Mitsubishi Materials Corporation

Mitsubishi Metal Corporation

Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Kinzoku Kabushiki Kaisha

Nippon Telegraph and Telephone Corporation

The United States of America as Represented by the United States

Dai Nippon Insatsu Kabushiki Kaisha

Mitsubishi Kinzoku K.k.

Takuo Takeshita

Ryoji Nakayama

Tadashi Sugihara

Tamotsu Ogawa

Sadaaki Hagino

Yukihiro Ohuchi

Kouichi Ishiyama

Motokazu Suzuki

Yoshinari Ishii

Muneaki Watanabe

Yasuhiro Hanaue

Tetsuro Yamaguchi

Shouichi Kubo

Yoshiki Hoshino

Hideaki Yoshida

Takashi Inaguchi

Masashi Nagao

Hideto Yoshimura

Norikazu Komada

Karl A Gschneidner, Jr

Takeshi Sakurai

Etsuji Kimura

Uichiro Mizutani

Kazunori Igarashi

Ginya Ishiguro

Yoshio Kanda

Toshio Kimura

Kiyoyuki Ookubo

Kazuki Takashima

Yukihiro Ouchi

Yasuaki Yoshioka

Hideki Tonda

Hachiro Saito

Shuichi Fujino

Etsuji Kimua

Yoshinari Ishill

Yoshio Murakami

Bernard J Beaudry

Tatsuro Ajima

Satoru Mori

A solid resin-coated composite magnet powder for producing an improved anisotropic bonded magnet contains individual anisotropic magnet powder particles each having a surface coated with a solid resin layer thereon. A method is disclosed for producing a solid resin-coated magnet powder, including the steps of kneading an anisotropic magnet powder with a solid resin under a reduced pressure, granulating the resultant mixture to produce a solid resin-coated composite magnet powder, and milling the composite magnet powder produced to separate the solid resin-coated composite magnet powder into individual anisotropic magnet powder particles coated with the solid resin.

Solid resin-coated magnet powder and a method for producing an

This invention relates to a magnetic recording powder having a low Curie temperature and a high saturation magnetization (.sigma.s). The magnetic recording powder of this invention is of a composite oxide having a hexagonal ferrite type crystal structure comprises: (a) between 14 and 20 atomic % of at least one of strontium oxide and barium oxide, (b) between 15 and 40 atomic % of chromium oxide, (c) between 2 and 15 atomic % of at least one member of the group consisting of zinc oxide, magnesium oxide and copper oxide, (d) between 2 and 15 atomic % of at least one member of the group consisting of titanium oxide, zirconium oxide and tin oxide, with substantial remainder being iron oxide and unavoidable impurities. Further, the magnetic recording powder of this invention is of a composite oxide having saturation magnetization (.sigma.s) of 15 emu/g or higher, and a Curie temperature (Tc) of 155.degree. C. or lower.

Magnetic recording powder having low curie temperature and high

The present invention presents a method and an apparatus for heat treating a metallic material by performing hydrogen absorption in or desorption from the metallic material. The method includes the steps of recovering the hydrogen gas released from a desorption step and recycling it to a hydrogen absorbing step. Hydrogen recovering can be performed either in a device containing a hydrogen absorbing alloy or in a second heat treating furnace containing the metallic material. Various controlling devices are used to regulate the process of heat treating and recovering of hydrogen gas.

Method for heat treating metallic materials and apparatus therefor

A magnetically anisotropic R-T-B-M powder material which is starting with an R-T-B-M raw alloy material having a c-axis crystal orientation of an R.sub.2 T.sub.14 B-type intermetallic compound phase. In one embodiment, the starting material is compressed sintered in a magnetic field and recompressed in a magnetic field. In a second embodiment, the starting material is hot-pressed and homogenized. A method of manufacturing anisotropic magnets such as bond and full density magnets made from the magnetically anisotropic R-T-B-M powder material is disclosed.

Method of manufacturing magnetically anisotropic R-T-B-M powder material

The present invention provides a method for producing a rare earth alloy magnet powder exhibiting stable and superior magnetic properties using hydrogenation followed by dehydrogenation. In a method for producing a rare earth alloy magnet powder wherein a homogenized rare earth alloy magnet alloy material is subjected to hydrogenation at a temperature in a range between 750.degree. C. and 950.degree. C., followed by dehydrogenation at a temperature in a range between 750.degree. C. and 950.degree. C.; cooled; and crushed, both the hydrogenation and the dehydrogenation are carried out in a vacuum tube furnace; and the alloy material in the dehydrogenation step maintains a temperature drop of at most 50.degree. C. due to an endothermic reaction which occurs during the dehydrogenation step.

Method for producing rare earth alloy magnet powder

A hot press molded body or an HIP molded body having one of a composition comprising R: 10-20 atomic %, B: 3-20 atomic %, and a total amount of one or a plurality of Ga, Zr, and Hf: 0.001-5.0 atomic %, a remainder comprising Fe and unavoidable impurities; or a composition comprising R: 10-20 atomic %, B: 3-20 atomic %, and a total amount of one or a plurality of Ti, V, Nb, Ta, Al, and Si: 0.001-5.0 atomic %, a remainder comprising Fe and unavoidable impurities; or a composition comprising Co: 0.1-50 atomic % added to one of the above compositions, having an aggregate structure of crystallized grains having as a main phase thereof a R.sub.2 Fe.sub.14 B type or R.sub.2 (Fe, Co).sub.14 B type intermetallic compound having a tetragonal structure, the crystallized grains having dimensions of 0.05-20 .mu.m; and individual crystallized grains comprising more than 50 volume % of the total crystallized grains comprising the aggregate structure, have a value of less than 2 of a ratio b/a of a smallest grain diameter a and a largest grain diameter b.

