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WO2018038170A1 - Aimant fritté à base de terres rares et procédé de fabrication dudit aimant - Google Patents

Aimant fritté à base de terres rares et procédé de fabrication dudit aimant Download PDF

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Publication number
WO2018038170A1
WO2018038170A1 PCT/JP2017/030165 JP2017030165W WO2018038170A1 WO 2018038170 A1 WO2018038170 A1 WO 2018038170A1 JP 2017030165 W JP2017030165 W JP 2017030165W WO 2018038170 A1 WO2018038170 A1 WO 2018038170A1
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Prior art keywords
sintered magnet
rare earth
magnet
filled
orientation
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Japanese (ja)
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眞人 佐川
林　眞一
磯谷　桂太
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NDFEB Corp
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NDFEB Corp
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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
    • 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

Definitions

  • the present invention relates to a long magnetic anisotropic rare earth sintered magnet for obtaining a plurality of magnets having uniform magnetic characteristics and a method for manufacturing the same, and in particular, to use a long solenoid coil for magnetic field orientation,
  • the main feature is that it does not require strong compression molding pressure to give the molded body strength like the mold press method of, and reaches the sintering process without causing disturbance of magnetic field orientation due to compression molding
  • the present invention relates to a method for producing a long magnetic anisotropic rare earth sintered magnet.
  • rare earth sintered magnets include SmCo sintered magnets and RFeB sintered magnets.
  • RFeB sintered magnets are mainly composed of rare earth, iron, and boron, not only far exceeding the properties of permanent magnet materials, but also abundant in resources such as neodymium (a rare earth element), iron, and boron. It is cheaper than SmCo magnets with Sm and Co as the main ingredients, which are raw materials that are scarce and expensive, and has been steadily marketed as an ideal permanent magnet material since its appearance in 1982 Is expanding.
  • Main applications include computer HDD (hard disk drive) magnetic head drive motor VCM (voice coil motor), luxury speakers, headphones, battery-assisted bicycles, golf carts, permanent magnet magnetic resonance diagnostic equipment (MRI), etc. There is. In addition, it is being put to practical use in the drive motors of hybrid cars and electric vehicles, energy-saving and low-noise large-sized home appliances (coolers and refrigerators), and industrial motors. Contributing significantly.
  • the RFeB magnetic anisotropic sintered magnet was invented in 1982 by the present inventors (Patent Document 1).
  • This RFeB magnetic anisotropic sintered magnet has a tetragonal crystal structure, and has an R 2 Fe 14 B intermetallic compound having magnetic anisotropy as a main phase.
  • it is necessary to take advantage of the characteristics of magnetic anisotropy.
  • casting and hot working Patent No. 2,561,704
  • die-upset machining of quenched alloys Patent No. 4,792,367 etc.
  • the sintering method is the best method for obtaining a dense and homogeneous microstructure required for high performance permanent magnets.
  • the initial RFeB magnetic anisotropic sintered magnet manufacturing method includes the steps of composition blending, melting, casting, grinding, compression molding in a magnetic field, sintering, heat treatment, processing, and surface treatment. Since the invention of the RFeB magnetic anisotropic sintered magnet, numerous technological improvements have been made in each process.
  • RFeB magnetic anisotropic sintered magnets include other rare earth elements (for example, Dy, Tb, Pr, etc.), Co, and a small amount of Al for improving coercive force, other magnetic characteristics, temperature characteristics, and corrosion resistance. , Cu, Si, Ga, Nb, and the like, and impurities such as oxygen, carbon, hydrogen, and nitrogen contained in the raw material and the manufacturing process are included. Addition of heavy rare earth elements (Dy, Tb, etc.) is most effective in improving the coercive force (Japanese Patent No. 1802487). If a large amount of heavy rare earth elements is used, the coercive force increases, but the saturation magnetization decreases and the maximum energy product decreases.
  • Dy and Tb are limited in resources and expensive, it is impossible to cover electric vehicles and industrial / household motors for which demand is expected to greatly increase in the future.
  • Dy, Tb, etc. are penetrated from the magnet surface into the inside while heat-treating after making the sintered body, and the coercive force in the vicinity of the grain boundary of the microcrystalline particles is increased, resulting in a high maximum energy product.
  • a grain boundary diffusion method for increasing the coercive force while maintaining the above Japanese Patent Laid-Open No. 2005-11973, etc.
  • Sintered magnets require a dense and homogeneous microstructure. Initially, casting ingots were generally made from molten alloy and pulverized, but when the molten alloy was quenched by the strip casting method, the composition was uniformly dispersed and a raw material alloy with a dense structure was obtained. Characteristics can be obtained (Japanese Patent No. 2665590). In addition to the melting method, there is a reduction diffusion method in which an RFeB alloy powder is directly obtained by mixing and heating a metal Ca to a rare earth oxide powder, iron powder, ferroboron powder or the like.
  • a powder having a sharp particle size distribution is obtained, and jet mill pulverization using an inert gas such as nitrogen is the mainstream.
  • a lubricant or binder may be added to the fine powder.
  • the fine powder is compression molded in a magnetic field.
  • a die press method is generally used, but a CIP method (Patent No. 3383448) and an RIP method (Patent No. 2030923) are methods for obtaining a higher degree of orientation and a higher energy product.
  • a CIP method Patent No. 3383448
  • an RIP method Patent No. 2030923
  • a mixture of mineral oil, synthetic oil or vegetable oil and fine powder is injected into a mold at high pressure and wet compression molded in a magnetic field.
  • Patent No. 2731337 etc. it is said that a high sintering density and high magnetic properties can be obtained when the slurry is pressure-injected and pressure-filled.
  • the die press method can only apply pressure from one direction, which causes the orientation of fine powder to be disturbed. If pressure can be applied isotropically from all directions, the disturbance of orientation due to pressurization is reduced.
  • a fine powder is put in a plastic mold such as a rubber container in advance, a magnetic field is applied from the outside, and CIP (Cold Isostatic Pressing) is performed.
  • CIP Cold Isostatic Pressing
  • a magnetic field is preliminarily molded at a pressure of 0.7 ton / cm 2 with a parallel press with a cross-sectional area of 152 mm ⁇ 37 mm in parallel with the pressing direction until the height reaches 128 mm, and transferred to a rubber mold.
