Permanent Magnet Patents (Class 148/101)
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Patent number: 9039920Abstract: There are provided a permanent magnet and a manufacturing method thereof enabling carbon content contained in magnet particles to be reduced in advance before sintering even when wet milling is employed. Coarsely-milled magnet powder is further milled by a bead mill in a solvent together with an organometallic compound expressed with a structural formula of M-(OR)X (M represents V, Mo, Zr, Ta Ti W or Nb, R represents a substituent group consisting of a straight-chain or branched-chain hydrocarbon, X represents an arbitrary integer) so as to uniformly adhere the organometallic compound to particle surfaces of the magnet powder. Thereafter, a compact body of compacted magnet powder is held for several hours in hydrogen atmosphere at 200 through 900 degrees Celsius to perform hydrogen calcination process. Thereafter, through sintering process, a permanent magnet 1 is formed.Type: GrantFiled: March 28, 2011Date of Patent: May 26, 2015Assignee: NITTO DENKO CORPORATIONInventors: Izumi Ozeki, Katsuya Kume, Keisuke Hirano, Tomohiro Omure, Keisuke Taihaku, Takashi Ozaki
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Patent number: 9028624Abstract: Provided is a NdFeB sintered magnet which can be used in the grain boundary diffusion method as a base material in which RH can be easily diffused through the rare-earth rich phase and which itself has a high coercive force, a high maximum energy product and a high squareness ratio, as well as a method for producing such a magnet. A NdFeB system sintered has an average grain size of the main-phase grains magnet is equal to or smaller than 4.5 ?m, the carbon content of the entire NdFeB system sintered magnet is equal to or lower than 1000 ppm, and the percentage of the total volume of a carbon rich phase in a rare-earth rich phase at a grain-boundary triple point in the NdFeB system sintered magnet to the total volume of the rare-earth rich phase is equal to or lower than 50%.Type: GrantFiled: December 27, 2012Date of Patent: May 12, 2015Assignee: Intermetallics Co., Ltd.Inventors: Masato Sagawa, Tetsuhiko Mizoguchi
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Patent number: 9005374Abstract: There are provided a permanent magnet and a manufacturing method thereof capable of decreasing an activity level of a calcined body activated by a calcination process. To fine powder of milled neodymium magnet is added an organometallic compound solution containing an organometallic compound expressed with a structural formula of M-(OR)x (M represents V, Mo, Zr, Ta, Ti, W or Nb, R represents a substituent group consisting of a straight-chain or branched-chain hydrocarbon, x represents an arbitrary integer) so as to uniformly adhere the organometallic compound to particle surfaces of the neodymium magnet powder. Thereafter, desiccated magnet powder is held for several hours in hydrogen atmosphere at 200 through 900 degrees Celsius. Thereafter, the powdery calcined body calcined through the calcination process in hydrogen is held for several hours in vacuum atmosphere at 200 through 600 degrees Celsius for a dehydrogenation process.Type: GrantFiled: March 28, 2011Date of Patent: April 14, 2015Assignee: Nitto Denko CorporationInventors: Izumi Ozeki, Katsuya Kume, Keisuke Hirano, Tomohiro Omure, Keisuke Taihaku, Takashi Ozaki
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Publication number: 20150093285Abstract: The present invention relates to a magnetic material, which contains at least one transition metal (TM), at least one rare earth metal (RE) and tungsten, wherein the proportion of transition metal (TM) is 60 to 90% by mass, the proportion of rare earth metal (RE) is 10 to 20% by mass, and the proportion of tungsten (W) is 5 to 25% by mass, in each case in relation to the total mass of the magnetic material.Type: ApplicationFiled: April 19, 2013Publication date: April 2, 2015Inventors: Stefan Hinderberger, Christian Wegierski, Peter Barth, Gerhard Schneider, Arne Huber, Juergen Oberle, Dagmar Goll, Friederike Koeppen, Lars Bommer, Roland Stein, Markus Raith, Alberto Martinez-Limia, Roman Karimi, Ingrid Wuehrl, T-akashi Shigematsu
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Patent number: 8974608Abstract: A powder magnetic core with improved high frequency magnetic characteristics and reduced eddy current loss is manufactured by a manufacturing method including the steps of (a) providing coated soft magnetic particles which are particles composed of soft magnetic material which each have been coated with an insulating coating, and insulator particles; (b) forming a magnetic layer by press molding the coated soft magnetic particles in a mold assembly; (c) forming an insulator layer on the magnetic layer by press molding the insulator particles in the mold assembly; and (d) repeating the steps (b) and (c) to fabricate a laminate of alternating magnetic layers and insulator layers and provide the powder magnetic core.Type: GrantFiled: April 16, 2008Date of Patent: March 10, 2015Assignee: Fuji Electric Co., Ltd.Inventors: Takayuki Hirose, Masaharu Edo, Akira Sato
