Patents Examined by John Sheehan
  • Patent number: 8268092
    Abstract: Provided are a magnetic sheet for use in a radio frequency identification (RFID) antenna, an RFID antenna including the magnetic sheet, and a method of manufacturing the magnetic sheet, in which the magnetic sheet includes an amorphous alloy selected from the group consisting of Fe—Si—B, Fe—Si—B—Cu—Nb, Fe—Zr—B and Co—Fe—Si—B. The magnetic sheet is made by laminating amorphous alloy ribbons made of an amorphous alloy between magnetic sheet layers formed of alloy powder including at least one amorphous alloy and then compression-molding the amorphous alloy ribbons, to thereby control microcrack of the amorphous alloy ribbons and enhance characteristic of an end-product. The magnetic sheet is also thin, and has an excellent magnetic permeability, and a simple manufacturing process.
    Type: Grant
    Filed: July 22, 2010
    Date of Patent: September 18, 2012
    Assignee: Amotech Co., Ltd.
    Inventors: Jae Suk Yang, Hyeon Chul Lim, Byoung Ki Lee, Yong Sup Lee, Yong Hyun Kim, Yong Sul Song, Sang Kyun Kwon, Beom Jin Kim
  • Patent number: 8268093
    Abstract: 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: Grant
    Filed: May 18, 2007
    Date of Patent: September 18, 2012
    Assignee: Hitachi Metals, Ltd.
    Inventors: Takeshi Nishiuchi, Noriyuki Nozawa, Satoshi Hirosawa, Tomohito Maki, Katsunori Bekki
  • Patent number: 8268097
    Abstract: A grain-oriented electrical steel sheet has a tension film that does not include chromium. In the present invention, the tension film, including a phosphate and silica as constituents, includes a manganese compound and a potassium compound. The mole ratio K/Mn of potassium to manganese in the film is set to a certain range. The film can be produced by preparing a coating solution by adding a compound, which includes the phosphate and the silica and also includes the potassium and the manganese, and applying the coating solution on a grain-oriented electrical steel sheet after final annealing is completed, followed by drying and baking.
    Type: Grant
    Filed: March 30, 2009
    Date of Patent: September 18, 2012
    Assignee: Nippon Steel Corporation
    Inventors: Fumiaki Takahashi, Kazutoshi Takeda, Hiroyasu Fujii, Shuichi Yamazaki, Yoshiaki Natori
  • Patent number: 8262808
    Abstract: 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: Grant
    Filed: December 19, 2007
    Date of Patent: September 11, 2012
    Assignee: ULVAC, Inc.
    Inventors: Hiroshi Nagata, Kyuzo Nakamura, Takeo Katou, Atsushi Nakatsuka, Ichirou Mukae, Masami Itou, Ryou Yoshiizumi, Yoshinori Shingaki
  • Patent number: 8252123
    Abstract: 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: Grant
    Filed: October 27, 2010
    Date of Patent: August 28, 2012
    Assignee: Shin-Etsu Chemical Co., Ltd.
    Inventors: Hiroaki Nagata, Tadao Nomura, Takehisa Minowa
  • Patent number: 8252124
    Abstract: The present invention provides a powder magnetic core low in the loss and high in the saturation magnetic flux density and a method for manufacturing the same. More specifically, the present invention provides a powder magnetic core that comprises a soft magnetic metal powder having an average particle size (D50) of 0.5 to 5 ?m, a half width of diffraction peak in a <110> direction of ?-Fe as measured by X-ray powder diffraction of 0.2 to 5.0°, and an Fe content of 97.0% by mass or more, the core having an oxygen content of 2.0% by mass or more.
