WO2019114487A1 - 稀土永磁材料及其制备方法 - Google Patents

稀土永磁材料及其制备方法 Download PDF

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WO2019114487A1
WO2019114487A1 PCT/CN2018/115474 CN2018115474W WO2019114487A1 WO 2019114487 A1 WO2019114487 A1 WO 2019114487A1 CN 2018115474 W CN2018115474 W CN 2018115474W WO 2019114487 A1 WO2019114487 A1 WO 2019114487A1
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powder
diffusion
rare earth
magnet
preparation
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PCT/CN2018/115474
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English (en)
French (fr)
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周磊
刘涛
程星华
喻晓军
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安泰科技股份有限公司
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Priority to KR1020207011738A priority Critical patent/KR102287740B1/ko
Priority to ES18887290T priority patent/ES2912741T3/es
Priority to EP18887290.7A priority patent/EP3726549B1/en
Priority to SI201830685T priority patent/SI3726549T1/sl
Priority to US16/770,608 priority patent/US11984258B2/en
Publication of WO2019114487A1 publication Critical patent/WO2019114487A1/zh

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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
    • 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
    • H01F41/0293—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 diffusion of rare earth elements, e.g. Tb, Dy or Ho, into permanent magnets
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    • 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
    • B22F3/10—Sintering only
    • B22F3/105—Sintering only by using electric current other than for infrared radiant energy, laser radiation or plasma ; by ultrasonic bonding
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    • B22F3/24—After-treatment of workpieces or articles
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C32/00—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ
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    • C22C—ALLOYS
    • C22C32/00—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ
    • C22C32/001—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with only oxides
    • C—CHEMISTRY; METALLURGY
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    • 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
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C10/00—Solid state diffusion of only metal elements or silicon into metallic material surfaces
    • C23C10/02—Pretreatment of the material to be coated
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C10/00—Solid state diffusion of only metal elements or silicon into metallic material surfaces
    • C23C10/28—Solid state diffusion of only metal elements or silicon into metallic material surfaces using solids, e.g. powders, pastes
    • C23C10/30—Solid state diffusion of only metal elements or silicon into metallic material surfaces using solids, e.g. powders, pastes using a layer of powder or paste on the surface
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C10/00—Solid state diffusion of only metal elements or silicon into metallic material surfaces
    • C23C10/60—After-treatment
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C12/00—Solid state diffusion of at least one non-metal element other than silicon and at least one metal element or silicon into metallic material surfaces
    • C23C12/02—Diffusion in one step
    • 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
    • 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
    • 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
    • B22F3/10—Sintering only
    • B22F3/105—Sintering only by using electric current other than for infrared radiant energy, laser radiation or plasma ; by ultrasonic bonding
    • B22F2003/1051—Sintering only by using electric current other than for infrared radiant energy, laser radiation or plasma ; by ultrasonic bonding by electric discharge
    • 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
    • B22F3/24—After-treatment of workpieces or articles
    • B22F2003/248—Thermal after-treatment
    • B—PERFORMING OPERATIONS; TRANSPORTING
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    • B22F2301/00—Metallic composition of the powder or its coating
    • B22F2301/35—Iron
    • B22F2301/355—Rare Earth - Fe intermetallic alloys
    • 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
    • B22F2304/00—Physical aspects of the powder
    • B22F2304/10—Micron size particles, i.e. above 1 micrometer up to 500 micrometer
    • 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 invention belongs to the technical field of rare earth permanent magnet materials, in particular to a rare earth permanent magnet material and a preparation method thereof.
  • the method adopts pressing, plasma sintering and grain boundary diffusion integration technology, and uses less heavy rare earth amount to achieve remarkable magnet performance. Improve, high quality and use heavy rare earth.
  • Sintered NdFeB rare earth permanent magnet is the most magnetic permanent magnet material, widely used in electronics, electromechanical, instrumentation and medical fields. It is the fastest growing and the best prospect in the world. With the rapid development of hybrid vehicles, high-temperature permanent magnets with operating temperatures above 200 °C are required. Therefore, higher requirements are placed on the high-temperature magnetic properties of NdFeB magnets.
  • NdFeB magnets have a sharp drop in coercivity at high temperatures and cannot meet the requirements for use.
  • the Dy or Tb element is doped in the NdFeB magnet to improve the coercive force of the magnet, thereby improving the high temperature magnetic properties of the magnet.
  • Dy preferentially occupies the 4f crystal position in NdFeB, and each Nd is replaced by Dy to form Dy 2 Fe 14 B.
  • the coercive force is greatly improved.
  • Dy also affects the microstructure of the magnetic material and can inhibit the grain. Growing up, this is another reason to increase coercivity. However, the coercive force does not increase linearly with the increase of Dy content.
  • the magnetic moments of Nd and iron are arranged in parallel, and Dy and iron are arranged in anti-parallel, and therefore, the remanence Br and the maximum magnetic energy product (BH)max of the magnet are lowered.
  • Sintered NdFeB magnets have poor formability and must be post-processed to achieve acceptable dimensional accuracy. However, due to the great brittleness of the material itself, the loss of raw materials in the post-processing is as high as 40-50%, which causes a huge waste of rare earth resources, and the machining also increases the manufacturing cost of the material.
  • the bonded NdFeB magnets are basically isotropic and have low magnetic properties, and cannot be applied to fields requiring high magnetic properties.
  • the object of the present invention is to provide a rare earth permanent magnet material and a preparation method thereof, which adopts pressing, plasma sintering and grain boundary diffusion techniques, and uses less heavy rare earth amount to achieve remarkable magnet performance. Improve, high quality and use heavy rare earth.
  • the method of the present invention not only realizes the orderly arrangement of rare earth elements on the surface and inside of the NdFeB matrix, but also increases the coercive force of the magnet, while the residual magnetism is not substantially reduced.
  • the heavy rare earth element-rich compound and the pure metal powder are attached to the surface of the magnet by an SPS hot pressing process, and grain boundary diffusion is achieved by the subsequent heat treatment, thereby improving the coercive force characteristic of the magnet.
  • the heavy rare earth element-containing powder used in the present invention is a fluoride or an oxide of Dy ⁇ Tb ⁇ Ho ⁇ Gd ⁇ Nd ⁇ Pr, and the pure metal powder is one or more of Al ⁇ Cu ⁇ Ga ⁇ Zn ⁇ Sn and the like. .
  • a method for preparing a rare earth permanent magnet material comprising:
  • a composite powder for diffusion is deposited on the surface of the NdFeB magnetic powder layer and subjected to spark plasma sintering treatment to obtain a neodymium-iron-boron magnet having a diffusion layer formed on the surface thereof, and the composition ratio of the composite powder for diffusion is H 100-xy M x Q y , wherein H is one or more of metal powders of Dy, Tb, Ho and Gd, or H is a fluoride powder or oxide powder of Dy, Tb, Ho and Gd
  • M is a Nd, Pr or NdPr metal powder, Q is one or more of Cu, Al, Zn and Sn metal powders; x and y are M components and Q components respectively
  • the atomic percentage in the composite powder for diffusion, x is 0-20 (such as 1, 3, 5, 7, 9, 11, 13, 15, 17, 19), and y is 0-40 (such as 1, 5, 10) , 15, 20, 25, 30, 35, 39);
  • the diffused neodymium iron boron magnet is tempered to obtain the rare earth permanent magnet material.
  • the method for preparing a rare earth permanent magnet material of the invention has a heavy rare earth element mainly distributed in a grain boundary or a transition region between a grain boundary and a main phase to prepare a magnet having an equivalent coercive force, and the method of the invention is relatively simple to treat NdFeB
  • the method of the present invention has a small amount of rare earth elements and the residual magnetization is substantially unchanged.
  • the x and y are not zero at all; more preferably, the value of x ranges from 2 to 15 (such as 3, 4, 6, 8, 10, 12, 14), the value of y ranges from 4 to 25 (such as 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 24).
  • the composition ratio of the composite powder for diffusion is (TbF 3 ) 95 Nd 2 Al 3 , (DyF 3 ) 95 Nd 1 A l4 , (TbF 3 ) 95 Cu 5 .
  • the composite powder for diffusion has a particle size of -150 mesh.
  • the powder particle size is too fine, the preparation process cost is intensified, and it is easy to agglomerate, which is not conducive to molding; when it is too large, the effect in the subsequent sintering diffusion process is poor.
  • the preparation of the composite powder for diffusion comprises: mixing the powders of the three components of H, M and Q in an oxygen-free environment, and then sieving through 150 mesh. After the sieve is taken, a composite powder for diffusion is obtained; the oxygen-free environment is preferably a nitrogen atmosphere; the particle size of the H component is -150 mesh, and the particle size of the M component is -150 mesh, The Q component has a powder particle size of -150 mesh.
  • the neodymium iron boron magnetic powder is obtained by air flow milling.
  • the composite powder for diffusion deposited on the surface of the NdFeB magnetic powder layer has a thickness of 5 to 30 ⁇ m (for example, 6 ⁇ m, 8 ⁇ m, 10 ⁇ m, 12 ⁇ m, 15 ⁇ m, 18 ⁇ m, 21 ⁇ m, 23 ⁇ m, 25 ⁇ m, 27 ⁇ m, 29 ⁇ m); more preferably, the surface on which the composite powder for diffusion is laid is perpendicular to the orientation of the neodymium iron boron magnetic powder.
  • the conditions of the discharge plasma sintering treatment are: a degree of vacuum of not less than 10 -3 Pa (for example, 10 -3 Pa, 8 ⁇ 10 -4 Pa, 5 ⁇ 10 - 4 Pa, 1 ⁇ 10 -4 Pa, 9 ⁇ 10 -5 Pa, 5 ⁇ 10 -5 Pa), pressure 20-60Mpa (such as 22Mpa, 25Mpa, 30Mpa, 35Mpa, 40Mpa, 45Mpa, 50Mpa, 55Mpa, 59Mpa)
  • the temperature is 700-900 ° C (such as 710 ° C, 750 ° C, 800 ° C, 820 ° C, 850 ° C, 880 ° C); more preferably, the holding plasma sintering process has a holding pressure of 0-15 min (such as 1 min) , 3 min, 5 min, 7 min, 9 min, 11 min, 13 min).
  • the composite powder of the composition formula H 100-xy M x Q y after sintering by plasma sintering is adhered to the surface of the neodymium iron boron magnet formed by the neodymium iron boron magnetic powder to form a diffusion layer.
  • the SPS treatment of the invention achieves the purpose of preforming, and the powder of the sintered NdFeB magnet and the composite powder on the surface change from a simple physical contact to a close chemical bond under pressure and temperature, thereby facilitating subsequent sintering diffusion.