  • CIP was performed at a pressure of 3 tons / cm 2 to obtain a molded body of 140 ⁇ 121 ⁇ 35 (magnetization direction) mm.
  • the magnetization direction is the shortest 35mm.
  • the purpose of the CIP treatment is to reduce the disorder of orientation and to obtain a robust molded body.
  • the present inventors previously proposed the RIP (RubberRIsostatic Pressing) method (patent No. 2030923, etc.) as a method for obtaining an effect substantially equivalent to CIP.
  • the RIP method a fine powder is placed in a rubber mold, a pulse magnetic field is applied, and the entire rubber mold is inserted into a mold press and pressed.
  • pressure is applied isotropically and a pulsed magnetic field can be used. Therefore, the characteristics are higher than those of the die press method.
  • This method is more suitable for mass production than the CIP method because it can automate the rubber mold filling, pulse magnetic field application, compression molding, and demagnetization processes continuously.
  • a rubber mold since a rubber mold is used, it takes a lot of time to take out the green compact, and it is difficult to automate the process up to the sintering furnace conveyance, so a production method for mass production has not been achieved.
  • Patent Document 2 Pressure-Less Process
  • Patent Document 3 the new PLP method (Patent Document 3) by the present inventors have been proposed for the purpose of compensating for the drawbacks of the compression molding method such as a die press. Details of the PLP method and the new PLP method will be described later.
  • the green compact after the die press is transported and arranged on the sintering platen.
  • the green compact pressed in a magnetic field is an aggregate of small magnet particles, and the green compact also has the properties of a magnet. Therefore, it collides with the suction repulsive force between the green compacts, and chipping and cracking occur. Therefore, a method of previously demagnetizing the green compact is employed. In practice, it is performed by applying a reverse magnetic field or an alternating decay magnetic field in the most compressed state in the die press. Since the particles cannot move in the compressed state, the orientation of the particles is not greatly disturbed even if a reverse magnetic field or an alternating magnetic field is applied.
  • a large sintered body may be manufactured by a die press method, and a predetermined shape may be obtained by processing. Since RFeB intermetallic compounds are very hard, they are mainly cut by diamond abrasive wheels. Since the RFeB magnet has a large coercive force, the normal product thickness is on the order of several mm. If the cutting blade thickness is thick, the yield deteriorates, which is not preferable. Therefore, a method using a thin grinding wheel with diamond abrasive grains embedded on a base plate made of cemented carbide (Patent No. 2868180) and cutting with a wire saw (Patent No. 4668804 etc.) have also been applied. Improvements have been made.
  • the main component of the RFeB magnet is composed of rare earth elements and iron, and is easily oxidized. Therefore, various treatment methods such as resin coating, plating, and aluminum vapor deposition have been used according to applications.
  • RFeB sintered magnets require high magnetic field strength, a high energy product with a large residual magnetic flux density Br and maximum energy product BHmax, and heavy rare earths such as Dy and Tb for use in applications such as temperature rise and magnet demagnetization.
  • high coercivity materials that have high coercivity while adding elements and sacrificing Br and BHmax.
  • grain boundary diffusion methods have been developed to increase coercive force while maintaining high Br and BHmax, and demand is increasing especially in the motor region.
  • a representative device that converts electrical energy into mechanical energy is a motor, and since the advent of RFeB magnets, motors equipped with permanent magnets have developed dramatically. Among them, since a motor mounted on a hybrid car or an electric vehicle is used with a DC power source, a permanent magnet that does not consume electric energy is used in the field portion.
  • a permanent magnet is used for a motor, a surface magnet type motor system in which a plurality of arcuate segment magnets are arranged along the circumference of the rotor, and a plurality of permanent magnets are provided in a groove in which a magnetic circuit is previously formed by a silicon steel plate or the like.
  • the composition, sintered density, orientation, etc. must be kept uniform. There is almost no problem with the uniformity of composition as long as it is within the same lot.
  • an electromagnet including a coil, a yoke, and a magnetic pole is disposed outside the die punch to orient the fine powder.
  • Magnetic fluxes directed in the same direction repel each other, and a uniform parallel magnetic field cannot be realized in a plurality of cavities provided in the die. That is, a green compact with the same degree of orientation cannot be obtained.
  • the plurality of compression-molded bodies are sintered side by side on a sintering table.
  • the sintering base used for mass production is large, and the influence of temperature and atmosphere differs depending on the position of the placement, and a product having a uniform sintering density cannot always be obtained.
  • ⁇ Magnetic field orientation and pressurization must be performed in this order. If pressure is applied first, magnetic field orientation is hindered. In the die press method, disorder of the orientation degree cannot be avoided in either the right-angle press method or the parallel press method. Assume x-, y-, and z-triaxes. In the parallel pressing method, a magnetic field is applied in the z-axis direction, and pressure is applied in the z-axis direction at the same time. Microparticles arranged in the z-axis direction by a magnetic field are also pressurized from the z-axis direction, tilted in the x-axis direction and the y-axis direction due to friction caused by contact between powders and the mold, and the arrangement is disturbed. .
  • the right-angle press method a magnetic field is applied in the x-axis direction, the pressure is applied from the z-axis direction. Similarly, it tilts in the x-axis direction and y-axis direction due to friction, but when it tilts in the y-axis direction, the powder only rotates and the arrangement itself is small.
  • the parallel press method disturbs the arrangement in two directions with respect to the ideal arrangement, but the right angle press method disturbs the arrangement only in one direction, and the right angle press method has higher magnetic properties. In this way, an ideal magnetic field orientation cannot be obtained by the die press method.
  • the reason why the die press is used is that it has a net shape that is close to the final shape and dimensions, and can be automated with good yield. That's why. Applying a magnetic field is an indispensable process for orienting the particles, and various improvements have been attempted, such as the structure of the press die and the use of a pulsed magnetic field. did not come.
  • a method of adding a lubricant has been proposed in order to enhance the orientation of fine powder during molding (Japanese Patent No. 3345947).
  • the lubricant has the effect of reducing the friction of the fine powder, and improves the degree of orientation when compressed while applying a magnetic field.
  • a large amount of lubricant is added for the purpose of obtaining a sufficient lubricating effect, a long time is required during sintering for degreasing.
