CN112420306B - High-performance sintered NdFeB magnetic ring and preparation method thereof - Google Patents
High-performance sintered NdFeB magnetic ring and preparation method thereof Download PDFInfo
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- CN112420306B CN112420306B CN202011291846.7A CN202011291846A CN112420306B CN 112420306 B CN112420306 B CN 112420306B CN 202011291846 A CN202011291846 A CN 202011291846A CN 112420306 B CN112420306 B CN 112420306B
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- 229910001172 neodymium magnet Inorganic materials 0.000 title claims abstract description 25
- 238000002360 preparation method Methods 0.000 title claims abstract description 17
- 239000000843 powder Substances 0.000 claims abstract description 120
- 238000000227 grinding Methods 0.000 claims abstract description 86
- 239000000956 alloy Substances 0.000 claims abstract description 78
- 229910045601 alloy Inorganic materials 0.000 claims abstract description 76
- 238000005266 casting Methods 0.000 claims abstract description 37
- 239000002994 raw material Substances 0.000 claims abstract description 34
- 238000005245 sintering Methods 0.000 claims abstract description 29
- 238000001816 cooling Methods 0.000 claims abstract description 28
- 238000005496 tempering Methods 0.000 claims abstract description 27
- 238000003723 Smelting Methods 0.000 claims abstract description 23
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims abstract description 18
- 239000001257 hydrogen Substances 0.000 claims abstract description 18
- 229910052739 hydrogen Inorganic materials 0.000 claims abstract description 18
- 238000003756 stirring Methods 0.000 claims abstract description 18
- 238000000462 isostatic pressing Methods 0.000 claims abstract description 16
- 238000000465 moulding Methods 0.000 claims abstract description 14
- 238000010438 heat treatment Methods 0.000 claims abstract description 13
- 239000000314 lubricant Substances 0.000 claims abstract description 12
- 238000002156 mixing Methods 0.000 claims abstract description 11
- 238000006356 dehydrogenation reaction Methods 0.000 claims abstract description 9
- 239000010949 copper Substances 0.000 claims description 23
- 239000002245 particle Substances 0.000 claims description 20
- 229910052802 copper Inorganic materials 0.000 claims description 17
- 238000000034 method Methods 0.000 claims description 17
- 239000000203 mixture Substances 0.000 claims description 15
- 229910052779 Neodymium Inorganic materials 0.000 claims description 14
- 239000006247 magnetic powder Substances 0.000 claims description 12
- 229910052771 Terbium Inorganic materials 0.000 claims description 10
- 229910052742 iron Inorganic materials 0.000 claims description 10
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 7
- 238000011049 filling Methods 0.000 claims description 3
- 239000011261 inert gas Substances 0.000 claims description 3
- 238000002844 melting Methods 0.000 claims description 3
- 230000008018 melting Effects 0.000 claims description 3
- 238000002074 melt spinning Methods 0.000 claims 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 18
- 230000000052 comparative effect Effects 0.000 description 12
- 238000005336 cracking Methods 0.000 description 12
- 230000008569 process Effects 0.000 description 8
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 6
- 235000021355 Stearic acid Nutrition 0.000 description 5
- 238000010902 jet-milling Methods 0.000 description 5
- QIQXTHQIDYTFRH-UHFFFAOYSA-N octadecanoic acid Chemical compound CCCCCCCCCCCCCCCCCC(O)=O QIQXTHQIDYTFRH-UHFFFAOYSA-N 0.000 description 5
- OQCDKBAXFALNLD-UHFFFAOYSA-N octadecanoic acid Natural products CCCCCCCC(C)CCCCCCCCC(O)=O OQCDKBAXFALNLD-UHFFFAOYSA-N 0.000 description 5
- 239000008117 stearic acid Substances 0.000 description 5
- 229910052692 Dysprosium Inorganic materials 0.000 description 4
- QJVKUMXDEUEQLH-UHFFFAOYSA-N [B].[Fe].[Nd] Chemical compound [B].[Fe].[Nd] QJVKUMXDEUEQLH-UHFFFAOYSA-N 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 238000003825 pressing Methods 0.000 description 4
- 230000005855 radiation Effects 0.000 description 4
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 3
- 229910052786 argon Inorganic materials 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 238000007792 addition Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 description 1
- 230000002457 bidirectional effect Effects 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 238000000280 densification Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000005389 magnetism Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000012188 paraffin wax Substances 0.000 description 1
- 238000004321 preservation Methods 0.000 description 1
- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- 150000002910 rare earth metals Chemical class 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000000790 scattering method Methods 0.000 description 1
- 229920002545 silicone oil Polymers 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- LGQXXHMEBUOXRP-UHFFFAOYSA-N tributyl borate Chemical compound CCCCOB(OCCCC)OCCCC LGQXXHMEBUOXRP-UHFFFAOYSA-N 0.000 description 1
- XOOUIPVCVHRTMJ-UHFFFAOYSA-L zinc stearate Chemical compound [Zn+2].CCCCCCCCCCCCCCCCCC([O-])=O.CCCCCCCCCCCCCCCCCC([O-])=O XOOUIPVCVHRTMJ-UHFFFAOYSA-L 0.000 description 1
