WO2012176514A1 - 希土類永久磁石及び希土類永久磁石の製造方法 - Google Patents
希土類永久磁石及び希土類永久磁石の製造方法 Download PDFInfo
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
- H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
- H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
- H01F1/06—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys in the form of particles, e.g. powder
- H01F1/08—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys in the form of particles, e.g. powder pressed, sintered, or bound together
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
- H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
- H01F41/0253—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing permanent magnets
- H01F41/0266—Moulding; Pressing
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
- B22F1/10—Metallic powder containing lubricating or binding agents; Metallic powder containing organic material
- B22F1/103—Metallic powder containing lubricating or binding agents; Metallic powder containing organic material containing an organic binding agent comprising a mixture of, or obtained by reaction of, two or more components other than a solvent or a lubricating agent
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
- B22F3/22—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces for producing castings from a slip
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/005—Ferrous alloys, e.g. steel alloys containing rare earths, i.e. Sc, Y, Lanthanides
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
- H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
- H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
- H01F1/047—Alloys characterised by their composition
- H01F1/053—Alloys characterised by their composition containing rare earth metals
- H01F1/055—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
- H01F1/057—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
- H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
- H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
- H01F1/047—Alloys characterised by their composition
- H01F1/053—Alloys characterised by their composition containing rare earth metals
- H01F1/055—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
- H01F1/057—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
- H01F1/0571—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes
- H01F1/0575—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes pressed, sintered or bonded together
- H01F1/0577—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes pressed, sintered or bonded together sintered
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
- H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F7/00—Magnets
- H01F7/02—Permanent magnets [PM]
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F2998/00—Supplementary information concerning processes or compositions relating to powder metallurgy
- B22F2998/10—Processes characterised by the sequence of their steps
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C2202/00—Physical properties
- C22C2202/02—Magnetic
Definitions
- the present invention relates to a rare earth permanent magnet and a method for producing a rare earth permanent magnet.
- a powder sintering method is generally used conventionally.
- the powder sintering method first, magnet powder obtained by pulverizing raw materials by a jet mill (dry pulverization) or the like is manufactured. Thereafter, the magnet powder is put into a mold and press-molded into a desired shape while applying a magnetic field from the outside. Then, the solid magnet powder formed into a desired shape is manufactured by sintering at a predetermined temperature (for example, 1100 ° C. for Nd—Fe—B magnets).
- the permanent magnet is manufactured by the above-described powder sintering method
- the powder sintering method it is necessary to ensure a certain porosity in the press-molded magnet powder for magnetic field orientation.
- magnet powder having a certain porosity is sintered, it is difficult to uniformly contract during the sintering, and deformation such as warpage and dent occurs after sintering.
- the sintered magnet can be dense and dense, and distortion occurs on the magnet surface. Therefore, conventionally, it was necessary to compress the magnet powder in a size larger than the desired shape, assuming that the magnet surface can be distorted in advance. Then, after sintering, a diamond cutting and polishing operation is performed to correct the shape into a desired shape. As a result, the number of manufacturing steps increases, and the quality of the manufactured permanent magnet may decrease.
- a technique has been proposed in which a green sheet is produced by kneading magnet powder and a binder, and a permanent magnet is produced by sintering the produced green sheet (for example, JP-A-1-150303).
- a rare earth magnet for example, a neodymium magnet
- a rare earth element for example, Nd
- oxygen for example, Nd
- the rare earth element and oxygen are combined in the sintering process to form a metal oxide. Things will be formed.
- the rare earth element is combined with oxygen so that the rare earth element is insufficient in comparison with the content based on the stoichiometric composition (for example, Nd 2 Fe 14 B for neodymium magnets), and ⁇ Fe is contained in the main phase of the sintered magnet.
- the magnetic properties are greatly reduced due to precipitation.
- the problem becomes large.
- the present invention has been made to solve the above-mentioned conventional problems, and when adding a binder or an organic solvent to a magnet powder to form a green sheet for sintering, the amount of oxygen contained in the magnet is reduced. As a result, it is an object of the present invention to provide a rare earth permanent magnet and a method for producing the rare earth permanent magnet which can prevent the deterioration of the magnet characteristics.
- the rare earth permanent magnet according to the present invention is selected from a step of pulverizing a magnet raw material into magnet powder, a binder composed of the pulverized magnet powder and hydrocarbon, and an organic compound composed of hydrocarbon 1 Produced by a step of producing a slurry by kneading an organic solvent of at least seeds, a step of forming the slurry into a sheet shape to produce a green sheet, and a step of sintering the green sheet It is characterized by.
- the rare earth permanent magnet according to the present invention may be removed by scattering the binder by holding the green sheet at a binder decomposition temperature in a non-oxidizing atmosphere for a predetermined time before sintering the green sheet. It is characterized by.
- the green sheet in the step of removing the binder by scattering, is held at 200 ° C. to 900 ° C. for a certain time in a hydrogen atmosphere or a mixed gas atmosphere of hydrogen and an inert gas. It is characterized by doing.
- the magnet raw material in the step of pulverizing the magnet raw material into magnet powder, the magnet raw material is wet pulverized in the organic solvent and the slurry is generated in the step of generating the slurry.
- the slurry is produced by adding the binder to the organic solvent containing.
- the method for producing a rare earth permanent magnet includes a step of pulverizing a magnet raw material into magnet powder, and one type selected from the pulverized magnet powder, a binder composed of hydrocarbons, and an organic compound composed of hydrocarbons.
- the method for producing a rare earth permanent magnet according to the present invention is to scatter the binder by holding the green sheet at a binder decomposition temperature for a certain time in a non-oxidizing atmosphere before sintering the green sheet. It is characterized by removing.
