Using Phosphorus(p), Boron(b), Or Silicon(si) Or Compound Thereof Patents (Class 75/349)
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Patent number: 11715592Abstract: In one embodiment, a magnet includes a three-dimensional structure with nanoscale features, where the three-dimensional structure has a near net shape corresponding to a predefined shape.Type: GrantFiled: September 4, 2018Date of Patent: August 1, 2023Assignee: Lawrence Livermore National Security, LLCInventors: Sarah Baker, Joshua Kuntz, Scott K. Mccall, Christine A. Orme, Alexander A. Baker, Jonathan R. I. Lee
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Patent number: 10629344Abstract: A process for producing Co, Al alloyed NdFeB nanoparticles, by a microwave assisted combustion process, followed by a reduction diffusion process, includes the steps of: preparing a first solution of boric acid dissolved in 4 N HNO3, dissolving iron nitrate nonahydrate, neodymium nitrate hexahydrate, cobalt nitrate hexahydrate, aluminium nitrate, the first solution in deionized water to form a second solution, adding glycine to the second solution in a molar ratio of 1:1 to form a third solution, subjecting the third solution to microwave radiation, thereby forming an first powder of NdFeCoAlB oxides, mixing the first powder with calcium hydride in a mass ratio of 1:1.1 (NdFeCoAlB oxides:CaH2) to form a second powder, compacted into a powder block, annealing the second powder in a vacuum furnace, washing the annealed second powder with a solution of ethylenediaminetetraacetic acid; and vacuum drying the second powder.Type: GrantFiled: August 18, 2017Date of Patent: April 21, 2020Assignee: ROLLS-ROYCE plcInventors: Raju V Ramanujan, Harshida G Parmar, Tan Xiao
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Patent number: 8861663Abstract: A method of operation in an ethernet receiver circuit is disclosed. The method comprises sampling an input signal to generate a sampled signal having a sampled noise component and a sampled data component. The sampled signal is sliced, and a slicer error determined based on the slicing of the sampled signal. A subsequently sampled noise component is filtered based on the slicer error.Type: GrantFiled: January 13, 2012Date of Patent: October 14, 2014Assignee: Aquantia CorporationInventors: Hossein Sedarat, Fadi Saibi
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Patent number: 8617290Abstract: The present invention relates to a method for manufacturing a Fe—Si alloy powder. A method for manufacturing a Fe—Si alloy powder includes: providing a mixture of an Al2O3 powder, an active agent powder, a Si powder, and a Fe powder; heating the mixture with a temperature of 700° C. to 1200° C. in the hydrogen atomosphere; magnetically separating a Fe-containing material from the mixture; and separating a Fe—Si alloy powder by soaking the Fe-containing material in an alkali solution. In the heating of the mixture, the Si powder is deposited on the surface of the Fe powder and diffused into the Fe powder.Type: GrantFiled: October 22, 2010Date of Patent: December 31, 2013Assignee: Korea Institute of Science and TechnologyInventors: Ji-Young Byun, Yoon-Bae Kim, Hyun-Kwang Seok, Jang-Won Kim, Dow-Bin Hyun, Heon-Phil Ha, Do-Hyung Kim
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Patent number: 8398741Abstract: Fine composite metal particle comprising a metal core and a coating layer of carbon, and being obtained by reducing metal oxide powder with carbon powder.Type: GrantFiled: January 4, 2011Date of Patent: March 19, 2013Assignee: Hitachi Metals, Ltd.Inventors: Yasushi Kaneko, Shigeo Fujii, Hisato Tokoro
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Patent number: 7497892Abstract: Magnetic particles of the present invention comprising monocrystals of rare earth element-transition metal-metalloid having particle diameters of 5 nm to 50 nm. The magnetic particles are produced by a producing method comprising a step of fabricating a quenched thin band comprising rare earth element-transition metal-metalloid. A magnetic recording medium of the present invention includes the magnetic layer which contains therein the magnetic particles and the binder, and which is formed on the non-magnetic substrate.Type: GrantFiled: September 30, 2005Date of Patent: March 3, 2009Assignee: FUJIFILM CorporationInventor: Yasushi Hattori
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Publication number: 20080066575Abstract: The disclosure provides a rare earth anisotropic hard magnetic material, which has, on atomic percent basis, a composition of (Sm1-?R?)xFe100-x-y-zMyIz, wherein, R is Pr alone or a combination of Pr with at least one rare earth element selected from the group consisting of La, Ce, Nd, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y; M is at least one element selected from the group consisting of Si, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Nb, Mo, Al, and Zr; I is N alone or a combination of N and C; 0.01???0.30; 7?x?12, 0.01?y?8.0, 6?z?14.4, and which anisotropic rare earth hard magnetic material is crystallized in a Th2Zn17-type structure, of which crystalline grains are in a flake shape with a gain size ranging from 1 to 5 ?m, and c-axis of the crystalline grains, an easy magnetization direction, being oriented along the minor axis of the flake crystalline grains.Type: ApplicationFiled: April 13, 2007Publication date: March 20, 2008Inventor: Yingchang Yang