  • the process if the plasma sintering temperature is too low, the bonding between the powders will be loose, and problems such as falling edges will occur in the subsequent process. Excessive pressure can cause performance degradation.
  • the orientation direction of the neodymium iron boron magnetic powder layer is controlled to a thickness of 1 to 12 mm.
  • the diffusion heat treatment is carried out under the condition that the degree of vacuum is not less than 10 -3 Pa (for example, 10 -3 Pa, 8 ⁇ 10 -4 Pa, 5 ⁇ 10 -4 Pa). , 1 ⁇ 10 -4 Pa, 9 ⁇ 10 -5 Pa, 5 ⁇ 10 -5 Pa), temperature is 700-950 ° C (such as 710 ° C, 750 ° C, 800 ° C, 820 ° C, 850 ° C, 880 ° C, 900 °C, 920 ° C, 940 ° C), holding time is 2 to 30 hours (such as 3h, 5h, 8h, 12h, 15h, 20h, 25h, 28h); more preferably, the diffusion heat treatment is carried out in a vacuum heat treatment furnace of.
  • the degree of vacuum is not less than 10 -3 Pa (for example, 10 -3 Pa, 8 ⁇ 10 -4 Pa, 5 ⁇ 10 -4 Pa).
  • temperature is 700-950 ° C (such as 710 ° C, 750 °
  • the holding temperature is too low, the diffusion treatment effect is not obvious; if the holding temperature is too high, the grain will grow abnormally, and the magnetic properties will be deteriorated; the selection of the holding time is related to the thickness of the magnet, and the thick processing time may be longer. The matching of temperature and time will help to achieve both good processing and efficient use of energy.
  • the cooling means cooling with the furnace to not higher than 50 ° C (for example, 48 ° C, 45 ° C, 40 ° C, 35 ° C, 30 ° C).
  • the temperature of the tempering treatment is 420 to 640 ° C (such as 430 ° C, 450 ° C, 480 ° C, 520 ° C, 550 ° C, 590 ° C, 620 ° C, 630)
  • the holding time is 2 to 10 hours (for example, 3h, 5h, 8h, 9h).
  • the formation and retention of the grain boundary phase rich in heavy rare earth elements is favored, and the performance of the product exceeding the preferred temperature range is slightly lowered.
  • a rare earth permanent magnet material prepared by the above method.
  • the method of the present invention combines pressing, plasma sintering and grain boundary diffusion techniques, and uses a small amount of heavy rare earth to achieve a significant improvement in the performance of the magnet.
  • the high quality utilizes heavy rare earth, which is on the surface of the sintered NdFeB magnet.
  • the heavy rare earth element, rare earth element and pure metal element diffuse through the grain boundary to the inside of the magnet at a high temperature, and then tempering at 420-640 ° C for 2 to 10 hours, finally improving the magnetic properties of the NdFeB magnet, by this method,
  • the coercive force of the sintered NdFeB magnet is increased by 4000 to 16300 Oe, the residual magnetism is only reduced by 1-2%, and the equivalent performance magnet can save 35% of the heavy rare earth.
  • the invention has the advantages that the NdFeB matrix and the rare earth-rich compound and the pure metal powder are well combined by the SPS technology and the infiltration technology integration method, and the rare earth compound and the pure metal in the powder layer are processed after the high temperature treatment.
  • the powder diffuses into the boundary between the main phase and the yttrium-rich phase in the magnet; the coercivity of the NdFeB magnet is significantly improved by these treatments.
  • the invention opens up a novel route for improving the performance of the rare earth permanent magnet material NdFeB.
  • the invention is used to improve the performance of the magnet.
  • the high efficiency, the combination of the heavy rare earth element and the base magnet solid phase is more favorable for diffusion; on the other hand, the amount of heavy rare earth used is greatly reduced, the cost of the product is lowered, and the cost performance of the product is more Advantage.
  • the yield of the finished product is improved (the present invention directly diffuses and infiltrates after press molding, and does not need to cut a large piece of magnet compared with the conventional infiltration technique, thereby reducing the cutting process.
  • Example 1 is a graph showing the overall magnetic properties of a magnet prepared in Example 1.
  • the neodymium iron boron magnetic powder used in the following examples was obtained by air flow milling, which may be a commercially available product, and may of course be prepared by a usual method.
  • the SPS technique employed in the present invention is a pressure sintering method that uses a direct current pulse current to conduct sintering.
  • the basic principle is that the discharge plasma generated by the direct current pulse current flowing into the electrode causes the particles in the sintered body to generate Joule heat uniformly and activate the surface of the particle, thereby achieving sintering while being pressurized.
  • the SPS technology applied to the invention has the following characteristics: (1) the sintering temperature is low, generally low is 700-900 ° C; (2) the sintering holding time is short, only 3-15 minutes; (3) can be fine and uniform Organization; (4) can obtain high density materials.
  • the composite powder is configured according to the powder composition formula (TbF 3 ) 95 Nd 2 Al 3 (the lower leg in the formula is the atomic percentage of the corresponding element): the TbF3 powder (particle size: -150 mesh), the metal Nd powder (weighed) Particle size: -150 mesh), metal Al powder (particle size: -150 mesh), the above powder was uniformly mixed, and passed through a 150 mesh sieve, and the sieved material was taken as a composite powder, wherein the powder mixing and sieving process was carried out under a nitrogen atmosphere. .
  • NdFeB Commercial magnetic powder of NdFeB produced by airflow (in the ratio of Nd 9.2 Pr 3 Dy 1.2 Tb 0.6 Fe 80 B 6 , wherein the lower leg is marked as the atomic percentage of the corresponding component) is loaded into the hard alloy
  • a composite powder of the step (1) of 20 ⁇ m thick is laid on the surface layer perpendicular to the orientation, and the surface is obtained by hot-press sintering under the conditions of a vacuum degree of 10 -3 Pa, a pressure of 30 MPa, and 750 ° C using a spark plasma sintering technique.
  • a NdFeB magnet of a cured (TbF 3 ) 95 Nd 2 Al 3 powder solidified layer was cured; wherein the orientation direction was 6 mm thick.
  • step (3) placing a neodymium iron boron magnet having a uniform powder solidified layer on the surface obtained in the step (2) in a vacuum heat treatment furnace, and performing heat treatment at a vacuum of 10 -3 Pa and 800 ° C for 6 hours for diffusion heat treatment;
  • the furnace is cooled to no more than 50 °C.
  • the magnet obtained in the step (3) was further tempered at 510 ° C for 4 hours to obtain a magnet having improved properties, that is, the rare earth permanent magnet material of the present invention.
  • Comparative Example 1 was set up when the magnet with improved performance was prepared according to the method of the present embodiment.
  • the preparation method of the comparative example 1 is as follows: using conventional powder metallurgy technology (for detailed production technology, see Zhou Shouzeng et al. 2012 by Metallurgical Industry Press) The contents of Chapters 7-11 of the "Sintered NdFeB Rare Earth Permanent Magnetic Materials and Technology" are published. The smelting, milling, pressing and sintering are carried out in the same composition as in Example 1. The properties of the magnets are shown in the table. Shown in 1.
  • Fig. 1 is a BH graph showing the performance test of the magnet of Example 1 and Comparative Example 1 of the present invention; it can be seen from the figure that the technical treatment of steps (2), (3), and (4) of the present embodiment, sintering ⁇ The coercive force of iron-boron increased from 25070Oe to 41330Oe, an increase of 16260Oe, and a slight decrease in remanence, that is, from 13010Gs to 12790Gs, it was reduced by 220Gs.
  • the coercive force integrated magnetic properties H cj + BH (max) of the sintered NdFeB after treatment reached 80.66.
  • the composite powder is configured in accordance with the powder ratio formula (DyF 3 ) 95 Nd 1 Al 4 (the lower leg in the formula is the atomic percentage of the corresponding element).
  • DyF 3 powder -150 mesh; metal Nd powder, -150 mesh; metal Al powder, -150 mesh; mix the above powder uniformly, and sieve through 150 mesh, powder mixing and sieving process under nitrogen atmosphere .
  • step (3) placing the magnet with a uniform powder solidified layer on the surface obtained in step (2) in a vacuum heat treatment furnace, vacuuming 10 -3 Pa, holding at 800 ° C for 6 hours; cooling with the furnace to not higher than 50 ° C .
  • the magnet obtained in the step (3) was subjected to tempering treatment at 510 ° C for 4 hours to obtain a magnet having improved properties.
  • Comparative Example 2 was set up when the magnet with improved performance was prepared according to the method of the present embodiment.
  • the preparation method of the comparative example 2 is as follows: using conventional powder metallurgy technology (for detailed production technology, see 2012, by Metallurgical Industry Press, edited by Zhou Shouzeng et al. The contents of Chapters 7-11 of the published "Sintered NdFeB Rare Earth Permanent Magnetic Materials and Technology" are smelted, powdered, pressed and sintered according to the same composition formula as in Example 2; Shown in 1.
  • the rare earth permanent magnet material prepared in this example has a coercive force of 7700 Oe and a slight decrease in remanence and a decrease of 185 Gs.
  • the performance test results of the magnets of Example 2 and Comparative Example 2 are shown in Table 1.
  • the composite powder is configured in accordance with the powder ratio formula (TbF 3 ) 95 Cu 5 (the lower leg in the formula is the atomic percentage of the corresponding element).
  • TbF 3 powder, -150 mesh; metal Cu powder, -150 mesh was weighed; the above powder was uniformly mixed and sieved through 150 mesh, and the powder mixing and sieving process was carried out under a nitrogen atmosphere.
  • step (3) placing the magnet with a uniform powder solidified layer on the surface obtained in step (2) in a vacuum heat treatment furnace, vacuuming 10 -3 Pa, holding at 850 ° C for 6 hours; cooling with the furnace to not higher than 50 ° C .
  • the magnet obtained in the step (3) was further tempered at 510 ° C for 4 hours to obtain a magnet having improved performance.
  • Comparative Example 3 was set up when the magnet with improved performance was prepared according to the method of the present embodiment.
  • the preparation method of the comparative example 3 is as follows: using conventional powder metallurgy technology (for detailed production technology, see Zhou Shouzeng et al. 2012 by Metallurgical Industry Press) The contents of the "Sintered NdFeB Rare Earth Permanent Magnetic Materials and Technology” published in Chapters 7-11) are smelted, powdered, pressed, and sintered in the same composition as in Example 3. The properties of the magnets are shown in the table. Shown in 1.
  • the rare earth permanent magnet material prepared in this example has a coercive force of 14000 Oe, a slight decrease in remanence and a decrease of 190 Gs.
  • the performance test results of the magnets of Example 3 and Comparative Example 3 are shown in Table 1.
  • the composite powder was placed in accordance with the powder ratio formula (HoF 3 ) 97 Pr 1 Cu 2 (the lower leg in the formula is the atomic percentage of the corresponding element). Weigh HoF 3 powder, -150 mesh; metal Pr powder, -150 mesh; metal Cu powder, -150 mesh; mix the above powder uniformly, and sieve through 150 mesh, powder mixing and sieving process under nitrogen atmosphere .