    Type: Grant
    Filed: March 11, 2011
    Date of Patent: August 28, 2012
    Assignee: TDK Corporation
    Inventors: Masahito Koeda, Tomofumi Kuroda, Tomokazu Ishikura, Akihiro Harada, Hiroyuki Ono, Osamu Kido, Satoko Ueda
  • Patent number: 8236110
    Abstract: The invention produces a grain-oriented electrical steel sheet having a primary recrystallization structure in which Goss-oriented crystal grains and crystal grains having a coincidence orientation relationship to the Goss orientation are aligned in the rolling direction. It is characterized heating a slab containing, in mass %, C: 0.025 to 0.10%, Si: 2.5 to 4.5%, Mn: 0.03 to 0.55%, and Al: 0.007 to 0.040% to 1,100 to 1,450° C.
    Type: Grant
    Filed: April 22, 2008
    Date of Patent: August 7, 2012
    Assignee: Nippon Steel Corporation
    Inventors: Takao Mukai, Shinya Hayashi, Atsushi Tanaka, Hiroyuki Mimura, Hisataka Uto
  • Patent number: 8231739
    Abstract: A method of manufacturing oriented Si steel containing Cu with high electric-magnetic property comprises: hot rolling slab; after first cold rolling, heating it to 800° C. or higher temperature and performing intermediate decarburization annealing in a protective atmosphere with PH2O/PH2 of 0.50˜0.88 for 3-8 minutes, to decrease carbon content of the steel plate to less than 30 ppm; then peening and acid-pickling to remove oxide of Fe on surface and to control oxygen content to lower than 500 ppm; secondary cold rolling to final thickness and coating separation agent in water-slurry form; drying to decrease water content to lower than 1.5%; high-temperature annealing in a protective atmosphere containing hydrogen with oxidation degree (PH2O/PH2) of 0.0001-0.2; finally applying a tension coating and leveling tension annealing.
    Type: Grant
    Filed: April 24, 2009
    Date of Patent: July 31, 2012
    Assignee: Baoshan Iron & Steel Co., Ltd.
    Inventors: Yaming Ji, Huande Sun, Guohua Yang, Yongjie Yang, Yunpeng Xu, Changguo Huang, Guobao Li
  • Patent number: 8231740
    Abstract: A rare earth permanent magnet material is prepared by covering a sintered magnet body of R1—Fe—B composition wherein R1 is a rare earth element, with a powder comprising at least 30% by weight of an alloy of R2aTbMcAdHe wherein R2 is a rare earth element, T is Fe and/or Co, and M is Al, Cu or the like, and having an average particle size up to 100 ?m, and heat treating the powder-covered magnet body at a suitable temperature, for causing R2, T, M and A in the powder to be absorbed in the magnet body.
    Type: Grant
    Filed: April 12, 2007
    Date of Patent: July 31, 2012
    Assignee: Shin-Etsu Chemical Co., Ltd.
    Inventors: Hajime Nakamura, Takehisa Minowa, Koichi Hirota
  • Patent number: 8226779
    Abstract: A manufacturing method of a magnetic core includes a first step of applying a treatment liquid for forming an insulating film to iron powder; a second step of heat-treating the iron powder to which the treatment liquid has been applied, at a temperature higher than 350 degrees; a third step of compacting the heat-treated iron powder to form a magnetic core; and a forth step of heat-treating the magnetic core at a temperature ranging from 600 degrees to 800 degrees.
    Type: Grant
    Filed: April 9, 2008
    Date of Patent: July 24, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Takao Imagawa, Yuichi Satsu, Matahiro Komuro, Hiroyuki Suzuki
  • Patent number: 8216393
    Abstract: A powder composite core is to be particularly dense and strong while being produced from soft magnetic alloys. In particular, the expansion of the heat-treated core is to be avoided. To produce this core, a strip of a soft magnetic alloy is first comminuted to form particles. The particles are mixed with a first binder having a curing temperature T1,cure and a decomposition temperature T1,decompose and a second binder having a curing temperature T2,cure and a decomposition temperature T2,decompose, wherein T1,cure<T2,cure?T1,decompose<T2,decompose. The mix is pressed to produce a magnet core while the first binder is cured. The magnet core is then subjected to a heat treatment accompanied by the curing of the second binder at a heat treatment temperature TAnneal>T2,cure.