  • Certain liquid lubricants for example, Japanese Patent Application Laid-Open No. 2000-306753 are excellent in volatility and hardly remain in the sintered body.
  • a static magnetic field is applied by an electromagnet.
  • the static magnetic field generated by the electromagnet is limited to 10 to 15 kOe (1 to 1.5 Tesla) at most because of the saturation of the magnetic flux by the iron core.
  • Japanese Patent No. 3307418 proposes an alignment method using a pulsed magnetic field. A pulsed magnetic field of 1.5 to 5.5 Tesla can be applied, and the effect of improving Br (residual magnetic flux density) has been confirmed.
  • fine particles whose main phase is an intermetallic compound having a tetragonal Nd 2 Fe 14 B type crystal structure are firmly bonded by sintering.
  • This compound has an easy magnetization axis (magnetic anisotropy) in the major axis direction (c-axis direction), and finely pulverized powder in the manufacturing process is arranged in one direction by applying a magnetic field from the outside.
  • the arrangement is disturbed by applying a strong pressure to the fine particles arranged by the magnetic field. The reason why a strong pressure is applied in the die press method is to facilitate handling when moving to the next process.
  • a method of adding a binder and a lubricant and a method of wet molding in oil have been proposed, but both are premised on compression molding with strong pressure.
  • components such as a binder are strongly confined in the green compact and are not easily removed in the degreasing step prior to sintering.
  • Degreasing may be carried out completely by heating at a low temperature for a long time, but the productivity is significantly reduced. If the component is left overheated at a high temperature, impurities such as carbon react with the constituent elements to deteriorate the magnetic properties and deteriorate the corrosion resistance.
  • the right angle press method is used for the production of high-performance magnets with a high degree of orientation.
  • Japanese Patent No. 2922535 is intended to make the magnetic field in the cavity uniform by providing a tilt angle in the ferromagnetic part of the mold at the time of magnetic field orientation in order to correct the non-uniformity in the magnet part with high performance.
  • the easy magnetization direction of the magnet in this example is not the long direction.
  • the RIP described above is also intended to obtain a robust powder compact using a mold press machine, and is not intended to obtain a long and magnetically anisotropic sintered magnet with little variation.
  • the die press method is considered the most mass-productive because of its net shape.
  • the die pressing method is directed to obtaining a plurality of RFeB magnetically anisotropic sintered magnets having uniform and small magnetic properties and a long magnetic anisotropic sintered magnet for supplying such magnets. Absent.
  • Patent Document 2 a PLP method
  • Patent Document 3 a new PLP method
  • PLP method sintering process
  • the filled container is transferred to the sintering process as it is, handling from the molding to the sintering process is omitted, and there is no compression molding process or demagnetization process that disturbs the orientation.
  • the new PLP method there are cases where only the bottom plate (for example, made of stainless steel) used in the powder feeding and filling process and the filled molded body are moved to another base plate (for example, made of carbon) and sintered. Since it is performed automatically in an oxygen atmosphere, there is no need for handling.
  • the bottom plate is made of a material that is not damaged in the sintering process and does not react with the alloy powder, the laminated block may be sintered together with the bottom plate. This is safer because it is not necessary to move the laminated block of the alloy powder filled orientation molded body from the bottom plate to the base plate, particularly when the strength of the orientation filled molded body is not sufficient.
  • the filled sintered body filled in a certain packing density range using the PLP method / new PLP method is contracted and sintered in an almost intact shape.
  • the RFeB magnetic anisotropic sintered magnet body is known to have a different shrinkage ratio during sintering in the orientation direction and the direction perpendicular thereto, but the shrinkage ratio slightly different for each material is required. Then, it is possible to obtain a filled molded body having an arbitrary size and shape by calculating backwards.
  • the purpose of the PLP method and the new PLP method is to obtain a net shape that is close to the final shape and dimensions, which is an advantage of the die press method.
  • Patent Document 1 and Patent Document 2 describing the PLP method and the new PLP method, it is described that the variation in the characteristics of a plurality of magnets is good, but it is described above in comparison with the prior art and actually measured.
  • the characteristic variation of a plurality of magnets oriented and sintered at the same time was not at a level within a range of 1%.
  • the long magnetic anisotropic rare earth sintered magnet according to the present invention has a permeance coefficient of 12 or more, an orientation degree Br / Js of 94% or more, a variation in orientation degree in the longitudinal direction of 1% or less, and sintering.
  • the length of the magnet in the longitudinal direction is 40 mm or more.
  • the long magnetic anisotropic rare earth sintered magnet is a long magnetic anisotropic RFeB sintered magnet.
  • the permeance coefficient is 12 or more
  • the orientation degree Br / Js is 96% or more
  • the variation of the orientation degree in the longitudinal direction is 1% or less
  • the length of the sintered magnet in the longitudinal direction is 40 mm or more. This is a long magnetic anisotropic rare earth sintered magnet.
  • the present invention is also a single magnetic anisotropic rare earth sintered magnet obtained by cutting the long magnetic anisotropic rare earth sintered magnet.
  • the manufacturing method of the present invention includes a powder feeding step of feeding alloy powder into a filling container having a side face divided into two or more parts, and filling for filling the alloy powder into the filling container to produce a filled molded body
  • the filling step and the orientation step are performed in different places, It is a manufacturing method for obtaining a long magnetic anisotropic sintered magnet with small variations.
  • the method for producing a rare earth magnet comprises a step of high-density filling a packed container with a rare earth magnet alloy fine powder having an average particle diameter D 50 measured by a laser-type powder particle size distribution analyzer of 5 ⁇ m or less, A step of orienting the alloy fine powder in a magnetic field in a state filled in a filling container; and a step of sintering the alloy fine powder in a state filled in the filling container. It is a manufacturing method for obtaining a long magnetic anisotropic rare earth sintered magnet with small variations by performing it consistently in a container that is a gas atmosphere.
  • the manufacturing method of the present invention is the method of manufacturing a rare earth magnet having the above characteristics, wherein the alloy fine powder of the rare earth magnet filled in the high density filling step is an alloy fine powder of the RFeB magnet,
  • the RFeB magnet alloy fine powder is filled in the filling container at a density between 46.4% and 55% of the true density.
  • a magnetic pole is provided on the end face in the longitudinal direction of the filling container.