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Patent number: 7214343Abstract: The method for producing a granulated powder of the present invention includes the steps of: preparing an R—Fe—B alloy powder; and granulating the alloy powder using at least one kind of granulating agent selected from normal paraffins, isoparaffins and depolymerized oligomers, to prepare a granulated powder. The produced R—Fe—B alloy granulated powder is excellent in flowability and compactibility as well as in binder removability.Type: GrantFiled: March 27, 2002Date of Patent: May 8, 2007Assignee: Neomax Co., Ltd.Inventors: Futoshi Kuniyoshi, Yuji Kaneko, Akihito Tsujimoto, Kazunari Shimauchi, Kazuo Tanaka, Shizuo Mori, Kiyofumi Suzuki
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Patent number: 7195661Abstract: Magnetic materials having a coercivity not less than about 1000 Oersted are prepared in a single step procedure. A molten mixture of a desired composition having a relatively high boron content is cooled at a rate slower than about 105 degrees Celsius per second. Preferably, the molten mixture is cooled by depositing it on a chilled surface such that it forms a layer between about 120 and about 300, and preferably between about 120 and about 150, microns thick.Type: GrantFiled: February 24, 2003Date of Patent: March 27, 2007Assignee: Pioneer Metals and Technology, Inc.Inventor: John Keem
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Patent number: 6827758Abstract: A method for manufacturing magnetic metal powder is provided. In the method, a powdered magnetic metal oxide is supplied to a heat treatment furnace with a carrier gas composed of a reducing gas. The heat treatment furnace is maintained at temperatures above a reducing action starting temperature for the powdered magnetic metal oxide and above a melting point of the magnetic metal in the powder. The powdered magnetic metal oxide is subject to a reducing process, and then magnetic metal particles, the resultant reduced product, is melted to form a melt. The melt is re-crystallized in a succeeding cooling step, to obtain single crystal magnetic metal power in substantially spherical form.Type: GrantFiled: May 29, 2002Date of Patent: December 7, 2004Assignee: TDK CorporationInventors: Minoru Takaya, Yoshiaki Akachi, Hisashi Kobuke, Hiroyuki Uematsu
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Patent number: 6702870Abstract: The invention concerns a process permitting the preparation of a new powder, which as such or further processed is useful within a wide variety of different fields and which has magnetic and electric properties. The powder includes at least 0.5% by weight of iron containing silicate and at least 10% by weight of metallic iron and/or alloyed iron and is prepared by a process comprising the steps of mixing an iron containing powder and a silicon containing powder; and reducing the obtained mixture at a temperature above about 450° C.Type: GrantFiled: November 25, 2002Date of Patent: March 9, 2004Assignee: Höganäs ABInventors: Lars Hultman, Nils Jonsson, Britt Benemark, Peter Grahn
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Patent number: 6676730Abstract: The present invention relates to a method of producing Nd—Fe—B based nanophase powder, or more particularly, to a method of producing Nd2Fe14B phase powder of 1 &mgr;m or less, having Nd2Fe14B crystal grains of 50 nm or less, which comprises the following steps of: producing a precursor powder having a mixture of elements of Nd, Fe and B by means of spray-drying a mixed aqueous solution comprising Nd metal salt, Fe metal salt, and boric acid; producing an oxide composite powder by means of desaltation of said powder; reducing the composite oxide powder, and ball-milling of said composite powder comprising Nd oxides and &agr;-Fe; producing a mixed powder of Nd2Fe14B/CaO phase by mixing Ca to said composite powder after milling; and removing CaO by washing said composite powder with water, followed by drying.Type: GrantFiled: May 23, 2001Date of Patent: January 13, 2004Assignee: Korea Institute of Machinery and MaterialsInventors: Byung Kee Kim, Chul Jin Choi, Xing Long Dong
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Publication number: 20030217620Abstract: The present invention relates to an improved process for the production of neodymium-iron-boron permanent magnet alloy powder. The neodymium-iron-boron alloy prepared by the process of the present invention can be processed further to get anisotropic permanent magnets, bonded as well as sintered.Type: ApplicationFiled: March 20, 2003Publication date: November 27, 2003Applicant: COUNCIL SCIENTIFIC AND INDUSTRIAL RESEARCHInventors: Patcha Ramachandra Rao, Venkatesh Rao, Arvind Sinha