- the green sheet in the step of removing the binder by scattering, is heated at 200 ° C. to 900 ° C. in a hydrogen atmosphere or a mixed gas atmosphere of hydrogen and an inert gas. It is characterized by holding for a certain time.
- the magnet raw material in the step of pulverizing the magnet raw material into magnet powder, the magnet raw material is wet pulverized in the organic solvent and pulverized in the step of generating the slurry.
- the slurry is produced by adding the binder to the organic solvent containing the magnet powder.
- the permanent magnet is composed of a magnet obtained by sintering a green sheet obtained by kneading and molding a magnet powder, a binder, and an organic solvent. Therefore, deformation such as warping and dent after sintering does not occur, and pressure unevenness at the time of pressing is eliminated, so there is no need for correction processing after sintering, which simplifies the manufacturing process. can do. Thereby, a permanent magnet can be formed with high dimensional accuracy. Further, even when the permanent magnet is thinned, it is possible to prevent the processing man-hours from increasing without reducing the material yield.
- the amount of oxygen contained in the magnet during sintering is reduced. be able to. As a result, it can suppress that a metal oxide is formed in a sintering process, and can prevent that a magnet characteristic falls.
- the rare earth permanent magnet according to the present invention before the green sheet is sintered, the binder is scattered and removed by holding the green sheet at a binder decomposition temperature in a non-oxidizing atmosphere for a certain period of time.
- the amount of carbon contained in the magnet can be reduced in advance. As a result, it is possible to suppress the precipitation of ⁇ Fe in the main phase of the magnet after sintering, to densely sinter the entire magnet, and to prevent the coercive force from being lowered.
- the carbon sheet contained in the magnet is obtained by calcining the green sheet kneaded with the binder in a hydrogen atmosphere or a mixed gas atmosphere of hydrogen and an inert gas. It can reduce more reliably.
- the rare earth permanent magnet of the present invention when the magnet is wet pulverized, it is contained in the magnet at the time of sintering by using one or more organic solvents selected from organic compounds comprising hydrocarbons.
- the amount of oxygen can be reduced. As a result, it can suppress that a metal oxide is formed in a sintering process, and can prevent that a magnet characteristic falls.
- a permanent magnet is produced by kneading magnet powder, a binder, and an organic solvent, and sintering a formed green sheet. Since deformation due to sintering is uniform, deformation such as warping and dent after sintering does not occur, and pressure unevenness during pressing is eliminated, so it is necessary to perform correction after sintering The manufacturing process can be simplified. Thereby, a permanent magnet can be formed with high dimensional accuracy. Further, even when the permanent magnet is thinned, it is possible to prevent the processing man-hours from increasing without reducing the material yield.
- the amount of oxygen contained in the magnet during sintering is reduced. be able to. As a result, it can suppress that a metal oxide is formed in a sintering process, and can prevent that a magnet characteristic falls.
- the green sheet before the green sheet is sintered, the green sheet is held at a binder decomposition temperature in a non-oxidizing atmosphere for a certain period of time to scatter and remove the binder. Therefore, the amount of carbon contained in the magnet can be reduced in advance. As a result, it is possible to suppress the precipitation of ⁇ Fe in the main phase of the magnet after sintering, to densely sinter the entire magnet, and to prevent the coercive force from being lowered.
- the green sheet in which the binder is kneaded is calcined in a hydrogen atmosphere or a mixed gas atmosphere of hydrogen and an inert gas to be contained in the magnet.
- the amount of carbon can be reduced more reliably.
- the method for producing a rare earth permanent magnet according to the present invention when the magnet is wet pulverized, by using one or more organic solvents selected from organic compounds comprising hydrocarbons, The amount of oxygen contained in can be reduced. As a result, it can suppress that a metal oxide is formed in a sintering process, and can prevent that a magnet characteristic falls.
- FIG. 1 is an overall view showing a permanent magnet according to the present invention.
- FIG. 2 is a diagram for explaining the effect at the time of sintering based on the improvement of the thickness accuracy of the green sheet according to the present invention.
- FIG. 3 is a diagram showing problems when the thickness accuracy of the green sheet according to the present invention is low.
- FIG. 4 is an explanatory view showing a manufacturing process of the permanent magnet according to the present invention.
- FIG. 5 is an explanatory view showing a green sheet forming process, in particular, of the manufacturing process of the permanent magnet according to the present invention.
- FIG. 6 is an explanatory diagram showing the pressure-sintering step of the green sheet, among the manufacturing steps of the permanent magnet according to the present invention.
- FIG. 7 is a diagram showing various measurement results for the magnets of Example 1 and Comparative Examples 1 and 2.
- FIG. 8 is a diagram showing various measurement results for the magnets of Example 2 and Comparative Examples 3 and 4.
- FIG. 8 is a diagram showing various measurement results for
- FIG. 1 is an overall view showing a permanent magnet 1 according to the present invention.
- the permanent magnet 1 shown in FIG. 1 has a fan shape, but the shape of the permanent magnet 1 varies depending on the punched shape.
- the permanent magnet 1 according to the present invention is an Nd—Fe—B based magnet.
- the content of each component is Nd: 27 to 40 wt%, B: 1 to 2 wt%, and Fe (electrolytic iron): 60 to 70 wt%.
- FIG. 1 is an overall view showing a permanent magnet 1 according to the present embodiment.
- the permanent magnet 1 is a thin-film permanent magnet having a thickness of, for example, 0.05 mm to 10 mm (for example, 1 mm). And it produces by sintering the molded object (green sheet) shape
- a resin, a long-chain hydrocarbon, a mixture thereof, or the like is used as the binder mixed with the magnet powder.