  • a long solenoid coil is used for orientation of the alloy powder.
  • the present invention is also a method for manufacturing a single magnetic anisotropic rare earth sintered magnet, characterized in that the long magnetic anisotropic rare earth sintered magnet obtained by the above manufacturing method is cut.
  • the present invention has been found as a method for solving the problems and contradictions of the conventional methods in a method for producing a magnetically anisotropic sintered magnet of a rare earth magnet such as an RFeB magnet or an RCo magnet. That is, according to the present invention, there is no need for a large molding apparatus such as a die press, and there is no need to make a robust green compact for handling, so there is no disturbance in orientation, and the entire sintered magnet is uniform. A long magnetic anisotropic rare earth sintered magnet with small variations in orientation degree Br / Js and residual magnetic flux density Br can be obtained.
  • a strong pulse magnetic field can be applied by the solenoid coil, and since there is no step of applying high pressure or demagnetizing the green compact, a sintered body having a high orientation can be obtained.
  • chemically active fine powders containing rare earth elements can be processed without exposure to the atmosphere, powders with small particle sizes can be handled, and rare earth magnets with high coercivity can be obtained without necessarily using Tb or Dy. .
  • the degree of orientation of the rare earth sintered magnet can be expressed by Br / Js.
  • Br is the residual magnetic flux density
  • Js is the saturation magnetic flux density.
  • a comparison between the value of the saturation magnetization Js that reaches saturation when a magnetic field is applied to the magnet and the value of the residual magnetic flux density Br when the magnetic field is returned to zero represents the ratio between finely aligned fine particles and finely aligned fine particles. This is one of the excellent methods for knowing the degree of orientation.
  • the long magnetic anisotropic rare earth sintered magnet of the present invention can be cut to obtain a plurality of magnets with small variations.
  • the sintered density of the sintered magnet is mainly determined by the sintering temperature.
  • the sintering density varies due to temperature conditions and other factors.
  • the sintered density is substantially constant.
  • the saturation magnetization should be the same if the sintered density of each magnet is confirmed to be the same. It is sufficient to compare the variation in the residual magnetic flux density Br when measuring the magnetic characteristics. In this case, the variation of Br in the present invention is within 1%.
  • the end of the sintered magnet in the longitudinal direction is placed under different conditions from the central part depending on the atmosphere during sintering and other conditions, the end of the sintered magnet is omitted from the measurement of magnetic properties.
  • the thickness omitted from this end is 2 mm or more, preferably 5 mm.
  • the thickness of the sample piece used for the magnetic properties is set to 5 mm or more in consideration of the measurement variation possessed by the magnetic property measuring instrument.
  • the long magnet of the present invention when used, for example, when a plurality of permanent magnets are used for one or a plurality of motors, a plurality of permanent magnets with small variations in the magnetic characteristics of the magnets are provided, thereby Energy loss such as vibration and heat generation can be reduced.
  • FIG. 1-1 shows the orientation degree Br / Js and the squareness Hk / Hcj of the demagnetization curve for a plurality of samples cut out from one long RFeB magnetic anisotropic sintered magnet manufactured by the manufacturing method of the present invention.
  • Hcj is shown. It is a graph of the magnet size ratio and permeance coefficient of a cylindrical (columnar) magnet. It is a graph of the magnet size ratio of a square-shaped magnet, and a permeance coefficient.
  • the production method of the present invention is to produce a long NdFeB magnetic anisotropic sintered magnet with small variations in magnetic properties by the PLP method or the new PLP method.
  • the permeance coefficient is 12 or more
  • the degree of orientation Br / Js is 94% or more
  • the variation in the degree of orientation in the longitudinal direction is 1% or less
  • the length of the sintered magnet in the longitudinal direction A long magnetic anisotropic rare earth sintered magnet having a length of 40 mm or more is obtained. If this long magnet body is obtained, a plurality of magnets having uniform magnetic characteristics can be obtained by cutting thinly in the magnetization direction.
  • the permeance coefficient is explained, for example, in the book “Permanent Magnets-Materials Science and Applications” edited by Hayato Sagawa et al., 11-1-3 “Demagnetizing Fields and Permeance of a Single Magnet”, Agne Technology Center, September 15, 2007.
  • Single magnetic anisotropic permanent magnets magnetized in one direction have N-pole and S-pole magnetic poles on the end face.
  • a magnetic field in the opposite direction appears inside the magnet due to the magnetic poles on the end face. This is called a demagnetizing field.
  • the magnitude of the demagnetizing field is expressed using a demagnetizing factor N determined by the magnet shape.
  • the permeance coefficient is used as a standard. Since permanent magnets have various shapes such as a rectangular parallelepiped, a cylinder, and a cylinder, they are suitable for expressing the magnet shape (length and cross-sectional area) in an integrated manner. This is because it is considered an indicator. In the case of the long magnetic anisotropic rare earth sintered magnet of the present invention, the disturbance due to the demagnetizing field after orientation can be remarkably reduced.
  • 2 and 3 are graphs of the permeance coefficient of a single magnet.
  • the ratio T / D 0 of the magnet length T of the magnet and the outer diameter D 0 corresponds to 3.0 from FIG. If the magnet length is 40 mm, D 0 corresponds to 13.3 mm, which corresponds to the minimum size of a magnet used for high-grade applications such as motors.
  • the PLP method and the new PLP method are applied to the method for producing a magnetic anisotropic rare earth sintered magnet of the present invention.
  • a fine container is filled with a fine powder according to a desired size and shape, oriented by applying a magnetic field from the outside, and then sintered as it is. After the fine powder is confined in the filling container, a magnetic field is applied and the process proceeds to the sintering process as it is, so that the fine powder does not fly and even a rare earth magnet fine powder can be handled safely.
  • alloy fine powders of RFeB magnets with an average particle size D 50 measured by a laser-type powder particle size distribution analyzer in a filled container of 0.5 ⁇ m to 5 ⁇ m are between 46.4% and 55% of the true density.
  • it is a method for producing a magnetic anisotropic rare earth sintered magnet, characterized in that each of the above steps is performed consistently in a container which is an oxygen-free or inert gas atmosphere.
  • the PLP method is characterized in that the process from handling fine powder to the sintering process is performed consistently in an oxygen-free atmosphere. Since the fine powder finer than the conventional fine powder can be handled, the average particle diameter D of the fine powder used is set to 0.5 ⁇ m to 5 ⁇ m.