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Publication number: 20030177867Abstract: The invention concerns a process permitting the preparation of a new powder, which as such or further processed is useful within a wide variety of different fields and which has magnetic and electric properties. The powder includes at least 0.5% by weight of iron containing silicate and at least 10% by weight of metallic iron and/or alloyed iron and is prepared by a process comprising the steps of mixing an iron containing powder and a silicon containing powder; and reducing the obtained mixture at a temperature above about 450° C.Type: ApplicationFiled: November 25, 2002Publication date: September 25, 2003Inventors: Lars Hultman, Nils Jonsson, Britt Benemark, Peter Grahn, Svante Grahn
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Patent number: 6524399Abstract: Magnetic materials having a coercivity not less than about 1000 Oersted are prepared in a single step procedure. A molten mixture of a desired composition having a relatively high boron content is cooled at a rate slower than about 105 degrees Celsius per second. Preferably, the molten mixture is cooled by depositing it on a chilled surface such that it forms a layer between about 120 and about 300, and preferably between about 120 and about 150, microns thick.Type: GrantFiled: March 5, 1999Date of Patent: February 25, 2003Assignee: Pioneer Metals and Technology, Inc.Inventor: John Keem
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Patent number: 6517934Abstract: A rare earth-iron-boron magnetic powder comprising a rare earth element, iron and boron, which has a coercive force of 80 to 400 kA/m, a saturation magnetization of 10 to 25 &mgr;W/g, an average particle size of 5 to 200 nm, and a particulate or ellipsoidal particle shape, and a magnetic recording medium having a magnetic layer which contains this magnetic powder and a binder, in which magnetic recording medium it is possible to practically use a very thin magnetic layer of 0.3 &mgr;m or less.Type: GrantFiled: October 10, 2000Date of Patent: February 11, 2003Assignee: Hitachi Maxell, Ltd.Inventor: Mikio Kishimoto
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Publication number: 20020005088Abstract: The present invention relates to a method of producing Nd—Fe—B based nanophase powder, or more particularly, to a method of producing Nd2Fe14B phase powder of 1 &mgr;m or less, having Nd2Fe14B crystal grains of 50 nm or less, which comprises the following steps of: producing a precursor powder having a mixture of elements of Nd, Fe and B by means of spray-drying a mixed aqueous solution comprising Nd metal salt, Fe metal salt, and boric acid; producing an oxide composite powder by means of desaltation of said powder; reducing the composite oxide powder, and ball-milling of said composite powder comprising Nd oxides and &agr;-Fe; producing a mixed powder of Nd2Fe14B/CaO phase by mixing Ca to said composite powder after milling; and removing CaO by washing said composite powder with water, followed by drying.Type: ApplicationFiled: May 23, 2001Publication date: January 17, 2002Applicant: Korea Institute of Machinery and MaterialsInventors: Byung Kee Kim, Chul Jin Choi, Xing Long Dong
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Patent number: 6103021Abstract: The present invention is directed to provide a method of preparing a raw material powder for permanent magnets superior in moldability, especially in moldability and productivity of bonded magnets. The method comprises subjecting an acicular iron powder having an aspect ratio of not smaller than 5:1 to heating at 800-900.degree. C. in fluidized state with a gas stream containing no oxygen until the acicular iron powder is transformed into a columnar shape iron powder having an aspect ratio of not larger than 3:1, a die-like shape iron powder or a spherical shape iron powder. The acicular iron powder may contain or may be attached by such a component effective for improving magnetic properties as a rare earth element metal, a rare earth element metal oxide, boron, cobalt and nickel.Type: GrantFiled: July 9, 1998Date of Patent: August 15, 2000Assignees: Kawasaki Teitoku Co., Ltd., Sanei Kasei Co., Ltd, Komeya, Inc.Inventors: Shigenobu Sekine, Hiroji Sato
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Patent number: 6051047Abstract: The present invention relates to the preparation of Nd--Fe--B permanent magnetic alloys and more particularly to a process of preparing Nd--Fe--B permanent magnetic alloys with neodymium, iron and boron as their basic constituents, wherein ammonium hydroxide (concentrated ammonia water) and ammonium carbonate are used as the precipitant, and neodymium salts, ferrous salts and soluble boron compounds as the starting materials for alloy elements such as neodymium, iron and boron, in addition, machining surplus or wastes of Nd--Fe--B alloys can also be used as raw materials so as to avoid the use of expensive rare earth metal. The process of the present invention comprises the steps of co-precipitation, hydrogen pre-reduction, calcium reduction-diffusion, rinsing, drying and powder manufacturing etc. and is capable of significantly reducing the costs compared with any of the existing processes.Type: GrantFiled: January 15, 1998Date of Patent: April 18, 2000Assignees: Nankai University, Tianjin Kenda Industry & Trade Group CompanyInventors: Yongqia Zhou, Xuying Hu, Panwen Shen, Shoumin Zhang