Classifications
-
- 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
-
- B22F1/0003—
-
- 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
- B22F3/02—Compacting only
- B22F3/04—Compacting only by applying fluid pressure, e.g. by cold isostatic pressing [CIP]
-
- 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
- B22F5/00—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product
- B22F5/10—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product of articles with cavities or holes, not otherwise provided for in the preceding subgroups
- B22F5/106—Tube or ring forms
-
- 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
- B22F9/00—Making metallic powder or suspensions thereof
- B22F9/02—Making metallic powder or suspensions thereof using physical processes
- B22F9/023—Hydrogen absorption
-
- 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
- B22F9/00—Making metallic powder or suspensions thereof
- B22F9/02—Making metallic powder or suspensions thereof using physical processes
- B22F9/04—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling
-
- 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
- H01F1/0555—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 pressed, sintered or bonded together
- H01F1/0557—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 pressed, sintered or bonded together sintered
-
- 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
-
- 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
-
- 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
- B22F9/00—Making metallic powder or suspensions thereof
- B22F9/02—Making metallic powder or suspensions thereof using physical processes
- B22F9/04—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling
- B22F2009/044—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling by jet milling
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Chemical & Material Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Hard Magnetic Materials (AREA)
Abstract
The invention provides a preparation method of a high-performance sintered NdFeB magnetic ring, which comprises the following steps: (1) Preparing an alloy A raw material, smelting and casting the alloy A raw material to obtain an ingot A; preparing an alloy B raw material, smelting and casting the alloy B raw material, and obtaining a casting sheet B with the average thickness of 0.2-0.4 mm; (2) Respectively carrying out hydrogen crushing treatment on the cast ingot A and the cast sheet B to obtain coarse crushing powder A and coarse crushing powder B, and carrying out dehydrogenation heat treatment to ensure that the hydrogen content of the coarse crushing powder A and the coarse crushing powder B is less than or equal to 1000ppm; (3) The coarse crushing powder A and the coarse crushing powder B are respectively sent into an air flow mill for grinding to obtain air flow grinding powder A and air flow grinding powder B; (4) Mixing the air flow grinding powder A and the air flow grinding powder B, adding a lubricant, stirring for 2-6 h, entering a magnetic ring magnetic field press for orientation molding after stirring, and carrying out isostatic pressing treatment; (5) high-temperature sintering, cooling and tempering heat treatment.
Description
Technical Field
The invention belongs to the field of rare earth permanent magnet material preparation, and relates to a high-performance sintered NdFeB magnetic ring and a preparation method thereof.
Background
The permanent magnet component of the traditional permanent magnet motor adopts a magnetic shoe splicing ring, is prepared in a splicing mode, has a complex process, and has the defects that the geometric center is not coincident with the magnetic field center, the surface magnetism is distributed in a zigzag shape and the like. The magnetic ring has the advantages of compact structure, simple assembly, stable output waveform and the like, the weight and the energy consumption of the motor are obviously reduced, and the operation stability is improved. For this reason, permanent magnet components in high performance permanent magnet motors are gradually being converted from conventional magnetic shoe splice rings to integral magnet rings. However, in the sintering densification process of the sintered NdFeB magnetic ring, the product is extremely easy to crack due to the anisotropy of shrinkage of the magnetic ring. If the sintered NdFeB magnetic ring is prepared by adopting a casting technology, the magnetic ring is more prone to cracking due to the obviously increased orientation shrinkage coefficient compared with the ingot casting technology. If the original ingot casting technology is continuously adopted to prepare the sintered NdFeB magnetic ring, the performance of the magnetic ring is difficult to improve, and the requirement of some high-end application fields on the performance of the magnetic ring cannot be met.
Disclosure of Invention
Aiming at the defects existing in the prior art, the invention provides a novel preparation method of the sintered NdFeB magnetic ring, and the obtained sintered NdFeB magnetic ring has excellent magnetic property and is not easy to crack, so that the requirements of the high-end application field can be met.
