Patents by Inventor Katsunori Iwasaki

Katsunori Iwasaki has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5096509
    Abstract: A the magnetically anisotropic magnetic powder having an average particle size of 1-1000 .mu.m and made from a magnetically anisotropic R-TM-B-Ga or R-TM-B-Ga-M alloy having an average crystal grain size of 0.01-0.5 .mu.m, wherein R represents one or more rare earth elements including Y, TM represents Fe which may be partially substituted by Co, B boron, Ga gallium, and M one or more elements selected from the group consisting of Nb, W, V, Ta, Mo, Si, Al, Zr, Hf, P, C and Zn. This is useful for anisotropic resin-bonded magnet with high magnetic properties.
    Type: Grant
    Filed: December 13, 1988
    Date of Patent: March 17, 1992
    Assignee: 501 Hitachi Metals, Ltd.
    Inventors: Minoru Endoh, Yasuto Nozawa, Katsunori Iwasaki, Shigeho Tanigawa, Masaaki Tokunaga
  • Patent number: 5085715
    Abstract: A process for producing magnetically anisotropic powder having "flattened" crystal grains of an R-TM-B-M system alloy with preferably (c)/(a) greater than 2, where (c) is the grain size perpendicular to the C-axis and (a) the grain size parallel to the C-axis, includes the steps of plastically deforming a green compact of flakes formed by rapidly-quenching the alloy melt, and then crushing the plastically deformed body. In the alloy system, R is at least one of the rare earth elements including Y, TM is Fe or Fe a part of which has been substituted with Co, B is boron, and M is an additive selected from Si, Al, Nb, Zr, P and C.
    Type: Grant
    Filed: December 4, 1989
    Date of Patent: February 4, 1992
    Assignee: Hitachi Metals, Ltd.
    Inventors: Masatoki Tokunaga, Yasuto Nozawa, Katsunori Iwasaki
  • Patent number: 5039292
    Abstract: Disclosed is a device for manufacturing Nd-Fe-B alloy magnet materials, and in particular, for manufacturing an integral, columnar-ring-shaped Nd-Fe-B magnet which is multi-pole-magnetized along the circumference thereof and which is used as the rotor magnet of a high-efficiency stepping motor. The device of this invention is composed of a die punch, an upper and a lower punch having two concentric sections. The space is defined by the die and the upper and lower punches includes induction means for heating the green compact or the densified compact and sealing means for keeping the die under a reduced pressure condition or in an inert gas atmosphere.
    Type: Grant
    Filed: July 19, 1990
    Date of Patent: August 13, 1991
    Assignee: Hitachi Metals, Ltd.
    Inventors: Shigeho Tanigawa, Katsunori Iwasaki, Yasuto Nozawa
  • Patent number: 5026419
    Abstract: Anisotropic hot-worked permanent magnets are made from an R-T-B alloyed powder to which is added a combination internal lubricant including a carbon-based material such as graphite and a glass material such as glass from the B.sub.2 O.sub.3 --SiO.sub.2 --BiO.sub.3 glass system. The internal lubricant provides improved formability during the hot-working step, such as die-upsetting, and provides finished magnet products wherein the individual grains are more uniformly plastically deformed throughout the product.
    Type: Grant
    Filed: April 25, 1990
    Date of Patent: June 25, 1991
    Assignee: Hitachi Metals, Ltd.
    Inventors: Katsunori Iwasaki, Shigeho Tanigawa, Masaaki Tokunaga
  • Patent number: 4985086
    Abstract: A method of producing a magnetically anisotropic Nd-Fe-B magnet material comprising the steps of: charging a green body produced by pressing a flaky or powdery material consisting of an amorphous alloy and/or a finely crystallized alloy, into a cavity defined by a die having a hole extending therethrough, a lower plunger inserted into said hole, and an upper plunger having a larger diameter than that of said hole; pressing said green body by elevating said lower plunger while keeping a temperature thereof (pressing temperature) at 600.degree.-850.degree.; elevating the resulting pressed body by elevating said lower plunger while heating; and upsetting said pressed body while keeping a temperature thereof (upsetting temperature) at 600.degree.-850.degree. C. to provide it with magnetic anisotropy.
    Type: Grant
    Filed: June 2, 1989
    Date of Patent: January 15, 1991
    Assignee: Hitachi Metals, Ltd.
    Inventors: Katsunori Iwasaki, Yasuto Nozawa, Shigeho Tanigawa
  • Patent number: 4983232
    Abstract: A the magnetically anisotropic magnetic powder having an average particle size of 1-1000 .mu.m and made from a magnetically anisotropic R-TM-B-Ga or R-TM-B-Ga-M alloy having an average crystal grain size of 0.01-0.5 .mu.m, wherein R represents one or more rare earth elements including Y, TM represents Fe which may be partially substituted by Co, B boron, Ga gallium, and M one or more elements selected from the group consisting of Nb, W, V, Ta, Mo, Si, Al, Zr, Hf, P, C and Zn. This is useful for anisotropic resin-bonded magnet with high magnetic properties.
    Type: Grant
    Filed: October 27, 1987
    Date of Patent: January 8, 1991
    Assignee: Hitachi Metals, Ltd.
