Dust Cores Patents (Class 148/104)
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Patent number: 6940388Abstract: A dust core consists essentially of ferromagnetic powder; and an insulating binder, in which the ferromagnetic powder is dispersed; wherein the insulating binder is a silicone resin comprising a trifunctional alkyl-phenyl silicone resin and optionally containing an inorganic insulator such as an inorganic oxide, carbide or nitride. Preferably the alkyl-phenyl silicone resin is a methyl-phenyl silicone resin and comprises about 20 to 70 mol % of trifunctional groups. The dust core can be produced by pressure-molding a ferromagnetic powder, a lubricant and a trifunctional alkyl-phenyl silicone resin binder and heat treating the molded core at a temperature in the range of about 300 to about 800 ° C. for a time period in the range of about 20 minutes to about 2 hours in a non-oxidizing atmosphere. The dust core has high magnetic permeability representing the direct current superimposition characteristics, has reduced core loss and has increased mechanical strength.Type: GrantFiled: April 11, 2003Date of Patent: September 6, 2005Assignee: TDK CorporationInventor: Hideharu Moro
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Patent number: 6808807Abstract: A coated ferromagnetic particle comprises a ferromagnetic core and a coating. The coating comprises a residue resulting from a thermal treatment of a coating material comprising a polymer selected from the group consisting of polyorganosiloxanes, polyorganosilanes, and mixtures thereof. A composite magnetic article comprises a compacted and annealed article of a desired shape. The composite magnetic article comprises a plurality of coated ferromagnetic articles. Each coated ferromagnetic particle comprises a ferromagnetic core and a coating. The coating comprises a residue resulting from a thermal treatment of a coating material comprising a polymer selected from the group consisting of polyorganosiloxanes, polyorganosilanes, and mixtures thereof.Type: GrantFiled: June 14, 2002Date of Patent: October 26, 2004Assignee: General Electric CompanyInventors: Krishnamurthy Anand, Gerald Burt Kliman, Luana Emiliana Iorio, Suchismita Sanyal, Amitabh Verma, Kanchan Kumari, Srinidhi Sampath
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Patent number: 6793742Abstract: An alloy powder for bonded rare earth magnets is prepared by melting an alloy consisting essentially of 20-30 wt % of Sm or a mixture of rare earth elements (inclusive of Y) containing at least 50 wt % of Sm, 10-45 wt % of Fe, 1-10 wt % of Cu, 0.5-5 wt % of Zr, and the balance of Co, quenching the melt by a strip casting technique, to form a rare earth alloy strip containing at least 20% by volume of equiaxed crystals with a grain size of 1-200 &mgr;m and having a gage of 0.05-3 mm, and heat treating the strip in a non-oxidizing atmosphere at 1000-1300° C. for 0.5-20 hours, followed by aging treatment and grinding.Type: GrantFiled: May 21, 2002Date of Patent: September 21, 2004Assignee: Shin-Etsu Chemical Co., Ltd.Inventors: Kazuaki Sakaki, Koji Sato, Takahiro Hashimoto, Takehisa Minowa
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Publication number: 20040173287Abstract: High-permeability, low-core-loss soft magnetic composite materials, compositions containing the same, and methods for making the same are described. These magnetic materials are made by forming fiber or flake shaped particles from a ferromagnetic material, annealing the particles, and then coating an insulating material on the particles. These particles can then be compacted to form an article that has high permeability, high saturation, low core loss, and is a suitable replacement for laminations in various applications, such as motors.Type: ApplicationFiled: March 3, 2003Publication date: September 9, 2004Applicant: General Electric CompanyInventors: Luana Emiliana Iorio, Paul Alfred Siemers, Gerald Burt Kliman, K. Anand, Amitabh Verma
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Patent number: 6788185Abstract: A powder core is obtained by compaction-forming magnetic powder. The magnetic powder is an alloy comprising 1-10 wt % Si, 0.1-1.0 wt % O, and balance Fe. An insulator comprising SiO2 and MgO as main components is interposed between powder particles having a particle size of 150 &mgr;m or less.Type: GrantFiled: July 29, 2003Date of Patent: September 7, 2004Assignee: NEC Tokin CorporationInventors: Teruhiko Fujiwara, Masayoshi Ishii, Yoshitaka Saito
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Publication number: 20040168747Abstract: The step of preparing a rapidly solidified alloy by rapidly quenching a melt of an R-T-B-C based rare-earth alloy (where R is at least one of the rare-earth elements including Y, T is a transition metal including iron as its main ingredient, B is boron, and C is carbon) and the step of thermally treating and crystallizing the rapidly solidified alloy are included. The step of thermally treating results in producing a first compound phase with an R2Fe14B type crystal structure and a second compound phase having a diffraction peak at a site with an interplanar spacing d of 0.295 nm to 0.300 nm (i.e., where 2&thgr;=30 degrees). An intensity ratio of the diffraction peak of the second compound phase to that of R2Fe14B type crystals representing a (410) plane is at least 10%. The present invention provides an R-T-B-C based rare-earth alloy magnetic material, including carbon (C) as an indispensable element but exhibiting excellent magnetic properties, and makes it possible to recycle rare-earth magnets.Type: ApplicationFiled: December 17, 2003Publication date: September 2, 2004Inventors: Hiroyuki Tomizawa, Yuji Kaneko