- a resin for example, polyisobutylene (PIB), butyl rubber (IIR), polyisoprene (IR), polybutadiene, polystyrene, styrene-isoprene block copolymer (SIS), styrene-butadiene block copolymer Polymer (SBS), 2-methyl-1-pentene polymer resin, 2-methyl-1-butene polymer resin, ⁇ -methyl styrene polymer resin, polybutyl methacrylate, polymethyl methacrylate and the like are used.
- PIB polyisobutylene
- IIR butyl rubber
- IR polyisoprene
- SIS styrene-isoprene block copolymer
- SBS styrene-butadiene block copolymer Polymer
- the resin used for the binder in order to reduce the amount of oxygen contained in the magnet, a polymer (for example, polyisobutylene, etc.) made of hydrocarbons, having depolymerization properties and excellent in thermal decomposability is used. Is desirable. In order to properly dissolve the binder in a general-purpose solvent such as toluene, it is desirable to use a resin other than polyethylene and polypropylene as the resin used for the binder.
- a long chain hydrocarbon when used for the binder, it is preferable to use a long chain saturated hydrocarbon (long chain alkane) that is solid at room temperature and liquid at room temperature or higher. Specifically, it is preferable to use a long-chain saturated hydrocarbon having 18 or more carbon atoms.
- the amount of binder added is an amount that appropriately fills the gaps between the magnet particles in order to improve the sheet thickness accuracy when the mixture of the magnet powder and the binder is formed into a sheet shape.
- the ratio of the binder to the total amount of the magnet powder and the binder in the mixture after addition of the binder is 1 wt% to 40 wt%, more preferably 2 wt% to 30 wt%, and even more preferably 3 wt% to 20 wt%.
- organic solvents added to the magnetic powder when producing green sheets include alcohols such as isopropyl alcohol, ethanol and methanol, lower hydrocarbons such as pentane and hexane, and aromatics such as benzene, toluene and xylene.
- Esters such as ethyl acetate, ketones, mixtures thereof and the like can be used, but in the present invention, as described later, the organic compound is selected from hydrocarbons for the purpose of reducing the amount of oxygen contained in the magnet. It is desirable to use one or more organic solvents.
- the one or more organic solvents selected from organic compounds composed of hydrocarbons include toluene, hexane, pentane, benzene, xylene, and mixtures thereof.
- toluene or hexane is used.
- the organic solvent may contain a small amount of an organic compound other than the organic compound made of hydrocarbon.
- pressure sintering is used as a method for sintering the green sheet.
- pressure sintering include hot press sintering, hot isostatic pressing (HIP) sintering, ultra-high pressure synthetic sintering, gas pressure sintering, and discharge plasma (SPS) sintering.
- HIP hot isostatic pressing
- SPS discharge plasma
- a sintering method in which sintering is performed in a shorter time and at a lower temperature.
- a sintering method that can reduce the warpage generated in the magnet after sintering. Therefore, in the present invention, among the above sintering methods, it is desirable to use uniaxial pressure sintering in which pressure is applied in the uniaxial direction and SPS sintering in which sintering is performed by current sintering.
- SPS sintering is a sintering method in which a graphite sintering mold having a sintering object disposed therein is heated while being pressed in a uniaxial direction. Further, in SPS sintering, in addition to thermal and mechanical energy used for general sintering, electromagnetic energy by pulse energization and self-heating of the work piece are obtained by pulse current heating and mechanical pressure. The discharge plasma energy generated between the particles is used as a driving force for the sintering. Therefore, rapid heating / cooling is possible compared to atmosphere heating in an electric furnace or the like, and sintering can be performed in a lower temperature range.
- a green body obtained by punching a green sheet into a desired product shape (for example, a fan shape shown in FIG. 1) is placed in a sintering mold of an SPS sintering apparatus.
- a desired product shape for example, a fan shape shown in FIG. 1
- a plurality (for example, ten pieces) of the molded bodies 2 are arranged in the sintering mold 3 at the same time.
- the thickness accuracy of the green sheet is within ⁇ 5%, more preferably within ⁇ 3%, and even more preferably within ⁇ 1% of the design value.
- the sintering temperature there is a variation in the sintering temperature, and it cannot be sintered properly.
- FIG. 4 is an explanatory view showing a manufacturing process of the permanent magnet 1 according to the present embodiment.
- an ingot made of a predetermined fraction of Nd—Fe—B (eg, Nd: 32.7 wt%, Fe (electrolytic iron): 65.96 wt%, B: 1.34 wt%) is manufactured. Thereafter, the ingot is roughly pulverized to a size of about 200 ⁇ m by a stamp mill or a crusher. Alternatively, the ingot is melted, flakes are produced by strip casting, and coarsely pulverized by hydrogen crushing.
- the coarsely pulverized magnet powder is either (a) in an atmosphere made of an inert gas such as nitrogen gas, Ar gas, or He gas having substantially 0% oxygen content, or (b) having an oxygen content of 0.0001.
- the oxygen concentration of substantially 0% is not limited to the case where the oxygen concentration is completely 0%, but may contain oxygen in such an amount that a very small amount of oxide film is formed on the surface of the fine powder. Means good.
- wet pulverization may be used as a method for pulverizing the magnet raw material.
- the coarsely pulverized magnet powder is finely pulverized to an average particle size of a predetermined size or less (for example, 0.1 ⁇ m to 5.0 ⁇ m) using toluene as a solvent.
- the magnet powder contained in the organic solvent after the wet pulverization is dried by vacuum drying or the like, and the dried magnet powder is taken out.
- solvent used for wet grinding 1 or more types of organic solvents selected from the organic compound which consists of hydrocarbons are used.
- organic solvents selected from the organic compound which consists of hydrocarbons.
- toluene there are hexane, pentane, benzene, xylene, and mixtures thereof.
- a binder solution to be added to the fine powder finely pulverized by the jet mill 11 or the like is prepared.