  • HoF 3 powder ratio formula
  • step (3) placing the magnet with a uniform powder solidified layer on the surface obtained in step (2) in a vacuum heat treatment furnace, the vacuum degree should be less than 10 -3 Pa, and the temperature is kept at 800 ° C for 6 hours; 50 ° C.
  • the magnet obtained in the step (3) was further tempered at 510 ° C for 4 hours to obtain a magnet having improved performance.
  • Comparative Example 4 was set up when the magnet with improved performance was prepared according to the method of the present embodiment.
  • the preparation method of the comparative example 4 is as follows: using conventional powder metallurgy technology (for detailed production technology, see Zhou Shouzeng et al. 2012 by Metallurgical Industry Press) The contents of Chapters 7-11 of the published "Sintered NdFeB Rare Earth Permanent Magnet Materials and Technology" are smelted, powdered, pressed, and sintered in the same composition formula as in Example 4; Shown in 1.
  • the rare earth permanent magnet material prepared in this example has a coercive force of 4500 Oe and a slight decrease in remanence and a decrease of 215 Gs.
  • the performance test results of Example 4 and Comparative Example 4 magnets are shown in Table 1.
  • a composite powder is disposed in accordance with a powder ratio formula ((DyTb)F 3 ) 96 Cu 1 Al 3 (the lower leg in the formula is the atomic percentage of the corresponding element).
  • step (3) placing the magnet with a uniform powder solidified layer on the surface obtained in step (2) in a vacuum heat treatment furnace, vacuuming 10 -3 Pa, holding at 800 ° C for 6 hours; cooling with the furnace to not higher than 50 ° C .
  • the magnet obtained in the step (3) was further tempered at 510 ° C for 4 hours to obtain a magnet having improved performance.
  • Comparative Example 5 was set up when the magnet with improved performance was prepared according to the method of the present embodiment.
  • the preparation method of the comparative example 5 is as follows: using conventional powder metallurgy technology (for detailed production technology, see 2012, by Metallurgical Industry Press, edited by Zhou Shouzeng et al. The contents of the "Sintered NdFeB Rare Earth Permanent Magnetic Materials and Technology” published in Chapters 7-11) are smelted, powdered, pressed, and sintered in the same composition as in Example 5. The properties of the magnets are shown in the table. Shown in 1.
  • the rare earth permanent magnet material prepared in this example has a coercive force of 12000 Oe, a slight decrease in remanence and a decrease of 188 Gs.
  • the performance test results of the magnets of Example 5 and Comparative Example 5 are shown in Table 1.
  • the composite powder is disposed in accordance with the powder proportion formula (GdF 3 ) 98 Cu 2 (the lower leg in the formula is the atomic percentage of the corresponding element).
  • GdF 3 powder, -150 mesh; metal Cu powder, -150 mesh was weighed; the above powder was uniformly mixed and sieved through 150 mesh, and the powder mixing and sieving process was carried out under a nitrogen atmosphere.
  • step (3) placing the magnet with a uniform powder solidified layer on the surface obtained in step (2) in a vacuum heat treatment furnace, the vacuum degree should be less than 10 -3 Pa, and the temperature is kept at 800 ° C for 6 hours; 50 ° C.
  • the magnet obtained in the step (3) was further tempered at 510 ° C for 4 hours to obtain a magnet having improved performance.
  • Comparative Example 6 was set up when the magnet with improved performance was prepared according to the method of the present embodiment.
  • the preparation method of the comparative example 6 is as follows: using conventional powder metallurgy technology (for detailed production technology, see 2012, by Metallurgical Industry Press, edited by Zhou Shouzeng et al. The contents of Chapters 7-11 of the published "Sintered NdFeB Rare Earth Permanent Magnetic Materials and Technology" are smelted, powdered, pressed, and sintered in the same composition as in Example 6. The properties of the magnets are shown in the table. Shown in 1.
  • the rare earth permanent magnet material prepared in this example has a coercive force of 4,600 Oe and a slight decrease in remanence and a decrease of 218 Gs.
  • the performance test results of the magnets of Example 6 and Comparative Example 6 are shown in Table 1.
  • the composite powder is configured according to the powder proportion formula (TbO 3 ) 94 Nd 1 Al 5 (the lower leg in the formula is the atomic percentage of the corresponding element). Weigh TbO 3 powder, -150 mesh; metal Nd powder, -150 mesh; metal Al powder, -150 mesh; mix the above powder uniformly and sieve through 150 mesh, powder mixing and sieving process must be carried out under nitrogen atmosphere .
  • step (3) placing the magnet with a uniform powder solidified layer on the surface obtained in step (2) in a vacuum heat treatment furnace, vacuuming 10 -3 Pa, holding at 800 ° C for 6 hours; cooling with the furnace to not higher than 50 ° C .
  • the magnet obtained in the step (3) was further tempered at 510 ° C for 4 hours to obtain a magnet having improved performance.
  • Comparative Example 7 was set up when the magnet with improved performance was prepared according to the method of the present embodiment.
  • the preparation method of the comparative example 7 is as follows: using conventional powder metallurgy technology (for detailed production technology, see Zhou Shouzeng et al. 2012 by Metallurgical Industry Press) The contents of Chapters 7-11 of the published "Sintered NdFeB Rare Earth Permanent Magnet Materials and Technology" are smelted, powdered, pressed and sintered in the same composition formula as in Example 7; Shown in 1.
  • the rare earth permanent magnet material prepared in this example has a coercive force of 9000 Oe and a slight decrease in remanence and a decrease of 195 Gs.
  • the performance test results of the magnets of Example 7 and Comparative Example 7 are shown in Table 1.
  • a composite powder is disposed in accordance with a powder ratio formula (DyO 3 ) 97 (PrNd) 2 Al 1 (the lower leg in the formula is the atomic percentage of the corresponding element).
  • DyO 3 powder -150 mesh; metal PrNd powder (Pr and Nd mass ratio is 1:4), -150 mesh; metal Al powder, -150 mesh; mix the above powder uniformly and sieve through 150 mesh
  • the powder mixing and sieving process is carried out under a nitrogen atmosphere.
  • step (3) placing the magnet with a uniform powder solidified layer on the surface obtained in step (2) in a vacuum heat treatment furnace, the vacuum degree should be less than 10 -3 Pa, and the temperature is kept at 800 ° C for 6 hours; 50 ° C.
  • the magnet obtained in the step (3) was further tempered at 510 ° C for 4 hours to obtain a magnet having improved performance.
  • Comparative Example 8 was set up when the magnet with improved performance was prepared according to the method of the present embodiment.
  • the preparation method of the comparative example 8 is as follows: using conventional powder metallurgy technology (for detailed production technology, see Zhou Shouzeng et al. 2012 by Metallurgical Industry Press) The contents of the "Sintered NdFeB Rare Earth Permanent Magnetic Materials and Technology” published in Chapters 7-11) are smelted, powdered, pressed, and sintered in the same composition as in Example 8. The properties of the magnets are shown in the table. Shown in 1.
  • the rare earth permanent magnet material prepared in this example has a coercive force of 7700 Oe, a slight decrease in remanence and a decrease of 197 Gs.
  • the performance test results of the magnets of Example 8 and Comparative Example 8 are shown in Table 1.
  • the composite powder is configured according to the powder ratio formula (TbF 3 ) 46 (DyO 3 ) 48 Nd 2 ZnSnCu 2 (the lower leg in the formula is the atomic percentage of the corresponding element).
  • TbF 3 and DyO 3 powder 150 mesh; metal Nd powder, 150 mesh; metal Zn, Sn, Cu powder, 150 mesh; mix the above powder uniformly, and sieve through 150 mesh, powder mixing and sieving process It is carried out under a nitrogen atmosphere.
  • step (3) placing the magnet with a uniform powder solidified layer on the surface obtained in step (2) in a vacuum heat treatment furnace, the vacuum degree should be less than 10 -3 Pa, and the temperature is kept at 800 ° C for 6 hours; 50 ° C.
  • the magnet obtained in the step (3) was further tempered at 510 ° C for 4 hours to obtain a magnet having improved performance.
  • the comparative example 9 is set.
  • the preparation method of the comparative example 9 is as follows: the conventional powder metallurgy technology is used (for detailed production technology, see Zhou Shouzeng et al. 2012 by the Metallurgical Industry Press The contents of Chapters 7-11 of the published "Sintered NdFeB Rare Earth Permanent Magnet Materials and Technology" are smelted, powdered, pressed and sintered in the same composition formula as in Example 9; Shown in 1.
  • the rare earth permanent magnet material prepared in this example has a coercive force of 9100 Oe, and the residual magnetization is slightly lowered, which is reduced by 190 Gs.
  • the performance test results of the magnets of Example 9 and Comparative Example 9 are shown in Table 1.
  • the process parameters of the embodiment 10-13 are the same as those of the embodiment 2 except that the thickness of the composite powder is different from that of the embodiment 2; wherein the thickness of the composite powder layer in the embodiment 10 is about 12 ⁇ m, and the thickness of the composite powder layer in the embodiment 11 is about The thickness of the composite powder layer in Example 12 was about 5 ⁇ m, and the thickness of the composite powder layer in Example 13 was about 30 ⁇ m.
  • the performance test results of the magnets of Examples 10-13 and 2 are shown in Table 2.
  • Example 14-15 except that the holding temperature and the holding time in the vacuum heat treatment of the step (3) are different from those in the second embodiment, the other process parameters are the same as those in the embodiment 2; wherein the vacuum heat treatment condition in the embodiment 14 is: 950 ° C heat preservation. 4h, the vacuum heat treatment conditions in Example 15 were: 700 ° C for 30 h.
  • Table 2 The results of the magnet performance tests of Examples 14-15 and Example 2 are shown in Table 2.
  • Example 16-17 except that the temperature and time of the tempering treatment in step (4) are different from those in the second embodiment, the other process parameters are the same as in the embodiment 2; wherein the tempering treatment condition in the embodiment 16 is: tempering at 420 ° C After treatment for 10 h, the tempering treatment conditions in Example 17 were: tempering treatment at 640 ° C for 2 h.
  • Table 2 The performance test results of the magnets of Examples 16-17 and Example 2 are shown in Table 2.
  • Example 2 25*15*3 13.625 25.53
  • Example 10 25*15*3 13.75 20.55
  • Example 11 25*15*3 13.69 23.05
  • Example 12 25*15*3 13.78 19.24
  • Example 13 25*15*3 13.61 25.65
  • Example 14 25*15*3 13.55 25.02
  • Example 15 25*15*3 13.76 20.73
  • Example 16 25*15*3 13.64 24.52
  • Example 17 25*15*3 13.63 24.06
  • Example 18-23 except that the composite powder composition used was different from that of Example 2, the other process parameters were the same as in Example 2; the specific composite powder composition and the performance test results of Examples 18-23 and Example 2 were as shown in Table 3. Show.
  • Examples 24-26 The composite powders used in Examples 1-3 were directly added to the sintered NdFeB powder and mixed by SPS hot pressing, followed by sintering and aging, SPS hot pressing, sintering and aging process parameters and corresponding The examples are the same; the test results of Examples 24-26, Examples 1-3 and Comparative Examples 1-3 are shown in Table 4.