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Patent number: 6777097Abstract: On a surface of a rare earth permanent magnet R—T—M—B wherein R is a rare earth element, T is Fe or Fe and Co, M is Ti, Nb, Al, V, Mn, Sn, Ca, Mg, Pb, Sb, Zn, Si, Zr, Cr, Ni, Cu, Ga, Mo, W or Ta, 5 wt %≦R≦40 wt %, 50 wt %≦90 wt %, 0 wt %≦M≦8 wt %, and 0.2 wt %≦B≦8 wt %, a solution comprising a flake fine powder of Al, Mg, Ca, Zn, Si, Mn or an alloy thereof and a silicone resin is applied and baked to form an adherent composite coating, thereby providing a corrosion resistant rare earth permanent magnet.Type: GrantFiled: June 14, 2002Date of Patent: August 17, 2004Assignee: Shin-Etsu Chemical Co., Ltd.Inventors: Ryuji Hamada, Takehisa Minowa
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Patent number: 6749767Abstract: A mixed powder useful as a starting material for dust core comprises a uniform mixture of a soft magnetic powder and a binder resin so that the resultant dust core has an electric resistance capable of suppressing an eddy current between the soft magnetic powdery particles and high mechanical strength at room temperatures and also at high temperatures. In the mixed powder, the binder resin is made of a phenolic resin powder which has a methylol groups in the molecule and preferably has an average particle size of 30 &mgr;m or below and wherein when the phenolic resin powder is dissolved in boiling methanol in large excess, a content of an undissolved matter is at least 4 wt % based on the total of the phenolic resin. A dust core obtained from the mixed powder and its fabrication method are also described.Type: GrantFiled: March 19, 2002Date of Patent: June 15, 2004Inventors: Hiroyuki Mitani, Tsukasa Yuri, Kazuhisa Fujisawa, Yoshikazu Seki, Masahiro Murakami, Hirofumi Houjou
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Publication number: 20040045635Abstract: Briefly, in accordance with one embodiment of the present invention, a process for making a magnetic composite which comprises providing a polymeric resin and a magnetic powder, the magnetic powder having a mean particle size with a value for standard deviation that is less than the value for the mean particle size of the said magnetic powder, the said magnetic composite being made by mixing said magnetic powder with said polymeric resin and molding the said mixture into a desired shape and a size and said magnetic composite having a magnetic permeability between 30 and 50. In another embodiment the present invention is a composition for a magnetic composite comprising a polymeric resin and a magnetic powder, the said powder having a mean particle size with a value of standard deviation that is less than the value of the mean particle size of the magnetic powder, wherein said magnetic composite has a magnetic permeability between about 30 and about 50.Type: ApplicationFiled: September 9, 2002Publication date: March 11, 2004Applicant: General Electric CompanyInventors: Krisanu Bandyopadhyay, Kunj Tandon, Amit Chakrabarti
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Publication number: 20030209286Abstract: A method of manufacturing electric machines comprised of geometrically patterned arrays of permanent magnets, soft magnetic materials, and electrical conductors deposited by kinetic spraying methods directly atop a carrier. The magnets and planar coils of the present invention may be integrally formed atop carriers to form electrical machines such as motors, generators, alternators, solenoids, and actuators. The manufacturing techniques used in this invention may produce highly defined articles that do not require additional shaping or attaching steps. Very high-purity permanent and soft magnetic materials, and conductors with low oxidation are produced.Type: ApplicationFiled: June 17, 2003Publication date: November 13, 2003Applicant: Ford Motor CompanyInventors: Franco Leonardi, John Matthew Ginder, Robert Corbly McCune
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Patent number: 6646532Abstract: Preparation is made of alloy powder comprising 3.0-8.0 wt % Si, 0.1-1.0 wt % O, 0-2.0 wt % (0 being exclusive) of at least one element selected from Mn, Al, V, Cr, and Ti, and balance Fe and having a particle size substantially equal to 150 &mgr;m or less. A binder is mixed with the alloy powder to form a mixture. The mixture is compaction-formed by the use of a die. Thus, a powder core is obtained which has a 20 kHz a.c. permeability equal to 20 or more under an applied d.c. magnetic field of 12000 A/m, a core loss characteristic of 1000 kW/m3 under the conditions of 20 kHz and 0.1 T, saturation magnetization of 10000 G or more, and coercive force of 3.0 Oe or less.Type: GrantFiled: February 26, 2002Date of Patent: November 11, 2003Assignee: NEC Tokin CorporationInventors: Teruhiko Fujiwara, Masayoshi Ishii, Yoshitaka Saito
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Patent number: 6627003Abstract: A method of forming a shimming body for a NMR assembly is provided. A magnetizable metal powder of known magnetic properties is provided. The powder is uniformly dispersed into a non-magnetic material to form a mixture having a selected uniform density. A selected weight of magnetic material is determined for a particular installation of an NMR assembly. The mixture is heated. A selected volume corresponding to the selected weight of magnetic material is extruded into a container. The mixture is cooled to form a shimming body.Type: GrantFiled: January 7, 2002Date of Patent: September 30, 2003Assignee: GE Medical Systems Global Technology Company, LLCInventors: Gregory F. Hayworth, Delton A. Grey, Jr., Granville G. Ward, Jr.