- the binder a resin, a long-chain hydrocarbon, a mixture thereof, or the like that is made of hydrocarbon as described above, has depolymerization properties, and is excellent in thermal decomposability is used.
- a binder solution is produced by diluting a binder in an organic solvent.
- the organic solvent used for the dilution one or more organic solvents selected from organic compounds composed of hydrocarbons as described above are used. For example, there are toluene, hexane, pentane, benzene, xylene, a mixture thereof, and the like. In the present invention, particularly toluene or hexane is used.
- the binder solution is added to the fine powder classified by the jet mill 11 or the like.
- the slurry 12 in which the fine powder of the magnet raw material, the binder, and the organic solvent are mixed is generated.
- the amount of the binder solution added is such that the ratio of the binder to the total amount of the magnet powder and the binder in the slurry after the addition is 1 wt% to 40 wt%, more preferably 2 wt% to 30 wt%, still more preferably 3 wt% to The amount is preferably 20 wt%.
- the slurry 12 is produced by adding 100 g of a 20 wt% binder solution to 100 g of magnet powder.
- the binder solution is added in an atmosphere made of an inert gas such as nitrogen gas, Ar gas, or He gas.
- an inert gas such as nitrogen gas, Ar gas, or He gas.
- a green sheet 13 is formed from the generated slurry 12.
- the produced slurry 12 can be applied by an appropriate method on a support substrate 14 such as a separator and dried as necessary.
- the coating method is preferably a method having excellent layer thickness controllability such as a doctor blade method, a die method, or a comma coating method.
- it is desirable to use a die method or a comma coating method that is particularly excellent in layer thickness controllability that is, a method capable of high accuracy on the base material.
- a die method is used.
- the support base material 14 for example, a silicone-treated polyester film is used.
- the green sheet 13 is dried by holding at 90 ° C. for 10 minutes and then holding at 130 ° C. for 30 minutes. Furthermore, it is preferable to sufficiently defoam the mixture so that bubbles do not remain in the spreading layer by using an antifoaming agent in combination.
- FIG. 5 is a schematic view showing a process of forming the green sheet 13 by a die method.
- the die 15 used in the die system is formed by overlapping the blocks 16 and 17 with each other, and a slit 18 and a cavity (liquid reservoir) 19 are formed by a gap between the blocks 16 and 17.
- the cavity 19 communicates with a supply port 20 provided in the block 17.
- the supply port 20 is connected to a slurry supply system constituted by a metering pump (not shown) or the like, and the measured slurry 12 is supplied to the cavity 19 via the supply port 20 by a metering pump or the like. Is done.
- the slurry 12 supplied to the cavity 19 is fed to the slit 18 and is discharged from the discharge port 21 of the slit 18 with a predetermined application width with a uniform amount in the width direction by a constant amount per unit time.
- the support base material 14 is conveyed at a preset speed with the rotation of the coating roll 22. As a result, the discharged slurry 12 is applied to the support base material 14 with a predetermined thickness.
- the thickness accuracy of the green sheet 13 to be formed is within ⁇ 5%, more preferably within ⁇ 3%, and even more preferably within ⁇ 1% with respect to the design value (for example, 4 mm).
- the set thickness of the green sheet 13 is desirably set in the range of 0.05 mm to 10 mm.
- the productivity must be reduced because multiple layers must be stacked.
- the thickness is greater than 10 mm, it is necessary to reduce the drying speed in order to suppress foaming during drying, and productivity is significantly reduced.
- a pulsed magnetic field is applied to the green sheet 13 coated on the support substrate in a direction intersecting the transport direction before drying.
- the intensity of the applied magnetic field is 5000 [Oe] to 150,000 [Oe], preferably 10,000 [Oe] to 120,000 [Oe].
- the direction in which the magnetic field is oriented needs to be determined in consideration of the direction of the magnetic field required for the permanent magnet 1 formed from the green sheet 13, but is preferably in the in-plane direction.
- the green sheet 13 formed from the slurry 12 is punched into a desired product shape (for example, a fan shape shown in FIG. 1), and a formed body 25 is formed.
- a desired product shape for example, a fan shape shown in FIG. 1
- the molded body 25 is temporarily maintained in hydrogen by holding it for several hours (for example, 5 hours) at a binder decomposition temperature in a non-oxidizing atmosphere (in particular, a hydrogen atmosphere or a mixed gas atmosphere of hydrogen and inert gas in the present invention).
- a binder decomposition temperature in particular, a hydrogen atmosphere or a mixed gas atmosphere of hydrogen and inert gas in the present invention.
- Perform baking In the case of performing in a hydrogen atmosphere, for example, the supply amount of hydrogen during calcination is set to 5 L / min.
- the binder can be decomposed into monomers by a depolymerization reaction or the like and scattered to be removed. That is, so-called decarbonization for reducing the amount of carbon in the molded body 25 is performed.
- the calcination treatment in hydrogen is performed under the condition that the carbon content in the molded body 25 is 1000 ppm or less, more preferably 500 ppm or less. Accordingly, the entire permanent magnet 1 can be densely sintered by the subsequent sintering process, and the residual magnetic flux density and coercive force are not reduced.
- the binder decomposition temperature is determined based on the analysis results of the binder decomposition product and decomposition residue. Specifically, a temperature range is selected in which decomposition products of the binder are collected, decomposition products other than the monomers are not generated, and products due to side reactions of the remaining binder components are not detected even in the analysis of the residues. Although it varies depending on the type of the binder, it is set to 200 ° C. to 900 ° C., more preferably 400 ° C. to 600 ° C. (eg 600 ° C.).
- the calcining treatment is performed at the thermal decomposition temperature and binder decomposition temperature of the organic compound constituting the organic solvent. Thereby, the remaining organic solvent can be removed.
