CN117612856A - Anisotropic magnetic material forming method - Google Patents
Anisotropic magnetic material forming method Download PDFInfo
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- CN117612856A CN117612856A CN202311653789.6A CN202311653789A CN117612856A CN 117612856 A CN117612856 A CN 117612856A CN 202311653789 A CN202311653789 A CN 202311653789A CN 117612856 A CN117612856 A CN 117612856A
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- magnetic powder
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- epoxy resin
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- 238000000034 method Methods 0.000 title claims abstract description 67
- 239000000696 magnetic material Substances 0.000 title claims abstract description 23
- 239000006247 magnetic powder Substances 0.000 claims abstract description 120
- 239000003822 epoxy resin Substances 0.000 claims abstract description 70
- 229920000647 polyepoxide Polymers 0.000 claims abstract description 70
- PRQMIVBGRIUJHV-UHFFFAOYSA-N [N].[Fe].[Sm] Chemical group [N].[Fe].[Sm] PRQMIVBGRIUJHV-UHFFFAOYSA-N 0.000 claims abstract description 68
- 238000000465 moulding Methods 0.000 claims abstract description 52
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 28
- 238000004381 surface treatment Methods 0.000 claims abstract description 23
- 238000003825 pressing Methods 0.000 claims abstract description 22
- 239000007788 liquid Substances 0.000 claims abstract description 21
- 239000002245 particle Substances 0.000 claims abstract description 21
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 20
- 238000000576 coating method Methods 0.000 claims abstract description 12
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 claims description 52
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 claims description 48
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 claims description 22
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 17
- 239000007822 coupling agent Substances 0.000 claims description 14
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 12
- 229910019142 PO4 Inorganic materials 0.000 claims description 11
- 229910000147 aluminium phosphate Inorganic materials 0.000 claims description 11
- 239000003795 chemical substances by application Substances 0.000 claims description 11
- 239000011248 coating agent Substances 0.000 claims description 11
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 claims description 11
- 239000010452 phosphate Substances 0.000 claims description 11
- 239000000203 mixture Substances 0.000 claims description 10
- 239000000843 powder Substances 0.000 claims description 10
- 239000000654 additive Substances 0.000 claims description 9
- 230000000996 additive effect Effects 0.000 claims description 9
- 239000002131 composite material Substances 0.000 claims description 9
- 229920001568 phenolic resin Polymers 0.000 claims description 9
- 239000005011 phenolic resin Substances 0.000 claims description 9
- KXGFMDJXCMQABM-UHFFFAOYSA-N 2-methoxy-6-methylphenol Chemical group [CH]OC1=CC=CC([CH])=C1O KXGFMDJXCMQABM-UHFFFAOYSA-N 0.000 claims description 8
- ULKLGIFJWFIQFF-UHFFFAOYSA-N 5K8XI641G3 Chemical compound CCC1=NC=C(C)N1 ULKLGIFJWFIQFF-UHFFFAOYSA-N 0.000 claims description 8
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 claims description 8
- 230000005672 electromagnetic field Effects 0.000 claims description 8
- ODLMAHJVESYWTB-UHFFFAOYSA-N ethylmethylbenzene Natural products CCCC1=CC=CC=C1 ODLMAHJVESYWTB-UHFFFAOYSA-N 0.000 claims description 8
- RKISUIUJZGSLEV-UHFFFAOYSA-N n-[2-(octadecanoylamino)ethyl]octadecanamide Chemical compound CCCCCCCCCCCCCCCCCC(=O)NCCNC(=O)CCCCCCCCCCCCCCCCC RKISUIUJZGSLEV-UHFFFAOYSA-N 0.000 claims description 8