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Patent number: 6036742Abstract: Finely divided phosphorus-containing iron is prepared by reacting iron pentacarbonyl with a volatile phosphorus compound, in particular PH.sub.3, in the gas phase. The resulting phosphorus-containing iron powders and iron whiskers have a particularly low content of extraneous elements.Type: GrantFiled: February 12, 1998Date of Patent: March 14, 2000Assignee: BASF AktiengesellschaftInventors: Bernd Leutner, Gabriele Friedrich, Reinhold Schlegel
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Patent number: 5968226Abstract: The disclosure describes spindle-shaped magnetic iron-based alloy particles containing cobalt and iron as the main ingredients in which the Co content is 1.0 to 50.0 atm % (calculated as Co) based on the total Fe in the spindle-shaped magnetic iron-based alloy particles, and which the spindle-shaped magnetic iron-based alloy particles have an average major axis diameter of 0.05 to 0.18 .mu.m, a size distribution (standard deviation/major axis diameter) of not more than 0.25, an average minor axis diameter of 0.010 to 0.020 .mu.m, an aspect ratio (major axis diameter/minor axis diameter) of 4 to 15, an X-ray crystallite size D.sub.110 of 120 to 180 .ANG., a coercive force of 1720 to 2500 Oe, a saturation magnetization of not less than 110 emu/g, and a saturation magnetization decrement percentage of not more than 17%.Type: GrantFiled: December 31, 1996Date of Patent: October 19, 1999Assignee: Toda Kogyo CorporationInventors: Kenji Okinaka, Yasutaka Ota
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Patent number: 5925404Abstract: The quantity of impurities in a magnetic material is decreased to produce a magnetic material with good quality, and a decrease in the cost of the magnetic material is realized by desulfurization. A magnetic raw material for metallic thin film magnetic recording media which contains sulfur more than 20 ppm is desulfurized to obtain the magnetic material for metallic thin film magnetic recording media with the sulfur content adjusted to 20 ppm or below, and a metallic thin film magnetic recording medium having a magnetic layer vaporized thereon with the magnetic material is fabricated.Type: GrantFiled: October 6, 1997Date of Patent: July 20, 1999Assignee: Sony CorporationInventors: Kazunobu Chiba, Tustomu Takeda, Hiroyuki Yamada, Hideo Katagiri, Hiroshi Osumi
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Patent number: 5865873Abstract: The present invention is directed to provide a method of preparing a raw material powder for permanent magnets superior in moldability, especially in moldability and productivity of bonded magnets. The method comprises subjecting an acicular iron powder having an aspect ratio of not smaller than 5:1 to heating at 800.degree.-900.degree. C. in fluidized state with a gas stream containing no oxygen until the acicular iron powder is transformed into a columnar shape iron powder having an aspect ratio of not larger than 3:1, a die-like shape iron powder or a spherical shape iron powder. The acicular iron powder may contain or may be attached by such a component effective for improving magnetic properties as a rare earth element metal, a rare earth element metal oxide, boron, cobalt and nickel.Type: GrantFiled: January 6, 1997Date of Patent: February 2, 1999Assignees: Sawasaki Teitoku Co., Ltd., Sanei Kasei Co., Ltd., Komeya Inc.Inventors: Shigenobu Sekine, Hiroji Sato
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Patent number: 5643491Abstract: In a method of fabricating an R--Fe--B based alloy magnetic powder excellent in magnetic anisotropy, and an R--Fe--B--Co based alloy magnetic powder excellent in magnetic anisotropy and temperature characteristic an R--Fe--B based alloy is subjected to hydrogenation under pressurized hydrogen gas and to dehydrogenation. Excellent magnetic properties and stable with less variation in range can be attained in an industrial fabrication by using a plurality of divided reaction tubes. Moreover, the R--Fe--B--Co based alloy magnetic powder is constituted of an aggregate structure including, as a main phase, a recrystallized structure of an extremely fine R.sub.2 Fe.sub.14 B type phase with an average grain size of 0.05 to 3 .mu.m, and has excellent magnetic anisotropy and temperature characteristic. Additionally, a resin bonded magnet excellent in magnetic properties and temperature characteristic is fabricated by injection molding or compression molding using the above R--Fe--B--Co based alloy magnetic powder.Type: GrantFiled: August 17, 1994Date of Patent: July 1, 1997Assignee: Aichi Steel Works, Ltd.Inventors: Yoshinobu Honkura, Hironari Mitarai, Chisato Mishima, Yoshikazu Amahiro, Hiroshi Matsuoka, Yoshinobu Sugiura