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Patent number: 8961868Abstract: In a nanocomposite bulk magnet according to the present invention, nanocomposite magnet powder particles, including an Nd2Fe14B crystalline phase and an ?-Fe phase, are combined together. The composition of the magnet is represented by T100-x-y-z-n(B1-qCq)xRyTizMn, where T is at least one transition metal element selected from the group consisting of Fe, Co and Ni and always including Fe, R is at least one rare-earth element including substantially no La or Ce, M is an additive metallic element, and x, y, z, n and q satisfy 4 at %?x?10 at %, 6 at %?y?10 at %, 0.05 at %?z?5 at %, 0 at %?n?10 at %, and 0?q?0.5, respectively. The powder particles have a minor-axis size of less than 40 ?m. And powder particles, of which the major-axis size exceeds 53 ?m, account for at least 90 mass % of the entire magnet. And those powder particles are directly combined with each other. Consequently, a full-dense magnet, of which the density is 96% or more of the true density of its material alloy, is realized.Type: GrantFiled: March 30, 2010Date of Patent: February 24, 2015Assignee: Hitachi Metals, Ltd.Inventor: Toshio Miyoshi
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Patent number: 8945318Abstract: In an R—Fe—B based rare-earth sintered magnet according to the present invention, at a depth of 20 ?m under the surface of its magnet body, crystal grains of an R2Fe14B type compound have an (RL1-xRHx)2Fe14B (where 0.2?x?0.75) layer with a thickness of 1 nm to 2 ?m in their outer periphery. In this case, the light rare-earth element RL is at least one of Nd and Pr, and the heavy rare-earth element RH is at least one element selected from the group consisting of Dy, Ho and Tb.Type: GrantFiled: April 26, 2012Date of Patent: February 3, 2015Assignee: Hitachi Metals, Ltd.Inventors: Koshi Yoshimura, Hideyuki Morimoto, Tomoori Odaka
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Publication number: 20140328712Abstract: A vacuum heat treatment method for NdFeB rare earth permanent magnetic devices and an equipment thereof are disclosed. A rotary vacuum heat treatment equipment is for processing the NdFeB rare earth permanent magnetic devices with a vacuum heat treatment and obviously improves magnetic performance of the NdFeB rare earth permanent magnetic device, especially coercivity, which facilitates reducing a usage of heavy rare earth elements and protecting rare earth resources. Thus the vacuum heat treatment method and the equipment thereof are able to manufacture high-performance rare earth permanent magnetic devices.Type: ApplicationFiled: September 11, 2013Publication date: November 6, 2014Applicant: China North Magnetic & Electronic Technology Co., LTDInventor: Haotian Sun
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Publication number: 20140299810Abstract: A permanent magnet may include a Fe16N2 phase constitution.Type: ApplicationFiled: August 17, 2012Publication date: October 9, 2014Applicant: REGENTS OF THE UNIVERSITY OF MINNESOTAInventors: Jian-Ping Wang, Shihai He, Yanfeng Jiang
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Patent number: 8845821Abstract: A sintered R—Fe—B based rare-earth magnet body 1 including, as a main phase, crystal grains of an R2Fe14B type compound that includes a light rare-earth element RL, which is Nd and/or Pr, as a major rare-earth element R is provided. A bulk body 2 including a heavy rare-earth element RH, which is at least one of Dy, Ho and Tb is also provided. The sintered magnet body 1 and the bulk body 2 are arranged in a processing chamber 4 with a vapor control member 3 interposed between the sintered magnet body 1 and the bulk body 2. And the inside of the processing chamber 4 is heated to a temperature of 700° C. to 1000° C., thereby diffusing the heavy rare-earth element RH inside the sintered magnet body 1 while supplying the heavy rare-earth element RH from the bulk body 2 to the surface of the sintered magnet body 1 via the vapor control member 3.Type: GrantFiled: July 8, 2010Date of Patent: September 30, 2014Assignee: Hitachi Metals, Ltd.Inventors: Tomoori Odaka, Hideyuki Morimoto
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Patent number: 8821650Abstract: A process for mechanically strengthening a permanent magnet includes providing nanofibers or nanotubes, providing a ferromagnetic metal, defining a mixture by mixing the ferromagnetic metal with the nanofibers or nanotubes and sintering the mixture.Type: GrantFiled: August 4, 2009Date of Patent: September 2, 2014Assignee: The Boeing CompanyInventor: Michael Strasik
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Patent number: 8821649Abstract: Characteristics of a magnetic material are improved without using a heavy rare earth element as a scarce resource. By incorporating fluorine into a magnetic powder and controlling the crystal orientation in crystal grains, a magnetic material securing magnetic characteristics such as coercive force and residual flux density can be fabricated. As a result, the resource problem with heavy rare earth elements can be solved, and the magnetic material can be applied to magnetic circuits that require a high energy product, including various rotating machines and voice coil motors of hard discs.Type: GrantFiled: February 17, 2011Date of Patent: September 2, 2014Assignee: Hitachi, Ltd.Inventors: Takayuki Kanda, Matahiro Komuro, Hiroyuki Suzuki, Yuichi Satsu
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Patent number: 8801870Abstract: The objective of the present invention is to provide a method for making a NdFeB sintered magnet, capable of enhancing the effect of increasing the coercive force and preventing the instability of the effects, and in addition, being inexpensive. The method for making a NdFeB sintered magnet according to the present invention has processes of coating a NdFeB sintered magnet with a powder containing Dy and/or Tb, then heating the NdFeB sintered magnet, and thereby diffusing Rh in the powder into the NdFeB sintered magnet through a grain boundary, and is characterized in that the powder contains 0.5 through 50 weight percent of Al in a metallic state; and the amount of oxygen contained in the NdFeB sintered magnet is equal to or less than 0.4 weight percent.Type: GrantFiled: April 21, 2008Date of Patent: August 12, 2014Assignee: Intermetallics Co., Ltd.Inventor: Masato Sagawa