The invention provides a high-performance sintered NdFeB magnetic ring, wherein the preparation raw materials of the sintered NdFeB magnetic ring comprise alloy A and alloy B;
the alloy A comprises the components of R xTyMzB(1-x-y-z), wherein R is one or more of Nd, pr, la, ce, ga, ho, dy and Tb, M is one or more of Cu, al and Ga, T is Fe and Co, and the mass ratio of Fe to Co is (40-100): 1, x is 30.5 to 35 weight percent, y is 55 to 70 weight percent, and z is 0.1 to 2.0 weight percent;
The alloy B comprises the components of R xTyMzB(1-x-y-z), wherein R is one or more of Nd, pr, la, ce, ga, ho, dy and Tb, M is one or more of Cu, al and Ga, T is Fe and Co, and the mass ratio of Fe to Co is (40-100): 1, x is 29 to 33wt%, y is 55 to 70wt%, and z is 0.1 to 2.0wt%.
The invention also provides a preparation method of the sintered NdFeB magnetic ring, which comprises the following steps:
(1) The alloy A comprises the components of R xTyMzB(1-x-y-z), wherein R is one or more of Nd, pr, la, ce, ga, ho, dy and Tb, M is one or more of Cu, al and Ga, T is Fe and Co, and the mass ratio of Fe to Co is (40-100): 1, x is 30.5 to 35 weight percent, y is 55 to 70 weight percent, and z is 0.1 to 2.0 weight percent;
The alloy B comprises the components of R xTyMzB(1-x-y-z), wherein R is one or more of Nd, pr, la, ce, ga, ho, dy and Tb, M is one or more of Cu, al and Ga, T is Fe and Co, and the mass ratio of Fe to Co is (40-100): 1, x is 29 to 33wt%, y is 55 to 70wt%, and z is 0.1 to 2.0wt%.
Preparing an alloy A raw material according to the composition of the alloy A, smelting and casting the alloy A raw material to obtain an ingot A; preparing an alloy B raw material according to the composition of the alloy B, smelting and casting the alloy B raw material, and obtaining a casting sheet B with the average thickness of 0.2-0.4 mm;
(2) Respectively carrying out hydrogen crushing treatment on the cast ingot A and the cast sheet B to obtain coarse crushing powder A and coarse crushing powder B, and carrying out dehydrogenation heat treatment to ensure that the hydrogen content of the coarse crushing powder A and the coarse crushing powder B is less than or equal to 1000ppm;
(3) The coarse crushing powder A and the coarse crushing powder B are respectively sent into an air flow mill for grinding to obtain air flow grinding powder A and air flow grinding powder B;
(4) Mixing the air flow grinding powder A and the air flow grinding powder B, adding a lubricant, stirring for 2-6 h, entering a magnetic ring magnetic field press for orientation molding after stirring, and carrying out isostatic pressing treatment;
(5) High-temperature sintering, cooling and tempering heat treatment.
Preferably, the smelting temperature of the alloy A and the alloy B is 1450-1550 ℃ and the casting temperature is 1400-1450 ℃; when alloy B is cast, the rotating speed of the copper roller is 1.0-1.5 m/s.
Preferably, the average particle diameter of the air-jet milled powder A in the step (3) is 4-6 μm, and the average particle diameter of the air-jet milled powder B is 2-3 μm.
Preferably, the mixture of the air-flow grinding powder A and the air-flow grinding powder B in the step (4) contains 10 to 20 weight percent of the air-flow grinding powder B.
Preferably, the magnetic field intensity of the orientation molding in the step (4) is 1.0-1.4T, and the isostatic pressing pressure is 150-200 MPa.
Preferably, the high-temperature sintering temperature in the step (5) is 1030-1100 ℃, and the sintering time is 4-6 h.
Preferably, the cooling step of step (5) includes: vacuum self-cooling to 600-750 deg.c, filling inert gas to 300-400 deg.c, and cooling to room temperature.
Preferably, the tempering heat treatment in the step (5) includes: the primary tempering temperature is 800-950 ℃ and the tempering time is 2-4 hours; the secondary tempering temperature is 450-580 ℃, and the tempering time is 4-6 hours.
Compared with the prior art, the invention has the beneficial effects that:
(1) According to the invention, the cast ingot A and the cast piece B are respectively cast through the bidirectional alloy, and are respectively crushed and co-sintered, so that the magnetic performance of the magnetic ring is improved and the cracking rate of the magnetic ring is reduced through the preparation method;
(2) The content of the air flow grinding powder B is controlled to be 10-20wt%, so that the proportion of the air flow grinding powder A to the air flow grinding powder B is proper, and the improvement of the magnetic performance of the magnetic ring and the reduction of the cracking rate are facilitated;
(3) The invention controls the average grain diameter of the air flow grinding magnetic powder A to be 4-6 mu m, the average grain diameter of the air flow grinding magnetic powder B to be 2-3 mu m, and the cast ingot is ground into larger grain diameter, and the cast sheet is ground into smaller grain diameter, thereby being beneficial to improving the magnet performance and reducing the cracking rate.