- the thermal decomposition temperature of the organic compound is determined depending on the type of the organic solvent to be used, but basically the thermal decomposition of the organic compound can be performed at the binder decomposition temperature.
- a sintering process is performed to sinter the molded body 25 that has been calcined by the calcining process in hydrogen.
- sintering is performed by pressure sintering.
- pressure sintering include hot press sintering, hot isostatic pressing (HIP) sintering, ultra-high pressure synthetic sintering, gas pressure sintering, and discharge plasma (SPS) sintering.
- HIP hot isostatic pressing
- SPS discharge plasma
- FIG. 6 is a schematic view showing a pressure sintering process of the compact 25 by SPS sintering.
- SPS sintering As shown in FIG. 6, first, the compact 25 is placed on a graphite sintering die 31. Note that the above-described calcination treatment in hydrogen may also be performed in a state where the molded body 25 is installed in the sintering mold 31. Then, the compact 25 placed on the sintering die 31 is held in the vacuum champ 32, and an upper punch 33 and a lower punch 34 made of graphite are set.
- the slurry was applied to a substrate by a die method to form a green sheet, and further punched into a desired product shape. Thereafter, the green sheet was calcined and then sintered by SPS sintering (pressurization value: 30 MPa, sintering temperature: increased to 940 ° C. at 10 ° C./min and held for 5 minutes). The other steps are the same as those described in the above [Permanent magnet manufacturing method].
- Example 2 The magnet raw material was pulverized by wet pulverization using a bead mill. Specifically, it was first pulverized with ⁇ 2 mm zirconia beads for 2 hours, and then pulverized with ⁇ 0.5 mm zirconia beads for 2 hours. Toluene was used as an organic solvent at the time of pulverization, wet pulverization, and then a similar slurry was produced by adding polyisobutylene as a binder to an organic solvent containing the pulverized magnet powder. Other conditions are the same as in the first embodiment.
- Example 1 and Comparative Examples 1 and 2 The oxygen concentration [ppm] and carbon concentration [ppm] remaining in the magnets of Example 1 and Comparative Examples 1 and 2 were measured.
- FIG. 7 shows a list of measurement results.
- Example 1 using only toluene, which is an organic compound composed of a hydrocarbon, as an organic solvent when generating a slurry is ethyl acetate, which is an organic compound containing oxygen atoms in addition to hydrocarbons. It can be seen that the amount of oxygen contained in the magnet can be reduced as compared with Comparative Examples 1 and 2 using a mixed solvent of methanol. In particular, in the permanent magnet of Example 1, the amount of oxygen remaining in the magnet after sintering can be 3000 ppm or less, more specifically 2000 ppm or less. As a result, it is possible to prevent the precipitation of ⁇ Fe without bonding Nd and oxygen in the sintering process to form an Nd oxide.
- the example shows higher values than the comparative example in terms of residual magnetic flux density and coercive force. From the above, when producing a permanent magnet using dry grinding, the amount of oxygen contained in the magnet during sintering is reduced by using one or more organic solvents selected from organic compounds consisting of hydrocarbons. It can be seen that the magnetic properties can be prevented from deteriorating.
- Example 2 using only toluene, which is an organic compound composed of a hydrocarbon, as an organic solvent in wet pulverization is a mixture of ethyl acetate or methanol, which is an organic compound containing oxygen atoms in addition to hydrocarbons
- the amount of oxygen contained in the magnet can be reduced as compared with Comparative Examples 3 and 4 using a solvent.
- the amount of oxygen remaining in the magnet after sintering can be 3000 ppm or less, more specifically 2500 ppm or less. As a result, it is possible to prevent the precipitation of ⁇ Fe without bonding Nd and oxygen in the sintering process to form an Nd oxide.
- the example shows higher values than the comparative example in terms of residual magnetic flux density and coercive force.
- the amount of oxygen contained in the magnet during sintering is reduced by using one or more organic solvents selected from organic compounds comprising hydrocarbons. It can be seen that the magnetic properties can be prevented from deteriorating.
- the amount of carbon in the magnet can be greatly reduced by using polyisobutylene having excellent thermal decomposability as a binder and performing calcination in hydrogen.
- the amount of carbon remaining in the magnet after sintering is 500 ppm or less, and voids are generated between the main phase and the grain boundary phase of the magnet.
- the magnet raw material is pulverized into magnet powder, and the pulverized magnet powder, a binder composed of hydrocarbons, and an organic compound composed of hydrocarbons.
- the slurry 12 is produced
- the produced green sheet 13 is maintained at a binder decomposition temperature for a certain period of time in a non-oxidizing atmosphere, whereby the binder is decomposed into a monomer by a depolymerization reaction or the like to be scattered and removed, and the green sheet from which the binder has been removed is fired.
- the permanent magnet 1 is manufactured by raising the temperature and performing sintering. As a result, since the shrinkage due to sintering is uniform, deformation such as warping and dent after sintering does not occur, and pressure unevenness at the time of pressing is eliminated. Therefore, the manufacturing process can be simplified. Thereby, a permanent magnet can be formed with high dimensional accuracy.
- the processing man-hours from increasing without reducing the material yield.
- one or more organic solvents selected from organic compounds consisting of hydrocarbons as the organic solvent
- a binder consisting of hydrocarbons as the binder
- the amount of oxygen contained in the magnet during sintering is reduced. be able to.
- the binder is scattered and removed by holding the green sheet 13 at a binder decomposition temperature in a non-oxidizing atmosphere for a certain period of time. Can be reduced.
- the amount of carbon can be more reliably reduced.
- the green sheet with the binder kneaded is held at 200 ° C. to 900 ° C., more preferably 400 ° C. to 600 ° C. for a certain time in a hydrogen atmosphere or a mixed gas atmosphere of hydrogen and an inert gas. The amount of carbon contained in the magnet can be more reliably reduced.