    Type: Grant
    Filed: July 11, 2007
    Date of Patent: July 10, 2012
    Assignee: Vacuumschmelze GmbH & Co. KG
    Inventors: Markus Brunner, Georg Werner Reppel
  • Patent number: 8211246
    Abstract: In one embodiment, a permanent magnet has a composition represented by (Sm1-xRx)(FepMqCurCo1-p-q-r)z, where R is at least one element selected from Nd and Pr, M is at least one element selected from Ti, Zr and Hf, and 0.22?p?0.45, 0.005?q?0.05, 0.01 ?r?0.1, 0.05?x<0.5, and 7?z?9. The permanent magnet includes a Th2Zn17 crystal phase as a main phase, and a ratio of diffraction peak intensity I(113) from a (113) plane of the Th2Zn17 crystal phase in powder X-ray diffraction to diffraction peak intensity I(300) from a (300) plane in powder X-ray diffraction is in a range of 0.9?I(113)/I(300)?1.7.
    Type: Grant
    Filed: March 16, 2011
    Date of Patent: July 3, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masaya Hagiwara, Shinya Sakurada, Yosuke Horiuchi, Keiko Okamoto, Tsuyoshi Kobayashi, Shiori Kaji
  • Patent number: 8206516
    Abstract: In a method for producing an R—Fe—B based rare-earth sintered magnet according to the present invention, first, provided is an R—Fe—B based rare-earth sintered magnet body including, as a main phase, crystal grains of an R2Fe14B type compound that includes a light rare-earth element RL, which is at least one of Nd and Pr, as a major rare-earth element R. Thereafter, the sintered magnet body is heated while a heavy rare-earth element RH, which is at least one element selected from the group consisting of Dy, Ho and Tb, is supplied to the surface of the sintered magnet body, thereby diffusing the heavy rare-earth element RH into the rare-earth sintered magnet body.
    Type: Grant
    Filed: March 1, 2007
    Date of Patent: June 26, 2012
    Assignee: Hitachi Metals, Ltd.
    Inventors: Koshi Yoshimura, Hideyuki Morimoto, Tomoori Odaka
  • Patent number: 8187392
    Abstract: 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: Grant
    Filed: July 1, 2008
    Date of Patent: May 29, 2012
    Assignee: Hitachi Metals, Ltd.
    Inventors: Koshi Yoshimura, Hideyuki Morimoto, Tomoori Odaka
  • Patent number: 8187394
    Abstract: A powder magnetic core is provided for operating at high frequencies that is obtained by pressure forming an iron-based magnetic powder covered with an insulation film, which has a specific resistance more than 1000, preferably more than 2000, and most preferably more than 3000 ??m, and a saturation magnetic flux density B above 1.5, preferably above 1.7, and most preferably above 1.9 (T). A method for the preparation of such cores as well as a powder which is suitable for the preparation also are provided.
    Type: Grant
    Filed: December 6, 2007
    Date of Patent: May 29, 2012
    Assignee: Hoganas AB
    Inventors: Zhou Ye, Björn Skårman
  • Patent number: 8182620
    Abstract: A magnetic alloy having a composition represented by the general formula of Fe100-x-yCuxBy(atomic %), wherein x and y are numbers meeting the conditions of 0.1?x?3, and 10?y?20, or the general formula of Fe100-x-y-zCuxByXz(atomic %), wherein X is at least one element selected from the group consisting of Si, S, C, P, Al, Ge, Ga and Be, and x, y and z are numbers meeting the conditions of 0.1?x?3, 10?y?20, 0<z?10, and 10<y+z?24), the magnetic alloy having a structure containing crystal grains having an average diameter of 60 nm or less in an amorphous matrix, and a saturation magnetic flux density of 1.7 T or more.