Detailed Description
The method for preparing the high-performance sintered neodymium-iron-boron magnetic ring of the present invention will be described in detail below, and the technical term or scientific term used at this time is generally understood by those skilled in the art of the present invention unless otherwise defined.
In this context, ingots and cast slabs are those conventionally defined in the art, i.e. ingots are obtained by melting an alloy material and casting them into a water-cooled mold, and cast slabs are obtained by melting an alloy material and casting them onto a copper roller having a certain rotational speed.
The average thickness of a cast sheet is defined herein as the average of any 100 cast sheet measurements, and the measuring tool may be a vernier caliper or a screw micrometer, etc.
The average particle diameter of the air-jet milled powder is defined herein as the median particle diameter of the volume-based particle diameter distribution measured by the laser diffraction scattering method.
The embodiment of the invention provides a preparation method of a high-performance sintered NdFeB magnetic ring, which comprises the following steps:
(1) Preparing an alloy A raw material according to the composition of the alloy A, smelting and casting the alloy A raw material to obtain an ingot A; preparing an alloy B raw material according to the composition of the alloy B, smelting the alloy B raw material, and casting and throwing the alloy B raw material to obtain a cast sheet B with the average thickness of 0.2-0.4 mm;
(2) Respectively carrying out hydrogen crushing treatment on the cast ingot A and the cast sheet B to obtain coarse crushing powder A and coarse crushing powder B, and carrying out dehydrogenation heat treatment to ensure that the hydrogen content of the coarse crushing powder A and the coarse crushing powder B is less than or equal to 1000ppm;
(3) The coarse crushing powder A and the coarse crushing powder B are respectively sent into an air flow mill for grinding to obtain air flow grinding powder A and air flow grinding powder B;
(4) Mixing the air flow grinding powder A and the air flow grinding powder B, adding a lubricant, stirring for 2-6 h, entering a magnetic ring magnetic field press for orientation molding after stirring, and carrying out isostatic pressing treatment;
(5) High-temperature sintering, cooling and tempering heat treatment.
The alloy A comprises the components of R xTyMzB(1-x-y-z), wherein R is one or more of Nd, pr, la, ce, ga, ho, dy and Tb, M is one or more of Cu, al and Ga, T is Fe and Co, and the mass ratio of Fe to Co is (40-100): 1, x is 30.5 to 35 weight percent, y is 55 to 70 weight percent, and z is 0.1 to 2.0 weight percent;
The alloy B comprises the components of R xTyMzB(1-x-y-z), wherein R is one or more of Nd, pr, la, ce, ga, ho, dy and Tb, M is one or more of Cu, al and Ga, T is Fe and Co, and the mass ratio of Fe to Co is (40-100): 1, x is 29 to 33wt%, y is 55 to 70wt%, and z is 0.1 to 2.0wt%.
Alloy A is smelted and cast into cast ingot, the smelting temperature is 1450-1550 ℃, and the casting temperature is 1400-1450 ℃; alloy B is smelted, cast and melt-spun into cast pieces, the smelting temperature is 1450-1550 ℃, the casting temperature is 1400-1450 ℃, and the rotating speed of a copper roller is 1.0-1.5 m/s. The advantages of the cast ingot sintered magnetic ring and the cast sheet sintered magnetic ring are effectively combined through respectively crushing and co-sintering the cast ingot A and the cast sheet B, so that the magnetic performance of the magnetic ring is improved, and the cracking rate of the magnetic ring is reduced.
The average particle diameter of the air-flow grinding magnetic powder A ground by the ingot A is preferably 4-6 mu m, and the average particle diameter of the air-flow grinding magnetic powder B ground by the ingot B is preferably 2-3 mu m. The cast ingot is ground into larger particle size, and the cast sheet is ground into smaller particle size, so that the magnet performance is improved and the cracking rate is reduced.
In the mixture of the air flow grinding powder A and the air flow grinding powder B in the step (4), the content of the air flow grinding powder B is 10-20wt%. Controlling the ratio of the air-flow grinding powder A and the air-flow grinding powder B has great influence on the performance of the final magnetic ring, when the content of the air-flow grinding powder B is low, the magnetic performance of the magnetic ring is low, and when the content of the air-flow grinding powder B is high, the cracking ratio of the magnetic ring is increased.
