: August 19, 1997Assignee: Hitachi Metals, Ltd.Inventors: Yoshihito Yoshizawa, Shunsuke Arakawa, Katsuhisa Sugimoto
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Patent number: 5630885Abstract: An alloy ingot for permanent magnet consists essentially of rare earth metal and iron and optionally boron. The two-component alloy ingot contains 90 vol % or more of crystals having a crystal grain size along a short axis of 0.1 to 100 .mu.m and that along a long axis of 0.1 to 100 .mu.m. The three-component alloy ingot contains 90 vol % or more of crystals having a crystal grain size along a short axis of 0.1 to 50 .mu.m and that along a long axis of 0.1 to 100 .mu.m. The alloy ingot is produced by solidifying the molten alloy uniformly at a cooling rate of 10.degree. to 1000.degree. C./sec. at a sub-cooling degree of 10.degree. to 500.degree. C. A permanent magnet and anisotropic powders are produced from the alloy ingot.Type: GrantFiled: April 4, 1996Date of Patent: May 20, 1997Assignee: Santoku Metal Industry, Co., Ltd.Inventors: Kazuhiko Yamamoto, Yuichi Miyake, Chikara Okada
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Patent number: 5589221Abstract: 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.0.9, 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 nm.Type: GrantFiled: May 11, 1995Date of Patent: December 31, 1996Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Masayoshi Hiramoto, Osamu Inoue, Koichi Kugimiya, Kenji Iijima
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Patent number: 5580396Abstract: There is disclosed a process for optimizing the magnetic properties of a multiphase product of composition rare earth/iron/boron endowed with permanent magnet properties at ambient temperature. This composition serves as a precursor, which is first subjected to a decrepitation treatment by hydrogenation under low pressure at low temperature to obtain an intermediate hydride in pulverulent form. The pulverulent intermediate hydride is subsequently subjected to a first heat treatment under vacuum for partial dehydrogenation at a temperature below its element separation temperature. The non-separated product thereby obtained is subjected to a second heat post-treatment under an initial primary vacuum and extensively dehydrogenated until the primary vacuum is reestablished at a temperature close to 600.degree. C. The precursor can be an isotropic material obtained by fast quenching, such as wheel quenching or hot welding with a forging ratio of at least 10.Type: GrantFiled: October 5, 1994Date of Patent: December 3, 1996Assignee: Centre National de la Recherche Scientifique (CNRS)Inventors: Daniel Fruchart, Salvatore Miraglia, Paul Mollard, Rene Perrier de la Bathie, Robert Fruchart
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Patent number: 5486239Abstract: A magnetically anisotropic R-T-B-M powder material which is starting with an R-T-B-M raw alloy material having a c-axis crystal orientation of an R.sub.2 T.sub.14 B-type intermetallic compound phase. In one embodiment, the starting material is compressed sintered in a magnetic field and recompressed in a magnetic field. In a second embodiment, the starting material is hot-pressed and homogenized. A method of manufacturing anisotropic magnets such as bond and full density magnets made from the magnetically anisotropic R-T-B-M powder material is disclosed.Type: GrantFiled: October 29, 1993Date of Patent: January 23, 1996Assignee: Mitsubishi Materials CorporationInventors: Ryoji Nakayama, Takuo Takeshita, Yoshinari Ishill
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Patent number: 5478411Abstract: A process is provided for modifying the magnetic properties of an intermetallic compound comprising at least iron, or a combination of iron with at least one transition metal, and at least one rare earth element. The process comprises heating the intermetallic compound in a reaction gas containing at least one element of groups IIIA, IVA or VIA of the Periodic Table in the gaseous phase to interstitially incorporate the element or elements of these groups into the crystal lattice of the intermetallic compound. Novel magnetic materials showing easy uniaxial anisotropy, increased spontaneous magnetization and Curie temperatures are produced by the process.Type: GrantFiled: June 16, 1994Date of Patent: December 26, 1995Assignee: Provost, Fellows and Scholars of the College of the Holy and Undivided Trinity of Queen Elizabeth Near DublinInventors: John M. D. Coey, Hong Sun, David P. Hurley