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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: 5599378Abstract: Disclosed herein are spindle-shaped magnetic iron based alloy particles containing at least one selected from the group consisting of Ni, Al, Si, P, Co, Mg, B and Zn, which have a particle length of 0.05 to 0.40 .mu.m, a crystallite size of 110 to 180 .ANG., a specific surface area of 30 to 60 m.sup.2 /g, a coercive force of 1,300 to 1,700 Oe and a saturation magnetization (.sigma.s) of not less than 100 emu/g and a process for producing the same.Type: GrantFiled: May 25, 1995Date of Patent: February 4, 1997Assignee: Toda Kogyo Corp.Inventors: Akio Mishima, Tosiharu Harada, Mamoru Tanihara, Yasutaka Ota, Kenji Okinaka, Kohji Mori, Hirofumi Kawasaki, Norimichi Nagai, Katsunori Fujimoto, Yoshiro Okuda
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Patent number: 5512317Abstract: A doped magnetic iron oxide particle suitable for use in magnetic recording media, and methods of preparing the doped magnetic iron oxide particle, are disclosed. The doped magnetic iron oxide particle has the general formula:Co.sub.x Fe.sup.+2.sub.1-x Fe.sub.2.sup.+3 O.sub.4, wherein O<x.ltoreq.1,wherein essentially all of the cobalt(II) and iron(II) dopants are present in a shell surrounding a core of a magnetic iron oxide particle. The doped magnetic iron oxide particle has a narrow switching distribution, high squareness, high coercivity and high remanence.Type: GrantFiled: January 9, 1995Date of Patent: April 30, 1996Assignee: Minnesota Mining and Manufacturing CompanyInventor: Albena V. Blagev
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Patent number: 5486240Abstract: A method of making a permanent magnet wherein 1) a melt is formed having a base alloy composition comprising RE, Fe and/or Co, and B (where RE is one or more rare earth elements) and 2) TR (where TR is a transition metal selected from at least one of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, and Al) and at least one of C and N are provided in the base alloy composition melt in substantially stoichiometric amounts to form a thermodynamically stable compound (e.g. TR carbide, nitride or carbonitride). The melt is rapidly solidified in a manner to form particulates having a substantially amorphous (metallic glass) structure and a dispersion of primary TRC, TRN and/or TRC/N precipitates. The amorphous particulates are heated above the crystallization temperature of the base alloy composition to nucleate and grow a hard magnetic phase to an optimum grain size and to form secondary TRC, TRN and/or TRC/N precipitates dispersed at grain boundaries.Type: GrantFiled: April 25, 1994Date of Patent: January 23, 1996Assignee: Iowa State University Research Foundation, Inc.Inventors: R. William McCallum, Daniel J. Branagan
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Patent number: 5484628Abstract: Acicular cobalt-containing magnetic iron oxides having a high coercive force and a core/shell structure and hence low temperature dependence of the coercive force are prepared by a process in which, in a first stage, surface activation is effected by means of iron(II) and cobalt ions under alkaline conditions on the iron oxide core under an inert gas atmosphere and thereafter, in a second stage, an epitactic coating of cobalt ferrite is applied, which coating is formed oxidatively from iron (II) and cobalt (II) hydroxide, likewise under alkaline reaction conditions. The total amount of cobalt ions used for doping remains unchanged compared with the known doped iron oxides or is even smaller. In the second process stage, the achievable coercive force can be controlled by the proportion of air in the gas mixture during the formation of the epitactic coating.Type: GrantFiled: August 16, 1994Date of Patent: January 16, 1996Assignee: BASF Magnetics GmbHInventors: Ekkehard Schwab, Ronald J. Veitch, Reinhard Korner, Emil Pfannebecker, Bernd Hoppner
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Patent number: 5480471Abstract: A permanent magnet alloy and method for production thereof. The permanent magnet alloy has a rare earth element including Nd, B, Fe, C, and oxygen, with additions of Co and at least one of Cu, Ga and Ag. The alloy may be produced by contacting particles thereof with carbon- and oxygen-containing material to achieve desired carbon and oxygen contents.Type: GrantFiled: April 29, 1994Date of Patent: January 2, 1996Assignee: Crucible Materials CorporationInventors: Andrew S. Kim, Floyd E. Camp