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Publication number: 20140210581Abstract: The invention provides rare earth-free permanent magnetic materials and methods of making them. The materials can be used to produce magnetic structures for use in a wide variety of commercial applications, such as motors, generators, and other electromechanical and electronic devices. Magnets fabricated using the materials can be substituted for magnets requiring rare earth elements that are costly and in limited supply. The invention provides two different types of magnetic materials. The first type is based on an iron-nickel alloy that is doped with one or more doping elements to promote the formation of L10 crystal structure. The second type is a nanocomposite particle containing magnetically hard and soft phases that interact to form an exchange spring magnetic material. The hard phase contains Fe or FeCo, and the soft phase contains AlMnC.Type: ApplicationFiled: July 16, 2012Publication date: July 31, 2014Inventors: Laura H. Lewis, Jeffrey E. Shield, Katayun Barmak
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Patent number: 8641833Abstract: An object of the present invention is to provide an R—Fe—B based sintered magnet having on a surface thereof a chemical conversion film with higher corrosion resistance than a conventional chemical conversion film such as a phosphate film, and a method for producing the same. The corrosion-resistant magnet of the present invention as a means for achieving the object is characterized by comprising a chemical conversion film containing at least Zr, Nd, fluorine, and oxygen as constituent elements and not containing phosphorus directly on a surface of an R—Fe—B based sintered magnet, wherein R is a rare-earth element including at least Nd.Type: GrantFiled: June 30, 2009Date of Patent: February 4, 2014Assignee: Hitachi Metals, Ltd.Inventors: Toshinobu Niinae, Koshi Yoshimura, Koji Kamiyama
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Patent number: 8641832Abstract: An objective of the present invention is to provide a method for producing a rare earth metal-based permanent magnet having an Al film containing Mg, which exhibits an excellent salt water resistance. The present invention, which is to accomplish the objective, is a method for producing a rare earth metal-based permanent magnet having formed on the surface thereof an Al film containing Mg by a vapor deposition, characterized in that the production method comprises, in the case of cooling the magnet from a high temperature of 160° C. or higher after the completion of the vapor deposition step inside the treating chamber of a deposition apparatus, rapidly cooling down the magnet at a cooling rate of 10° C./min or higher until the temperature of the magnet reaches at least 60° C.Type: GrantFiled: March 30, 2007Date of Patent: February 4, 2014Assignee: Hitachi Metals, Ltd.Inventors: Atsushi Kikugawa, Shinichiro Sakashita
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Publication number: 20140007980Abstract: In permanent magnets formed by division, a cut-out part is provided in a straight line in the matrix of the permanent magnets, a metal having a higher coercive force than the permanent magnet matrix is diffused into the interior of the matrix from a surface that includes the surface of the cut-out part of the permanent magnet matrix, and the permanent magnet matrix is divided into multiple permanent magnet parts along the straight cut-out part to form the permanent magnets. An Nd—Fe—B sintered magnet may be used as the permanent magnet matrix, and, dysprosium (Dy) may be used as the metal having a higher coercive force. Multiple indentations disposed in a straight line may be used as the cut-out parts, or a straight groove may also be used.Type: ApplicationFiled: June 27, 2013Publication date: January 9, 2014Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventor: Makoto KITAHARA
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Patent number: 8572830Abstract: A method and apparatus for producing a magnetic attachment mechanism is described. A method is provided for determining the magnetic field axis of an element prior to machining it. The magnetic field axis can be used as a reference to machine an outer surface of the magnetic element at a desired angle. The method provides a means to more precisely align magnetic field axes of corresponding magnets in a magnetic attachment system.Type: GrantFiled: August 11, 2011Date of Patent: November 5, 2013Assignee: Apple Inc.Inventor: Cesare A. Tolentino
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Patent number: 8562756Abstract: The present invention is aimed at providing a method for producing an NdFeB sintered magnet having a higher coercivity and higher squareness of the magnetization curve than ever before. A method for producing an NdFeB sintered magnet according to the present invention includes the steps of forming a layer containing Dy and/or Tb on the surface of an NdFeB sintered magnet base material and then performing a grain boundary diffusion process for diffusing Dy and/or Tb from the aforementioned layer through the crystal grain boundaries of the magnet base material into the magnet base material by heating the magnet base material to a temperature equal to or lower than the sintering temperature thereof, and this method is characterized in that a) the content of a rare earth in a metallic state in the magnet base material is equal to or higher than 12.Type: GrantFiled: January 9, 2009Date of Patent: October 22, 2013Assignee: Intermetallics Co., Ltd.Inventors: Masato Sagawa, Naoki Fujimoto