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Patent number: 6596096Abstract: Permanent magnets, devices including permanent magnets and methods for manufacture are described with the permanent magnet comprising, for example: iron-boron-rare earth alloy particulate having an intrinsic coercive force of at least about 1591 kiloamperes/meter (about 20 kiloOersteds) and a residual magnetization of at least about 0.8 tesla (about 8 kiloGauss), wherein the rare earth content comprises praseodymium, a light rare earth element selected from the group consisting of cerium, lanthanum, yttrium and mixtures thereof, and balance neodymium; and a binder bonding the particulate.Type: GrantFiled: August 14, 2001Date of Patent: July 22, 2003Assignee: General Electric CompanyInventors: Ralph James Carl, Gerald Burt Kliman, Juliana Chiang Shei, Mark Gilbert Benz, Judson Sloan Marte
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Patent number: 6591483Abstract: A method is provided for depositing a spatially fine pattern of magnets on a substrate. The substrate can be fabricated from any number of materials, such as plastics, metals or ceramics. When sufficiently magnetized, the magnets will provide a magnetic field that can be sensed by a magnetic proximity sensor, to determine the position of the magnets. The magnets can be arranged in a plurality of patterns, including radial or linear arrangements. The ability to arrange these magnets in varying patterns provides a wide capability of magnetic sensing applications.Type: GrantFiled: April 4, 2000Date of Patent: July 15, 2003Assignee: The Cherry CorporationInventor: Nicholas W. Kay
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Publication number: 20030127157Abstract: A soft magnetic powder material which includes an iron system powdered particle having an insulating coat with high insulation performance, a polyamide system resin, and a thermoplastic resin having a melting point equal to or higher than 200° C.Type: ApplicationFiled: December 18, 2002Publication date: July 10, 2003Applicant: AISIN SEIKI KABUSHIKI KAISHAInventors: Yoshiharu Iyoda, Kota Maruyama, Naoki Kamiya
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Patent number: 6565673Abstract: Carbon addition to the rapidly solidified, preferably melt spun, alloy system of Sm(Co, Fe, Cu, Zr) provides for good isotropic magnetic properties. Importantly, these alloys are nanocomposite in nature and comprise the SmCoC2 phase. Thermal processing of these materials can achieve good magnetic properties at lower temperatures and/or shorter processing times than conventional Sm(Co, Fe, Cu, Zr) powders for bonded magnet application.Type: GrantFiled: June 15, 2001Date of Patent: May 20, 2003Assignee: Santoku CorporationInventors: Wei Gong, Bao-Min Ma
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Publication number: 20030084964Abstract: The method for manufacturing alloy powder for R—Fe—B type rare earth magnets of the present invention includes a first pulverization step of coarsely pulverizing a material alloy for rare earth magnets and a second pulverization step of finely pulverizing the material alloy. In the first pulverization step, the material alloy is pulverized by a hydrogen pulverization method. In the second pulverization step, easily oxidized super-fine powder (particle size: 1.0 &mgr;m or less) is removed to adjust the particle quantity of the super-fine powder to 10% or less of the particle quantity of the entire powder.Type: ApplicationFiled: November 13, 2002Publication date: May 8, 2003Applicant: SUMITOMO SPECIAL METALS CO., LTD.Inventors: Katsumi Okayama, Naoyuki Ishigaki, Shuhei Okumura
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Patent number: 6558565Abstract: A composite magnetic body used for a choke coil, etc. is formed by compression molding of a mixture of magnetic alloy powder containing iron (Fe) and nickel (Ni) as the main component, an insulating material and a binder of an acrylic resin. In the composite magnetic body, high packing rate of the magnetic alloy powder and good insulation between the powder particles stand together, exhibiting a low core loss and a high magnetic permeability. The composite magnetic body can be formed in various core pieces of complex shapes.Type: GrantFiled: November 20, 2000Date of Patent: May 6, 2003Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Nobuya Matsutani, Yuji Mido, Hiroshi Fujii
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Publication number: 20030075243Abstract: A method of forming a shimming body for a NMR assembly is provided. A magnetizable metal powder of known magnetic properties is provided. The powder is uniformly dispersed into a non-magnetic material to form a mixture having a selected uniform density. A selected weight of magnetic material is determined for a particular installation of an NMR assembly. The mixture is heated. A selected volume corresponding to the selected weight of magnetic material is extruded into a container. The mixture is cooled to form a shimming body.Type: ApplicationFiled: January 7, 2002Publication date: April 24, 2003Inventors: Gregory F. Hayworth, Delton A. Grey, Granville G. Ward