Abstract

本发明公开了一种稀土永磁材料及其制备方法，该方法包括：烧结处理步骤，在钕铁硼磁粉末层的表面上铺设扩散用复合粉末并进行放电等离子烧结处理，得到表面固化有扩散层的钕铁硼磁体，所述扩散用复合粉末的组分比例式为H 100-x-yM xQ y，其中，H为Dy、Tb、Ho和Gd的金属粉末、氟化物粉末或氧化物粉末中的一种或多种，M为Nd、Pr或NdPr金属粉末，Q为Cu、Al、Zn和Sn金属粉末中的一种或多种；x和y分别为M组分和Q组分在所述扩散用复合粉末中的原子百分比，x为0-20，y为0-40；扩散热处理和回火步骤。本发明方法效率高、扩散效果好、重稀土用量降低。

Description

稀土永磁材料及其制备方法 技术领域
本发明属于稀土永磁材料技术领域，特别涉及一种稀土永磁材料及其制备方法，该方法采用压制、等离子烧结和晶界扩散集成技术，采用较少的重稀土量来达到磁体性能的显著提高，高质化利用重稀土。
背景技术
烧结NdFeB稀土永磁体是迄今为止磁性最强的永磁材料，广泛应用于电子、机电、仪表和医疗等诸多领域，是当今世界上发展最快，市场前景最好的永磁材料。随着混合动力汽车的快速发展，要求工作温度在200℃以上的高温永磁体，因此，对NdFeB磁体的高温磁性能提出了更高的要求。
普通NdFeB磁体在高温时矫顽力下降剧烈，不能满足使用要求。目前，主要是采用在NdFeB磁体中掺杂Dy或者Tb元素来提高磁体的矫顽力，进而提高磁体的高温磁性能。研究表明在NdFeB中Dy优先占据4f晶位，每份Nd被Dy置换形成Dy 2Fe 14B，此矫顽力会有很大提高，Dy对磁性材料的微观结构也有影响，能抑制晶粒的长大，这也是提高矫顽力的另一原因。但是矫顽力并不是随着Dy含量的增加而线性增加，当Dy含量较低时，矫顽力增加很快，以后增加变的缓慢；原因是部分Dy溶入晶界夹杂相中，并没有完全进入主相。目前，主要采用熔炼母合金时直接加入Dy金属的方法，传统的提高NdFeB烧结磁体Hcj的一种有效方法是通过重稀土元素如Dy、Tb取代磁体主相Nd 2Fe 14B中的Nd，形成(Nd、Dy) 2Fe 14B，(Nd、Dy) 2Fe 14B的各向异性强于Nd 2Fe 14B；因而，磁体的Hcj得到显著提高；但这些重稀土元素资源稀缺、价格昂贵，另一方面，Nd和铁的磁矩是平行排列，而Dy与铁则是反平行排列，因而，磁体的剩磁Br及最大磁能积(BH)max都会降低。烧结NdFeB磁体的成型性很差，必须经过后加工才能达到合格的尺寸精度。但由于材料本身脆性很大，使后加工中原材料的损失高达40—50％，造成了稀土资源的巨大浪费，同时机加工也提高了材料的制造成本。而粘结NdFeB磁体基本是各向同性的，磁性能较低，无法应用于对磁性要求较高的领域。
近些年，许多研究机构报道了多种将稀土元素从磁体表面扩散到基体内部的工艺。这种工艺方法使渗透的稀土元素沿着晶界以及主相晶粒表面区域，使得稀土元素能择优分布，不仅提高了矫顽力，还节约了贵重稀土的使用量，使剩磁及磁能积没有明显降低。但大批量生产中应用蒸镀或溅射方法存在效率较低，蒸镀过程中大量稀土金属散布在加热炉腔室内，造成了重稀土金属的不必要浪费。而在表面涂覆单一稀土氧化物或氟化物加热扩散则存在矫顽力提高受限的问题。
因此，需要一种矫顽力提升显著，生产效率高，处理成本费用低，具有显著的生产成本优势的稀土永磁材料。
发明内容
针对现有技术的缺陷，本发明的目的是提供一种稀土永磁材料及其制备方法，该方法采用压制、等离子烧结和晶界扩散技术，采用较少的重稀土量来达到磁体性能的显著提高，高质化利用重稀土。
本发明的方法不仅实现了稀土元素在NdFeB基体表面及内部的有序排 列，而且提高了磁体的矫顽力，同时剩磁基本没有明显降低。本发明将富含重稀土元素的化合物和纯金属粉末通过SPS热压过程附着在磁体表面，通过随后的热处理实现晶界扩散，从而提高磁体的矫顽力特性。本发明采用的含重稀土元素的粉末为Dy\Tb\Ho\Gd\Nd\Pr的氟化物或氧化物，纯金属粉末为Al\Cu\Ga\Zn\Sn等中的一种或几种。
为了实现上述目的，本发明采用了如下技术方案：
一种稀土永磁材料的制备方法，包括：
烧结处理步骤，在钕铁硼磁粉末层的表面上铺设扩散用复合粉末并进行放电等离子烧结处理，得到表面固化有扩散层的钕铁硼磁体，所述扩散用复合粉末的组分比例式为H 100-x-yM xQ y，其中，H为Dy、Tb、Ho和Gd的金属粉末中的一种或多种，或者H为Dy、Tb、Ho和Gd的氟化物粉末或氧化物粉末中的一种或多种，M为Nd、Pr或NdPr金属粉末，Q为Cu、Al、Zn和Sn金属粉末中的一种或多种；x和y分别为M组分和Q组分在所述扩散用复合粉末中的原子百分比，x为0-20(比如1、3、5、7、9、11、13、15、17、19)，y为0-40(比如1、5、10、15、20、25、30、35、39)；
扩散热处理步骤，对所述表面固化有扩散层的钕铁硼磁体进行扩散热处理，冷却得到扩散后的钕铁硼磁体；
回火处理步骤，对所述扩散后的钕铁硼磁体进行回火处理，得到所述稀土永磁材料。
本发明的稀土永磁材料制备方法，使重稀土元素主要分布在晶界或晶界与主相的过渡区域内，制备具有同等矫顽力的磁体，本发明的方法相对于直接将钕铁硼磁粉末与重稀土粉末混合的方式，本发明方法重稀稀土元素用量少，剩磁基本不变。
在上述制备方法中，作为一种优选实施方式，所述x和y不同时为零；更优选地，所述x的取值范围为2-15(比如3、4、6、8、10、12、14)，所述y的取值范围为4-25(比如5、7、9、11、13、15、17、19、21、23、24)。
在上述制备方法中，作为一种优选实施方式，所述扩散用复合粉末的组分比例式为(TbF 3) 95Nd 2Al 3、(DyF 3) 95Nd 1A l4、(TbF 3) 95Cu 5。
在上述制备方法中，作为一种优选实施方式，所述扩散用复合粉末的粒度为-150目。粉末粒度过细，制备工艺成本加剧，而且易于团聚，不利于成型；过大时在后续的烧结扩散过程效果差。
在上述制备方法中，作为一种优选实施方式，所述扩散用复合粉末的制备包括：在无氧环境下，将H、M和Q三种组分的粉末混合均匀，再经150目筛分后取筛下物，得到扩散用复合粉末；所述无氧环境优选为氮气环境；所述H组分的粉末粒度为-150目，所述M组分的粉末粒度为-150目，所述Q组分的粉末粒度为-150目。
在上述制备方法中，作为一种优选实施方式，所述钕铁硼磁粉末是采用气流磨制得的。
在上述制备方法中，作为一种优选实施方式，铺设在所述钕铁硼磁粉末层表面上的扩散用复合粉末的厚度为5-30μm(比如6μm、8μm、10μm、12μm、15μm、18μm、21μm、23μm、25μm、27μm、29μm)；更优选地，铺设所述扩散用复合粉末的表面与所述钕铁硼磁粉末的取向垂直。
在上述制备方法中，作为一种优选实施方式，所述放电等离子烧结处理的条件为：真空度不低于10 -3Pa(比如10 -3Pa、8×10 -4Pa、5×10 -4Pa、1×10 -4Pa、9×10 -5Pa、5×10 -5Pa)，压力为20-60Mpa(比如22Mpa、25Mpa、30Mpa、35Mpa、40Mpa、45Mpa、50Mpa、55Mpa、59Mpa)，温度为700-900℃(比如710℃、 750℃、800℃、820℃、850℃、880℃)；更优选地，所述放电等离子烧结处理的保温保压时间为0-15min(比如1min、3min、5min、7min、9min、11min、13min)。经放电等离子烧结后组分式为H 100-x-yM xQ y的复合粉末固化附着在钕铁硼磁粉末形成的钕铁硼磁体表面上，形成扩散层。本发明的SPS处理达到了预成型的目的，让烧结钕铁硼磁体的粉末和表面的复合粉末在压力和温度的作用下从简单的物理接触变为紧密的化学键结合，从而利于后续的烧结扩散过程；等离子烧结温度过低会使粉末间结合松散在后续的过程中会发生掉边等问题。过高压力时会导致性能恶化。
在上述制备方法中，作为一种优选实施方式，所述钕铁硼磁粉末层的取向方向控制在1-12mm厚度。