After mixing the air flow grinding powder A and the air flow grinding powder B, placing the mixture into a magnetic ring magnetic field press protected by inert atmosphere for orientation molding, and carrying out isostatic pressing treatment, wherein the magnetic field strength of the orientation molding is 1.0-1.4T, and the isostatic pressing treatment pressure is 150-200 MPa.
Placing the blank subjected to orientation molding and isostatic pressing treatment in a sintering furnace for high-temperature sintering, wherein the high-temperature sintering temperature is 1030-1100 ℃, and the sintering time is 4-6 h. The sintering cooling adopts multistage cooling, vacuum self-cooling is firstly carried out to 600-750 ℃, inert gas (argon or nitrogen) is filled into the furnace to self-cool to 300-400 ℃, and then a fan is started to air cool to room temperature to finish sintering. The adoption of multi-stage cooling can avoid the excessive cracking of the internal stress of the material caused by rapid cooling and the performance degradation caused by uneven tissue structure. Continuously heating to the primary tempering temperature of 800-950 ℃ and tempering for 2-4 hours; cooling to the second tempering temperature of 450-580 ℃ and tempering for 4-6 hours.
The lubricant of the invention is a lubricant conventionally used in the art for sintering neodymium iron boron magnetic rings, such as paraffin, glycerol, silicate, silicone oil, stearic acid, zinc stearate, tributyl borate and the like. The addition amount of the lubricant is 0.2-0.5wt% of the mixture of the air flow grinding magnetic powder A and the air flow grinding magnetic powder B.
The technical scheme of the present invention is further described and illustrated by the following specific examples, and the scope of the present invention is not limited by the following examples. Unless otherwise indicated, all materials used in the examples of the present invention are those commonly used in the art, and all methods used in the examples are those commonly used in the art.
Example 1
The sintered NdFeB magnetic ring of example 1 is prepared by the following method:
1) An industrial raw material PrNd (75 wt% Nd) alloy and pure Dy, fe, co, ga, cu, al metal are mixed according to the component (PrNd) 30Dy2.0Cu0.2Al0.3Ga0.20Co1.0B0.96Fe Remainder of the process (wt%) to form an alloy A, and mixed according to (PrNd)30.5Dy0.8Cu0.1Al0. 2Ga0.20Co1.2B0.96Fe Remainder of the process (wt％) to form an alloy B; smelting and casting an alloy A raw material to obtain an ingot A, smelting and casting an alloy B raw material to obtain a casting piece B with the average thickness of 0.3mm, wherein the smelting temperature of the alloy A and the alloy B is 1500 ℃, the casting temperature is 1440 ℃, and the rotating speed of a copper roller is 1.5m/s during casting of the alloy B;
2) Respectively carrying out hydrogen crushing treatment on the cast ingot A and the cast sheet B to obtain coarse crushing powder A and coarse crushing powder B, and carrying out dehydrogenation treatment at 580 ℃ after crushing to ensure that the hydrogen content of the coarse crushing powder A and the coarse crushing powder B is less than or equal to 1000ppm;
3) The coarse crushing powder A and the coarse crushing powder B are respectively sent into an air flow mill for grinding to obtain air flow grinding powder A and air flow grinding powder B, the average grain diameter of the air flow grinding powder A is controlled to be 5 mu m, and the average grain diameter of the air flow grinding powder B is controlled to be 3 mu m;
4) Mixing air flow grinding powder A and air flow grinding powder B according to a mass ratio of 85:15, adding 0.3wt% of lubricant stearic acid, stirring for 5 hours, entering a magnetic ring magnetic field press for orientation molding after stirring, pressing into a magnetic ring green body with a D30×D22×18 specification, and carrying out 180MPa isostatic pressing treatment on the molded radiation magnetic ring;
5) And (3) carrying out high-temperature sintering after isostatic pressing treatment, wherein the sintering temperature is controlled at 1060 ℃ and the sintering time is 5h. The sintering cooling adopts multistage cooling, namely, vacuum self-cooling is carried out at 700 ℃, argon is filled for self-cooling to 350 ℃, and then a fan is started for air cooling to room temperature to finish sintering. The tempering adopts secondary tempering: first-stage tempering at 850 ℃ and preserving heat for 3h; and (5) secondary tempering at 500 ℃ and preserving heat for 5 hours.
Example 2
Example 2 differs from example 1 only in that example 2 mixes the air-flow grinding powder a and the air-flow grinding powder B in a mass ratio of 90:10, and the other is the same as example 1, and is not described here again.
Example 3
Example 3 differs from example 1 only in that example 3 mixes the air-flow grinding powder a and the air-flow grinding powder B in a mass ratio of 80:20, and the other is the same as example 1, and is not described here again.