- the pulverization conditions, kneading conditions, calcination conditions, sintering conditions, etc. of the magnet powder are not limited to the conditions described in the above examples.
- the magnet raw material is pulverized by dry pulverization using a jet mill, but may be pulverized by wet pulverization using a bead mill.
- the magnet powder When magnet powder is pulverized by wet pulverization, it is desirable that the magnet powder be made into a slurry by adding a binder to an organic solvent containing the pulverized magnet powder after wet pulverization. Furthermore, as the organic solvent used for wet pulverization, it is desirable to use one or more organic solvents selected from organic compounds consisting of hydrocarbons. On the other hand, after the wet-pulverized magnet powder is once dried, the magnet powder may be made into a slurry by adding an organic solvent and a binder. However, in that case, it is desirable to use one or more organic solvents selected from organic compounds that are also composed of hydrocarbons as the organic solvent added to the dried magnet powder.
- the green sheet is formed by the slot die method, but other methods (for example, calendar roll method, comma coating method, extrusion molding, injection molding, mold molding, doctor blade method, etc.) can be used. It may be used to form a green sheet. However, it is desirable to use a method capable of forming the slurry on the substrate with high accuracy.
- the magnet was sintered by SPS sintering, you may sinter a magnet using other pressure sintering methods (for example, hot press sintering etc.).
- toluene or hexane is used as the organic solvent to be added to the magnet powder, but any organic solvent selected from organic compounds composed of hydrocarbons may be used.
- organic solvent selected from organic compounds composed of hydrocarbons
- pentane, benzene, xylene, or a mixture thereof may be used.
- the calcination treatment may be omitted. Even in that case, the binder is thermally decomposed during the sintering, and a certain decarburizing effect can be expected. Further, the calcination treatment may be performed in an atmosphere other than hydrogen.
- resin or long-chain hydrocarbon is used as the binder, but other materials may be used as long as they are made of hydrocarbon.
- the Nd—Fe—B type magnet is described as an example, but other magnets (for example, a cobalt magnet, an alnico magnet, a ferrite magnet, etc.) may be used. Further, in the present invention, the Nd component is larger than the stoichiometric composition in the present invention, but it may be stoichiometric.
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Abstract
Description
先ず、本発明に係る永久磁石1の構成について説明する。図1は本発明に係る永久磁石1を示した全体図である。尚、図1に示す永久磁石1は扇型形状を備えるが、永久磁石1の形状は打ち抜き形状によって変化する。
本発明に係る永久磁石1はNd-Fe-B系磁石である。尚、各成分の含有量はNd:27~40wt%、B:1~2wt%、Fe(電解鉄):60~70wt%とする。また、磁気特性向上の為、Dy、Tb、Co、Cu、Al、Si、Ga、Nb、V、Pr、Mo、Zr、Ta、Ti、W、Ag、Bi、Zn、Mg等の他元素を少量含んでも良い。図1は本実施形態に係る永久磁石1を示した全体図である。
更に、バインダーに樹脂を用いる場合には、例えばポリイソブチレン(PIB)、ブチルゴム(IIR)、ポリイソプレン(IR)、ポリブタジエン、ポリスチレン、スチレン-イソプレンブロック共重合体(SIS)、スチレン-ブタジエンブロック共重合体(SBS)、2-メチル-1-ペンテン重合樹脂、2-メチル-1-ブテン重合樹脂、α-メチルスチレン重合樹脂、ポリブチルメタクリレート、ポリメチルメタクリレート等を用いる。尚、α-メチルスチレン重合樹脂は柔軟性を与えるために低分子量のポリイソブチレンを添加することが望ましい。また、バインダーに用いる樹脂としては、磁石内に含有する酸素量を低減させる為に、炭化水素からなり、且つ解重合性があり、熱分解性に優れるポリマー(例えば、ポリイソブチレン等)を用いることが望ましい。