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Patent number: 8557057Abstract: A rare earth permanent magnet is prepared by disposing a powdered metal alloy containing at least 70 vol % of an intermetallic compound phase on a sintered body of R—Fe—B system, and heating the sintered body having the powder disposed on its surface below the sintering temperature of the sintered body in vacuum or in an inert gas for diffusion treatment. The advantages include efficient productivity, excellent magnetic performance, a minimal or zero amount of Tb or Dy used, an increased coercive force, and a minimized decline of remanence.Type: GrantFiled: October 27, 2010Date of Patent: October 15, 2013Assignee: Shin-Etsu Chemical Co., Ltd.Inventors: Hiroaki Nagata, Tadao Nomura, Takehisa Minowa
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Patent number: 8524013Abstract: There are provided a permanent magnet and a manufacturing method thereof capable of manufacturing metal alkoxide in better work environment, simpler production facilities and easier manufacturing process and also reducing the manufacturing costs. An electrolytic solution is obtained through dissolving chloride or injecting hydrogen chloride gas into alcohol which is same alcohol as is a constituent element of metal alkoxide to be manufactured. Then, electrolysis is performed on the electrolytic solution while using, for an anode, a ferroalloy that contains iron and metal which is a constituent element of the metal alkoxide to be manufactured in a predetermined weight ratio (such as 1:1), and, for a cathode, the same ferroalloy, carbon, platinum or stainless steel, so as to obtain an alcohol solution of the metal alkoxide. Then, a permanent magnet is manufactured using the alcohol solution of the metal alkoxide thus obtained.Type: GrantFiled: April 28, 2011Date of Patent: September 3, 2013Assignee: Nitto Denko CorporationInventors: Keisuke Taihaku, Katsuya Kume, Izumi Ozeki, Tomohiro Omure
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Patent number: 8518194Abstract: A magnetic article comprises, in total, elements in amounts capable of providing at least one (La1-aMa)(Fe1-b-cTbYc)13-dXe phase and less than 0.5 Vol % impurities, wherein 0?a?0.9, 0?b?0.2, 0.05?c?0.2, ?1?d?+1, 0?e?3, M is one or more of the elements Ce, Pr and Nd, T is one or more of the elements Co, Ni, Mn and Cr, Y is one or more of the elements Si, Al, As, Ga, Ge, Sn and Sb and X is one or more of the elements H, B, C, N, Li and Be. The magnetic article comprises a permanent magnet.Type: GrantFiled: September 30, 2009Date of Patent: August 27, 2013Assignee: Vacuumschmelze GmbH & Co. KGInventors: Matthias Katter, Joachim Gerster, Ottmar Roth
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Patent number: 8500922Abstract: The present invention relates to a permanent magnet manufactured by steps of: pulverizing a magnet raw material into fine particles having a grain size of 3 ?m or less; mixing the pulverized magnet raw material with a rust preventive oil in which a high-melting metal element-containing organic compound or a precursor of a high-melting ceramic is dissolved, thereby preparing a slurry; compression molding the slurry to form a molded body; and sintering the molded body.Type: GrantFiled: April 14, 2009Date of Patent: August 6, 2013Assignee: Nitto Denko CorporationInventors: Izumi Ozeki, Katsuya Kume, Junichi Nakayama, Yuuki Fukuda, Toshinobu Hoshino, Tomokazu Horio
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Patent number: 8500920Abstract: There are provided a permanent magnet and a manufacturing method thereof capable of densely sintering the entirety of the magnet without making a gap between a main phase and a grain boundary phase in the sintered magnet. To fine powder of milled neodymium magnet is added an organometallic compound solution containing an organometallic compound expressed with a structural formula of M-(OR)X (M represents V, Mo, Zr, Ta, Ti, W or Nb, R represents a substituent group consisting of a straight-chain or branched-chain hydrocarbon, X represents an arbitrary integer) so as to uniformly adhere the organometallic compound to particle surfaces of the neodymium magnet powder. Thereafter, a compact body formed through powder compaction is held for several hours in hydrogen atmosphere at 200 through 900 degrees Celsius. Thereafter, through sintering process, a permanent magnet is manufactured.Type: GrantFiled: March 28, 2011Date of Patent: August 6, 2013Assignee: Nitto Denko CorporationInventors: Izumi Ozeki, Katsuya Kume, Keisuke Hirano, Tomohiro Omure, Keisuke Taihaku, Takashi Ozaki
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Patent number: 8500921Abstract: There are provided a permanent magnet and a manufacturing method thereof capable of densely sintering the entirety of the magnet without making a gap between a main phase and a grain boundary phase in the sintered magnet. To fine powder of milled neodymium magnet is added an organometallic compound solution containing an organometallic compound expressed with a structural formula of M-(OR)x (M represents V, Mo, Zr, Ta, Ti, W or Nb, R represents a substituent group consisting of a straight-chain or branched-chain hydrocarbon, x represents an arbitrary integer) so as to uniformly adhere the organometallic compound to particle surfaces of the neodymium magnet powder. Thereafter, desiccated magnet powder is held for several hours in hydrogen atmosphere at 200 through 900 degrees Celsius. Thereafter, the powdery calcined body calcined through the calcination process in hydrogen is held for several hours in vacuum atmosphere at 200 through 600 degrees Celsius for a dehydrogenation process.Type: GrantFiled: March 28, 2011Date of Patent: August 6, 2013Assignee: Nitto Denko CorporationInventors: Izumi Ozeki, Katsuya Kume, Keisuke Hirano, Tomohiro Omure, Keisuke Taihaku, Takashi Ozaki