Example 4
Example 4 differs from example 1 only in that example 4 mixes the air-flow grinding powder a and the air-flow grinding powder B in a mass ratio of 95:5, and the other is the same as example 1, and is not described here again.
Example 5
Example 5 differs from example 1 only in that example 5 mixes the air-flow grinding powder a and the air-flow grinding powder B in a mass ratio of 75:25, and the other is the same as example 1, and is not described here again.
Example 6
The sintered neodymium-iron-boron magnetic ring of example 6 was prepared by the following method:
1) An industrial raw material PrNd (75 wt% Nd) alloy and pure Dy, fe, co, ga, cu, al metal are mixed according to the component (PrNd) 32Dy2.0Cu0.3Al0.4Ga0.25Co1.2B1.1Fe Remainder of the process (wt%) to form an alloy A, and mixed according to the component (PrNd) 30.1Dy0.9Cu0.15Al0.22Ga0.18Co1.0B0.98Fe Remainder of the process (wt%) to form an alloy B; smelting and casting an alloy A raw material to obtain an ingot A, smelting and casting an alloy B raw material to obtain a casting piece B with the average thickness of 0.3mm, wherein the smelting temperature of the alloy A and the alloy B is 1510 ℃, the casting temperature is 1450 ℃, and the rotating speed of a copper roller is 1.5m/s during casting of the alloy B;
2) Respectively carrying out hydrogen crushing treatment on the cast ingot A and the cast sheet B to obtain coarse crushing powder A and coarse crushing powder B, and carrying out dehydrogenation treatment at 560 ℃ after crushing to ensure that the hydrogen content of the coarse crushing powder A and the coarse crushing powder B is less than or equal to 1000ppm;
3) Feeding the coarse crushing powder A and the coarse crushing powder B into an air flow mill respectively for grinding to obtain air flow grinding powder A and air flow grinding powder B, wherein the average particle size of the air flow grinding powder A is controlled to be 5.5 mu m, and the average particle size of the air flow grinding powder B is controlled to be 2.5 mu m;
4) Mixing air flow grinding powder A and air flow grinding powder B according to a mass ratio of 87:13, adding 00.3wt% of lubricant stearic acid, stirring for 4 hours, entering a magnetic ring magnetic field press for orientation molding after stirring, pressing into a magnetic ring green body with a D30×D22×18 specification, and carrying out 190MPa isostatic pressing treatment on the molded radiation magnetic ring;
5) And (3) carrying out high-temperature sintering after isostatic pressing treatment, wherein the sintering temperature is controlled at 1050 ℃ and the sintering time is 5h. The sintering cooling adopts multistage cooling, namely 650 ℃ of vacuum self-cooling, argon filling self-cooling to 320 ℃, and then air cooling to room temperature by a fan, and the sintering is finished. The tempering adopts secondary tempering: first-stage tempering is carried out at 900 ℃, and heat preservation is carried out for 3 hours; and the secondary tempering is carried out at 520 ℃ for 4.5 hours.
Comparative example 1
The sintered NdFeB magnetic ring of comparative example 1 is prepared by the following method:
1) Mixing industrial raw material PrNd (75 wt% Nd) alloy and pure Dy, fe, co, ga, cu, al metal according to the ratio of the components (PrNd)30.1Dy1.82Cu0.18Al0.28Ga0.20Co1.04Zr0.1B0.96Fe Remainder of the process (wt％) of the mixture of 85:15 of the embodiment 1 to obtain alloy C, smelting and casting the raw material of the alloy C to obtain cast ingot C, wherein the smelting temperature is 1500 ℃ and the casting temperature is 1440 ℃;
2) Carrying out hydrogen crushing treatment on the cast ingot C to obtain coarse crushed powder C, and carrying out dehydrogenation treatment at 580 ℃ after crushing to ensure that the hydrogen content of the coarse crushed powder C is less than or equal to 1000ppm;
3) Feeding the coarse powder C into an air flow mill for grinding to obtain air flow grinding magnetic powder C, and controlling the average particle size of the air flow grinding magnetic powder C to be 5 mu m;
4) Mixing and stirring the air flow grinding powder C and 0.3wt% of lubricant stearic acid for 5 hours, entering a magnetic ring magnetic field press for orientation molding after stirring, pressing into a magnetic ring green body with the specification of D30×D22×18, wherein the magnetic field strength is 1.4T, and performing 180MPa isostatic pressing treatment on the molded radiation magnetic ring;
The subsequent steps are the same as in example 1.