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Publication number: 20030077382Abstract: Substantially spherical magneto-plumbite ferrite (barium or strontium ferrite) particles are formed from well-dispersed ultra-fine substantially spherical iron-based oxide and/or hydroxide particles as precursor particles. The precursor particles are mixed with a colloidal barium or strontium carbonate (BaCO3 or SrCO3), and with small amounts of a byproduct, such as sodium or potassium chloride (NaCl or KCl) or hydroxide (NaOH or KOH) or nitrate (NaNO3 or KNO3), functioning as a flux to lower the calcination temperature. The particles are filtered out of the mixture, dried, and calcined for a time sufficiently long and/or at a temperature sufficiently high to form magneto-plumbite ferrite from the precursor particles, and for a time sufficiently short and/or a temperature sufficiently low to maintain the general spherical shape of the precursor particles.Type: ApplicationFiled: July 8, 2002Publication date: April 24, 2003Inventors: Yang-Ki Hong, Hong Sik Jung, Patrick R. Taylor
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Publication number: 20030070729Abstract: Permanent magnets, devices including permanent magnets and methods for manufacture are described with the permanent magnet comprising, for example: iron-boron-rare earth alloy particulate having an intrinsic coercive force of at least about 1591 kiloamperes/meter (about 20 kiloOersteds) and a residual magnetization of at least bout 0.8 tesla (about 8 kiloGauss), wherein the rare earth content comprises praseodymium, a light rare earth element selected from the group consisting of cerium, lanthanum, yttrium and mixtures thereof, and balance neodymium; and a binder bonding the particulate.Type: ApplicationFiled: August 14, 2001Publication date: April 17, 2003Applicant: General Electric CompanyInventors: Ralph James Carl, Gerald Burt Kliman, Juliana Chiang Shei, Mark Gilbert Benz, Judson Sloan Marte
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Patent number: 6544352Abstract: Disclosed is a method for the compaction of a soft magnetic powder capable of manufacturing a green compact which has attained high density and high strength, is excellent in mechanical properties and magnetic properties, and does not cause a reduction in electrical resistance. Soft magnetic powder particles individually surface-coated with an insulating vitreous layer containing P, Mg, B, and Fe as essential components are used, and a lubricant is applied to the inner wall surface of a compaction die. The soft magnetic powder is subjected to compaction at from not less than room temperature to less than 50° C. without mixing the lubricant with the soft magnetic powder, followed by annealing at from 50 to 300° C.Type: GrantFiled: June 1, 2001Date of Patent: April 8, 2003Assignee: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)Inventors: Hiroyuki Mitani, Takehiro Tsuchida, Yuichi Seki, Akihiko Kagawa, Tetsuya Sawayama, Yoshikazu Seki, Masaaki Sato
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Patent number: 6485579Abstract: The invention concerns a process for the preparation of soft magnetic composite products comprising the steps of providing particles of an iron based soft magnetic material with an electrically insulating layer; optionally mixing the dry powder with a lubricant; compacting the powder and heating the obtained component at an elevated temperature in the presence of water vapour. The invention also comprises the iron powder compact subjected to this treatment.Type: GrantFiled: January 18, 2000Date of Patent: November 26, 2002Assignee: Höganäs ABInventors: Magdalena Nillius, Patricia Jansson
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Publication number: 20020157733Abstract: The invention relates to magnets, particularly bonded magnets, of the Re—Fe—B type made from atomized magnetic powders and to methods of producing the powders and the magnet. The magnetic powders comprise, by weight, about 15% to 25% of RE; about 0.8% to 2.0% of B; about 1% to 10% of T; and balanced with Fe, Co, or mixtures thereof; wherein RE is one or more rare earth elements selected from the group consisting of Y, La, Ce, Pr, Nd, Sm, Er, Gd, Tb, Dy, Ho, Tm, Yb and Lu, and T is one or more elements selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W. To produce bonded magnets, the atomized powders are heat treated, combined with a binder, pressed or molded, and cured to produce the bonded magnets.Type: ApplicationFiled: February 28, 2001Publication date: October 31, 2002Inventors: Charles Howard Sellers, Barry Hal Rabin, Wilhelm Ervens, Joseph James Worden, Viswanathan Panchanathan