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Patent number: 8491728Abstract: There are provided a permanent magnet and a manufacturing method thereof that enables concentration of V, Mo, Zr, Ta, Ti, W or Nb contained in an organometallic compound in grain boundaries of the permanent magnet. To fine powder of milled neodymium magnet is added an organometallic compound solution containing an organometallic compound expressed with a structural formula of M-(OR)x (M represents V, Mo, Zr, Ta, Ti, W or Nb, R represents a substituent group consisting of a straight-chain or branched-chain hydrocarbon, x represents an arbitrary integer) so as to uniformly adhere the organometallic compound to particle surfaces of the neodymium magnet powder. Thereafter, a compact body obtained by compacting the magnet powder is held for several hours in hydrogen atmosphere at 200 through 900 degrees Celsius so as to perform a calcination process in hydrogen. Thereafter, through sintering, a permanent magnet is manufactured.Type: GrantFiled: March 28, 2011Date of Patent: July 23, 2013Assignee: Nitto Denko CorporationInventors: Izumi Ozeki, Katsuya Kume, Keisuke Hirano, Tomohiro Omure, Keisuke Taihaku, Takashi Ozaki
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Patent number: 8480815Abstract: A method of making a permanent magnet is described. In one embodiment, the method includes providing a first alloy powder having a desired composition, the alloy powder containing neodymium, iron, and boron; coating the first alloy powder with dysprosium, dysprosium alloy, terbium, or terbium alloy so that the first alloy powder has a surface concentration of dysprosium, terbium, or both in excess of a bulk concentration of dysprosium, terbium, or both; and forming the permanent magnet from the coated alloy powder using a powder metallurgy process, the permanent magnet having a non-uniform distribution of dysprosium, terbium, or both therein. Permanent magnets are also described.Type: GrantFiled: January 14, 2011Date of Patent: July 9, 2013Assignee: GM Global Technology Operations LLCInventor: Yucong Wang
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Patent number: 8480816Abstract: There are provided a permanent magnet and a manufacturing method thereof capable of preventing degrade in the magnetic properties by densely sintering the entirety of the magnet. To fine powder of milled neodymium magnet is added an organometallic compound solution containing an organometallic compound expressed with a structural formula of M-(OR)X (M represents Dy or Tb, R represents a substituent group consisting of a straight-chain or branched-chain hydrocarbon, X represents an arbitrary integer) so as to uniformly adhere the organometallic compound to particle surfaces of the neodymium magnet powder. Thereafter, the desiccated magnet powder is calcined by utilizing plasma heating and the powdery calcined body is sintered so as to form a permanent magnet 1.Type: GrantFiled: March 28, 2011Date of Patent: July 9, 2013Assignee: Nitto Denko CorporationInventors: Izumi Ozeki, Katsuya Kume, Keisuke Hirano, Tomohiro Omure, Keisuke Taihaku, Takashi Ozaki
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Patent number: 8480818Abstract: There are provided a permanent magnet and a manufacturing method thereof capable of preventing grain growth in a main phase and enabling rare-earth rich phase to be uniformly dispersed. To fine powder of milled neodymium magnet material is added an organometallic compound solution containing an organometallic compound expressed with a structural formula of M-(OR)x (in the formula, M represents Cu or Al, R represents a substituent group consisting of a straight-chain or branched-chain hydrocarbon, x represents an arbitrary integer) so as to uniformly adhere the organometallic compound to particle surfaces of the neodymium magnet powder. Thereafter, a compact body formed by compacting the above neodymium magnet powder is held for several hours in hydrogen atmosphere at 200 through 900 degrees Celsius. Thereafter, through a sintering process, a permanent magnet is manufactured.Type: GrantFiled: March 28, 2011Date of Patent: July 9, 2013Assignee: Nitto Denko CorporationInventors: Izumi Ozeki, Katsuya Kume, Keisuke Hirano, Tomohiro Omure, Keisuke Taihaku, Takashi Ozaki
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Publication number: 20130160896Abstract: Useful permanent magnet materials are formed by processing molten alloys of cerium, iron, and boron to form permanent magnet compositions with appreciable coercivity and remanence. For example, Ce16.7Fe77.8B5.6 has been produced with coercivity, Hci of 6.18 kOe and remanence, Br of 4.92 kG. In a preferred practice, streams of the molten alloy are rapidly quenched (e.g., by melt spinning) to form magnetically-soft melt-spun material which is suitably annealed to obtain permanent magnet properties. Cobalt may be substituted for a portion of the iron content to increase the Curie temperature of the permanent magnet material. The rapid quench-anneal process is conducted to produce a fine-grain crystalline microstructure containing the Ce2(Fe,Co)14B phase in an amount of about seventy to ninety-five mass percent of the composition with a suitable amount of one or more secondary phases.Type: ApplicationFiled: February 22, 2013Publication date: June 27, 2013Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLCInventor: GM GLOBAL TECHNOLOGY OPERATIONS LLC