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Patent number: 5474624Abstract: The present invention relates to a method of stably manufacturing a Fe-base soft magnetic alloy having steps of subjecting an amorphous alloy mainly composed of Fe to heat treatment in which the amorphous alloy is heated to 400.degree. to 750.degree. C. at a heating rate of 1.0.degree. C./minute or higher so that at least 50% or more of the structure of the amorphous alloy is made of fine crystalline grains formed into a body-centered cubic structure and having an average grain size of crystal of 30 nm or smaller as to have a high magnetic permeability and saturation magnetic flux density.Type: GrantFiled: September 14, 1993Date of Patent: December 12, 1995Assignee: Alps Electric Co., Ltd.Inventors: Kiyonori Suzuki, Akihiro Makino, Tsuyoshi Masumoto, Akihisa Inoue
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Patent number: 5466304Abstract: Disclosed are an amorphous iron based alloy having excellent magnetic characteristics as well as bendability and a method of manufacturing the amorphous iron based alloy. The amorphous iron based alloy has a mean centerline Ra surface roughness of about 0.8 .mu.m or less and the formula Fe.sub.X B.sub.Y Si.sub.Z Mn.sub.a in approximate proportions wherein:75.ltoreq.X.ltoreq.82 at %7.ltoreq.Y.ltoreq.15 at %,7.ltoreq.Z.ltoreq.17 at %, and0.2.ltoreq.a.ltoreq.0.5 at %.The method of manufacturing the amorphous iron based alloy comprises quenching and solidifying a molten alloy having the formula Fe.sub.X B.sub.Y Si.sub.Z Mn.sub.a in approximate proportions wherein:75.ltoreq.X.ltoreq.82 at %7.ltoreq.Y.ltoreq.15 at %,7.ltoreq.Z.ltoreq.17 at %, and0.2.ltoreq.a.ltoreq.0.5 at %, andeffecting the quenching and solidifying steps in a Co.sub.2 atmosphere containing H.sub.2 in an amount of about 1-4% by volume.Type: GrantFiled: November 22, 1994Date of Patent: November 14, 1995Assignee: Kawasaki Steel CorporationInventors: Fumio Kogiku, Masao Yukumoto, Seiji Okabe
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Patent number: 5439534Abstract: A magnetic core having a low core loss and having stable characteristics in a low magnetic permeability region can be obtained at a high yield by applying a heat treatment to a magnetic core main body obtained by winding or laminating a ferrous amorphous ribbon In a wet atmosphere containing a limited amount of steam.Type: GrantFiled: November 4, 1992Date of Patent: August 8, 1995Assignee: Mitsui Petrochemical Industries, Ltd.Inventors: Masato Takeuchi, Yoshihiko Hirota, Hiroshi Ohmori, Masaru Yoshimura
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Patent number: 5431746Abstract: Methods for preparing magnetic strips are provided in which the strips are manufactured to a thickness of less than about 0.005 inches and are made of a ferrous alloy having a carbon content of from about 0.4 to about 1.2 weight percent. The strips are prepared by first manufacturing an alloy having a carbon content below about 0.5 weight percent to the desired thickness and then subjecting the strip to a carburizing step to raise the carbon content in the strip.Type: GrantFiled: August 30, 1993Date of Patent: July 11, 1995Assignee: SPS Technologies, Inc.Inventors: Neil R. Manning, Richard L. Anderson
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Patent number: 5417773Abstract: The present invention provides a method for producing a rare earth alloy magnet powder exhibiting stable and superior magnetic properties using hydrogenation followed by dehydrogenation. In a method for producing a rare earth alloy magnet powder wherein a homogenized rare earth alloy magnet alloy material is subjected to hydrogenation at a temperature in a range between 750.degree. C. and 950.degree. C., followed by dehydrogenation at a temperature in a range between 750.degree. C. and 950.degree. C.; cooled; and crushed, both the hydrogenation and the dehydrogenation are carried out in a vacuum tube furnace; and the alloy material in the dehydrogenation step maintains a temperature drop of at most 50.degree. C. due to an endothermic reaction which occurs during the dehydrogenation step.Type: GrantFiled: October 6, 1994Date of Patent: May 23, 1995Assignee: Mitsubishi Materials CorporationInventors: Ryoji Nakayama, Takuo Takeshita, Yoshinari Ishii, Tamotsu Ogawa