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Patent number: 6375759Abstract: A new class of processes for fabrication of precision miniature rare earth permanent magnets is disclosed. Such magnets typically have sizes in the range 0.1 to 10 millimeters, and dimensional tolerances as small as one micron. Very large magnetic fields can be produced by such magnets, lending to their potential application in MEMS and related electromechanical applications, and in miniature millimeter-wave vacuum tubes. This abstract contains simplifications, and is supplied only for purposes of searching, not to limit or alter the scope or meaning of any claims herein.Type: GrantFiled: November 30, 1999Date of Patent: April 23, 2002Assignee: Sandia CorporationInventors: Todd R. Christenson, Terry J. Garino, Eugene L. Venturini
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Patent number: 6368423Abstract: The invention improves the thermal conductivity of the material powder to be fired and also makes it possible to produce an amorphous magnetically soft body within a shortened period of time. The amorphous magnetically soft body is produced by preforming the material powder into a body first, and heating the preformed body without pressing. Stated more specifically, an amorphous magnetically soft body is produced from a material powder comprising a powder of an amorphous magnetically soft alloy, a glass having a softening point lower than the crystallization starting temperature of the alloy and a binding resin, by pressing the material powder in a preforming die to prepare a preformed body by the binding property of the resin, and firing the preformed body without pressing at a temperature higher than the softening point of the glass and lower than the crystallization starting temperature of the alloy to join the particles of the alloy with the glass.Type: GrantFiled: September 7, 2000Date of Patent: April 9, 2002Assignee: Kubota CorporationInventors: Isamu Otsuka, Toru Kawai, Atsunobu Shintani, Hiroshi Yamamoto, Isao Endo
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Publication number: 20020014280Abstract: To provide a powder for dust cores capable of improving magnetic properties such as magnetic permeability in a molded compacted powder magnetic core and mechanical properties such as size precision of the molded compacted powder magnetic core and radial crushing strength and, a dust core using the powder. A powder for a dust core contains a ferromagnetic powder, an insulating material containing silicone resin and/or phenol resin, and a lubricant, wherein the lubricant contains aluminum stearate, and a dust core using the powder for a dust core.Type: ApplicationFiled: June 26, 2001Publication date: February 7, 2002Inventor: Hideharu Moro
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Patent number: 6340397Abstract: A ferromagnetic powder comprising ferromagnetic particles coated with a material that does not degrade at temperatures above 150° C. and permits adjacent particles to strongly bind together after compaction such that parts made from the ferromagnetic powder have a transverse rupture strength of about 8,000 to about 20,000 pounds/square inch before sintering, The coating includes from 2 to 4 parts of an oxide and one part of a chromate, molybdate, oxalate, phosphate, or tungstate. The coating may be substantially free of organic materials. The invention also includes a method of making the ferromagnetic powder, a method of making soft magnetic parts from the ferromagnetic powder, and soft magnetic parts made from the ferromagnetic powder.Type: GrantFiled: February 11, 1999Date of Patent: January 22, 2002Assignee: Materials Innovation, Inc.Inventors: David S. Lashmore, Glenn L. Beane, Lev Deresh, Zonglu Hua
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Patent number: 6302972Abstract: An inventive material alloy for a nanocomposite magnet is represented by a general formula Fe100−x−yRxBy, Fe100−x−y−zRxByCoz, Fe100−x−y−uRxByMu or Fe100−x−y−z−uRxByCozMu. R is a rare-earth element. 90 atomic percent or more of R is Pr and/or Nd, while equal to or larger than 0 atomic percent and less than 10 atomic percent of R is another lanthanoid and/or Y. M is at least one element selected from the group consisting of Al, Si, Ti, V, Cr, Mn, Ni, Cu, Ga, Zr, Nb, Mo, Hf, Ta, W, Pt, Pb, Au and Ag. The molar fractions x, y, z and u meet the inequalities of 2≦x≦6, 16≦y≦20, 0.2≦z≦7 and 0.01≦u≦7, respectively. The alloy includes a metastable phase Z represented by at least one of a plurality of Bragg reflection peaks observable by X-ray diffraction analysis. The at least one peak corresponds to a lattice spacing of 0.179 nm±0.005 nm.Type: GrantFiled: December 6, 1999Date of Patent: October 16, 2001Assignee: Sumitomo Special Metals Co., LTDInventors: Satoshi Hirosawa, Hirokazu Kanekiyo, Yasutaka Shigemoto
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Publication number: 20010015239Abstract: The method for producing iron-base alloy permanent magnet powder of the present invention includes the steps of: chilling an Fe—R—B molten alloy by melt quenching, thereby forming a rapidly solidified alloy having a thickness in a range of 80 &mgr;m to 300 &mgr;m; crystallizing the rapidly solidified alloy by heat treatment, thereby producing an alloy having permanent magnet properties; and pulverizing the alloy to produce powder having an average particle size in a range of 50 &mgr;m to 300 &mgr;m or less and a ratio of minor axis size to major axis size of powder particles in a range of 0.3 to 1.0.Type: ApplicationFiled: December 13, 2000Publication date: August 23, 2001Inventor: Hirokazu Kanekiyo