    Inventors: Minoru Endoh, Yasuto Nozawa, Katsunori Iwasaki, Shigeho Tanigawa, Masaaki Tokunaga
  • Patent number: 4978398
    Abstract: A magnetically anisotropic hot-worked magnet made of an R-T-B alloy containing a transition metal T as a main component, a rare earth element R including yttrium, and boron B; the magnet having fine crystal grains having an average grain size of 0.02-1.0 .mu.m, and having a carbon content of 0.8 weight % or less than an oxygen content of 0.5 weight % or less. The angular variance of orientation of the crystal grains is within 30.degree. from the C axes of the crystal grains when measured by X-ray. This magnet can be produced by mixing the magnet flakes with an additive composed of at least one organic compound having a boiling point of 50.degree. C. or higher.
    Type: Grant
    Filed: March 23, 1989
    Date of Patent: December 18, 1990
    Assignee: Hitachi Metals, Ltd.
    Inventors: Katsunori Iwasaki, Shigeho Tanigawa, Masaaki Tokunaga
  • Patent number: 4960469
    Abstract: Disclosed are a method of and a device for manufacturing Nd-Fe-B alloy magnet materials, and in particular, for manufacturing an integral, columnar-ring-shaped Nd-Fe-B magnet which is multi-pole-magnetized along the circumference thereof and which is used as the rotor magnet of a high-efficiency stepping motor. According to the method, a green compact or a densified compact is first prepared from a selected flake or a powder material composed of amorphous and/or fine-crystallized particles obtained through rapid quenching of the molten alloy. It is then provided with magnetic anisotropy through plastic deformation effected radially inwardly along substantially the entire periphery of the compact initially deformed to receive a mandrel-core, and maintained at a temperature of 600 to 850 degrees C. Subsequently, the deformed body is magnetized with the desired radial or polar magnetization pattern.
    Type: Grant
    Filed: November 23, 1988
    Date of Patent: October 2, 1990
    Assignee: Hitachi Metals, Ltd.
    Inventors: Shigeho Tanigawa, Katsunori Iwasaki, Yasuto Nozawa
  • Patent number: 4960474
    Abstract: In a magnetically anisotropic magnet for use in a motor, comprising at least one rare earth element (R), Fe and boron (B), said magnet having fine crystal grains, the improvement comprising Ga added in the magnet so that the magnet has a surface magnification of not less than 6, a residual magnetic flux density in the direction of easy magnetization of not less than 11 kG and a coercive force of not less than 12 kOe.The invention also provide a method of producing the magnetically anisotropic magnet for use in a motor, comprising the steps of: forming flakes by rapid quenching a molten alloy consisting of at least one rare earth element (R), Fe, boron (B) and an optical metal element (M); compacting the flakes to provide a green compact; and warm plastic working the green compact at a temperature between 600.degree. C. and 800.degree. C. at a strain rate of 0.0001 to 0.1 per second with a plastic working ratio (ho/h) of not less than 2.
    Type: Grant
    Filed: September 8, 1988
    Date of Patent: October 2, 1990
    Assignee: Hitachi Metals, Ltd.
    Inventors: Yasuto Nozawa, Shigeho Tanigawa, Katsunori Iwasaki
  • Patent number: 4952239
    Abstract: Magnetically anisotropic powder and resin-bonded magnets made therefrom have "flattened" crystal grains of an R-TM-B-M system alloy with preferably (c)/(a) greater than 2, where (c) is the grain size perpendicular to the C-axis and (a) the grain size parallel to the C-axis. The "flattened" grains are produced by plastically deforming a green compact of flakes formed by rapidly-quenching an alloy melt, and then crushing the plastically deformed body. In the alloy system, R is at least one of the rare earth elements including Y, TM is Fe or Fe a part of which has been substituted with Co, B is boron, and M is an additive selected from Si, Al, Nb, Zr, P and C.
    Type: Grant
    Filed: June 14, 1989
    Date of Patent: August 28, 1990
    Assignee: Hitachi Metals, Ltd.
    Inventors: Masatoki Tokunaga, Yasuto Nozawa, Katsunori Iwasaki
  • Patent number: 4952251
    Abstract: Anisotropic hot-worked permanent magnets are made from an R-T-B alloyed powder to which is added a combination internal lubricant including a carbon-based material such as graphite and a glass material such as glass from the B.sub.2 O.sub.3 -SiO.sub.2 BiO.sub.3 glass system. The internal lubricant provides improved formability during the hot-working step, such as die-upsetting, and provides finished magnet products wherein the individual grains are more uniformly plastically deformed throughout the product.
    Type: Grant
    Filed: May 23, 1989
    Date of Patent: August 28, 1990
    Assignee: Hitachi Metals, Ltd.
    Inventors: Katsunori Iwasaki, Shigeho Tanigawa, Masaaki Tokunaga
  • Patent number: 4921553
    Abstract: Magnetically anisotripic powder and resin-bonded magnets made therefrom have "flattened" crystal grains of an R-TM-B-M system alloy with preferably (c)/(a) greater than 2, where (c) is the grain size perpendicular to the C-axis and (a) the grain size parallel to the C-axis. The "flattened" grains are produced by plastically deforming a green compact of flakes formed by rapidly-quenching an alloy melt, and then crushing the plastically deformed body. In the allow system, R is at least one of the rare earth elements including Y, TM is Fe or Fe a part of which has been substituted with Co, B is boron, and M is an additive selected from Si, Al, Nb, Zr, P and C.
    Type: Grant
    Filed: March 17, 1987
    Date of Patent: May 1, 1990
    Assignee: Hitachi Metals, Ltd.
    Inventors: Masatoki Tokunga, Yasuto Nozawa, Katsunori Iwasaki