    Type: Grant
    Filed: July 19, 2010
    Date of Patent: May 22, 2012
    Assignee: Hitachi Metals, Ltd.
    Inventors: Motoki Ohta, Yoshihito Yoshizawa
  • Patent number: 8182619
    Abstract: First, an R—Fe—B based rare-earth sintered magnet body including, as a main phase, crystal grains of an R2Fe14B type compound that includes a light rare-earth element RL, which is at least one of Nd and Pr, as a major rare-earth element R is provided. Next, an M layer, including a metallic element M that is at least one element selected from the group consisting of Al, Ga, In, Sn, Pb, Bi, Zn and Ag, is deposited on the surface of the sintered magnet body and then an RH layer, including a heavy rare-earth element RH that is at least one element selected from the group consisting of Dy, Ho and Tb, is deposited on the M layer. Thereafter, the sintered magnet body is heated, thereby diffusing the metallic element M and the heavy rare-earth element RH from the surface of the magnet body deeper inside the magnet.
    Type: Grant
    Filed: July 5, 2011
    Date of Patent: May 22, 2012
    Assignee: Hitachi Metals, Ltd.
    Inventors: Hideyuki Morimoto, Tomoori Odaka, Masao Noumi
  • Patent number: 8182618
    Abstract: A sintered rare-earth magnet includes an Nd2Fe14B type crystalline phase as its main phase and Al as an additive. The magnet includes at least one light rare-earth element LR selected from the group consisting of yttrium and the rare-earth elements other than Dy, Ho and Tb, and at least one heavy rare-earth element HR selected from the group consisting of Dy, Ho and Tb. The mole fractions ?1, ?2 and ? of the light and heavy rare-earth elements LR and HR and Al satisfy the inequalities 25??1+?2?40 mass %, 0<?2?40 mass %, ?>0.20 mass %, and 0.04??/?2?0.12.
    Type: Grant
    Filed: November 30, 2006
    Date of Patent: May 22, 2012
    Assignee: Hitachi Metals, Ltd.
    Inventors: Noriyuki Nozawa, Tomoori Odaka, Yutaka Matsuura
  • Patent number: 8177921
    Abstract: An R—Fe—B based rare-earth sintered magnet according to the present invention includes, as a main phase, crystal grains of an R2Fe14B type compound that includes Nd, which is a light rare-earth element, as a major rare-earth element R. The magnet includes a heavy rare-earth element RH (which is at least one of Dy and Tb) that has been introduced through the surface of the sintered magnet by diffusion. The magnet has a region in which the concentration of the heavy rare-earth element RH in a grain boundary R-rich phase is lower than at the surface of the crystal grains of the R2Fe14B type compound but higher than at the core of the crystal grains of the R2Fe14B type compound.
    Type: Grant
    Filed: July 25, 2008
    Date of Patent: May 15, 2012
    Assignee: Hitachi Metals, Ltd.
    Inventors: Tomoori Odaka, Hideyuki Morimoto, Kohshi Yoshimura, Shigeru Takaki, Shinichiro Sakashita
  • Patent number: 8177923
    Abstract: A magnetic alloy having a composition represented by the general formula of Fe100-x-yCuxBy (atomic %), wherein x and y are numbers meeting the conditions of 0.1?x?3, and 10?y?20, or the general formula of Fe100-x-y-zCuxByXz (atomic %), wherein X is at least one element selected from the group consisting of Si, S, C, P, Al, Ge, Ga and Be, and x, y and z are numbers meeting the conditions of 0.1?x?3, 10?y?20, 0<z?10, and 10<y+z?24), the magnetic alloy having a structure containing crystal grains having an average diameter of 60 nm or less in an amorphous matrix, and a saturation magnetic flux density of 1.7 T or more.
    Type: Grant
    Filed: September 19, 2006
    Date of Patent: May 15, 2012
    Assignee: Hitachi Metals, Ltd.
    Inventors: Motoki Ohta, Yoshihito Yoshizawa