Nitto-Denko Corporation

Toyota Jidosha Kabushiki Kaisha

Izumi Ozeki

Katsuya Kume

Tomohiro Omure

Keisuke Taihaku

Takashi Ozaki

Keisuke Hirano

Toshiaki Okuno

Toshinobu Hoshino

Takashi Yamamoto

Junichi Nakayama

Yuuki Fukuda

Tomokazu Horio

Kenichi Fujikawa

Shoichiro Saito

Makoto Fujihara

Miho Yamaguchi

Kenji Nakamura

Kazuo Ouchi

Hirofumi Ebe

Eiichi Imoto

Hiroshi Matsuo

Masakazu Morimoto

Yuki Kato

Tomoya Matsuda

Katsuyuki Nakabayashi

Hirofumi Ono

Takuya Nobuta

Provided is a method for producing a sintered body that forms a rare-earth permanent magnet, has a single sintered structure and an arbitrary shape, and has easy magnetization axis orientations of different directions applied to the magnet material particles in a plurality of arbitrary regions. This method forms a three-dimensional first molded article from a composite material formed by mixing a resin material and magnet material particles containing a rare-earth substance. The first molded article is then subjected to a deforming force and a second molded article is formed in which the orientation direction of the easy magnetization axis of the magnet material particles in at least the one section of the horizontal cross-section is changed to a direction which differs from the orientation direction of the first molded article. The second molded article is heated to a sintering temperature and kept at the temperature for a period of time.

Method for producing sintered body that forms rare-earth permanent magnet and has non-parallel easy magnetization axis orientation

There are provided a rare-earth permanent magnet and a manufacturing method of a rare-earth permanent magnet capable of preventing deterioration of magnet properties. In the method, magnet material is milled into magnet powder. Next, a mixtureis prepared by mixing the magnet powder and a binder, and the mixtureis formed into a sheet-like shape to obtain a green sheet. Thereafter, magnetic field orientation is performed to the green sheet, which is then held for several hours in a non-oxidizing atmosphere at a pressure higher than normal atmospheric pressure, at 200 through 900 degrees Celsius for calcination. Thereafter, the calcined green sheetis sintered at a sintering temperature. Thereby a permanent magnetis manufactured.

Rare-earth permanent magnet and method for manufacturing rare-earth permanent magnet

The present invention provides a permanent magnet unit in which insulating layers are located at positions where an eddy current can be reduced most effectively. The permanent magnet unit includes at least one insulating layer, and a plurality of permanent magnet pieces located adjacent to each other with the at least one insulating layer in between. The at least one insulating layer is located at positions defined based on a magnitude of an eddy current flowing inside a permanent magnet, corresponding to a change in a magnetic field of the permanent magnet into which a plurality of the permanent magnet pieces are integrally formed without the at least one insulating layer.

Permanent magnet unit, rotating machine having permanent magnet unit, and method for manufacturing permanent magnet unit

Provided are a rare-earth permanent magnet whose magnet density after sintering is very high and a method for manufacturing a rare-earth permanent magnet. Thus, a magnet raw material is milled into magnet powder, and then, a compoundis formed by mixing the magnet powder thus milled with a binder. Next, the compoundthus formed is subjected to a hot-melt molding onto a supporting substrateso as to form a green sheetmolded to a sheet-like shape. Thereafter, while the green sheetthus molded is softened by heating, magnetic field orientation is carried out by applying a magnetic field to the green sheetthus heated; and further, the green sheethaving been subjected to the magnetic field orientation is calcined by a vacuum sintering, which is further followed by a pressure sintering to produce a permanent magnet

Rare earth permanent magnet and method for producing rare earth permanent magnet

There are provided a rare-earth permanent magnet, and a method for manufacturing a rare-earth permanent magnet and a system for manufacturing a rare-earth permanent magnet, capable of achieving improved shape uniformity. Magnet material is milled into magnet powder, and the milled magnet powder is formed into a formed body. The formed bodyis calcined and then sintered using a spark plasma sintering apparatus, so that a permanent magnetis manufactured. A die unitincluded in the spark plasma sintering apparatusthat performs spark plasma sintering at least includes in one direction an inflow holeconfigured to receive inflow of part of the pressurized formed body.

Rare-earth permanent magnet, method for manufacturing rare-earth permanent magnet and system for manufacturing rare-earth permanent magnet

There are provided a rare-earth permanent magnet and a manufacturing method thereof capable of preventing deterioration of magnet properties. In the method, magnet material is milled into magnet powder. Next, a mixture is prepared by mixing the magnet powder and a binder made of long-chain hydrocarbon and/or of a polymer or a copolymer consisting of monomers having no oxygen atoms. Next, the mixture is formed into a sheet-like shape so as to obtain a green sheet. After that, the green sheet is held for a predetermined length of time at binder decomposition temperature in a non-oxidizing atmosphere so as to remove the binder by causing depolymerization reaction or the like to the binder, which turns into monomer. The green sheet from which the binder has been removed is sintered by raising temperature up to sintering temperature. Thereby a permanent magnetis obtained.