Anisotropic rare earth-Fe-B system and rare earth-Fe-Co-B system magnet

Disclosed herein is an amorphous material in the form of foil for the regenerator, which is prepared by quenching a melt of a rare earth alloy by injection toward the surface of a roll running at a high speed, said alloy being composed of one or more rare earth elements in an amount of 50-99 atomic %, with the remainder being one or more iron family elements. This amorphous material has a large, stable specific heat capacity at very low temperatures.

Amorphous material for regenerator

An oxide superconducting material is coated with silver or an alloy thereof and shaped into a linear body, and the linear body is subjected to diameter reduction by means of groove roll rolling, a swaging machine and the like, and then differential speed rolling and heat treatment are repeatedly performed, whereby the linear body is shaped into a tape-shaped wire material. The microstructure control in the longitudinal direction is performed uniformly and efficiently, and a superconducting wire having a high c-axis orientation ratio and a large critical current density Jc at a service temperature is obtained.

Method for manufacturing an oxide superconducting tape

Apparatus for closed cycle hydrogenation recovery and rehydrogenation

There is disclosed a R--Fe--B or R--Fe--Co--B alloy permanent magnet powder which may contain Ga, Zr or Hf, or may further contain Al, Si or V. Each individual particle of the powder includes a structure of recrystallized grains containing a R.sub.2 Fe.sub.14 B or R.sub.2 (Fe,Co).sub.14 B intermetallic compound phase. The intermetallic compound phase has recrystallized grains of a tetragonal crystal structure having an average crystal grain size of 0.05 to 20 .mu.m. At least 50% by volume of the recrystallized grains of the aggregated structure are formed so that a ratio of the greatest dimension to the smallest dimension is less than 2 for each recrystallized grain. In order to manufacture the magnet powder, regenerative material and alloy material are prepared and their temperature is elevated in a hydrogen atmosphere. Then, the alloy material and the regenerative material are held in the same atmosphere at a temperature or 750.degree. C. to 950.degree. C., and then held in a vacuum at 750.degree. C. to 950.degree. C., and cooled and crushed. A bonded magnet produced using the above magnet powder is also disclosed.

Rare earth permanent magnet powder, method for producing same and bonded

The present invention is related to a superconductive ceramic wire and a method for making same. According to the first aspect of the invention, there is provided a method for making a superconductive ceramic wire, the method comprising the steps of: (a) preparing a superconductive porous ceramics; (b) depositing lead in the pores of the ceramics; (c) covering the lead-depositted ceramics with a metal; and (d) extending the metal-clad and lead-deposited ceramics. According to the second aspect of the invention, there is provided a superconductive ceramic wire which is obtained by: (a) preparing a superconductive porous ceramics; (b) depositing lead in the pores of the ceramics; (c) covering the lead-depositted ceramics with a metal; and (d) extending the metal-clad lead-depositted ceramics.

Superconductive ceramic wire and method for making same

A R-Fe-B or R-Fe-Co-B permanent magnet powder excellent in magnetic anisotropy and corrosion resistivity, having powder particles. The powder particles each consist essentially of, in atomic percentage:

Rare earth element-Fe-B or rare earth element-Fe-Co-B permanent magnet

Process for producing Bi-Ca-Sr-Cu-O, TL-Ca-Sr-Cu-O and Tl-Ba-Ca-Cu-O

There is disclosed a R-Fe-B or R-Fe-Co-B alloy permanent magnet powder which may contain Ga, Zr or Hf, or may further contain Al, Si or V. Each individual particle of the powder includes a structure of recrystallized grains containing a R.sub.2 Fe.sub.14 B or R.sub.2 (Fe,Co).sub.14 B intermetallic compound phase. The intermetallic compound phase has recrystallized grains of a tetragonal crystal structure having an average crystal grain size of 0.05 to 20 .mu.m. At least 50% by volume of the recrystallized grains of the aggregated structure are formed so that a ratio of the greatest dimension to the smallest dimension is less than 2 for each recrystallized grain. In order to manufacture the magnet powder, regenerative material and alloy material are prepared and their temperature is elevated in a hydrogen atmosphere. Then, the alloy material and the regenerative material are held in the same atmosphere at a temperature of 750.degree. C. to 950.degree. C., and then held in a vacuum at 750.degree. C. to 950.degree. C., and cooled and crushed. A bonded magnet produced using the above magnet powder is also disclosed.

Rare earth permanent magnet power, method for producing same and bonded

A magnetic recording powder for use as a material for magnetic recording media including magnetic tapes and magnetic cards, the powder having a high coercive force at room temperatures and a low Curie point, consists of at least one element selected from the group consisting of Y and rare-earth elements (R): 5-20 atomic %, B: 5-20 atomic %, Mn: 4-20 atomic %; and Fe and inevitable impurities: the balance. If required, the powder may further contain Al: 1-10 atomic %, and/or Cr: 1-10 atomic %. The powder has a mean particle size of 0.5-2 .mu.m and a mean crystal grain size of 0.1-0.4 .mu.m.

Magnetic recording powder having a high coercive force at room

Growing community of inventors

Omiya, Japan

Takuo Takeshita