- 238000003756 stirring Methods 0.000 claims description 8
- 238000001291 vacuum drying Methods 0.000 claims description 8
- 238000009736 wetting Methods 0.000 claims description 8
- 239000000314 lubricant Substances 0.000 claims description 7
- 229910052786 argon Inorganic materials 0.000 claims description 6
- 239000004848 polyfunctional curative Substances 0.000 claims description 6
- 238000005057 refrigeration Methods 0.000 claims description 6
- -1 amine compound Chemical class 0.000 claims description 5
- 239000000126 substance Substances 0.000 claims description 5
- 238000007723 die pressing method Methods 0.000 claims description 4
- 239000001307 helium Substances 0.000 claims description 4
- 229910052734 helium Inorganic materials 0.000 claims description 4
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 claims description 4
- ASWPBPHMBJLXOE-UHFFFAOYSA-N 1-(2-ethyl-4-methylimidazol-1-yl)-3-phenoxypropan-2-ol Chemical compound CCC1=NC(C)=CN1CC(O)COC1=CC=CC=C1 ASWPBPHMBJLXOE-UHFFFAOYSA-N 0.000 claims description 3
- LXBGSDVWAMZHDD-UHFFFAOYSA-N 2-methyl-1h-imidazole Chemical compound CC1=NC=CN1 LXBGSDVWAMZHDD-UHFFFAOYSA-N 0.000 claims description 3
- LLEASVZEQBICSN-UHFFFAOYSA-N 2-undecyl-1h-imidazole Chemical compound CCCCCCCCCCCC1=NC=CN1 LLEASVZEQBICSN-UHFFFAOYSA-N 0.000 claims description 3
- UIDDPPKZYZTEGS-UHFFFAOYSA-N 3-(2-ethyl-4-methylimidazol-1-yl)propanenitrile Chemical compound CCC1=NC(C)=CN1CCC#N UIDDPPKZYZTEGS-UHFFFAOYSA-N 0.000 claims description 3
- CJZGTCYPCWQAJB-UHFFFAOYSA-L calcium stearate Chemical compound [Ca+2].CCCCCCCCCCCCCCCCCC([O-])=O.CCCCCCCCCCCCCCCCCC([O-])=O CJZGTCYPCWQAJB-UHFFFAOYSA-L 0.000 claims description 3
- 239000008116 calcium stearate Substances 0.000 claims description 3
- 235000013539 calcium stearate Nutrition 0.000 claims description 3
- 230000008878 coupling Effects 0.000 claims description 3
- 238000010168 coupling process Methods 0.000 claims description 3
- 238000005859 coupling reaction Methods 0.000 claims description 3
- FATBGEAMYMYZAF-KTKRTIGZSA-N oleamide Chemical compound CCCCCCCC\C=C/CCCCCCCC(N)=O FATBGEAMYMYZAF-KTKRTIGZSA-N 0.000 claims description 3
- FATBGEAMYMYZAF-UHFFFAOYSA-N oleicacidamide-heptaglycolether Natural products CCCCCCCCC=CCCCCCCCC(N)=O FATBGEAMYMYZAF-UHFFFAOYSA-N 0.000 claims description 3
- XOOUIPVCVHRTMJ-UHFFFAOYSA-L zinc stearate Chemical compound [Zn+2].CCCCCCCCCCCCCCCCCC([O-])=O.CCCCCCCCCCCCCCCCCC([O-])=O XOOUIPVCVHRTMJ-UHFFFAOYSA-L 0.000 claims description 3
- 239000004593 Epoxy Substances 0.000 claims description 2
- 239000004698 Polyethylene Substances 0.000 claims description 2
- 229920000573 polyethylene Polymers 0.000 claims description 2
- 230000003647 oxidation Effects 0.000 abstract description 4
- 238000007254 oxidation reaction Methods 0.000 abstract description 4
- 238000004519 manufacturing process Methods 0.000 abstract description 3
- 238000002360 preparation method Methods 0.000 abstract description 3
- 238000005265 energy consumption Methods 0.000 abstract description 2
- 238000001816 cooling Methods 0.000 abstract 1
- 229910001172 neodymium magnet Inorganic materials 0.000 description 11
- 239000004033 plastic Substances 0.000 description 11
- 229920003023 plastic Polymers 0.000 description 11
- 238000010298 pulverizing process Methods 0.000 description 11
- 239000012752 auxiliary agent Substances 0.000 description 10
- IISBACLAFKSPIT-UHFFFAOYSA-N bisphenol A Chemical compound C=1C=C(O)C=CC=1C(C)(C)C1=CC=C(O)C=C1 IISBACLAFKSPIT-UHFFFAOYSA-N 0.000 description 10