尚、バインダーをトルエン等の汎用溶媒に対して適切に溶解させる為に、バインダーに用いる樹脂としてはポリエチレン、ポリプロピレン以外の樹脂を用いることが望ましい。
次に、本発明に係る永久磁石1の製造方法について図4を用いて説明する。図4は本実施形態に係る永久磁石1の製造工程を示した説明図である。
図5に示すようにダイ方式に用いられるダイ15は、ブロック16、17を互いに重ね合わせることにより形成されており、ブロック16、17との間の間隙によってスリット18やキャビティ(液溜まり)19を形成する。キャビティ19はブロック17に設けられた供給口20に連通される。そして、供給口20は定量ポンプ(図示せず)等によって構成されるスラリー供給系へと接続されており、キャビティ19には供給口20を介して、計量されたスラリー12が定量ポンプ等により供給される。更に、キャビティ19に供給されたスラリー12はスリット18へ送液されて単位時間一定量で幅方向に均一な圧力でスリット18の吐出口21から予め設定された塗布幅により吐出される。一方で、支持基材14はコーティングロール22の回転に伴って予め設定された速度で搬送される。その結果、吐出したスラリー12が支持基材14に対して所定厚さで塗布される。
また、特に磁石原料を有機溶媒中で湿式粉砕により粉砕した場合には、有機溶媒を構成する有機化合物の熱分解温度且つバインダー分解温度で仮焼処理を行う。それによって、残留した有機溶媒についても除去することが可能となる。有機化合物の熱分解温度については、用いる有機溶媒の種類によって決定されるが、上記バインダー分解温度であれば基本的に有機化合物の熱分解についても行うことが可能となる。
図6に示すようにSPS焼結を行う場合には、先ず、グラファイト製の焼結型31に成形体25を設置する。尚、上述した水素中仮焼処理についても成形体25を焼結型31に設置した状態で行っても良い。そして、焼結型31に設置された成形体25を真空チャンパー32内に保持し、同じくグラファイト製の上部パンチ33と下部パンチ34をセットする。そして、上部パンチ33に接続された上部パンチ電極35と下部パンチ34に接続された下部パンチ電極36とを用いて、低電圧且つ高電流の直流パルス電圧・電流を印加する。それと同時に、上部パンチ33及び下部パンチ34に対して加圧機構(図示せず)を用いて夫々上下方向から荷重を付加する。その結果、焼結型31内に設置された成形体25は、加圧されつつ焼結が行われる。また、生産性を向上させる為に、複数(例えば10個)の成形体に対して同時にSPS焼結を行うことが好ましい。尚、複数の成形体25に対して同時にSPS焼結を行う場合には、一の焼結型31に複数の成形体25を配置しても良いし、成形体25毎に異なる焼結型31に配置するようにしても良い。尚、成形体25毎に異なる焼結型31に配置する場合には、複数の焼結型31を備えたSPS焼結装置を用いて焼結を行う。そして、成形体25を加圧する上部パンチ33や下部パンチ34は複数の焼結型31の間で一体とする(即ち同時に加圧ができる)ように構成する。
尚、具体的な焼結条件を以下に示す。
加圧値:30MPa
焼結温度:940℃まで10℃/分で上昇させ、5分保持
雰囲気:数Pa以下の真空雰囲気
(実施例1)
実施例1はNd-Fe-B系磁石であり、合金組成はwt%でNd/Fe/B=32.7/65.96/1.34とする。また、ジェットミルを用いた乾式粉砕により磁石原料を粉砕した。また、バインダーとしてポリイソブチレンを用いるとともに、有機溶媒としてトルエンを用い、100gの磁石粉末に対して20wt%のバインダー溶液を100g添加することにより、添加後のスラリー中における磁石粉末とバインダーの合計量に対するバインダーの比率が16.7wt%となるスラリーを生成した。その後、スラリーをダイ方式により基材に塗工してグリーンシートを成形し、更に、所望の製品形状に打ち抜きした。その後、グリーンシートに対して仮焼処理を行った後に、SPS焼結(加圧値:30MPa、焼結温度:940℃まで10℃/分で上昇させ、5分保持)により焼結した。尚、他の工程は上述した[永久磁石の製造方法]と同様の工程とする。
ビーズミルを用いた湿式粉砕により磁石原料を粉砕した。具体的には、先ずφ2mmジルコニアビーズで2時間粉砕し、その後に、φ0.5mmジルコニアビーズで2時間粉砕した。粉砕時の有機溶媒としてトルエンを用い、湿式粉砕した後に、粉砕された磁石粉末を含む有機溶媒に、バインダーとしてポリイソブチレンを添加することによって同様のスラリーを生成した。他の条件は実施例1と同様である。
有機溶媒としてトルエンと酢酸エチルを8:2の割合で混合した溶媒を用いた。他の条件は実施例1と同様である。
有機溶媒としてトルエンとメタノールを8:2の割合で混合した溶媒を用いた。他の条件は実施例1と同様である。
有機溶媒としてトルエンと酢酸エチルを8:2の割合で混合した溶媒を用いた。他の条件は実施例2と同様である。
有機溶媒としてトルエンとメタノールを8:2の割合で混合した溶媒を用いた。他の条件は実施例2と同様である。
上記実施例1及び比較例1、2の各磁石内に残存する酸素濃度[ppm]及び炭素濃度[ppm]を測定した。図7に測定結果の一覧を示す。
上記実施例2及び比較例3、4の各磁石内に残存する酸素濃度[ppm]及び炭素濃度[ppm]を測定した。図8に測定結果の一覧を示す。
また、有機溶媒として炭化水素からなる有機化合物から選択される1種以上の有機溶媒を用い、更にバインダーとして炭化水素からなるバインダーを用いることにより、焼結時に磁石内に含有する酸素量を低減させることができる。その結果、焼結工程において金属酸化物が形成されることを抑え、磁石特性が低下することを防止できる。
また、グリーンシート13を焼結する前に、グリーンシート13を非酸化性雰囲気下でバインダー分解温度に一定時間保持することによりバインダーを飛散させて除去するので、磁石内に含有する炭素量を予め低減させることができる。その結果、焼結後の磁石の主相内にαFeが析出することを抑え、磁石全体を緻密に焼結することが可能となり、保磁力が低下することを防止できる。特に、バインダーとして熱分解性に優れるポリマーを用いれば、炭素量をより確実に低減させることが可能となる。
また、仮焼処理では、バインダーが混練されたグリーンシートを水素雰囲気下又は水素と不活性ガスの混合ガス雰囲気下で200℃~900℃、より好ましくは400℃~600℃に一定時間保持するので、磁石内に含有する炭素量をより確実に低減させることができる。
例えば、磁石粉末の粉砕条件、混練条件、仮焼条件、焼結条件などは上記実施例に記載した条件に限られるものではない。例えば、上記実施例ではジェットミルを用いた乾式粉砕により磁石原料を粉砕しているが、ビーズミルによる湿式粉砕により粉砕することとしても良い。また、湿式粉砕により磁石粉末を粉砕する場合には、湿式粉砕した後に、粉砕された磁石粉末を含む有機溶媒にバインダーを添加することによって磁石粉末をスラリー状とすることが望ましい。更に、湿式粉砕に用いる有機溶媒としては、炭化水素からなる有機化合物から選択される1種以上の有機溶媒を用いるのが望ましい。一方、湿式粉砕された磁石粉末を一旦乾燥させた後に、有機溶媒とバインダーとを添加することによって磁石粉末をスラリー状にしても良い。但し、その場合において、乾燥させた磁石粉末に添加する有機溶媒は、同じく炭化水素からなる有機化合物から選択される1種以上の有機溶媒を用いるのが望ましい。
11 ジェットミル
12 スラリー
13 グリーンシート
25 成形体
Claims (8)
- 磁石原料を磁石粉末に粉砕する工程と、