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Patent number: 6221270Abstract: A process for producing a compound for a rare earth metal resin-bonded magnet includes: a slurry preparation step of mixing materials containing a magnetic alloy powder of a rare earth metal alloy, a resin binder, and an organic solvent into a slurry; and a drying step of spraying and drying the slurry by means of a spray dryer apparatus to produce the compound containing the magnetic alloy powder of the rare earth metal alloy and the resin binder.Type: GrantFiled: June 18, 1999Date of Patent: April 24, 2001Assignee: Sumitomo Special Metal Co., Ltd.Inventors: Katsuyoshi Saito, Yasunari Kaneko, Naoyuki Ishigaki, Shin Mishima, Shinji Otsuki, Yoshihiko Nishino
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Patent number: 6193903Abstract: Ceramic-coated powdered ferromagnetic materials for forming magnetic articles, and which maintain the mechanical and magnetic properties of the articles at high temperatures, such as during annealing to relieve stresses induced during the forming operation. The ceramic coatings are formed by one of several techniques to provide an encapsulating layer on each ferromagnetic particle. The particles are then compacted to form a solid magnetic article, which can be annealed without concern for degrading the ceramic coating.Type: GrantFiled: May 14, 1999Date of Patent: February 27, 2001Assignee: Delphi Technologies, Inc.Inventors: David Earl Gay, David Allen Score
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Patent number: 6187259Abstract: The object of the present invention is to provide rare-earth system sintered magnets such as R—Fe—B system or R—Co system having excellent magnetic properties, unique configuration of a small size, thin wall thickness and intricate geometry. With the method for preparing the present invention, a granulation of alloy powders can be achieved easily, a chemical reaction between rare-earth system and binder substances can be suppressed, so that the residual oxygen and carbon levels in the sintered products can be reduced. Moreover, by this production method, the flowability and lubricant capability during the forming process can be improved. The dimension accuracy and productivity are also enhanced. A certain type of binder is added to rare-earth alloy powders and kneaded into a slurry state. The slurry is then formed into granulated powders by spray-dryer equipment. The thus granulated powders are molded, and sintered through a powder metallurgy technique.Type: GrantFiled: March 19, 1997Date of Patent: February 13, 2001Assignee: Sumitomo Special Metals Co., Ltd.Inventors: Osamu Yamashita, Yoshihisa Kishimoto, Wataru Takahashi, Nobushige Hiraishi, Yoshiyuki Hashimasa, Masakazu Ohkita
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Patent number: 6183657Abstract: In a core material for the noise filter, powders of a flat and soft magnetic material is dispersed and buried into an insulating material such as rubber or plastic.Type: GrantFiled: May 18, 1999Date of Patent: February 6, 2001Assignee: Daido Tokushuko Kabushiki KaishaInventors: Akihiko Saito, Michiharu Ogawa, Kazuhisa Tsutsui, Shinichiro Yahagi
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Patent number: 6149704Abstract: A dust core ferromagnetic powder comprises a ferromagnetic metal powder, an insulating material, and a lubricant. The insulating material comprises a phenol resin and/or a silicone resin, and the lubricant comprises at least one compound selected from the group consisting of magnesium stearate, calcium stearate, strontium stearate, and barium stearate. It is possible to achieve a dust core having high saturation magnetic flux density, low losses, and satisfactory permeability with its dependence on frequency being improved.Type: GrantFiled: July 29, 1999Date of Patent: November 21, 2000Assignee: TDK CorporationInventors: Hideharu Moro, Takeo Tsukada, Katsuhiko Wakayama
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Patent number: 6139765Abstract: A magnetic powder and a permanent magnet are provided which have magnetic properties enhanced by magnetic interaction. Disclosed are a magnetic powder comprising a mixture of two or more powders including a magnetic powder A (residual magnetic flux density: BrA, coercive force: HcA) and a magnetic powder B (residual magnetic flux density: BrB, coercive force: HcB) of which the residual magnetic flux densities and the coercive forces have the following relationships: BrA>BrB and HcA<HcB, and a bonded magnet or a sintered magnet produced from the magnetic powder, and a method for mixing magnetic powders and a process for producing a magnet.Type: GrantFiled: April 25, 1997Date of Patent: October 31, 2000Assignee: Seiko Epson CorporationInventors: Atsunori Kitazawa, Toshiyuki Ishibashi, Koji Akioka