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Patent number: 8425695Abstract: A rare earth sintered magnet includes a main phase that includes an R2T14B phase of crystal grain where R is one or more rare earth elements including Nd, T is one or more transition metal elements including Fe or Fe and Co, and B is B or B and C; a grain boundary phase in which a content of R is larger than a content of the R2T14B phase; and a grain boundary triple point that is surrounded by three or more main phases. The grain boundary triple point includes an R75 phase containing R of 60 at % to 90 at %, Co, and Cu. The relational expression 0.05?(Co+Cu)/R<0.5 is satisfied. An area where a Co-rich region overlaps with a Cu-rich region in a cross-sectional area of the grain boundary triple point is 60% or more.Type: GrantFiled: July 8, 2011Date of Patent: April 23, 2013Assignee: TDK CorporationInventors: Takuma Hayakawa, Ryouta Kunieda
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Patent number: 8421292Abstract: A permanent magnet motor includes: a rotor and a stator; and a plurality of permanent magnets placed on either the rotor or the stator. Each permanent magnet is an R—Fe—B based rare-earth sintered magnet including a light rare-earth element RL (at least one of Nd and Pr) as a major rare-earth element R, and partially includes a high coercivity portion in which a heavy rare-earth element RH (at least one element selected from the group consisting of Dy, Ho and Tb) is diffused in a relatively higher concentration than in the other portion.Type: GrantFiled: March 25, 2008Date of Patent: April 16, 2013Assignee: Hitachi Metals, Ltd.Inventors: Mitsutoshi Natsumeda, Yoshinori Takayama, Motoharu Shimizu
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Patent number: 8420010Abstract: A method for preparing a rare earth permanent magnet material is characterized by comprising the steps of disposing a powder mixture on a surface of a sintered magnet body of R1—Fe—B composition wherein R1 is at least one element selected from rare earth elements inclusive of Sc and Y, the powder mixture comprising a powder containing at least 0.5% by weight of M which is at least one element selected from Al, Cu, and Zn and having an average particle size equal to or less than 300 ?m and a powder containing at least 30% by weight of a fluoride of R2 which is at least one element selected from rare earth elements inclusive of Sc and Y and having an average particle size equal to or less than 100 ?m, and heat treating the magnet body having the powder disposed on its surface at a temperature equal to or below the sintering temperature of the magnet body in vacuum or in an inert gas, for causing at least one of M and R2 in the powder mixture to be absorbed in the magnet body.Type: GrantFiled: March 28, 2007Date of Patent: April 16, 2013Assignee: Shin-Etsu Chemical Co., Ltd.Inventors: Hajime Nakamura, Takehisa Minowa, Koichi Hirota
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Publication number: 20130087248Abstract: A method for producing a sintered R-T-B based magnet includes the steps of: providing a sintered R-T-B based magnet body 1; providing an RH diffusion source including a heavy rare-earth element RH (which is at least one of Dy and Tb) and 30 mass % to 80 mass % of Fe; loading the sintered R-T-B based magnet body 1 and the RH diffusion source 2 into a processing chamber 3 so that the magnet body 1 and the diffusion source 2 are movable relative to each other and are readily brought close to, or in contact with, each other; and performing an RH diffusion process in which the sintered magnet body 1 and the RH diffusion source 2 are heated to a processing temperature of more than 850° C. through 1000° C. while being moved either continuously or discontinuously in the processing chamber.Type: ApplicationFiled: July 12, 2011Publication date: April 11, 2013Inventor: Futoshi Kuniyoshi
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Patent number: 8414709Abstract: The present invention is aimed at providing a method for producing an NdFeB sintered magnet having a higher coercivity and higher squareness of the magnetization curve than ever before. A method for producing an NdFeB sintered magnet according to the present invention includes the steps of forming a layer containing Dy and/or Tb on the surface of an NdFeB sintered magnet base material and then performing a grain boundary diffusion process for diffusing Dy and/or Tb from the aforementioned layer through the crystal grain boundaries of the magnet base material into the magnet base material by heating the magnet base material to a temperature equal to or lower than the sintering temperature thereof, and this method is characterized in that a) the content of a rare earth in a metallic state in the magnet base material is equal to or higher than 12.Type: GrantFiled: January 9, 2009Date of Patent: April 9, 2013Assignee: Intermetallics Co., Ltd.Inventors: Masato Sagawa, Naoki Fujimoto
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Patent number: 8388766Abstract: An anisotropic rare earth sintered magnet has a tetragonal R2Fe14B compound as a major magnetic phase, wherein R is Nd or a mixture of Nd with at least one rare earth element. Grains of the compound phase have two crystallographic axes, c and a-axes aligned. The biaxially aligned magnet exhibits a coercivity Hc of at least 1.6 MA/m.Type: GrantFiled: October 24, 2011Date of Patent: March 5, 2013Assignee: Shin-Etsu Chemical Co., Ltd.Inventor: Ken Ohashi
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Patent number: 8388769Abstract: To mold a high-resistance magnet at low temperature, including room temperature, the magnet includes magnetic powders, metallic powders having a lower hardness than the magnetic powders and a high-resistance layer, wherein the magnetic powders occupy a larger volume than the metallic powders. In particular, the high-resistance layer contains a fluorine compound and is placed between the magnetic powder and the metallic powders.Type: GrantFiled: December 19, 2006Date of Patent: March 5, 2013Assignee: Hitachi, Ltd.Inventors: Matahiro Komuro, Yuichi Satsu, Takashi Yasuhara