- QJVKUMXDEUEQLH-UHFFFAOYSA-N [B].[Fe].[Nd] Chemical compound [B].[Fe].[Nd] QJVKUMXDEUEQLH-UHFFFAOYSA-N 0.000 description 8
- 239000002994 raw material Substances 0.000 description 7
- 239000000463 material Substances 0.000 description 6
- 229920005989 resin Polymers 0.000 description 6
- 239000011347 resin Substances 0.000 description 6
- 229910000859 α-Fe Inorganic materials 0.000 description 5
- 239000011230 binding agent Substances 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 229910052761 rare earth metal Inorganic materials 0.000 description 2
- 150000002910 rare earth metals Chemical class 0.000 description 2
- 239000005062 Polybutadiene Substances 0.000 description 1
- 229910052772 Samarium Inorganic materials 0.000 description 1
- YWTMTKBIVNUPNG-UHFFFAOYSA-N [N].[Fe].[Nd] Chemical compound [N].[Fe].[Nd] YWTMTKBIVNUPNG-UHFFFAOYSA-N 0.000 description 1
- AHFHMGFBODNOJT-UHFFFAOYSA-N azane;ethane Chemical compound N.CC AHFHMGFBODNOJT-UHFFFAOYSA-N 0.000 description 1
- YYXHRUSBEPGBCD-UHFFFAOYSA-N azanylidyneiron Chemical compound [N].[Fe] YYXHRUSBEPGBCD-UHFFFAOYSA-N 0.000 description 1
- 238000000498 ball milling Methods 0.000 description 1
- 238000013329 compounding Methods 0.000 description 1
- 238000000748 compression moulding Methods 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 238000007865 diluting Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 229920001971 elastomer Polymers 0.000 description 1
- 238000004134 energy conservation Methods 0.000 description 1
- 125000002485 formyl group Chemical class [H]C(*)=O 0.000 description 1
- 230000008014 freezing Effects 0.000 description 1
- 238000007710 freezing Methods 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- LNEPOXFFQSENCJ-UHFFFAOYSA-N haloperidol Chemical compound C1CC(O)(C=2C=CC(Cl)=CC=2)CCN1CCCC(=O)C1=CC=C(F)C=C1 LNEPOXFFQSENCJ-UHFFFAOYSA-N 0.000 description 1
- 238000001746 injection moulding Methods 0.000 description 1
- 239000003949 liquefied natural gas Substances 0.000 description 1
- 229910001004 magnetic alloy Inorganic materials 0.000 description 1
- 230000005389 magnetism Effects 0.000 description 1
- 230000005415 magnetization Effects 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 229920006122 polyamide resin Polymers 0.000 description 1
- 229920002857 polybutadiene Polymers 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000005060 rubber Substances 0.000 description 1
- GVGXPXPGZLUONX-UHFFFAOYSA-N samarium Chemical compound [Sm][Sm][Sm][Sm][Sm][Sm][Sm][Sm][Sm][Sm][Sm][Sm][Sm][Sm] GVGXPXPGZLUONX-UHFFFAOYSA-N 0.000 description 1
- 229920002050 silicone resin Polymers 0.000 description 1
Classifications
-
- 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
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Hard Magnetic Materials (AREA)
Abstract
The invention relates to a molding method of an anisotropic magnetic material, which comprises a magnetic powder surface treatment process, an epoxy resin coating process, a low-temperature crushing process and an orientation molding process. Wherein the low-temperature crushing procedure is mechanical crushing after liquid nitrogen cooling. The preparation process can completely separate the magnetic powder agglomerates to form single-particle magnetic powder coated by the epoxy resin, the magnetic powder particles are not damaged by oxidation, the epoxy resin is not solidified, and compared with the traditional pressing process, the preparation process has the advantages of simple process, high production efficiency and low energy consumption, and finally the anisotropic samarium-iron-nitrogen bonded magnet with high coercivity and high maximum magnetic energy product is prepared.