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Patent number: 5451245Abstract: Acicular magnetic iron particles comprising acicular iron substrate particles having first layer consisting of at least one of hydrous oxides and anhydrous oxides of aluminum and zirconium and mixtures thereof and second layer consisting of hydrous oxides and anhydrous oxides of aluminum and mixtures thereof coated on the surfaces of the particles are produced by coating the surfaces of hydrated iron oxide particles as substrate with at least one of aluminum compounds and zirconium compounds, then heating the coated substrate particles to convert to hematite particles, thereafter coating the surfaces of the resultant hematite substrate particles with at least one of aluminum compounds, and then reducing under heat the coated hematite particles.Type: GrantFiled: March 4, 1994Date of Patent: September 19, 1995Assignee: Ishihara Sangyo Kaisha, Ltd.Inventors: Eiji Nomura, Toshihiko Kawamura, Kenji Hatanaka, Nariaki Moriyama
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Patent number: 5372629Abstract: Apparatus and method for making powder from a metallic melt by atomizing the melt to form droplets and reacting the droplets downstream of the atomizing location with a reactive gas. The droplets are reacted with the gas at a temperature where a solidified exterior surface is formed thereon and where a protective refractory barrier layer (reaction layer) is formed whose penetration into the droplets is limited by the presence of the solidified surface so as to avoid selective reduction of key reactive alloyants needed to achieve desired powder end use properties. The barrier layer protects the reactive powder particles from environmental constituents such as air and water in the liquid or vapor form during subsequent fabrication of the powder to end-use shapes and during use in the intended service environment.Type: GrantFiled: August 5, 1992Date of Patent: December 13, 1994Assignee: Iowa State University Research Foundation, Inc.Inventors: Iver E. Anderson, Barbara K. Lograsso, Robert L. Terpstra
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Patent number: 5366761Abstract: A method for preparing a barium-ferrite-coated, needle-shaped .gamma.-Fe.sub.2 O.sub.3 magnetic powder of better properties is provided. The method includes the following steps of a) letting an iron-containing solution undergo a reaction to precipitate a needle-shaped .alpha.-FeOOH phase powder, b) mixing said .alpha.-FeOOH powder into a barium-containing solution in a predetermined Fe/Ba ratio, c) filtering without washing the precipitated powder, and d) subjecting the precipitated powder to heat treatments including calcination, reduction and oxidation.Type: GrantFiled: June 11, 1993Date of Patent: November 22, 1994Assignee: National Science CouncilInventors: Tsung-Shune Chin, Sung-Lin Hsu, Ming-Cheng Deng
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Patent number: 5242508Abstract: A method for making an isotropic permanent magnet comprises atomizing a melt of a rare earth-transition metal alloy (e.g., an Nd--Fe--B alloy enriched in Nd and B) under conditions to produce protectively coated, rapidly solidified, generally spherical alloy particles wherein a majority of the particles are produced/size classified within a given size fraction (e.g., 5 to 40 microns diameter) exhibiting optimum as-atomized magnetic properties and subjecting the particles to concurrent elevated temperature and elevated isotropic pressure for a time effective to yield a densified, magnetically isotropic magnet compact having enhanced magnetic properties and mechanical properties.Type: GrantFiled: April 15, 1992Date of Patent: September 7, 1993Assignee: Iowa State University Research Foundation, Inc.Inventors: R. William McCallum, Kevin W. Dennis, Barbara K. Lograsso, Iver E. Anderson
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Acicular magnetic iron based alloy particles for magnetic recording and method of producing the same
Patent number: 5238483Abstract: Disclosed herein are acicular magnetic iron based alloy particles for magnetic recording, containing 1.5 to 10 mol % of B based on Fe (calculated as B) and 1.5 to 10 mol % of Co based on Fe (calculated as Co) in the vicinity of the surfaces of said particles and having a saturation magnetization of not less than 125 emu/g and an S.F.D. value of not more than 0.50, and a process for producing the same.Type: GrantFiled: July 29, 1992Date of Patent: August 24, 1993Assignee: Toda Kogyo CorporationInventors: Akio Mishima, Mamoru Tanihara, Yasutaka Ota, Hirofumi Kawasaki, Kenji Okinaka, Kunio Ikemoto, Kousaku Tamari, Kohji Mori, Norimichi Nagai -
Patent number: 5221322Abstract: Ultrafine particles of Fe-Co-P material with a Fe/Co atomic ratio of from 95/5 to 70/30 and a (Fe+Co)/P atomic ratio of from 85/15 to 60/40 show improved ferromagnetic properties. The average particle size is from 0.005 to 0.1 .mu.m. Such ultrafine particles are prepared through gas phase reaction by evaporating a source material. They are useful in both magnetic and thermomagnetic recording media ensuring high density recording.Type: GrantFiled: March 23, 1992Date of Patent: June 22, 1993Assignee: TDK CorporationInventors: Yasumichi Tokuoka, Jiro Yoshinari