  • a method for producing a magnetic anisotropic rare earth sintered magnet by a new PLP method is a method of supplying alloy powder to a mold having side walls divided into two or more parts, and filling the mold with the alloy powder.
  • the average particle size of the fine powder used can be 2 ⁇ m or less, and can be 1 ⁇ m or less.
  • the median value (D 50 ) of particle diameters measured by a laser type powder particle size distribution measuring device is used as the average particle diameter.
  • the rare earth magnet used in the present invention is preferably an RFeB magnet.
  • the RFeB magnet is composed of 2 to 30% of R (R is at least one of rare earth elements including Y), B2 to 28%, and the balance substantially Fe in atomic percent.
  • R is at least one of rare earth elements including Y
  • B2 to 28% the balance substantially Fe in atomic percent.
  • less than 50% of Fe may be replaced with Co.
  • part of Fe is Ti, Ni, Bi, V, Nb, Ta, Cr, Mo, W, Mn, Al, Sb, Ge, Sn , Zr, Hr, Ga, etc.
  • These additive elements may be added in combination, but in any case, the total amount is preferably 6 atomic% or less.
  • V and Mo are preferable.
  • the sum of R1 (one or more of Dy, Tb, Gd, Ho, Er, Tm, Yb) and R2 (one or more of the rare earth elements including Y other than R1 with a total of Nd / Pr of 80% or more) When R is R, a composition comprising R1 12 to 20%, B 4 to 20% and the balance Fe is a preferable composition range in which high squareness of the demagnetization curve and high coercive force can be obtained. In the case of the RFeB magnet, the sintering is performed between 900 and 1200 ° C.
  • the rare earth magnet of the present invention can also be applied to a cobalt magnet (RCo magnet).
  • RCo magnets the composition range of 1-5 type magnets is RTx (R is Sm or Sm and one or a combination of two or more of La, Ce, Pr, Nd, Y, Gd, and T is Co or Co.
  • R is Sm or Sm and one or a combination of two or more of La, Ce, Pr, Nd, Y, Gd, and T is Co or Co.
  • Mn, Fe, Cu, and Ni, 3.6 ⁇ x ⁇ 7.5 One or a combination of two or more of Mn, Fe, Cu, and Ni, 3.6 ⁇ x ⁇ 7.5
  • its sintering temperature is 1050-1200 ° C.
  • the composition range of the 2-17 type RCo magnet is R (where R is Sm or two or more rare earth elements containing 50% by weight or more of Sm) 20 to 30% by weight, Fe 10 to 45% by weight, Cu 1 to 10% 1% or more of Zr, Nb, Hf, V, 0.5 to 5% by weight, the balance Co and unavoidable impurities.
  • the sintering temperature is 1050 to 1250 ° C. In both the 1-5 type and the 2-17 type, the coercive force can be increased by performing a heat treatment at 900 ° C. or lower during sintering.
  • Rare earth sintered magnets with excellent magnetic properties require a dense and homogeneous microstructure.
  • a strip casting method has been proposed as a method for obtaining a fine and dense alloy ingot (Japanese Patent No. 2665590).
  • the average crystal grain size of the strip cast slab is 3 to 20 ⁇ m.
  • the average crystal grain size of the strip cast alloy is preferably 3 ⁇ m or less, more preferably 2 ⁇ m or less.
  • a magnetic field is applied from the outside to orient the fine powder filled in the filling container. If the entire filling container is non-magnetic, it is preferable because the external magnetic field works effectively on the magnetic powder that is a magnetic substance.
  • the material is selected from non-magnetic stainless steel, refractory metals such as molybdenum and tungsten, carbon, and various ceramics.
  • the powder in the filling container is in a movable state.
  • the orientation of the powder may be disturbed by the magnetic moment of each magnetized powder or the magnetic field formed by the entire powder in the filled container. If the magnetic poles of the ferromagnetic material are arranged at both ends of the filling container, the disturbance of the powder after applying the magnetic field can be avoided by changing the flow of the magnetic flux.
  • the actual neodymium magnet sintered body currently on the market has a crystal grain size of 5 to 10 ⁇ m, and the particle size of the fine powder before sintering is 3 to 5 ⁇ m at D 50 .
  • D 50 represents the median value of the particle size distribution measured with a laser particle size distribution measuring instrument or the like.
  • the rare-earth magnet alloy composition comprising 30 percent or more rare earth elements by weight, in the conventional die-pressing method has been difficult to D 50 of handle 5 [mu] m (3 [mu] m in FSSS) following fine powder.
  • fine powder is filled in a filled container in an inert atmosphere such as oxygen-free or nitrogen, oriented by a magnetic field, and carried into a sintering furnace, so there is no step to touch air, even if it is fine. Even if it is powder, there is no danger in handling.
  • the rare-earth magnet alloy composition containing a rare earth element 30 weight percent or more, in the conventional die-pressing method was impossible to handle a fine powder D 50
  • the RFeB magnet is a single domain fine particle type, and the size of the single domain particle is about 0.2 to 0.3 microns.
  • the crystal grain size of the actual RFeB sintered magnet is about 5 to 10 ⁇ m, and the particle size of the fine powder before sintering is about 4 to 5 ⁇ m at D 50 .
  • a large coercive force can be obtained if the crystal particle size is the size of a single domain particle. But to achieve that, smaller powders must be used.
  • the conventional die press, manufacturing process by CIP and RIP avoids the influence of oxygen and moisture contained in the atmosphere. Impossible. If RFeB alloy powder with a particle size as small as 2 ⁇ m is exposed to the atmosphere, the possibility of ignition and explosion increases, and stable production cannot be achieved. If it is not necessary to ignite, the fine powder has a large surface area, so the amount of oxygen increases and the magnetic properties deteriorate. In order to avoid oxidation, if chemical substances such as those used in binders, lubricants, and wet presses are used in combination, the chemical component reacts with the powder component because of the large surface area of the fine powder, and before the sintering process.
  • the degreasing process requires a remarkably long time, resulting in poor productivity and reduced magnetic properties. Since these effects cannot be avoided by conventional methods, such fine powders cannot be handled.