The present invention relates to a permanent magnet obtained by wet-mixing a Dy compound or a Tb compound with a magnet raw material to coat a surface of the magnet raw material with the Dy compound or the Tb compound, and sintering a green sheet obtained by mixing the resulting magnet raw material with a resin binder and molding the resulting mixture. Since the present invention has the above-mentioned constitution, it becomes possible to sufficiently improve coercive force by Dy or Tb while decreasing the amount of Dy or Tb used. Further, it can be prevented that Dy or Tb is solid-solutionized in magnet particles to decrease residual magnetization.

Permanent magnet and method for manufacturing the same

A method for producing a permanent magnet for a motor, including a step of producing a slurry of a magnet powder, a step of molding the slurry into a sheet form to prepare green sheets of the magnet powder, and a step of alternately laminating the green sheets of the magnet powder and an insulating layer and sintering the laminated plural layers.

Permanent magnet for motor, and method for manufacturing the permanent magnet for motor

There are provided a permanent magnet and a manufacturing method thereof enabling carbon content contained in magnet particles to be reduced in advance before sintering even when wet milling is employed. Coarsely-milled magnet powder is further milled by a bead mill in a solvent together with an organometallic compound expressed with a structural formula of M&#x2212;(OR)(M includes at least one of neodymium, praseodymium, dysprosium and terbium, each being a rare earth element, R represents a substituent group consisting of a straight-chain or branched-chain hydrocarbon, x represents an arbitrary integer) so as to uniformly adhere the organometallic compound to particle surfaces of the magnet powder. Thereafter, a compact body of compacted magnet powder is held for several hours in hydrogen atmosphere at 200 through 900 degrees Celsius to perform hydrogen calcination process. Thereafter, through sintering process, a permanent magnetis manufactured.

Permanent magnet and manufacturing method thereof

There are provided a permanent magnet and a manufacturing method thereof capable of decreasing an activity level of a calcined body activated by a calcination process. To fine powder of milled neodymium magnet is added an organometallic compound solution containing an organometallic compound expressed with a structural formula of M&#x2212;(OR)(M represents Dy or Tb, R represents a substituent group consisting of a straight-chain or branched-chain hydrocarbon,represents an arbitrary integer) so as to uniformly adhere the organometallic compound to particle surfaces of the neodymium magnet powder. Thereafter, desiccated magnet powder is held for several hours in hydrogen atmosphere at 200 through 900 degrees Celsius. Thereafter, the powdery calcined body calcined through the calcination process in hydrogen is held for several hours in vacuum atmosphere at 200 through 600 degrees Celsius for a dehydrogenation process. Thereafter, through powder compaction and sintering process, the powdery calcined body is formed into a permanent magnet.

There are provided a permanent magnet and a manufacturing method thereof enabling carbon content contained in magnet particles to be reduced in advance before sintering even when wet milling is employed. Coarsely-milled magnet powder is further milled by a bead mill in a solvent together with an organometallic compound expressed with a structural formula of M-(OR)(M represents V, Mo, Zr, Ta Ti W or Nb, R represents a substituent group consisting of a straight-chain or branched-chain hydrocarbon, X represents an arbitrary integer) so as to uniformly adhere the organometallic compound to particle surfaces of the magnet powder. Thereafter, a compact body of compacted magnet powder is held for several hours in hydrogen atmosphere at 200 through 900 degrees Celsius to perform hydrogen calcination process. Thereafter, through sintering process, a permanent magnetis formed.

There are provided a permanent magnet and a manufacturing method thereof capable of decreasing an activity level of a calcined body activated by a calcination process. To fine powder of milled neodymium magnet is added an organometallic compound solution containing an organometallic compound expressed with a structural formula of M-(OR)(M represents V, Mo, Zr, Ta, Ti, W or Nb, R represents a substituent group consisting of a straight-chain or branched-chain hydrocarbon,represents an arbitrary integer) so as to uniformly adhere the organometallic compound to particle surfaces of the neodymium magnet powder. Thereafter, desiccated magnet powder is held for several hours in hydrogen atmosphere at 200 through 900 degrees Celsius. Thereafter, the powdery calcined body calcined through the calcination process in hydrogen is held for several hours in vacuum atmosphere at 200 through 600 degrees Celsius for a dehydrogenation process.

There are provided a permanent magnet and a manufacturing method thereof capable of manufacturing metal alkoxide in better work environment, simpler production facilities and easier manufacturing process and also reducing the manufacturing costs. An electrolytic solution is obtained through dissolving chloride or injecting hydrogen chloride gas into alcohol which is same alcohol as is a constituent element of metal alkoxide to be manufactured. Then, electrolysis is performed on the electrolytic solution while using, for an anode, a ferroalloy that contains iron and metal which is a constituent element of the metal alkoxide to be manufactured in a predetermined weight ratio (such as 1:1), and, for a cathode, the same ferroalloy, carbon, platinum or stainless steel, so as to obtain an alcohol solution of the metal alkoxide. Then, a permanent magnet is manufactured using the alcohol solution of the metal alkoxide thus obtained.

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Ibaraki, Japan

Izumi Ozeki