在上述制备方法中，作为一种优选实施方式，所述扩散热处理的条件为：真空度不低于10 -3Pa(比如10 -3Pa、8×10 -4Pa、5×10 -4Pa、1×10 -4Pa、9×10 -5Pa、5×10 -5Pa)，温度为700-950℃(比如710℃、750℃、800℃、820℃、850℃、880℃、900℃、920℃、940℃)，保温时间为2～30小时(比如3h、5h、8h、12h、15h、20h、25h、28h)；更优选地，所述扩散热处理是在真空热处理炉中进行的。保温温度过低，则扩散处理效果不明显；保温温度过高，将导致晶粒异常长大，反而使磁性能恶化；保温时间的选择与磁体厚度相关，厚的处理时间可偏长些。温度和时间的匹配将有助于既发挥很好的处理效果，也有效利用能源。
在上述制备方法中，作为一种优选实施方式，所述冷却是指：随炉冷却至不高于50℃(比如48℃、45℃、40℃、35℃、30℃)。
在上述制备方法中，作为一种优选实施方式，所述回火处理的温度为420～640℃(比如430℃、450℃、480℃、520℃、550℃、590℃、620℃、 630)，保温时间为2～10小时(比如3h、5h、8h、9h)。在该回火制度下，利于富含重稀土元素的晶界相的形成和保持，超出该优选温度范围的产品的性能会略有降低。
以上方法中的优选方式可以任意方式组合使用。
采用上述方法制备的稀土永磁材料。
综合以上，本发明的方法是采用压制、等离子烧结和晶界扩散技术相结合，采用较少的重稀土量来达到磁体性能的显著提高，高质化利用重稀土，其是在烧结NdFeB磁体表面形成一种结合力较好的富含稀土元素的化合物和纯金属粉末形成的混合粉末固化层(也称为扩散层)，随后将整个磁体加热至700～950℃温度，保温2～30h，使其中的重稀土元素、稀土元素和纯金属元素在高温下通过晶界向磁体内部扩散，再在420～640℃回火处理2～10小时，最终提高NdFeB磁体磁性能，通过这种方法，可以将烧结NdFeB磁体的矫顽力提高4000～16300Oe，剩磁仅降低1-2％，同等性能磁体可节约重稀土使用量35％。
本发明的优点在于：通过SPS技术和渗透技术集成的方法将NdFeB基体和富含稀土元素的化合物和纯金属粉末很好的结合在一起，经高温处理后，粉末层内的稀土化合物和纯金属粉末在磁体内扩散至主相和富钕相交界区域富集；通过这些处理NdFeB磁体的矫顽力有显著提高。本发明为稀土永磁材料NdFeB性能的改善开辟了一条新颖的路线。采用本发明来改善磁体性能，一方面效率高、重稀土元素和基体磁体固相结合，更利于扩散；另一方面使用的重稀土量大幅降低，降低了产品的成本，使产品的性价比更具优势。采用压制SPS技术烧结和渗透一体化集成后，成品收率提高(本发明压制成型后直接扩散渗透，和以往的渗透技术相比较不需要将大块的 磁体切割加工，消减了切割加工带来的产品不良和损失；整个过程，没有和自然环境接触，最大限度的限制了产品的氧化损失)，矫顽力提升显著，生产效率高，处理成本费用低，具有显著的生产成本优势。
附图说明
图1为实施例1制备的磁体的综合磁性能图。
具体实施方式
以下将结合实例对本发明进行进一步说明，本发明的实施例仅用于说明本发明，并非限定本发明。
以下实施例中使用的钕铁硼磁粉末是采用气流磨制得的，其可以为市售产品，当然也可以根据常用方法自行制备。
本发明采用的SPS技术是一种利用直流脉冲电流通电烧结的加压烧结方法。其基本原理是通过对电极通入直流脉冲电流瞬时产生的放电等离子使烧结体内部各个颗粒均匀的自身产生焦耳热并使颗粒表面活化，在加压的同时实现烧结。该SPS技术应用到本发明中具有如下特点：(l)烧结温度低，一般低为700－900℃；(2)烧结保温时间短，只需3-15分钟；(3)可获得细小、均匀的组织；(4)能获得高致密度材料。
实施例1
(1)按照粉末组分式(TbF 3) 95Nd 2Al 3(式中的下脚标为对应元素的原子百分比)配置复合粉末：称取TbF3粉末(粒度：-150目)，金属Nd粉末(粒度：-150目)，金属Al粉末(粒度：-150目)，将上述粉末混合均 匀，并过150目筛，取筛下物作为复合粉末，其中粉末混合和过筛过程在氮气环境下进行。
(2)将气流磨制得的钕铁硼商业用磁粉末(成分配比：Nd 9.2Pr 3Dy 1.2Tb 0.6Fe 80B 6，其中下脚标为对应组分的原子百分比)装入硬质合金模具内，同时在与取向垂直的表面层铺设20μm厚的步骤(1)配置的复合粉末，使用放电等离子烧结技术，在真空度10 -3pa，压力30Mpa，750℃条件下热压烧结获得表面固化附着(TbF 3) 95Nd 2Al 3粉末固化层的钕铁硼磁体；其中取向方向为6mm厚度。
(3)将步骤(2)得到的表面有一层均匀的粉末固化层的钕铁硼磁体放置在真空热处理炉内，在真空度10 -3Pa、800℃条件下保温6小时进行扩散热处理；随炉冷却至不高于50℃。
(4)将步骤(3)得到的磁体再经510℃回火处理4小时，获得性能提高的磁体即本发明的稀土永磁材料。
在按照本实施例方法制备性能提高的磁体时设置了对比例1，该对比例1的制备方法具体如下：采用传统的粉末冶金技术(详细制作技术见周寿增等编著的2012年由冶金工业出版社出版的《烧结钕铁硼稀土永磁材料与技术》中7-11章所述内容)以与实施例1相同的组分配方进行冶炼、制粉、压型、烧结；其磁体所得性能如表1中所示。
图1为本发明的实施例1和对比例1磁体的性能测试的BH曲线图；从该图可以看出经过本实施例步骤(2)、(3)、(4)的技术处理，烧结钕铁硼的矫顽力从25070Oe提高到41330Oe，增加了16260Oe，剩磁稍有降低，即从13010Gs降低到12790Gs是，降低了220Gs。处理后烧结钕铁硼的矫顽力综合磁性能H cj+BH (max)达到了80.66。
实施例2
(1)按照粉末比例式(DyF 3) 95Nd 1Al 4(式中的下脚标为对应元素的原子百分比)配置复合粉末。称取DyF 3粉末，-150目；金属Nd粉末，-150目；金属Al粉末，-150目；将上述粉末混合均匀，并过150目筛分，粉末混合和过筛过程在氮气环境下进行。
(2)将气流磨制得的钕铁硼商业用磁粉末(成分配比：Nd 10.8Pr 3Tb 0.4Fe 79.8B 6，其中下脚标为对应组分的原子百分比)装入硬质合金模具内，同时在取向垂直方向的表面层铺设25μm厚的(1)中所述粉末，使用放电等离子烧结技术，在真空度10 -3pa，压力30Mpa，750℃条件下热压获得表面固化附着(DyF 3) 95Nd 1A l4粉末固化层的钕铁硼磁体；其中取向方向为7mm厚度。
(3)将步骤(2)得到的表面有一层均匀的粉末固化层的磁体放置在真空热处理炉内，真空度10 -3Pa，在800℃保温6小时；随炉冷却至不高于50℃。
(4)将步骤(3)得到的磁体经510℃回火处理4小时，获得性能提高的磁体。
在按照本实施例方法制备性能提高的磁体时设置了对比例2，该对比例2的制备方法具体如下：采用传统的粉末冶金技术(详细制作技术见周寿增等编著的2012年由冶金工业出版社出版的《烧结钕铁硼稀土永磁材料与技术》中7-11章所述内容)以与实施例2相同的组分配方进行冶炼、制粉、压型、烧结；其磁体所得性能如表1中所示。
本实施例制备得到的稀土永磁材料的矫顽力提高7700Oe，剩磁稍有降低，降低了185Gs。实施例2和对比例2磁体性能测试结果如表1所示。
实施例3
(1)按照粉末比例式(TbF 3) 95Cu 5(式中的下脚标为对应元素的原子百分比)配置复合粉末。称取TbF 3粉末，-150目；金属Cu粉末，-150目；将上述粉末混合均匀，并过150目筛分，粉末混合和过筛过程在氮气环境下进行。
(2)将气流磨制得的钕铁硼商业用磁粉末(成分配比：Nd 11.9Pr 3Dy 0.1Fe 79B 6，其中下脚标为对应组分的原子百分比)装入硬质合金模具内，同时在取向垂直方向的表面层铺设30μm厚的(1)中所述粉末，使用放电等离子烧结技术，在真空10 -3pa，压力50Mpa，780℃条件下热压获得表面固化附着(TbF 3) 95Cu 5粉末固化层的钕铁硼磁体；其中取向方向为12mm厚度。