Comparative example 2
The sintered NdFeB magnetic ring of comparative example 2 is prepared by the following method:
1) An industrial raw material PrNd (75 wt% Nd) alloy and pure Dy, fe, co, ga, cu, al metal are mixed according to the ratio of 85:15 of example 1 and then mixed according to the component (PrNd)30.1Dy1.82Cu0.18Al0.28Ga0.20Co1.04Zr0.1B0.96Fe Remainder of the process (wt％) to form alloy C; smelting and casting the alloy C raw material to obtain a cast sheet C with the average thickness of 0.3mm, wherein the smelting temperature is 1500 ℃, the casting temperature is 1440 ℃, and the rotating speed of a copper roller is 1.5m/s;
2) Carrying out hydrogen crushing treatment on the cast sheet C to obtain coarse crushed powder C, and carrying out dehydrogenation treatment at 580 ℃ after crushing to ensure that the hydrogen content of the coarse crushed powder C is less than or equal to 1000ppm;
3) Feeding the coarse powder C into an air flow mill for grinding to obtain air flow grinding powder B, and controlling the average grain diameter of the air flow grinding powder C to be 3 mu m;
4) Mixing and stirring the air flow grinding powder C and 0.3wt% of lubricant stearic acid for 5 hours, entering a magnetic ring magnetic field press for orientation molding after stirring, pressing into a magnetic ring green body with the specification of D30×D22×18, wherein the magnetic field strength is 1.4T, and performing 180MPa isostatic pressing treatment on the molded radiation magnetic ring;
The subsequent steps are the same as in example 1.
Comparative example 3
Comparative example 3 is different from example 1 in that comparative example 3 controls the average particle diameter of the air-jet milled powder a to 3 μm and the average particle diameter of the air-jet milled powder B to 5 μm, and the other matters are the same as example 1, and are not described herein.
Sample columns of sintered neodymium iron boron magnetic rings D3 x 3 prepared in examples 1-6 and comparative examples 1-3 were tested for magnetic properties on PFM (pulsed magnetic field magnetometer) equipment and checked for cracking of the magnetic rings, as shown in table 1 below.
TABLE 1 magnetic Properties and cracking conditions of the magnetic rings of examples 1-6 and comparative examples 1-3
As shown in table 1, examples 1-3 and example 6 are preferred examples, and the prepared magnetic ring has excellent magnetic properties and does not crack; the cast piece of the embodiment 4 has lower content and low magnetic performance of the magnetic ring, and the cast piece of the embodiment 5 has too high content, so that the cracking proportion of the magnetic ring is increased; in the comparative example 1, the cast ingot is directly adopted to prepare the magnetic ring, and the magnetic ring is not easy to crack after being sintered by the cast ingot, but the magnetic performance is reduced; in the comparative example 2, the magnetic ring is directly prepared by adopting a cast sheet, and the magnetic ring has higher magnetic performance by sintering the cast sheet, but the magnetic ring is extremely easy to crack; comparative example 3 the average particle diameter of the air-jet mill powder a was controlled to 3 μm and the average particle diameter of the air-jet mill powder B was controlled to 6 μm, resulting in a decrease in magnetic properties and an increase in the cracking ratio of the magnetic ring.
The specific embodiments described herein are offered by way of example only to illustrate the spirit of the invention. Those skilled in the art may make various modifications or additions to the described embodiments or substitutions thereof without departing from the spirit of the invention or exceeding the scope of the invention as defined in the accompanying claims.
Claims (7)
1. The high-performance sintered NdFeB magnetic ring is characterized in that the preparation raw materials of the sintered NdFeB magnetic ring comprise alloy A and alloy B;
the alloy A comprises the following components of R xTyMzB（1-x-y-z）, wherein R is one or more of Nd, pr, la, ce, ga, ho, dy and Tb, M is one or more of Cu, al and Ga, T is Fe and Co, and the mass ratio of Fe to Co is (40-100): 1, wherein x is 30.5-35 wt%, y is 55-70 wt% and z is 0.1-2.0 wt%;
the alloy B comprises the components of R xTyMzB（1-x-y-z）, wherein R is one or more of Nd, pr, la, ce, ga, ho, dy and Tb, M is one or more of Cu, al and Ga, T is Fe and Co, and the mass ratio of Fe to Co is (40-100): 1, wherein x is 29-33 wt%, y is 55-70 wt% and z is 0.1-2.0 wt%;
The preparation method of the sintered NdFeB magnetic ring comprises the following steps:
(1) Preparing an alloy A raw material according to the composition of the alloy A, smelting and casting the alloy A raw material to obtain an ingot A; preparing an alloy B raw material according to the composition of the alloy B, smelting and casting the alloy B raw material, and carrying out melt-spinning to obtain a casting sheet B with the average thickness of 0.2-0.4 mm;
(2) Respectively carrying out hydrogen crushing treatment on the cast ingot A and the cast sheet B to obtain coarse crushing powder A and coarse crushing powder B, and carrying out dehydrogenation heat treatment to ensure that the hydrogen content of the coarse crushing powder A and the coarse crushing powder B is less than or equal to 1000ppm;
(3) The coarse crushing powder A and the coarse crushing powder B are respectively sent into an air flow mill for grinding to obtain air flow grinding powder A and air flow grinding powder B;
(4) Mixing the air flow grinding powder A and the air flow grinding powder B, adding a lubricant, stirring for 2-6 hours, entering a magnetic ring magnetic field press for orientation molding after stirring, and carrying out isostatic pressing treatment;
(5) High-temperature sintering, cooling and tempering heat treatment;
The average particle size of the air flow grinding magnetic powder A in the step (3) is 5-6 mu m, and the average particle size of the air flow grinding magnetic powder B is 2-3 mu m;
in the step (4), the content of the air-flow grinding powder B in the mixture of the air-flow grinding powder A and the air-flow grinding powder B is 10-20wt%.