  • a sintered magnet is obtained using RFeB alloy powder having a D 50 value of 2 ⁇ m or less by the PLP method or the new PLP method, a neodymium sintered magnet with high orientation, high energy product and high coercive force can be obtained.
  • Addition of Dy or Tb has the effect of increasing the coercive force of the magnet by increasing the anisotropic energy of the R 2 Fe 14 B intermetallic compound.
  • the crustal abundance of heavy rare earth elements such as Dy and Tb is small compared to Nd, the price is expensive, and the saturation magnetization decreases when a large amount of heavy rare earth elements is added.
  • One of the features of the PLP method and the new PLP method is that there is no need to perform pressure molding with a large pressure like a die press, CIP, or RIP.
  • the powder oriented in the filling container is sintered while maintaining a high orientation without applying a force that disturbs the orientation by applying a strong pressure.
  • a high degree of orientation achieves a high residual magnetic flux density (Br) and a high maximum energy product ((BH) max).
  • the process from preparation of fine powder to sintering can be processed in a complete oxygen-free or inert atmosphere, and rare earth-containing magnet powder with a D 50 value of 1 ⁇ m or less is safe.
  • a magnet having a high coercive force can be obtained.
  • the RFeB magnet is a single domain fine particle type and the single domain particle diameter is about 0.2 to 0.3 ⁇ m, it is desirable that the crystal grain size of the sintered body is close to that.
  • the powder particle size needs to be 0.5 ⁇ m or less.
  • the process from preparation of fine powder to sintering can be processed in a complete oxygen-free or inert atmosphere, and the rare earth-containing magnet powder having a D 50 value of 0.5 ⁇ m or less can be handled safely. Can do.
  • the degree of filling of the fine powder is lower than the degree of filling in the conventional mold press method or the like.
  • a strong green compact strength is required for the green compact handling.
  • the powder filled in the filling container at a high density may be of such a degree that the container is uniformly filled so that a sufficient density can be obtained in the sintered body. Specifically, it is sufficient that the powder is not biased during pulse magnetic field orientation. Such a state can be confirmed by the presence or absence of fine pores in the cross-section of the sintered body after sintering, and it is preferable that there are almost no pores.
  • the filling density of the filling container is set to 46.4% or more as a range in which sufficient sintering density can be obtained and sufficient orientation can be achieved without causing disorder of the orientation, and the upper limit is 55%. 47% or more and 52% or less is a more preferable range.
  • a mechanical tapping method or an air tapping method Japanese Patent Laid-Open No. 2000-96104
  • Micron-sized magnet powder easily aggregates and forms a bridge when filling a container, making uniform filling difficult. If the mechanical tapping method or the air tapping method is used, the powder can be uniformly and uniformly filled in the container by applying periodic mechanical impact or air impact to the powder in the powder feeder.
  • a magnetic field is applied from the outside to align the individual fine powders in one direction.
  • the c-axis direction of the tetragonal structure compound corresponds to the easy magnetization axis, and when a magnetic field is applied, the powder is oriented in one direction.
  • the magnetic field generated by the electromagnet used in the mold press is about 1.5 Tesla at maximum.
  • a pulse magnetic field using an air-core coil can apply a strong magnetic field of 1.5 to 5.5 Tesla, and the magnetic characteristics are improved by actually applying a high magnetic field.
  • Japanese Patent No. 3307418 shows an example in which a pulsed magnetic field is used for magnetic orientation, but the entire specification only describes that a pulse magnetic field coil is disposed in a die press machine.
  • the air-core coil used in the present invention is preferably a cylindrical long solenoid coil.
  • a long magnetic coil is not used for a magnetic field coil of a pulse magnetic field used in a die press due to a restriction due to a structure of a press machine.
  • the coils used in CIP and RIP do not require uniformity in the degree of orientation of the entire magnet, and there is no necessity to use a long solenoid coil.
  • the long solenoid coil means that the coil length in the longitudinal direction is longer than the inner diameter of the coil and is longer than the long length of the long filling container.
  • the cross-sectional shape of the coil may be a rectangular cylinder, a hexagonal cylinder, a polygonal cylinder, or the like depending on the shape of the filling container. In the present invention, these are collectively referred to as a long solenoid coil.
  • a pulse current is passed through the solenoid coil, a large force is applied between the coils. Therefore, a cylindrical long solenoid coil is most
  • the magnetic fluxes in the same direction repel each other, the magnetic flux is distorted as it moves from the magnetic pole center to the end. That is, it is difficult to obtain a uniform and parallel magnetic field in a wide range with a die press.
  • the long solenoid coil can obtain a parallel and uniform magnetic field in a wide range inside.
  • the outer length of the long solenoid coil needs to be longer than the magnet length.
  • the inner diameter of the solenoid coil is preferably small and the length is preferably long.
  • the inner diameter of the coil is preferably 1.5 to 10 times the maximum dimension of the cross section of the filling container, and more preferably 3 to 10 times.
  • the ratio L / D between the inner diameter (D) and the length (L) of the long solenoid coil needs to be 2 or more, preferably 3 or more.
  • the magnetic field generated by the solenoid coil is preferably 3 Tesla or higher, and more preferably 5 Tesla or higher in order to obtain a high degree of orientation.
  • a pulse magnetic field is not necessarily required if the aim is only to reduce variation when a single long magnet is cut out rather than aiming for a high degree of orientation, and a magnetic field of 3 Tesla or less using a direct current may be used.
  • a magnetic field of 3 Tesla or less using a direct current may be used.
  • a parallel and uniform magnetic flux is secured over a long distance inside the long solenoid coil, but if a ferromagnetic material of magnet powder is placed inside, the magnetic flux is distorted due to the influence. If a magnetic pole made of a ferromagnetic material such as pure iron, silicon steel plate or permalloy is placed at the end of the filling container in the longitudinal direction, part of the distortion is corrected, and a uniform and uniform magnetic flux is applied to the fine powder in the filling container. It is preferable.
  • the saturation magnetization value of the RFeB sintered magnet is about 1.4 Tesla, and the saturation magnetization value of the fine powder aggregate is about half of that.
  • the degree of orientation can be further improved by using a magnetic pole containing 20% to 50% magnetic powder such as pure iron powder, solidified with a resin, etc., and using a magnetic pole close to the saturation magnetization value of the fine powder aggregate in the filled container.