Description
Technical Field
The invention belongs to the field of bonded magnetic composite materials, and relates to a molding method of an anisotropic magnetic material.
Background
The low-temperature pulverizing technology refers to a process of pulverizing a substance cooled to a embrittlement point temperature into particles or powder having a smaller particle diameter by an external force, and has been commercialized in the united states as early as 1948. Common low-temperature crushing processes include liquid nitrogen/liquid argon/liquid helium refrigeration low-temperature crushing method, air expansion refrigeration low-temperature crushing method, ammonia-ethane cascade refrigeration system low-temperature crushing method, liquefied natural gas cold energy low-temperature crushing method and the like. Compared with normal temperature crushing, the powder obtained by the low temperature crushing method has smaller particle size, narrow particle size distribution, good molding of crushed products, large bulk density and good fluidity, and can also prevent heat-sensitive materials from deteriorating due to heating in the crushing process, and the application researches of patents CN 111070494A, CN 103629840B, CN 205517962U and the like on the low temperature crushing process on rubber and grains show that the process has higher efficiency and better crushing effect compared with the conventional mechanical crushing.
The molded magnet is formed by mixing a binder with magnetic powder, adding an auxiliary agent such as a curing agent, a lubricant and the like, and then putting the mixture into a mold for compression molding, and belongs to one of bonded magnetic materials. Typical binders are unsaturated aldehyde resins, epoxy resins, phenolic resins, silicone resins, polybutadiene resins, etc.; the magnetic powder includes neodymium iron boron (Nd-Fe-B), samarium iron nitrogen (Sm-Fe-N), ferrite, etc. Compared with the sintered magnetic material, the magnetic plastic has the advantages of small density and high impact resistance, the magnetism of the magnetic plastic can be controlled by the content of magnetic powder, the chemical stability is good, and the magnetic plastic cannot be broken when in use; meanwhile, the material has the characteristics of high material utilization rate, easiness in processing any shape and the like, and plays a key role in miniaturization, light weight, compounding, high efficiency and energy conservation of electronic components.
Ferrite magnetic materials have the advantages of abundant resources and low price, and are widely applied to the field of high-frequency weak current, but because the magnetic energy stored in the unit volume is low and the saturation magnetization intensity is low, the ferrite magnetic materials are difficult to apply to the field of low-frequency strong current and high power which require high magnetic energy density. Neodymium iron boron is taken as a third-generation rare earth permanent magnet material, is widely focused by virtue of the extremely high magnetic energy product, has excellent magnetic performance, is widely applied to various fields of electronics, electric machinery, medical equipment, aerospace and the like, such as high-performance magnetic alloy prepared by RFB rare earth magnetic powder in U.S. patent Nos. 4851058 and 5411608, but also has the problems of low Curie temperature, easy corrosion, high cost and the like, and limits the application of the neodymium iron boron magnet in partial fields. The samarium-iron-nitrogen permanent magnet material has magnetic properties comparable to those of a neodymium-iron-boron material, has better thermal stability, oxidation resistance and corrosion resistance than those of the neodymium-iron-boron magnetic material, has lower raw material cost than that of the neodymium-iron-boron, and is an ideal raw material for preparing high-performance bonded magnets.