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Patent number: 5413639Abstract: A method of manufacturing a low-core-loss oriented electrical steel sheet. Thread-like grooves are formed in a cold-rolled grain oriented electrical steel sheet having a final thickness of about 0.27 mm or less in a direction within the range of about 30.degree. from the direction perpendicular to the rolling direction. The grooves and sheet satisfy the equationlog d.gtoreq.0.6 Ra+0.4where d is the groove depth (.mu.m), and Ra is the mean surface roughness of the steel sheet cold-rolled to final gauge. The steel sheet is thereafter decarburization annealed and final texture annealed.Type: GrantFiled: January 19, 1993Date of Patent: May 9, 1995Assignee: Kawasaki Steel CorporationInventors: Keiji Sato, Bunjiro Fukuda
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Patent number: 5411605Abstract: This invention is intended for providing a soft magnetic steel material having excellent DC magnetization properties and corrosion resistance, and capable of being manufactured at a low cost, and a method of manufacturing the same.The soft magnetic steel material of this invention contains 0.8 to 3.5% by weight of soluble aluminum, as well as limited amounts of C, total nitrogen, Si, Mn, P, S and total oxygen, and has an average ferrite crystal diameter of which the minimum has a specific relation to the thickness or diameter of the material. The material has a surface covered densely with aluminum oxide particles having a diameter of 0.01 to 5 microns. It exhibits a coercive force not exceeding 0.4 Oe in the absence of any strain and a magnetic flux density of 15,000 G or more at a magnetomotive force of 25 Oe. The aluminum oxide particles formed on the surface of the material are preferably formed with a density of 1.times.10.sup.12 to 1.times.10.sup.16 particles, or more preferably 1.times.10.sup.13 to 1.Type: GrantFiled: June 11, 1993Date of Patent: May 2, 1995Assignee: NKK CorporationInventors: Toshimichi Omori, Haruo Suzuki, Tetsuya Sampei, Takahiro Kanero, Masayoshi Nakagawa, Masayoshi Kurihara
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Patent number: 5399311Abstract: A magnet is formed as a ring magnet and magnetized by radial application of a magnetic field while the intensity of the magnetic field is changed periodically along the circumference of the ring magnet to give a circumferentially sinusoidal waveform distribution of magnetic flux density to the ring magnet in the magnetized state of the magnet.Type: GrantFiled: November 12, 1992Date of Patent: March 21, 1995Assignee: Daido Tokushuko Kabushiki KaishaInventors: Yasuaki Kasai, Hiyoshi Yamada, Norio Yoshikawa
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Patent number: 5395459Abstract: In a preferred method, a molten alloy of samarium and iron is formed with a proportion of about 1:4 to about 1:9 of samarium to iron. The molten alloy is then quenched in a non-oxidizing environment at a rate sufficient to form a solid crystalline alloy in the form of a thin ribbon. The ribbon is comminuted to form a powder and the powder is nitrided in a gaseous nitrogen atmosphere. Nitriding causes nitrogen to penetrate and occupy interstitial sites in the Sm-Fe alloy, producing a magnetically hard powder with a high coercivity typically 10 kOe, usually greater than 15 kOe and as high as about 20 to about 23 kOe.Type: GrantFiled: November 18, 1993Date of Patent: March 7, 1995Assignee: General Motors CorporationInventors: Frederick E. Pinkerton, Carlton D. Fuerst
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Patent number: 5395460Abstract: The present invention discloses a process for enhancing the harmonic output of a marker comprising the steps of providing an amorphous alloy having a composition (Fe.sub.1-x Ni.sub.x).sub.a M.sub.b (B.sub.1-y Si.sub.y).sub.c wherein "x" ranges from about 0.2 to about 0.9, "y" ranges from 0 up to about 0.5, "a" is between about 60 and about 90 atomic %, "b" is between about 0.1 to about 10 atomic %, "c" is between about 0.1 to about 30 atomic percent, and M is at least one metal selected from the group consisting of Mo, Cr, Hf, Nb, Ta, Ti, V, W, and Zr, the amorphous alloy having at least two crystallization temperatures, a first crystallization temperature at which a nanocrystalline phase is formed, and a second crystallization temperature at which a second crystalline phase is formed; annealing the amorphous alloy at a temperature between the first and the second crystallization temperatures for a time sufficient to increase at least one harmonic characteristic of the element.Type: GrantFiled: October 16, 1992Date of Patent: March 7, 1995Assignee: AlliedSignal Inc.Inventor: Ronald J. Martis