  • the external magnetic field generating source used for powder orientation is preferably a pulsed magnetic field.
  • the pulse magnetic field is applied by placing a filled container filled with fine powder in an air-core coil.
  • a high magnetic field strength can be given.
  • the pulse magnetic field for orienting the powder is preferably a method in which an alternating decay waveform magnetic field is applied in advance, and then a direct current pulse magnetic field is applied, rather than a single direct current pulse.
  • Patent No. 3307418 gives a magnetic field of 15-50 kOe in the manufacture of RFeB magnets, and it has been confirmed that the magnetic properties are improved.
  • the conventional die press method uses a pulse magnetic field in combination.
  • the magnetic field in the present invention needs to be a strong magnetic field, but may be any magnetic field as long as a strong magnetic field can be obtained by a superconducting coil in addition to the pulsed magnetic field.
  • the process from taking out the fine powder to the sintering furnace is consistently performed in an oxygen-free or inert atmosphere.
  • the fine powder is filled from a hopper through a high-density filling means such as mechanical tapping and air tapping into a filling container installed in an oxygen-free or inert gas atmosphere, and moves to a place provided with an orientation means in a magnetic field.
  • the filled container in which the powder is oriented by a magnetic field orientation means such as a pulsed magnetic field is conveyed to the sintering furnace entrance as it is.
  • the side wall of the filled container is removed and conveyed to the entrance of the sintering furnace.
  • a filling container with a fine powder to which a liquid lubricant has been added in advance is a preferable method in order to facilitate orientation in a magnetic field and increase the degree of orientation.
  • solid lubricants have low vapor pressure and high boiling point, while liquid lubricants have high vapor pressure and low boiling point.
  • a liquid lubricant is preferable. It is known to use methyl caproate or methyl caprylate together with saturated fatty acid as a liquid lubricant (Japanese Patent Laid-Open No. 2000-109903).
  • the amount of liquid lubricant added is preferably 0.5 to 1%.
  • the liquid lubricant of the present invention is only required to have lubricity and easily volatilize, such as methyl octylate, methyl decanoate, methyl caprylate, methyl laurate, methyl myristate, methyl palmitate, methyl stearate, etc. Can be used.
  • heating with the filled container and presintering, taking out from the filled container and raising only the magnet to the sintering temperature can increase the life of the filled container.
  • Pre-sintering is performed until a part of the powder is bonded and the shape can be preserved.
  • the pre-sintering temperature is preferably 500 ° C. or higher.
  • the pre-sintering temperature should be 50 ° C. or lower than the optimum sintering temperature.
  • RFeB magnets and RCo 5 type magnets contain more rare earth elements than the equilibrium composition of intermetallic compounds (R 2 Fe 14 B and RCo 5 ). They promote liquid phase sintering through a low melting eutectic composition with other constituent elements. That is, powder binding occurs due to the presence of the liquid phase, and then proceeds to the contraction stage. If pre-sintering is performed in a filled container, the target shape is preserved. The pre-sintered body can be taken out from the filling container and subjected to original sintering using another sintering base plate or the like.
  • aging treatment is performed in one or more stages in the temperature range of 350 ° C to 1000 ° C.
  • Moderate aging treatment has the effect of improving the coercive force by improving the grain boundary structure after sintering.
  • the RFeB sintered magnet is made of an intermetallic compound, and a diamond grindstone is used for cutting.
  • a diamond cutting wheel using cemented carbide has been developed, but the blade thickness is still over 1 mm.
  • the long magnetic anisotropic sintered magnet of the present invention can be cut to obtain a plurality of magnets with small variations in magnetic properties, which are high performance magnets used in high value-added products such as high performance motors. Become. Compared to the yield of conventional magnet products that may be discarded due to variations in magnetic characteristics, the yield of cutting scraps for cutting long magnets without characteristic variations according to the present invention is considered to be sufficiently effective. Cutting waste can be recycled as scrap.
  • the microstructure of the RFeB sintered magnet mainly consists of R2Fe14B intermetallic compound crystal grains and a grain boundary phase rich in R composition (referred to as "Nd rich phase"). Since the magnetization reversal of this magnet is a nucleation type that starts near the crystal grain boundary, increasing the concentration of heavy rare earth elements such as Dy and Tb near the crystal grain boundary improves the coercive force near the crystal grain boundary. As a result, magnetization reversal hardly occurs. Since RFeB magnetic anisotropic sintered magnets have a large coercive force, they are often used on the order of several millimeters at a practical level.
  • heat treatment is carried out in the presence of metals, alloys, compounds, etc. of heavy rare earth elements such as Dy and Tb on the surface of the magnet processed to a thickness of several mm.
  • the Nd-rich phase becomes like a liquid phase, and heavy rare earth elements diffuse into the grain boundary, increasing the coercivity near the grain boundary.
  • Hc of the magnet is improved without decreasing the residual magnetic flux density Br and the maximum energy product (BH) max.
  • the main component of the RFeB magnet is composed of rare earth elements and iron, and is easily oxidized. So far, resin coating, plating, aluminum vapor deposition, oxidation treatment, etc. are used depending on the application. In the case of the above-described embedded magnet type motor magnet for an automobile motor, it is used by being embedded with a resin in a preset groove.
  • the present invention can be applied to both Nd—Fe—B sintered magnets and Sm—Co based sintered magnets. Examples of the present invention are shown below, but the present invention is not limited to the examples.
  • rare earth sintered magnets there are RFeB sintered magnets and SmCo based sintered magnets. In the following examples, the results of the RFeB sintered magnet are technically applicable to SmCo-based sintered magnets.
  • NdFeB is made by occluding hydrogen in a strip cast alloy with a composition (weight fraction) of 26.0% Nd, 5.5% Pr, 0.89% Co, 0.99% B, 0.1% Cu, 0.25% Al, and the balance Fe, and NdFeB
  • An alloy coarsely pulverized powder for a sintered magnet was obtained.
  • This coarsely pulverized powder was pulverized by a jet mill using nitrogen gas to obtain an RFeB sintered magnet alloy fine powder.
  • the average particle diameter D 50 was 4.2 ⁇ m.
  • 0.1% by weight of zinc stearate was added and stirred and mixed with a mixer. A sintered magnet was produced using this alloy fine powder.