Most of the molded magnet products in the market at present are isotropic magnets with lower magnetic properties, namely one or more magnetic powder of neodymium iron boron, samarium iron nitrogen, neodymium iron nitrogen and ferrite are adopted, and are mixed with a binder, molded and cured, and then are placed into a magnetic field for magnetizing. Because the internal magnetic powder particles of the product are difficult to rotate after molding and curing, the orientation degree is lower when the external magnetic field is applied to orient, the magnetic performance of the prepared molded magnet is lower, for example, the magnetic energy product of the samarium-iron-nitrogen/epoxy resin molded magnet is less than 40kJ/m 3 It is difficult to apply to the high performance field. A method of obtaining a bonded magnet by ball milling and pulverizing neodymium iron boron magnetic powder, as mentioned in patent CN 1087744A, and pressing at room temperature, and a method of obtaining a bonded magnet by mixing neodymium iron boron magnetic powder and ferrite magnetic powder with epoxy resin, dissolving and drying the mixture with acetone, and then directly mechanically crushing the mixture, and pressing at room temperature, as mentioned in patent CN 106340367A. The mechanical crushing method used in the above process has the phenomena that the crushing of the bonded magnetic powder is incomplete and part of the magnetic powder particles are crushed, and equipment and the magnetic powder are rubbed during the crushing processPart of the magnetic powder is oxidized and epoxy resin is solidified by heat release, so that the magnetic powder has poor particle orientation condition and the magnetic performance of the magnet is low
Disclosure of Invention
The invention aims to disperse agglomerated magnetic powder into single particles by using a low-temperature crushing process, so that the magnetic powder is easy to rotate in an orientation magnetic field, the orientation degree of the magnetic powder is improved, and the anisotropic magnetic material forming method is provided.
The method comprises the following steps:
step 1, performing phosphating and coupling composite treatment on the surface of samarium-iron-nitrogen magnetic powder, and coating a phosphating film and a coupling agent on the surface of the powder;
step 2, coating the samarium-iron-nitrogen magnetic powder subjected to surface treatment by adopting epoxy resin;
and 3, adding the samarium-iron-nitrogen magnetic powder coated by the epoxy resin into a low-temperature pulverizer to pulverize, so that the agglomerated magnetic powder particles are completely dispersed into a single particle state.
And 4, adding the single-particle magnetic powder into a forming die for pressing, and applying an electromagnetic field for orientation while pressing, wherein the strength of the orientation field is 1-3 Tesla, and curing the magnet in a vacuum or non-oxidizing atmosphere environment at 150-190 ℃ after the die pressing is finished.
In one embodiment, step 1 is specifically:
the phosphate coupling agent and phosphoric acid are dissolved in absolute ethyl alcohol or methylbenzene according to a certain proportion to prepare a surface treating agent, and the dosage of the absolute ethyl alcohol or the acetone is limited by the condition that the magnetic powder can be completely coated;
100 parts of samarium-iron-nitrogen magnetic powder is added, fully stirred and uniformly mixed at 40-60 ℃, and then vacuum dried to obtain surface-treated samarium-iron-nitrogen magnetic powder;
in one embodiment, step 2 is specifically:
epoxy resin and a molding additive are dissolved in proper amount of ethyl acetate or acetone according to the proportion, and the dosage of the ethyl acetate or the acetone is limited by wetting magnetic powder;
adding the samarium-iron-nitrogen magnetic powder subjected to surface treatment, fully stirring at 20-40 ℃, and then vacuum drying to obtain the epoxy resin coated samarium-iron-nitrogen magnetic powder.
Preferably, the chemical components of the samarium iron nitrogen are as follows: sm accounts for 20wt.% to 30wt.%, fe accounts for 60wt.% to 80wt.%, and N accounts for 2wt.% to 4wt.%.
In one embodiment, the epoxy resin has an epoxy equivalent of 100-1000, and the epoxy resin is any one or more of E44, E55, 1003, 1004 and C704.
Preferably, the phosphate coupling agent and the phosphoric acid are used in an amount of 0.5% and 1% of the mass of the magnetic powder respectively.
Preferably, the molding aid is a mixture of a hardener, an accelerator and a lubricant, and the dosages of the molding aid respectively account for 15-30%, 1-10% and 5-20% of the mass of the epoxy resin.