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Patent number: 6129790Abstract: A ferromagnetic powder comprising ferromagnetic particles coated with a material that does not degrade at temperatures above 150.degree. C. and permits adjacent particles to strongly bind together after compaction such that parts made from the ferromagnetic powder have a transverse rupture strength of about 8,000 to about 20,000 pounds/square inch before sintering. The coating includes from 2 to 4 parts of an oxide and one part of a chromate, molybdate, oxalate, phosphate, or tungstate. The coating may be substantially free of organic materials. The invention also includes a method of making the ferromagnetic powder, a method of making soft magnetic parts from the ferromagnetic powder, and soft magnetic parts made from the ferromagnetic powder.Type: GrantFiled: February 11, 1999Date of Patent: October 10, 2000Assignee: Materials Innovation, Inc.Inventors: David S. Lashmore, Glenn L. Beane, Lev Deresh, Zonglu Hua
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Patent number: 6102980Abstract: A ferromagnetic powder composition for dust cores contains a ferromagnetic metal powder and 0.1-15% by volume based on the powder of titania sol and/or zirconia sol. The composition is pressure molded and desirably annealed into a dust core which exhibits a high magnetic flux density, low coercivity, low loss and high mechanical strength.Type: GrantFiled: March 26, 1998Date of Patent: August 15, 2000Assignee: TDK CorporationInventors: Masami Endo, Takeo Tsukada, Masaaki Kanasugi, Kazuhiro Okada, Hideharu Moro, Norishige Yamaguchi, Toshiaki Yamada, Hideki Kitashima
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Patent number: 6080245Abstract: A rare earth permanent magnet consisting essentially, by weight, of 27.0-31.0 % of at least one rare earth element including Y, 0.5-2.0 % of B, 0.02-0.15 % of N, 0.25 % or less of O, 0.15 % or less of C, at least one optional element selected from the group consisting of 0.1-2.0 % of Nb, 0.02-2.0 % of Al, 0.3-5.0 % of Co, 0.01-0.5 % of Ga and 0.01-1.0 % of Cu, and a balance of Fe, and a production method thereof. The contents of rare earth element, oxygen, carbon and oxygen in the magnet are regulated within the specific ranges.Type: GrantFiled: October 2, 1998Date of Patent: June 27, 2000Assignee: Hitachi Metals, Ltd.Inventors: Kimio Uchida, Masahiro Takahashi, Fumitake Taniguchi
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Patent number: 6063209Abstract: A magnetic core of a compressed compact comprises a mixture of magnetic powder and a spacing material, wherein the distance between adjacent magnetic powder particles is controlled by the spacing material. In this constitution, a magnetic core low in core loss, high in magnetic permeability, and excellent in direct-current superposing characteristic is realized.Type: GrantFiled: April 17, 1998Date of Patent: May 16, 2000Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Nobuya Matsutani, Yuji Mido
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Patent number: 6063303Abstract: The present invention relates to a magnetic powder that contains resin-coated magnetic particles. The resin-coated magnetic particles include magnetic particles A and B that are formed in non-spherical shapes, with the magnetic particles A and B coated with a resin C. The resin-coated magnetic particles make it possible to increase the filling quantity of the magnetic particles A and B when the magnetic powder is employed to constitute a magnetic molded article, to ultimately improve the electromagnetic characteristics of the magnetic molded article.Type: GrantFiled: February 22, 1999Date of Patent: May 16, 2000Assignee: TDK CorporationInventor: Hitoshi Ohtaki
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Patent number: 6001193Abstract: A method of producing a hard magnetic alloy compact at low cost, in which an alloy that contains not less than 50% by weight of an amorphous phase and exhibits hard magnetism in a crystallized state is solidified and molded at around its crystallization temperature under applied pressure by utilizing the softening phenomenon occurring during a crystallization process. The resulting compact has high hard magnetic characteristics and can be applied as permanent magnet members such as in motors, actuators, and speakers.Type: GrantFiled: March 25, 1997Date of Patent: December 14, 1999Assignees: Alps Electric Co., Ltd., Akihisa Inoue, Tsuyoshi MasumotoInventors: Akinori Kojima, Takao Mizushima, Akihiro Makino, Akihisa Inoue, Tsuyoshi Masumoto
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Patent number: 5997804Abstract: A rare earth permanent magnet consisting essentially, by weight, of 27.0-31.0% of at least one rare earth element including Y, 0.5-2.0% of B, 0.02-0.15% of N, 0.25% or less of O, 0.15% or less of C, at least one optional element selected from the group consisting of 0.1-2.0% of Nb, 0.02-2.0% of Al, 0.3-5.0% of Co, 0.01-0.5% of Ga and 0.01-1.0% of Cu, and a balance of Fe, and a production method thereof. The contents of rare earth element, oxygen, carbon and oxygen in the magnet are regulated within the specific ranges.Type: GrantFiled: May 21, 1997Date of Patent: December 7, 1999Assignee: Hitachi Metals Ltd.Inventors: Kimio Uchida, Masahiro Takahashi, Fumitake Taniguchi