  • a side surface of the filling container having a size of 20 mm ⁇ 20 mm ⁇ 108 mm was prepared on the inner side, and the same was placed on a nonmagnetic stainless steel base plate.
  • the side surface of the nonmagnetic stainless steel filling container is divided into four parts. Magnetic poles containing 40% pure iron powder and hardened with resin were placed at each end of the mold after assembly.
  • the method disclosed in the new PLP method in which the filled container is removed and sintered before the sintering step is applied. Details of the new PLP method are disclosed in Patent Document 3.
  • the target of the packing density in this example is set to 3.6 g / cm 3 , the amount of fine powder calculated from the volume of the filling container and the filling density is measured, and the fine powder is finely placed in a powder supply spacer provided in advance on the filling container. Powder was charged.
  • the dusting spacer is a container for receiving powder that does not fit in the filling container before reaching a predetermined filling density, and the inner portion has the same dimensions of 20 mm ⁇ 108 mm as the filling container.
  • the filling container and the dusting spacer are made to vibrate up and down and collide with the base plate placed below when descending, and then the flat bottom pushing punch member with a flat bottom surface falls from the top of the dusting spacer toward the fine powder And repeated several times until the height of the filled powder and the height of the filled container were the same.
  • the dusting spacer and punch were removed, and a lid plate was attached to the top surface of the filling container.
  • the filling container is moved into a long magnetic coil for magnetic field orientation having a coil inner diameter of 120 mm, a coil outer diameter of 160 mm, and a length of 445 mm, and a pulse magnetic field of 4 Tesla is applied in the longitudinal direction, and orientation filling molding is performed.
  • the body is moved into a long magnetic coil for magnetic field orientation having a coil inner diameter of 120 mm, a coil outer diameter of 160 mm, and a length of 445 mm, and a pulse magnetic field of 4 Tesla is applied in the longitudinal direction, and orientation filling molding is performed.
  • the body is moved into a long magnetic coil for magnetic field orientation having a coil inner diameter of 120 mm, a coil outer diameter of 160 mm, and a length of 445 mm, and a pulse magnetic field of 4 Tesla is applied in the longitudinal direction, and orientation filling molding is performed.
  • the body is moved into a long magnetic coil
  • the sintered body was subjected to a two-stage aging treatment in which it was rapidly cooled after heating at 800 ° C. for 1 hour in an argon gas atmosphere, and further cooled rapidly after heating at 500 ° C. for 1 hour to obtain a sintered body.
  • the long sintered magnet was processed to ⁇ 10 ⁇ 7 mm (magnetization direction) using a diamond grindstone and an electric discharge machine to be used as a measurement sample of a pulse BH tracer with a high magnetic field. Machining was performed with care because correct measurement values cannot be obtained if the magnetization direction is slightly inclined. The measurement was performed mainly on any nine magnet pieces constituting the central portion. The results are shown in Table 1 and FIG. This result is displayed in CGS unit system for the convenience of measuring instruments.
  • a long magnetic anisotropic rare earth magnet with uniform magnetic characteristics and small variations which reduces variations in magnets that cause rotation unevenness and vibration, is provided. Can be provided.

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  • Crystallography & Structural Chemistry (AREA)
  • Inorganic Chemistry (AREA)
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Abstract

L'invention concerne un aimant fritté à base de terres rares à anisotropie magnétique allongé ayant des caractéristiques magnétiques uniformes le long de la totalité de l'aimant allongé, et son procédé de fabrication. Ledit aimant fritté à base de terres rares à anisotropie magnétique est un aimant fritté à anisotropie magnétique allongé qui est destiné à permettre d'obtenir une pluralité d'aimants ayant des caractéristiques magnétiques uniformes après avoir été découpés en morceaux, et qui a une direction de magnétisation facile dans le sens de sa longueur. De plus, dans ce procédé de fabrication, une poudre fine, qui a été introduite dans un récipient de remplissage à une densité de remplissage modérée, est orientée et la poudre fine est ensuite déplacée vers une étape de frittage avec le récipient de remplissage inchangé, ou après le retrait du récipient de remplissage, et par conséquent un aimant fritté à base de terres rares à anisotropie magnétique allongé ayant des caractéristiques magnétiques uniformes et présentant peu de trouble dans le degré d'orientation lors du moulage par compression après l'orientation du champ magnétique peut être fabriqué grâce au procédé de fabrication.
PCT/JP2017/030165 2016-08-26 2017-08-23 Aimant fritté à base de terres rares et procédé de fabrication dudit aimant Ceased WO2018038170A1 (fr)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115206664A (zh) * 2022-08-01 2022-10-18 安泰爱科科技有限公司 一种钕铁硼永磁胚体加工用工装机构及其加工方法
CN117444202A (zh) * 2023-11-23 2024-01-26 瑞声开泰科技(马鞍山)有限公司 填充成型模具及填充成型方法、烧结NdFeB磁体制备方法

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007134353A (ja) * 2005-11-07 2007-05-31 Inter Metallics Kk 磁気異方性希土類焼結磁石の製造方法及び製造装置
WO2016047593A1 (fr) * 2014-09-28 2016-03-31 Ｎｄｆｅｂ株式会社 Procédé de fabrication d'un aimant fritté à base de terres rares, et dispositif de fabrication utilisé pour ledit procédé de fabrication

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007134353A (ja) * 2005-11-07 2007-05-31 Inter Metallics Kk 磁気異方性希土類焼結磁石の製造方法及び製造装置
WO2016047593A1 (fr) * 2014-09-28 2016-03-31 Ｎｄｆｅｂ株式会社 Procédé de fabrication d'un aimant fritté à base de terres rares, et dispositif de fabrication utilisé pour ledit procédé de fabrication

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115206664A (zh) * 2022-08-01 2022-10-18 安泰爱科科技有限公司 一种钕铁硼永磁胚体加工用工装机构及其加工方法
CN115206664B (zh) * 2022-08-01 2023-04-28 安泰爱科科技有限公司 一种钕铁硼永磁胚体加工用工装机构及其加工方法
CN117444202A (zh) * 2023-11-23 2024-01-26 瑞声开泰科技(马鞍山)有限公司 填充成型模具及填充成型方法、烧结NdFeB磁体制备方法

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