(3)将步骤(2)得到的表面有一层均匀的粉末固化层的磁体放置在真空热处理炉内，真空度10 -3Pa，在850℃保温6小时；随炉冷却至不高于50℃。
(4)将步骤(3)得到的磁体再经510℃回火处理4小时，获得性能提高的磁体。
在按照本实施例方法制备性能提高的磁体时设置了对比例3，该对比例3的制备方法具体如下：采用传统的粉末冶金技术(详细制作技术见周寿增等编著的2012年由冶金工业出版社出版的《烧结钕铁硼稀土永磁材料与技术》中7-11章所述内容)以与实施例3相同的组分配方进行冶炼、制粉、压型、烧结；其磁体所得性能如表1中所示。
本实施例制备得到的稀土永磁材料的矫顽力提高14000Oe，剩磁稍有 降低，降低了190Gs。实施例3和对比例3磁体性能测试结果如表1所示。
实施例4
(1)按照粉末比例式(HoF 3) 97Pr 1Cu 2(式中的下脚标为对应元素的原子百分比)配置复合粉末。称取HoF 3粉末，-150目；金属Pr粉末，-150目；金属Cu粉末，-150目；将上述粉末混合均匀，并过150目筛分，粉末混合和过筛过程在氮气环境下进行。
(2)将气流磨制得的钕铁硼商业用磁粉末(成分配比：Nd 11.8Pr 3Dy 0.1Fe 79B 6.1，其中下脚标为对应组分的原子百分比)装入硬质合金模具内，同时在取向垂直方向的表面层铺设20μm厚的(1)中所述粉末，使用放电等离子烧结技术，在真空10 -3pa，压力20Mpa，750℃条件下热压获得表面固化附着(HoF 3) 97Pr 1Cu 2粉末固化层的钕铁硼磁体；其中取向方向为3mm厚度。
(3)将步骤(2)得到的表面有一层均匀的粉末固化层的磁体放置在真空热处理炉内，真空度应小于10 -3Pa，在800℃保温6小时；随炉冷却至不高于50℃。
(4)将步骤(3)得到的磁体再经510℃回火处理4小时，获得性能提高的磁体。
在按照本实施例方法制备性能提高的磁体时设置了对比例4，该对比例4的制备方法具体如下：采用传统的粉末冶金技术(详细制作技术见周寿增等编著的2012年由冶金工业出版社出版的《烧结钕铁硼稀土永磁材料与技术》中7-11章所述内容)以与实施例4相同的组分配方进行冶炼、制粉、压型、烧结；其磁体所得性能如表1中所示。本实施例制备得到的稀土永磁材料的矫顽力提高4500Oe，剩磁稍有降低，降低了215Gs。实施例4和对 比例4磁体性能测试结果如表1所示。
实施例5
(1)按照粉末比例式((DyTb)F 3) 96Cu 1Al 3(式中的下脚标为对应元素的原子百分比)配置复合粉末。称取(DyTb)F 3粉末，-150目；金属Cu粉末，-150目；金属Al粉末，-150目；将上述粉末混合均匀，并过150目筛分，粉末混合和过筛过程在氮气环境下进行。
(2)将气流磨制得的钕铁硼商业用磁粉末(成分配比：Nd 14.6Tb 0.3Fe 79B 6.1，其中下脚标为对应组分的原子百分比)装入硬质合金模具内，同时在取向垂直方向的表面层铺设30μm厚的(1)中所述粉末，使用放电等离子烧结技术，在真空10 -3pa，压力20Mpa，750℃条件下热压获得表面固化附着((DyTb)F 3) 96Cu 1Al 3粉末固化层的钕铁硼磁体；其中取向方向为8mm厚度。
(3)将步骤(2)得到的表面有一层均匀的粉末固化层的磁体放置在真空热处理炉内，真空度10 -3Pa，在800℃保温6小时；随炉冷却至不高于50℃。
(4)将步骤(3)得到的磁体再经510℃回火处理4小时，获得性能提高的磁体。
在按照本实施例方法制备性能提高的磁体时设置了对比例5，该对比例5的制备方法具体如下：采用传统的粉末冶金技术(详细制作技术见周寿增等编著的2012年由冶金工业出版社出版的《烧结钕铁硼稀土永磁材料与技术》中7-11章所述内容)以与实施例5相同的组分配方进行冶炼、制粉、压型、烧结；其磁体所得性能如表1中所示。
本实施例制备得到的稀土永磁材料的矫顽力提高12000Oe，剩磁稍有 降低，降低了188Gs。实施例5和对比例5磁体性能测试结果如表1所示。
实施例6
(1)按照粉末比例式(GdF 3) 98Cu 2(式中的下脚标为对应元素的原子百分比)配置复合粉末。称取GdF 3粉末，-150目；金属Cu粉末，-150目；将上述粉末混合均匀，并过150目筛分，粉末混合和过筛过程在氮气环境下进行。
(2)将气流磨制得的钕铁硼商业用磁粉末(成分配比：Nd 11.5Pr 3Dy 0.3Fe 79.2B 6，其中下脚标为对应组分的原子百分比)装入硬质合金模具内，同时在取向垂直方向的表面层铺设20μm厚的(1)中所述粉末，使用放电等离子烧结技术，在真空10 -3pa，压力20Mpa，750℃条件下热压获得表面固化附着(GdF 3) 98Cu 2粉末固化层的钕铁硼磁体；其中取向方向为4mm厚度。
(3)将步骤(2)得到的表面有一层均匀的粉末固化层的磁体放置在真空热处理炉内，真空度应小于10 -3Pa，在800℃保温6小时；随炉冷却至不高于50℃。
(4)将步骤(3)得到的磁体再经510℃回火处理4小时，获得性能提高的磁体。
在按照本实施例方法制备性能提高的磁体时设置了对比例6，该对比例6的制备方法具体如下：采用传统的粉末冶金技术(详细制作技术见周寿增等编著的2012年由冶金工业出版社出版的《烧结钕铁硼稀土永磁材料与技术》中7-11章所述内容)以与实施例6相同的组分配方进行冶炼、制粉、压型、烧结；其磁体所得性能如表1中所示。
本实施例制备得到的稀土永磁材料的矫顽力提高4600Oe，剩磁稍有降 低，降低了218Gs。实施例6和对比例6磁体性能测试结果如表1所示。
实施例7
(1)按照粉末比例式(TbO 3) 94Nd 1Al 5(式中的下脚标为对应元素的原子百分比)配置复合粉末。称取TbO 3粉末，-150目；金属Nd粉末，-150目；金属Al粉末，-150目；将上述粉末混合均匀，并过150目筛分，粉末混合和过筛过程须氮气环境下进行。
(2)将气流磨制得的钕铁硼商业用磁粉末(成分配比：Nd 10.7Pr 3Tb 0.5Fe 80B 5.8，其中下脚标为对应组分的原子百分比)装入硬质合金模具内，同时在取向垂直方向的表面层铺设30μm厚的(1)中所述粉末，使用放电等离子烧结技术，在真空10 -3pa，压力50Mpa，780℃条件下热压获得表面固化附着(TbO 3) 94Nd 1Al 5粉末固化层的钕铁硼磁体；其中取向方向为12mm厚度。
(3)将步骤(2)得到的表面有一层均匀的粉末固化层的磁体放置在真空热处理炉内，真空度10 -3Pa，在800℃保温6小时；随炉冷却至不高于50℃。
(4)将步骤(3)得到的磁体再经510℃回火处理4小时，获得性能提高的磁体。
在按照本实施例方法制备性能提高的磁体时设置了对比例7，该对比例7的制备方法具体如下：采用传统的粉末冶金技术(详细制作技术见周寿增等编著的2012年由冶金工业出版社出版的《烧结钕铁硼稀土永磁材料与技术》中7-11章所述内容)以与实施例7相同的组分配方进行冶炼、制粉、压型、烧结；其磁体所得性能如表1中所示。
本实施例制备得到的稀土永磁材料的矫顽力提高9000Oe，剩磁稍有降 低，降低了195Gs。实施例7和对比例7磁体性能测试结果如表1所示。
实施例8
(1)按照粉末比例式(DyO 3) 97(PrNd) 2Al 1(式中的下脚标为对应元素的原子百分比)配置复合粉末。称取DyO 3粉末，-150目；金属PrNd粉末(Pr和Nd的质量比为1:4)，-150目；金属Al粉末，-150目；将上述粉末混合均匀，并过150目筛分，粉末混合和过筛过程在氮气环境下进行。
(2)将气流磨制得的钕铁硼商业用磁粉末(成分配比：Nd 12.2Pr 3.1Fe 78.6B 6.1，其中下脚标为对应组分的原子百分比)装入硬质合金模具内，同时在取向垂直方向的表面层铺设23μm厚的(1)中所述粉末，使用放电等离子烧结技术，在真空10 -3pa，压力40Mpa，760℃条件下热压获得表面固化附着(DyO 3) 97(PrNd) 2Al 1粉末固化层的钕铁硼磁体；其中取向方向为6.5mm厚度。