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Patent number: 8377233Abstract: A method for preparing a rare earth permanent magnet material comprises the steps of: disposing a powder comprising one or more members selected from an oxide of R2, a fluoride of R3, and an oxyfluoride of R4 wherein R2, R3 and R4 each are one or more elements selected from among rare earth elements inclusive of Y and Sc on a sintered magnet form of a R1—Fe—B composition wherein R1 is one or more elements selected from among rare earth elements inclusive of Y and Sc, and then heat treating the magnet form and the powder at a temperature equal to or below the sintering temperature of the magnet in vacuum or in an inert gas. The result high performance, compact or thin permanent magnet has a high remanence and coercivity at a high productivity.Type: GrantFiled: February 24, 2011Date of Patent: February 19, 2013Assignee: Shin-Etsu Chemical Co., Ltd.Inventors: Hajime Nakamura, Koichi Hirota, Takehisa Minowa
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Patent number: 8371021Abstract: A process of manufacturing segments, an anisotropic direction of which is continuously changed in a plane vertically by a uniform magnetic field maintained in a constant direction and a process of arranging a plurality of segments on a circumference, extruding the segments in a ring shape by rheology based on the viscous deformation of the segments, from one thrust-direction end surface of the segments, and subsequently compressing the segments from both thrust-direction end surfaces of the segments are necessarily included. A ring magnet, anisotropy of which is controlled in a continuous direction, is provided, and a source for generating a static magnetic field has energy density (BH) max?160 to 180 kJ/m3.Type: GrantFiled: May 20, 2009Date of Patent: February 12, 2013Assignee: Panasonic CorporationInventors: Fumitoshi Yamashita, Kiyomi Kawamura, Yukihiro Okada, Hiroshi Murakami
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Patent number: 8361242Abstract: A powder consists essentially by weight, of 28.00?R?32.00%, where R is at least one rare earth element including Y and the sum of Dy+Tb>0.5, 0.50?B?2.00%, 0.50?Co?3.50%, 0.050?M?0.5%, where M is one or more of the elements Ga, Cu and Al, 0.25 wt %<O?0.5%, 0.15% or less of C, balance Fe.Type: GrantFiled: March 24, 2011Date of Patent: January 29, 2013Assignee: Vacuumschmeize GmbH & Co. KGInventors: Rolf Blank, Matthias Katter, Werner Rodewald, Boris Wall
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Patent number: 8333848Abstract: The present invention relates to a permanent magnet manufactured by steps of: wet-pulverizing a high-melting metal element-containing organic compound or a precursor of a high-melting ceramic in a solvent together with a magnet raw material to pulverize the magnet raw material into fine particles having a grain size of 3 ?m or less and to coat a surface of the pulverized magnet raw material with the high-melting metal element-containing organic compound or the precursor of the high-melting ceramic; adding a resin binder to the magnet raw material coated with the high-melting metal element-containing organic compound or the precursor of the high-melting ceramic; producing a slurry by kneading the magnet raw material and the resin binder; molding the slurry into a sheet form to prepare a green sheet; and sintering the green sheet.Type: GrantFiled: April 14, 2009Date of Patent: December 18, 2012Assignee: Nitto Denko CorporationInventors: Izumi Ozeki, Katsuya Kume, Junichi Nakayama, Yuuki Fukuda, Toshinobu Hoshino, Tomokazu Horio
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Patent number: 8328954Abstract: Crystal fractured surfaces of raw meal powder having more equal crystal orientation relationship in the magnetic field are arranged to be assembled together so that a method of manufacturing a permanent magnet which has an extremely high degree of orientation can be provided. In this invention, raw meal powder (P) is filled into a cavity, the raw meal powder (P) is oriented in the magnetic field while being pressed or urged by pressing means that has a smaller area than the cross-sectional area of the cavity. Semi-finished product thus oriented is compression-molded into a predetermined shape in the magnetic field.Type: GrantFiled: December 25, 2008Date of Patent: December 11, 2012Assignee: Ulvac, Inc.Inventors: Hiroshi Nagata, Yoshinori Shingaki
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Patent number: 8317937Abstract: In order to make a sintered R-T-B-M magnet so that R2T14B phases that include a lot of Dy in the surface region of the main phase are distributed over the entire magnet, a region including a heavy rare-earth element RH at a high concentration is formed continuously beforehand at an interface between the crystals of an R2T14B compound that is the main phase of the sintered R-T-B-M magnet and the other phases.Type: GrantFiled: March 29, 2010Date of Patent: November 27, 2012Assignee: Hitachi Metals, Ltd.Inventor: Futoshi Kuniyoshi