2. The preparation method of the high-performance sintered NdFeB magnetic ring is characterized in that the preparation raw materials of the sintered NdFeB magnetic ring comprise alloy A and alloy B;
the alloy A comprises the following components of R xTyMzB（1-x-y-z）, wherein R is one or more of Nd, pr, la, ce, ga, ho, dy and Tb, M is one or more of Cu, al and Ga, T is Fe and Co, and the mass ratio of Fe to Co is (40-100): 1, wherein x is 30.5-35 wt%, y is 55-70 wt% and z is 0.1-2.0 wt%;
the alloy B comprises the components of R xTyMzB（1-x-y-z）, wherein R is one or more of Nd, pr, la, ce, ga, ho, dy and Tb, M is one or more of Cu, al and Ga, T is Fe and Co, and the mass ratio of Fe to Co is (40-100): 1, wherein x is 29-33 wt%, y is 55-70 wt% and z is 0.1-2.0 wt%;
the preparation method comprises the following steps:
(1) Preparing an alloy A raw material according to the composition of the alloy A, smelting and casting the alloy A raw material to obtain an ingot A; preparing an alloy B raw material according to the composition of the alloy B, smelting and casting the alloy B raw material, and carrying out melt-spinning to obtain a casting sheet B with the average thickness of 0.2-0.4 mm;
(2) Respectively carrying out hydrogen crushing treatment on the cast ingot A and the cast sheet B to obtain coarse crushing powder A and coarse crushing powder B, and carrying out dehydrogenation heat treatment to ensure that the hydrogen content of the coarse crushing powder A and the coarse crushing powder B is less than or equal to 1000ppm;
(3) The coarse crushing powder A and the coarse crushing powder B are respectively sent into an air flow mill for grinding to obtain air flow grinding powder A and air flow grinding powder B;
(4) Mixing the air flow grinding powder A and the air flow grinding powder B, adding a lubricant, stirring for 2-6 hours, entering a magnetic ring magnetic field press for orientation molding after stirring, and carrying out isostatic pressing treatment;
(5) High-temperature sintering, cooling and tempering heat treatment;
The average particle size of the air flow grinding magnetic powder A in the step (3) is 5-6 mu m, and the average particle size of the air flow grinding magnetic powder B is 2-3 mu m;
in the step (4), the content of the air-flow grinding powder B in the mixture of the air-flow grinding powder A and the air-flow grinding powder B is 10-20wt%.
3. The preparation method according to claim 2, wherein the melting temperature of alloy a and alloy B is 1450-1550 ℃ and the casting temperature is 1400-1450 ℃; when the alloy B is cast, the rotating speed of the copper roller is 1.0-1.5 m/s.
4. The preparation method of claim 2, wherein the magnetic field strength of the orientation molding in the step (4) is 1.0-1.4 t, and the isostatic pressing pressure is 150-200 mpa.
5. The method according to claim 2, wherein the high-temperature sintering temperature in the step (5) is 1030-1100 ℃ and the sintering time is 4-6 hours.
6. The method of claim 2, wherein the cooling step of step (5) comprises: vacuum self-cooling to 600-750 ℃, filling inert gas, self-cooling to 300-400 ℃, and then opening a fan for air cooling to room temperature.
7. The method according to claim 2, wherein the tempering heat treatment of step (5) comprises: the primary tempering temperature is 800-950 ℃, and the tempering time is 2-4 hours; the secondary tempering temperature is 450-580 ℃, and the tempering time is 4-6 hours.
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