(3)将步骤(2)得到的表面有一层均匀的粉末固化层的磁体放置在真空热处理炉内，真空度应小于10 -3Pa，在800℃保温6小时；随炉冷却至不高于50℃。
(4)将步骤(3)得到的磁体再经510℃回火处理4小时，获得性能提高的磁体。
在按照本实施例方法制备性能提高的磁体时设置了对比例8，该对比例8的制备方法具体如下：采用传统的粉末冶金技术(详细制作技术见周寿增等编著的2012年由冶金工业出版社出版的《烧结钕铁硼稀土永磁材料与技术》中7-11章所述内容)以与实施例8相同的组分配方进行冶炼、制粉、压型、烧结；其磁体所得性能如表1中所示。
本实施例制备得到的稀土永磁材料的矫顽力提高7700Oe，剩磁稍有降 低，降低了197Gs。实施例8和对比例8磁体性能测试结果如表1所示。
实施例9
(1)按照粉末比例式(TbF 3) 46(DyO 3) 48Nd 2ZnSnCu 2(式中的下脚标为对应元素的原子百分比)配置复合粉末。称取TbF 3和DyO 3粉末，150目；金属Nd粉末，150目；金属Zn、Sn、Cu粉末，150目；将上述粉末混合均匀，并过150目筛分，粉末混合和过筛过程在氮气环境下进行。
(2)将气流磨制得的钕铁硼商业用磁粉末(成分配比：Nd 11.5Tb 1.6Fe 80.9B 6，其中下脚标为对应组分的原子百分比)装入硬质合金模具内，同时在取向垂直方向的表面层铺设23μm厚的(1)中所述粉末，使用放电等离子烧结技术，在真空10 -3pa，压力40Mpa，760℃条件下热压获得表面固化附着(TbF 3) 46(DyO 3) 48Nd 2ZnSnCu 2粉末固化层的钕铁硼磁体；其中取向方向为6.5mm厚度。
(3)将步骤(2)得到的表面有一层均匀的粉末固化层的磁体放置在真空热处理炉内，真空度应小于10 -3Pa，在800℃保温6小时；随炉冷却至不高于50℃。
(4)将步骤(3)得到的磁体再经510℃回火处理4小时，获得性能提高的磁体。
在按照本实施例方法制备性能提高的磁体时设置了对比例9，该对比例9的制备方法具体如下：采用传统的粉末冶金技术(详细制作技术见周寿增等编著的2012年由冶金工业出版社出版的《烧结钕铁硼稀土永磁材料与技术》中7-11章所述内容)以与实施例9相同的组分配方进行冶炼、制粉、压型、烧结；其磁体所得性能如表1中所示。
本实施例制备得到的稀土永磁材料的矫顽力提高9100Oe，剩磁稍有降 低，降低了190Gs。实施例9和对比例9磁体性能测试结果如表1所示。
表1实施例1-9和对比例1-9磁体性能测试结果
编号 尺寸(mm 3) Br(kGs) Hcj(kOe) 编号 尺寸(mm 3) Br(kGs) Hcj(kOe)
实施例1 20*15*1.96 12.79 41.33 对比例1 20*15*1.96 13.01 25.07
实施例2 25*15*3 13.625 25.53 对比例2 25*15*3 13.81 17.83
实施例3 25*15*5 13.13 27.28 对比例3 25*15*5 13.32 13.28
实施例4 25*15*3 13.095 17.68 对比例4 25*15*3 13.31 13.18
实施例5 30*15*6 14.012 32.2 对比例5 30*15*6 14.2 20.2
实施例6 25*15*3 11.612 20.5 对比例6 25*15*3 11.83 15.9
实施例7 35*15*8 13.505 27.5 对比例7 35*15*8 13.7 18.5
实施例8 35*15*6 13.003 21.15 对比例8 35*15*6 13.2 13.45
实施例9 35*15*4.5 13.48 33.9 对比例9 35*15*4.5 13.67 24.8
实施例10-13
实施例10-13除复合粉末铺设厚度不同于实施例2外，其他工艺参数都与实施例2相同；其中，实施例10中复合粉末层厚度约为12μm，实施例11中复合粉末层厚度约为20μm，实施例12中复合粉末层厚度约为5μm，实施例13中复合粉末层厚度约为30μm。实施例10-13和实施例2磁体性能测试结果如表2所示。
实施例14-15
实施例14-15除第(3)步骤真空热处理中保温温度和保温时间不同于实施例2外，其他工艺参数都与实施例2相同；其中，实施例14中真空热处理条件为：950℃保温4h，实施例15中真空热处理条件为：700℃保温30h。实施例14-15和实施例2磁体性能测试结果如表2所示。
实施例16-17
实施例16-17除第(4)步骤回火处理温度和时间不同于实施例2外，其他工艺参数都与实施例2相同；其中，实施例16中回火处理条件为：420℃回火处理10h，实施例17中回火处理条件为：640℃回火处理2h。实施例16-17和实施例2磁体性能测试结果如表2所示。
表2实施例10-17和实施例2磁体性能测试结果
编号 尺寸(mm 3) Br(kGs) Hcj(kOe)
实施例2 25*15*3 13.625 25.53
实施例10 25*15*3 13.75 20.55
实施例11 25*15*3 13.69 23.05
实施例12 25*15*3 13.78 19.24
实施例13 25*15*3 13.61 25.65
实施例14 25*15*3 13.55 25.02
实施例15 25*15*3 13.76 20.73
实施例16 25*15*3 13.64 24.52
实施例17 25*15*3 13.63 24.06
实施例18-23
实施例18-23除所用复合粉末组成不同于实施例2外，其他工艺参数都与实施例2相同；具体的复合粉末组成以及实施例18-23和实施例2磁体性能测试结果如表3所示。
表3实施例18-23和实施例2磁体性能测试结果
编号 复合粉末组成 尺寸(mm 3) Br(kGs) Hcj(kOe)
实施例2 (DyF 3) 95Nd 1Al 4 25*15*3 13.625 25.53
实施例18 (DyF 3) 50Nd 10Al 40 25*15*3 13.71 22.09
实施例19 (DyF 3) 55Nd 20Al 25 25*15*3 13.69 22.92
实施例20 (DyF 3) 85Nd 5Al 10 25*15*3 13.66 24.96
实施例21 (DyF 3) 70Nd 10Al 20 25*15*3 13.68 23.61
实施例22 (DyF 3) 83Nd 10Al 7 25*15*3 13.66 24.8
实施例23 (DyF 3) 75Nd 18Al 7 25*15*3 13.67 24.32
实施例24-26
实施例24-26将实施例1-3所用复合粉末直接添加进烧结钕铁硼的粉末中混合后采用SPS热压制，随后烧结和时效，SPS热压制、烧结和时效的工艺参数和相对应的实施例相同；实施例24-26、实施例1-3和对比例1-3 的测试结果如表4所示。
表4实施例1-3、实施例24-26和对比例1-3磁体磁性能测试结果
编号 尺寸(mm 3) Br(kGs) Hcj(kOe)
对比例1 20*15*1.96 13.01 25.07
实施例1 20*15*1.96 12.79 41.33
实施例24 20*15*1.96 12.99 25.88
对比例2 25*15*3 13.81 17.83
实施例2 25*15*3 13.625 25.53
实施例25 25*15*3 13.8 18.35
对比例3 25*15*5 13.32 13.28
实施例3 25*15*5 13.13 27.28
实施例26 25*15*5 13.3 14.1
显然，上述实施例仅仅是为清楚地说明所作的举例，而并非对实施方式的限定。对于所属领域的普通技术人员来说，在上述说明的基础上还可以做出其它不同形式的变化或变动。这里无需也无法对所有的实施方式予以穷举。而由此所引伸出的显而易见的变化或变动仍处于本发明创造的保护范围之中。