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Publication number: 20120285583Abstract: Useful permanent magnet materials are formed by processing molten alloys of cerium, iron, and boron to form permanent magnet compositions with appreciable coercivity and remanence. For example, Ce16.7Fe77.8B5.6 has been produced with coercivity, Hci of 6.18 kOe and remanence, Br of 4.92 kG. In one practice, streams of the molten alloy are rapidly quenched (e.g., by melt spinning) to form magnetically-soft melt-spun material which is suitably annealed to obtain permanent magnet properties. In another practice, the streams of molten alloy are quenched at a predetermined quench rate to directly obtain permanent magnet properties in the cerium-iron-boron material.Type: ApplicationFiled: February 7, 2012Publication date: November 15, 2012Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLCInventors: Martin S. Meyer, Jan F. Herbst, Frederick E. Pinkerton
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Patent number: 8303732Abstract: A rare earth magnet having a composition represented by RTB wherein R denotes a rare earth element, T a transition metal and B boron, the magnet being composed of magnet powder constituted by crystalline particles. The particles of the magnetic powder have a ratio of a short diameter being 10 ?m or more to a long diameter is 0.5 or less. An element Rm having a magnetic anisotropy higher than that of the rare earth element is contained in the surface and inside of the magnet constituted by the magnet powder in an approximately constant concentration. An oxy-fluoride and carbon are present at boundaries of the particles of the magnet powder.Type: GrantFiled: January 29, 2010Date of Patent: November 6, 2012Assignee: Hitachi, Ltd.Inventors: Hiroyuki Suzuki, Takao Imagawa, Yuichi Satsu, Matahiro Komuro
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Patent number: 8287661Abstract: A method for producing a sintered R-T-B based magnet includes the steps of: providing R-T-B based alloy powders A and B so that the R-T-B based alloy powder B has a particle size D50 that is smaller by at least 1.0 ?m than that of the R-T-B based alloy powder A and that there is a difference ?RH of at least 4 mass % between the higher content of a heavy rare-earth element RH in the R-T-B based alloy powder B and the lower content of the heavy rare-earth element RH in the R-T-B based alloy powder A; mixing these two R-T-B based alloy powders A and B together; compacting the mixed R-T-B based alloy powder to obtain a compact with a predetermined shape; and sintering the compact.Type: GrantFiled: January 14, 2010Date of Patent: October 16, 2012Assignee: Hitachi Metals, Ltd.Inventors: Rintaro Ishii, Futoshi Kuniyoshi
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Patent number: 8277578Abstract: A rare earth permanent magnet is prepared by disposing a powdered metal alloy containing at least 70 vol % of an intermetallic compound phase on a sintered body of R—Fe—B system, and heating the sintered body having the powder disposed on its surface below the sintering temperature of the sintered body in vacuum or in an inert gas for diffusion treatment. The advantages include efficient productivity, excellent magnetic performance, a minimal or zero amount of Tb or Dy used, an increased coercive force, and a minimized decline of remanence.Type: GrantFiled: October 27, 2010Date of Patent: October 2, 2012Assignee: Shin-Etsu Chemical Co., Ltd.Inventors: Hiroaki Nagata, Tadao Nomura, Takehisa Minowa
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Patent number: 8268093Abstract: An R—Fe—B based porous magnet according to the present invention has an aggregate structure of Nd2Fe14B type crystalline phases with an average grain size of 0.1 ?m to 1 ?m. At least a portion of the magnet is porous and has micropores with a major axis of 1 ?m to 20 ?m.Type: GrantFiled: May 18, 2007Date of Patent: September 18, 2012Assignee: Hitachi Metals, Ltd.Inventors: Takeshi Nishiuchi, Noriyuki Nozawa, Satoshi Hirosawa, Tomohito Maki, Katsunori Bekki
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Patent number: 8262808Abstract: There is provided a method of manufacturing a permanent magnet which has an extremely high coercive force and high magnetic properties is manufactured at high productivity. There are executed: a first step of causing at least one of Dy and Tb to adhere to at least part of a surface of iron-boron-rare-earth based sintered magnet; and a second step of diffusing, through heat-treatment at a predetermined temperature, at least one of Dy and Tb adhered to the surface of the sintered magnet into grain boundary phase of the sintered magnet.Type: GrantFiled: December 19, 2007Date of Patent: September 11, 2012Assignee: ULVAC, Inc.Inventors: Hiroshi Nagata, Kyuzo Nakamura, Takeo Katou, Atsushi Nakatsuka, Ichirou Mukae, Masami Itou, Ryou Yoshiizumi, Yoshinori Shingaki
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Patent number: 8257511Abstract: One object of the present invention is to provide a method for manufacturing a permanent magnet which can effectively improving the magnetizing properties and coercive force with efficiently diffusing Dy into grain boundary phases without deteriorating a surface of sintered magnet of Nd—Fe—B family and does not require any subsequent working process. Sintered magnet S of Nd—Fe—B family and Dy are arranged in a processing chamber 20 apart from each other. Then Dy is evaporated by heating the processing chamber 20 under a reduced pressure condition to evaporate Dy with elevating the temperature of sintered magnet S to a predetermined temperature and to supply and deposit evaporated Dy atoms onto the surface of sintered magnet S. During which the supplying amount of Dy atoms onto the sintered magnet S is controlled so as to diffuse and homogeneously penetrate them into the grain boundary phases of sintered magnet before Dy layer is formed on the surface of sintered magnet.Type: GrantFiled: August 22, 2007Date of Patent: September 4, 2012Assignee: Ulvac, Inc.Inventors: Hiroshi Nagata, Yoshinori Shingaki