前記粉砕された磁石粉末と炭化水素からなるバインダーと炭化水素からなる有機化合物から選択される1種以上の有機溶媒とを混練することによりスラリーを生成する工程と、
前記スラリーをシート状に成形し、グリーンシートを作製する工程と、
前記グリーンシートを焼結する工程と、により製造されることを特徴とする希土類永久磁石。 - 前記グリーンシートを焼結する前に、前記グリーンシートを非酸化性雰囲気下でバインダー分解温度に一定時間保持することにより前記バインダーを飛散させて除去することを特徴とする請求項1に記載の希土類永久磁石。
- 前記バインダーを飛散させて除去する工程では、前記グリーンシートを水素雰囲気下又は水素と不活性ガスの混合ガス雰囲気下において200℃~900℃で一定時間保持することを特徴とする請求項2に記載の希土類永久磁石。
- 前記磁石原料を磁石粉末に粉砕する工程では、前記磁石原料を前記有機溶媒中で湿式粉砕し、
前記スラリーを生成する工程では、粉砕された前記磁石粉末を含む前記有機溶媒に前記バインダーを添加することにより前記スラリーを生成することを特徴とする請求項1乃至請求項3のいずれかに記載の希土類永久磁石。 - 磁石原料を磁石粉末に粉砕する工程と、
前記粉砕された磁石粉末と炭化水素からなるバインダーと炭化水素からなる有機化合物から選択される1種以上の有機溶媒とを混練することによりスラリーを生成する工程と、
前記スラリーをシート状に成形し、グリーンシートを作製する工程と、
前記グリーンシートを焼結する工程と、を有することを特徴とする希土類永久磁石の製造方法。 - 前記グリーンシートを焼結する前に、前記グリーンシートを非酸化性雰囲気下でバインダー分解温度に一定時間保持することにより前記バインダーを飛散させて除去することを特徴とする請求項5に記載の希土類永久磁石の製造方法。
- 前記バインダーを飛散させて除去する工程では、前記グリーンシートを水素雰囲気下又は水素と不活性ガスの混合ガス雰囲気下において200℃~900℃で一定時間保持することを特徴とする請求項6に記載の希土類永久磁石の製造方法。
- 前記磁石原料を磁石粉末に粉砕する工程では、前記磁石原料を前記有機溶媒中で湿式粉砕し、
前記スラリーを生成する工程では、粉砕された前記磁石粉末を含む前記有機溶媒に前記バインダーを添加することにより前記スラリーを生成することを特徴とする請求項5乃至請求項7のいずれかに記載の希土類永久磁石の製造方法。
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EP12803421.2A EP2685473A4 (en) | 2011-06-24 | 2012-03-15 | RARE EARTH PERMANENT MAGNET AND PROCESS FOR PRODUCING RARE EARTH PERMANENT MAGNET |
KR1020137003389A KR101878999B1 (ko) | 2011-06-24 | 2012-03-15 | 희토류 영구 자석 및 희토류 영구 자석의 제조 방법 |
CN201280002743.1A CN103081039B (zh) | 2011-06-24 | 2012-03-15 | 稀土类永久磁铁及稀土类永久磁铁的制造方法 |
US13/817,104 US20130141197A1 (en) | 2011-06-24 | 2012-03-15 | Rare-earth permanent magnet and method for manufacturing rare-earth permanent magnet |
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JP2011140917 | 2011-06-24 | ||
JP2011-140917 | 2011-06-24 |
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WO2012176514A1 true WO2012176514A1 (ja) | 2012-12-27 |
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PCT/JP2012/056717 WO2012176514A1 (ja) | 2011-06-24 | 2012-03-15 | 希土類永久磁石及び希土類永久磁石の製造方法 |
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US (1) | US20130141197A1 (ja) |
EP (1) | EP2685473A4 (ja) |
JP (1) | JP5307912B2 (ja) |
KR (1) | KR101878999B1 (ja) |
CN (1) | CN103081039B (ja) |
TW (1) | TWI453771B (ja) |
WO (1) | WO2012176514A1 (ja) |
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- 2012-03-15 US US13/817,104 patent/US20130141197A1/en not_active Abandoned
- 2012-03-15 CN CN201280002743.1A patent/CN103081039B/zh active Active
- 2012-03-15 KR KR1020137003389A patent/KR101878999B1/ko active IP Right Grant
- 2012-03-15 WO PCT/JP2012/056717 patent/WO2012176514A1/ja active Application Filing
- 2012-03-15 JP JP2012058081A patent/JP5307912B2/ja not_active Expired - Fee Related
- 2012-03-15 EP EP12803421.2A patent/EP2685473A4/en not_active Ceased
- 2012-03-20 TW TW101109565A patent/TWI453771B/zh not_active IP Right Cessation
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Also Published As
Publication number | Publication date |
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CN103081039A (zh) | 2013-05-01 |
EP2685473A1 (en) | 2014-01-15 |
EP2685473A4 (en) | 2015-04-15 |
CN103081039B (zh) | 2017-07-11 |
US20130141197A1 (en) | 2013-06-06 |
TW201301313A (zh) | 2013-01-01 |
KR20140036999A (ko) | 2014-03-26 |
JP5307912B2 (ja) | 2013-10-02 |
JP2013030745A (ja) | 2013-02-07 |
KR101878999B1 (ko) | 2018-08-17 |
TWI453771B (zh) | 2014-09-21 |
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