Claims (10)

  1. 一种稀土永磁材料的制备方法，其特征在于，包括：
    烧结处理步骤，在钕铁硼磁粉末层的表面上铺设扩散用复合粉末并进行放电等离子烧结处理，得到表面固化有扩散层的钕铁硼磁体，所述扩散用复合粉末的组分比例式为H 100-x-yM xQ y，其中，H为Dy、Tb、Ho和Gd的金属粉末中的一种或多种，或者H为Dy、Tb、Ho和Gd的氟化物粉末或氧化物粉末中的一种或多种，M为Nd、Pr或NdPr金属粉末，Q为Cu、Al、Zn和Sn金属粉末中的一种或多种；x和y分别为M组分和Q组分在所述扩散用复合粉末中的原子百分比，x为0-20，y为0-40；
    扩散热处理步骤，对所述表面固化有扩散层的钕铁硼磁体进行扩散热处理，冷却得到扩散后的钕铁硼磁体；
    回火处理步骤，对所述扩散后的钕铁硼磁体进行回火处理，得到所述稀土永磁材料。
  2. 根据权利要求1所述的制备方法，其特征在于，所述x和y不同时为零；优选地，所述x的取值范围为2-15，所述y的取值范围为4-25；更优选地，所述扩散用复合粉末的组分比例式为(TbF 3) 95Nd 2Al 3、(DyF 3) 95Nd 1A l4、(TbF 3) 95Cu 5。
  3. 根据权利要求1或2所述的制备方法，其特征在于，所述扩散用复合粉末的粒度为150目；优选地，所述扩散用复合粉末的制备包括：在无氧环境下，将H、M和Q三种组分的粉末混合均匀，再经150目筛分后取筛下物，得到扩散用复合粉末；所述无氧环境优选为氮气环境；所述H组 分的粉末粒度为-150目，所述M组分的粉末粒度为-150目，所述Q组分的粉末粒度为-150目。
  4. 根据权利要求1-3任一项所述的制备方法，其特征在于，铺设在所述钕铁硼磁粉末层表面上的扩散用复合粉末的厚度为5-30μm；优选地，铺设所述扩散用复合粉末的表面与所述钕铁硼磁粉末的取向垂直。
  5. 根据权利要求1-4任一项所述的制备方法，其特征在于，所述放电等离子烧结处理的条件为：真空度不低于10 -3Pa，压力为20-60Mpa，温度为700-900℃；优选地，所述放电等离子烧结处理的保温保压时间为0-15min。
  6. 根据权利要求1-5任一项所述的制备方法，其特征在于，所述钕铁硼磁粉末层的取向方向控制在1-12mm厚度。
  7. 根据权利要求1-6任一项所述的制备方法，其特征在于，所述扩散热处理的条件为：真空度不低于10 -3Pa，温度为700-950℃，保温时间为2～30小时；优选地，所述扩散热处理是在真空热处理炉中进行的。
  8. 根据权利要求1-7任一项所述的制备方法，其特征在于，所述冷却是指：随炉冷却至不高于50℃。
  9. 根据权利要求1-8任一项所述的制备方法，其特征在于，所述回火处理的温度为420～640℃，保温时间为2～10小时。
  10. 采用权利要求1-9任一方法制备的稀土永磁材料。
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Families Citing this family (5)

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CN108183021B (zh) * 2017-12-12 2020-03-27 安泰科技股份有限公司 稀土永磁材料及其制备方法
JP7167673B2 (ja) * 2018-12-03 2022-11-09 Tdk株式会社 Ｒ‐ｔ‐ｂ系永久磁石の製造方法
CN110033940A (zh) * 2019-05-10 2019-07-19 中国科学院宁波材料技术与工程研究所 一种含有Al和Cu的稀土铁硼永磁材料及其制备方法
CN111063536B (zh) * 2019-12-31 2022-03-22 浙江大学 一种适用于大块稀土永磁材料的晶界扩散方法
CN112820528A (zh) * 2020-05-06 2021-05-18 廊坊京磁精密材料有限公司 提高烧结钕铁硼矫顽力的方法

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005175138A (ja) * 2003-12-10 2005-06-30 Japan Science & Technology Agency 耐熱性希土類磁石及びその製造方法
CN104103414A (zh) * 2014-07-09 2014-10-15 北京工业大学 一种制备高矫顽力各向异性纳米晶钕铁硼永磁体的方法
CN105185498A (zh) * 2015-08-28 2015-12-23 包头天和磁材技术有限责任公司 稀土永磁材料及其制造方法
CN105761860A (zh) * 2014-11-06 2016-07-13 福特全球技术公司 具有高矫顽力和能量密度的细粒度钕铁硼磁体
CN108183021A (zh) * 2017-12-12 2018-06-19 安泰科技股份有限公司 稀土永磁材料及其制备方法

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5515539B2 (ja) * 2009-09-09 2014-06-11 日産自動車株式会社 磁石成形体およびその製造方法
US20110074530A1 (en) * 2009-09-30 2011-03-31 General Electric Company Mixed rare-earth permanent magnet and method of fabrication
EP2869311B1 (en) * 2013-10-29 2020-06-24 Institute Jozef Stefan Method of manufacturing fully dense Nd-Fe-B magnets with enhanced coercivity and gradient microstructure
KR20160147711A (ko) * 2014-04-25 2016-12-23 히다찌긴조꾸가부시끼가이사 R-t-b계 소결 자석의 제조 방법

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005175138A (ja) * 2003-12-10 2005-06-30 Japan Science & Technology Agency 耐熱性希土類磁石及びその製造方法
CN104103414A (zh) * 2014-07-09 2014-10-15 北京工业大学 一种制备高矫顽力各向异性纳米晶钕铁硼永磁体的方法
CN105761860A (zh) * 2014-11-06 2016-07-13 福特全球技术公司 具有高矫顽力和能量密度的细粒度钕铁硼磁体
CN105185498A (zh) * 2015-08-28 2015-12-23 包头天和磁材技术有限责任公司 稀土永磁材料及其制造方法
CN108183021A (zh) * 2017-12-12 2018-06-19 安泰科技股份有限公司 稀土永磁材料及其制备方法

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
See also references of EP3726549A4
ZHOU SHOUZENG ET AL.: "Sintered neodymium iron boron rare earth permanent magnet material and technology", 2012, METALLURGICAL INDUSTRY PRESS

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ES2912741T3 (es) 2022-05-27
EP3726549B1 (en) 2022-03-16
EP3726549A4 (en) 2021-01-06
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