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Patent number: 5185093Abstract: A magnetic metal powder, having a large specific surface are, a high coercive force, a high dispersibility and an excellent corrosion resistance, is produced by converting an aciculate goethite having a silicon and/or aluminum compound layer formed thereon or an aciculate goethite modified with a metal other than iron into magnetite, forming thereon a nonferrous transition metal compound layer, further forming thereon a silicon or aluminum compound layer, and reducing the coated magnetite to prepare a magnetic metal powder mainly composed of iron and having on the surface thereof a layer containing a nonferrous transition metal element, characterized in that the formation of the silicon and/or aluminum compound layer on the aciculate goethite and/or the formation of the nonferrous transition metal layer on the magnetite are conducted while conducting dispersion by means of a disperser.Type: GrantFiled: March 26, 1991Date of Patent: February 9, 1993Assignee: Kao CorporationInventors: Hiroaki Ichikawa, Yasuo Kadono, Katsuo Kojima, Hiroyuki Nakamura, Yoshio Aoki
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Patent number: 5183494Abstract: A process for producing rare earth-iron-boron permanent magnet alloy powders comprising; heating pellets comprising a mixture of rare earth oxides, iron power, ferroboron powder and calcium grandules for reaction/diffusion to obtain a rare earth-iron-boron alloy of uniform composition, crushing the resulting alloy to form a powder and contacting the powder with an aqueous solution of acetic acid containing a non-ionic surfactant and an alkai metal acetate.Type: GrantFiled: April 23, 1991Date of Patent: February 2, 1993Assignee: Industrial Technology Research InstiuteInventors: Ti Y. Liu, Chi J. Chen, Shou H. Chen
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Patent number: 5143542Abstract: The present invention provides a process for producing magnetic metal powder for magnetic recording using a metal compound mainly composed of a hydrous iron oxide on an iron oxide, characterized in that prior to subjecting the metal compound mainly composed of a hydrous iron oxide or an iron oxide to a reduction treatment, addition of a boron compound and a heat treatment at 350.degree.-750.degree. C. in a gas atmosphere having a water vapor partial pressure of 10 mmHg or higher are carried out. When a heat treatment at 550.degree.-900.degree. C. in a non-reducing atmosphere is carried out in combination with the above heat treatment, the effect of the present invention is further increased.Type: GrantFiled: December 20, 1990Date of Patent: September 1, 1992Assignee: Ishihara Sangyo Kaisha, Ltd.Inventors: Kokichi Miyazawa, Masatsuyo Maruo, Toshihiko Kawamura
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Patent number: 5096509Abstract: A the magnetically anisotropic magnetic powder having an average particle size of 1-1000 .mu.m and made from a magnetically anisotropic R-TM-B-Ga or R-TM-B-Ga-M alloy having an average crystal grain size of 0.01-0.5 .mu.m, wherein R represents one or more rare earth elements including Y, TM represents Fe which may be partially substituted by Co, B boron, Ga gallium, and M one or more elements selected from the group consisting of Nb, W, V, Ta, Mo, Si, Al, Zr, Hf, P, C and Zn. This is useful for anisotropic resin-bonded magnet with high magnetic properties.Type: GrantFiled: December 13, 1988Date of Patent: March 17, 1992Assignee: 501 Hitachi Metals, Ltd.Inventors: Minoru Endoh, Yasuto Nozawa, Katsunori Iwasaki, Shigeho Tanigawa, Masaaki Tokunaga
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Patent number: 5085715Abstract: A process for producing magnetically anisotropic powder having "flattened" crystal grains of an R-TM-B-M system alloy with preferably (c)/(a) greater than 2, where (c) is the grain size perpendicular to the C-axis and (a) the grain size parallel to the C-axis, includes the steps of plastically deforming a green compact of flakes formed by rapidly-quenching the alloy melt, and then crushing the plastically deformed body. In the alloy system, R is at least one of the rare earth elements including Y, TM is Fe or Fe a part of which has been substituted with Co, B is boron, and M is an additive selected from Si, Al, Nb, Zr, P and C.Type: GrantFiled: December 4, 1989Date of Patent: February 4, 1992Assignee: Hitachi Metals, Ltd.Inventors: Masatoki Tokunaga, Yasuto Nozawa, Katsunori Iwasaki
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Patent number: 5076836Abstract: A process for the preparation of ferromagnetic metallic particles for magnetic recording which comprises(I) a step of preparing a slurry of acicular iron oxide hydrate containing nickel and, if necessary, manganese,(II) a step of coating the surface of the above iron oxide hydrate with aluminum-containing iron oxide hydrate, thus giving a slurry containing the coated iron oxide hydrate and free aluminate ions,(III) a step of depositing aluminum and phosphorus and/or silicon on the outside surface of the aluminum-containing iron oxide hydrate, thereby giving a slurry of the iron oxide hydrate thus treated,(IV) a step of subjecting the slurry to washing, drying and dehydrating, reducing the obtained particles, and forming an oxide layer on the surface of the reduced particles.Type: GrantFiled: December 21, 1990Date of Patent: December 31, 1991Assignee: Mitsui Mining & Smelting Co., Ltd.Inventors: Isshi Hisaoka, Masakazu Konno, Nobuo Takagi
