Abstract: The method of producing an R—Fe—B magnet of the present invention is characterized in that R—Fe—B alloy fine powder is molded in a magnetic field and sintered using a lubricant for molding magnets containing specific components, individually or as a mixture, of specific amounts of methyl caproate and/or methyl caprylate, which provide high crystal orientation, and lubricant comprising depolymerized polymer for improving molded article strength, or a lubricant for molding magnets wherein Ti coupling agent that improves crystal orientation is added to this lubricant for molding magnets. Each particle of the fine powder has a high degree of crystal orientation in the direction of the magnetic field, and molded article strength is markedly improved, leading to improved mass-productivity and yield. Moreover, the above-mentioned lubricants do not react with this magnet powder during sintering and are emitted as a gas.
Type:
Grant
Filed:
March 28, 2000
Date of Patent:
March 26, 2002
Assignee:
Sumitomo Special Metals Co., Ltd.
Inventors:
Yuji Kaneko, Junichiro Baba, Kazuo Tanaka, Shizuo Mori
Abstract: A soft magnetic composite material obtained by dispersing a powdered magnetic material (A) composed of soft ferrite in a polymer (B), wherein the powdered magnetic material (A) is a powdered magnetic material of a random form obtained by grinding a sintered magnetic material, and the average particle size (d2) of the powdered magnetic material (A) is greater than the average crystal grain size (d1) of the sintered magnetic material by at least twice.
Abstract: In a composite magnetic body comprising flat soft magnetic powder dispersed in an organic binding agent, bio-composable plastic is used as the organic binding agent so that the composite magnetic body is free of possibility of pollution due to disposal thereof. As the bio-composable plastic, any of a microbe type, a chemical synthesis type and a natural high molecular type is used.
Abstract: The present application is directed to a new class of composite materials, called field-structured composite (FSC) materials, which comprise a oriented aggregate structure made of magnetic particles suspended in a nonmagnetic medium, and to a new class of processes for their manufacture. FSC materials have much potential for application, including use in chemical, optical, environmental, and mechanical sensors.
Type:
Grant
Filed:
May 27, 1999
Date of Patent:
September 18, 2001
Assignee:
Sandia Corporation
Inventors:
James E. Martin, Robert C. Hughes, Robert A. Anderson
Abstract: 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.
Abstract: This invention is directed to an extrusion-molded magnet comprising a samarium-iron-nitrogen material, which is novel and capable of exhibiting excellent magnetic properties, i.e., samarium-iron-nitrogen system magnetic particles excellent in magnetic properties.
A permanent magnet material comprising a samarium-iron-nitrogen system magnetized anisotropy particles and having increased inter-iron atom distance and elevated magnetic saturation. The magnet material is prepared by a method of causing nitrogen intrusion into the iron crystal lattice of a samarium-iron alloy by holding the alloy in a nitrogen gas at about 500 degrees C. The prepared permanent magnet material is added to a thermoplastic polyolefin system synthetic resin, and the admixture is thermally fused and kneaded. The paste thus obtained is charged into an extrusion molder and extruded through a magnetic field device, which is at an end of the extrusion molder and has an internal die, thus obtaining a molded magnet.
Abstract: 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.
Abstract: A Mn—Zn ferrite having large electrical resistance, which can withstand the use in high frequency region exceeding 1 MHz, is provided. The Mn—Zn ferrite comprises the following basic components: 44.0 to 50.0 mol % Fe2O3, 4.0 to 26.5 mol % ZnO, 0.1 to 8.0 mol % at least one member selected from the group consisting of TiO2 and SnO2, 0.1 to 16.0 mol % CuO, and the remainder being MnO. By the addition of TiO2, SnO2 and CuO, even if the material is sintered in the air, electrical resistance of 103 times or more as high as that of the conventional Mn—Zn ferrite can be obtained, and a high initial permeability of 300-400 as estimated can be secured even at high frequency of 5 MHz.
Type:
Grant
Filed:
August 16, 1999
Date of Patent:
January 30, 2001
Assignee:
Minebea Co., Ltd.
Inventors:
Osamu Kobayashi, Koji Honda, Shunji Kawasaki
Abstract: Disclosed is a method for the preparation of a ferrite beads composition suitable for compression-molding into a compression-molded ferrite body to be subjected to a sintering heat treatment to give a sintered ferrite member having usefulness as an electromagnetic material. The method comprises the steps of: forming ferrite beads from ferrite particles and an organic binder compound; and uniformly mixing the ferrite beads with a limited amount of a higher fatty acid ester of a hexitan compound such as sorbitan mono- or sesquioleate. The ferrite beads composition of the invention is advantageous not only in respect of the behavior in compression molding such as high density of the compression-molded body, low withdrawal pressure from the metal mold and a decrease in the phenomenon of springback but also in respect of the properties of the ferrite body after sintering.