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Patent number: 5993565Abstract: Composite bodies of magnetostrictive materials of the type RE-Fe.sub.2, where RE is one or more of the rare earth elements, preferably samarium or terbium, can be suitably hot pressed with a matrix metal selected from the group consisting of aluminum, copper, iron, magnesium or nickel to form durable and machinable magnetostrictive composites still displaying appreciable magnetostrictive strains.Type: GrantFiled: July 1, 1996Date of Patent: November 30, 1999Assignee: General Motors CorporationInventors: Frederick Eugene Pinkerton, Jan Francis Herbst, Tenneille Weston Capehart, Charles Bernard Murphy, Earl George Brewer
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Patent number: 5932134Abstract: The invention is directed to a composition containing from 45 to 99 weight percent of a permanent-magnetic and/or ferromagnetic metal-containing compound and from 1 to 55 weight percent of a polymer of formula IHO--?--CO--R.sub.1 --CO--X--Y--Z--!.sub.n --H (I)wherein R.sub.1 is phenyl, naphthyl, cyclohexyl, cyclohexenyl, or a C.sub.1 to C.sub.4 alkyl-substituted derivative thereof, and, if R.sub.1 is phenyl, the carboxy groups are in ortho, meta or para position to each other;X, Z are O or NR.sub.2, wherein R.sub.2 is H or C.sub.1 to C.sub.4 alkyl;Y is (CH.sub.2).sub.m or phenyl, cyclohexyl or cyclopentyl, and m is from 1 to 12; andn is an integer.Furthermore, the invention is directed to a process for producing said composition, a magnetic and a non-magnetic molded article made of said composition, the production of same and the use of said composition.Type: GrantFiled: April 7, 1997Date of Patent: August 3, 1999Assignee: A. Schulman GmbHInventors: Hubert Christ, Hans-Peter Meyerhoff
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Patent number: 5913255Abstract: A method of producing a radially anisotropic sintered R-Fe-B-based magnet wherein R is at least one rare earth element including Y, in which a green body stack comprising a plurality of compact bodies are formed in series by the same die. The density of the compact body is regulated to 3.1 g/cm.sup.3 or more, and increased at the final compacting step to a density at least 0.2 g/cm.sup.3 higher than that before the final compacting step. By so regulating the density of the green body, the cracking during the sintering process at the binding portion, an interface between the stacked compact bodies, can be minimized while retaining high magnetic properties of the resulting magnet.Type: GrantFiled: August 7, 1997Date of Patent: June 15, 1999Assignee: Hitachi Metals Ltd.Inventors: Akira Kikuchi, Shigeho Tanigawa
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Patent number: 5858124Abstract: A high-resistance rare earth magnet having a metal structure in which a rare earth magnet phase is dispersed throughout a compound phase comprising at least one compound selected from the group consisting of fluorides and oxides of Li, Na, Mg, Ca, Ba and Sr. The fluorides and oxides are effective for increasing the electrical resistance of a rare earth magnet to a level sufficient for practical use while maintaining high magnetic properties of the magnet.Type: GrantFiled: October 30, 1996Date of Patent: January 12, 1999Assignee: Hitachi Metals, Ltd.Inventors: Minoru Endo, Mitsuaki Mochizuki, Nobuhiko Fujimori
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Patent number: 5849109Abstract: Methods of producing a rare earth alloy magnet powder having superior magnetic anisotropy and an aggregate of fine recrystallized structure of a R.sub.2 T.sub.14 M type intermetallic compound phase. In the methods, a R--T--M--A--Mg alloy material containing Mg is subjected to the following steps: elevating the temperature of the R--T--M--A--Mg alloy material from room temperature to a temperature up to 500.degree. C. in a vacuum or inert gas atmosphere; hydrogen-occluding treatment in which hydrogen is occluded in the R.ltoreq.T--M--A--Mg alloy material to promote phase transformation by elevating the temperature from room temperature to a predetermined temperature ranging from 500.degree. to 1,000.degree. C.Type: GrantFiled: March 10, 1997Date of Patent: December 15, 1998Assignee: Mitsubishi Materials CorporationInventor: Hiroshi Ikeda
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Patent number: 5840133Abstract: A permanent magnet of a magnetically anisotropic sinter based on Fe--Mn--R, R representing one or more rare earth elements, which is inexpensive and superior in the low temperature characteristic and which consists, on the basis of atomic percent, of 5-35% of one or more rare earth elements R selected among Yb, Er, Tm and Lu, 1-25% of Mn and the rest of substantially of Fe, characterized in that a part of Fe is replaced by 50 atom. % or less (excluding zero %), based on the entire alloy structure, of Co.Type: GrantFiled: February 7, 1997Date of Patent: November 24, 1998Inventor: Yoshiaki Takahashi
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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