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Patent number: 5064465Abstract: A process for preparing by a reduction/diffusion method rare earth-iron-boron alloy powders useful in permanent magnets. The process generates rare earth-iron-boron alloy powders having large and uniform particle sizes with minimal contamination. The process entails the use of a seed alloy among the starting materials, the seed alloy having substantially the same composition as the rare earth-iron-boron alloy to be prepared.Type: GrantFiled: November 29, 1990Date of Patent: November 12, 1991Assignee: Industrial Technology Research InstituteInventors: Chi J. Chen, Cheng H. Lin, Tin Y. Liu, Ying C. Hung
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Patent number: 5028278Abstract: A ferromagnetic metal powder comprises a ferromagnetic metal particle composed mainly of iron, a silicon compound layer formed on the surface of the ferromagnetic metal particle in such an amount that the amount of silicon is 0.1 to 1% by weight based on iron in the ferromagnetic metal particle, and a layer containing a nonferrous transition metal element compound, which is formed on the silicon compound layer.Type: GrantFiled: December 20, 1989Date of Patent: July 2, 1991Assignee: KAO CorporationInventors: Yasuo Kadono, Masaaki Koga, Yoshio Aoki
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Patent number: 4994109Abstract: A method for producing permanent magnet alloy particles suitable for use in producing bonded permanent magnets. A melt or molten mass of a permanent magnet alloy having at least one rare earth element, at least one transition element, preferably iron, and boron is produced. The melt is inert gas atomized to form spherical particles within the size range of 1 to 1000 microns. The particles are heat treated in a nonoxidizing atmosphere for a time at temperature to significantly increase the intrinsic coercivity of the particles without sintering the particles to substantially full density. Thereafter, the particles are separated to produce a discrete particle mass. The particles during heat treatment may be maintained in motion to prevent sintering thereof.Type: GrantFiled: May 5, 1989Date of Patent: February 19, 1991Assignee: Crucible Materials CorporationInventors: Carol J. Willman, Edward J. Dulis, Francis S. Snyder
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Patent number: 4944801Abstract: A powder of a rare earth oxide, or a powder of a rare earth oxide and a rare earth metal is mixed with a powder containing iron, a powder containing boron and at least one material selected from among an alkali metal, an alkaline earth metal and a hydrogenated product thereof. The mixture is heated at a temperature of 900.degree. C. to 1200.degree. C. in a non-oxidizing atmosphere, subjected to wet treatment, and heated again at a temperature of 650.degree. C. to 1100.degree. C., whereby an alloy powder is obtained. Alternatively, the mixture is heated at a temperature of 900.degree. C. to 1200.degree. C., crushed into coarse particles, heated again at a temperature of 650.degree. C. to 1100.degree. C. and subjected to wet treatment. The powder is pulverized into a finer powder having an average particle diameter of 1 to 10 microns. The powder is used for making a magnet with a resin.Type: GrantFiled: July 5, 1989Date of Patent: July 31, 1990Assignee: Sumitomo Metal Mining Co. Ltd.Inventors: Takashi Ishikawa, Nobumitsu Oshimura, Kenji Ohmori
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Patent number: 4933004Abstract: Ferromagnetic metal particles of substantially iron are prepared by starting from an acicular .alpha.-FeOOH, applying a shape-stabilizing finish to the particle surface, heating at 500.degree.-850.degree. C. and subsequently reducing with gaseous reducing agents at 200.degree.-500.degree. C. to the metal, and starting .alpha.-FeOOH being prepared in the presence of zinc and phosphate ions.Type: GrantFiled: February 5, 1987Date of Patent: June 12, 1990Assignee: BASF AktiengesellschaftInventors: Klaus-Dieter Hoppe, Werner Steck, Jenoe Kovacs, Rainer Feser, Helmut Jakusch
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Patent number: RE38021Abstract: A the magnetically anisotropic magnetic powder having an average particle size of 1—1000 &mgr;m and made from a magnetically anisotropic R-TM-B-Ga or R-TM-B-Ga-M alloy having an average crystal grain size of 0.01-0.5 &mgr;m, wherein R represents one or more rare earth elements including Y, TM represents Fe which may be partially substituted by Co, B boron, Ga gallium, and M one or more elements selected from the group consisting of Nb, W, V, Ta, Mo, Si, Al, Zr, Hf, P, C and Zn. This is useful for anisotropic resin-bonded magnet with high magnetic properties.Type: GrantFiled: November 2, 2001Date of Patent: March 11, 2003Assignee: Hitachi Metals, Ltd.Inventors: Minoru Endoh, Masaaki Tokunaga