摘要:
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 magnet 1 is obtained.
摘要:
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 magnet 1 is obtained.
摘要:
There are provided a permanent magnet and a manufacturing method thereof enabling, even when wet milling is employed, carbon content contained in magnet particles to be reduced in advance before sintering, and also enabling the entirety of the magnet to be densely sintered without causing a gap between a main phase and a grain boundary phase in the sintered magnet. Coarsely-milled magnet powder is further milled by a bead mill in an organic solvent. Thereafter, the magnet powder is compacted to produce a formed body. Hydrogen calcination process is performed through holding the formed body for several hours in hydrogen atmosphere at a pressure higher than normal atmospheric pressure at 200 through 900 degrees Celsius. Thereafter, through sintering process, a permanent magnet 1 is manufactured.
摘要:
There are provided a rare-earth permanent magnet and a manufacturing method of the rare-earth permanent magnet capable of preventing deterioration of magnet properties. In the method, magnet material is milled into magnet powder, and the magnet powder is mixed with a binder made of a hydrocarbon to prepare slurry 12, and one or more kinds of organic solvents selected from a group of organic compounds consisting of hydrocarbons. Next, the slurry 12 is formed into a sheet-like shape to obtain a green sheet 13. After that, the green sheet 13 is held for a predetermined length of time at binder decomposition temperature in a non-oxidizing atmosphere so as to cause depolymerization reaction or the like to the binder, which turns into monomer and is removed. The green sheet 13 with the binder removed is sintered by raising temperature up to sintering temperature. Thereby a permanent magnet 1 is obtained.
摘要:
There are provided a rare-earth permanent magnet and a manufacturing method thereof capable of achieving improvement of magnetic properties by optimizing magnetic field orientation. In the method, magnet material is milled into magnet powder. Next, the magnet powder and a binder are mixed to obtain a mixture. Next, the thus prepared mixture is formed into long-sheet-like shape so as to obtain a green sheet 13. Before the thus formed green sheet 13 dries, magnetic field is applied in an in-plane and transverse direction or an in-plane and machine direction of the green sheet for magnetic field orientation. Thereby, a permanent magnet 1 is obtained.
摘要:
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 a fatty acid methyl ester and/or one of or a blend of polymers and copolymers each composed of monomers satisfying a given condition. Next, the mixture is formed into a sheet-like shape 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 magnet 1 is obtained.
摘要:
There are provided a rare-earth permanent magnet and a manufacturing method thereof capable of boosting productivity by improving thickness accuracy of a green sheet. In the method, magnet material is milled into magnet powder, and the magnet powder and a binder are mixed to obtain a mixture including 1 to 40 wt % of the binder therein. Next, by high precision coating of a substrate with the mixture, a green sheet is obtained at thickness precision within a margin of error of plus or minus 5% with reference to a designed value. Thereafter, the green sheet is held for predetermined time at binder decomposition temperature in non-oxidizing atmosphere, whereby depolymerization reaction or the like changes the binder into monomer and thus removes the binder. The green sheet with the binder removed therefrom undergoes pressure sintering such as SPS method so as to obtain a permanent magnet 1.
摘要:
There are provided a rare-earth permanent magnet and a manufacturing method thereof capable of simplifying manufacturing process and improving productivity through advanced ability to produce net shapes. In the method, magnet material is milled into magnet powder, and the magnet powder and a binder are mixed to prepare a mixture. Next, the prepared mixture is formed into a green sheet. Thereafter, the green sheet is held for predetermined time at binder decomposition temperature in non-oxidizing atmosphere, whereby depolymerization reaction or the like changes the binder into monomer and thus removes the binder. The green sheet with the binder removed therefrom undergoes pressure sintering such as SPS method so as to obtain a rare-earth permanent magnet 1.
摘要:
There are provided a permanent magnet and a manufacturing method thereof capable of densely sintering the entirety of the magnet without making a gap between a main phase and a grain boundary phase in the sintered magnet. 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)x (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 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.
摘要:
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, and also the entirety of the magnet to be densely sintered without making a gap between a main phase and a grain boundary phase in the sintered magnet. Coarsely-milled magnet powder is further milled by a bead mill in an organic solvent. 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 magnet 1 is formed.