Preferably, the hardener is phenolic resin, and is selected from one or more of 2402, 2123, 7522E, PF-8211 and PF-8217; the accelerator is an amine compound and is selected from one or more of 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole and 1- (2-hydroxy-3-phenoxypropyl) -2-ethyl-4-methylimidazole; the lubricant is a mixture of calcium stearate, zinc stearate, oleamide, ethylene bis stearamide and polyethylene wax.
In one embodiment, the cold source used for the low-temperature crushing is one or more of liquid nitrogen, liquid argon and liquid helium, and the treatment method is one of low-temperature crushing, normal-temperature/low-temperature crushing, electric impact crushing and air expansion refrigeration low-temperature crushing.
Compared with the prior art, the anisotropic magnetic material prepared by the low-temperature crushing and die-pressing orientation process has the following benefits:
firstly, the invention carries out phosphating and coupling composite treatment on the surface of samarium iron nitrogen magnetic powder, and coats a phosphating film and a coupling agent on the surface of the powder, thereby avoiding the oxidation of samarium iron nitrogen in the pretreatment and high-temperature curing process, improving the compatibility between the magnetic powder and resin, and improving the bonding effect of epoxy resin on the magnetic powder and the mechanical property of the product in the molding process.
Secondly, the invention breaks up the agglomerated magnetic powder particles after the epoxy resin coating treatment by a low-temperature crushing technology, and the agglomerates are separated from the frozen resin only under the premise that the magnetic powder is not damaged and are in a single particle state, so that the magnetic powder is not required to be heated in the mould pressing orientation process, the higher orientation degree can be obtained, and the influence on the coercivity of the magnetic powder is small.
Thirdly, the anisotropic magnetic composite material prepared by the invention has magnetic property which greatly exceeds that of an injection molding neodymium iron boron magnet and greatly reduces the cost; compared with the existing like-polarity samarium iron nitrogen mould pressing product, the magnetic performance is greatly improved.
Fourth, the preparation process cost of the magnetic composite material provided by the invention is greatly reduced, and compared with the traditional process of softening the magnetic composite material by heating resin and then orientating and pressing, the low-temperature freezing method simplifies the process flow, improves the production efficiency and reduces the production energy consumption.
Detailed Description
According to the invention, the magnetic powder coated by the binder is crushed in a low-temperature crushing mode, the resin strength is reduced in a low-temperature environment, so that the bonded magnetic powder can be fully crushed and completely separated under the condition that the magnetic powder particles are not damaged, and the magnetic powder is helped to obtain higher orientation degree; in addition, friction heating can be reduced in the low-temperature environment, and magnetic powder oxidation is prevented. Finally, the high-performance molding magnetic material is prepared.
A molding method of anisotropic magnetic material comprises the following components in percentage by mass:
1.5 to 4 percent of epoxy resin
95 to 98 percent of samarium-iron-nitrogen magnetic powder
0.5 to 1 percent of molding additive
The method comprises the following steps:
step 1, samarium-iron-nitrogen magnetic powder surface treatment
The phosphate coupling agent and phosphoric acid are dissolved in absolute ethyl alcohol or methylbenzene according to a certain proportion to prepare a surface treating agent, and the dosage of the absolute ethyl alcohol or the acetone is limited by the condition that the magnetic powder can be completely coated;
100 parts of samarium-iron-nitrogen magnetic powder is added, fully stirred and uniformly mixed at 40-60 ℃, and then vacuum-dried at 80 ℃ for 6 hours, thus obtaining the surface-treated samarium-iron-nitrogen magnetic powder.
Step 2, coating with epoxy resin
The epoxy resin and the molding additive are dissolved in proper amount of ethyl acetate or acetone according to the proportion, and the dosage of the ethyl acetate or the acetone is limited by wetting magnetic powder;
adding the samarium-iron-nitrogen magnetic powder subjected to surface treatment, fully stirring at 20-40 ℃, and then vacuum drying at 60 ℃ for 4 hours to obtain the epoxy resin coated samarium-iron-nitrogen magnetic powder.
Step 3, grinding the magnetic powder at low temperature
Adding the samarium-iron-nitrogen magnetic powder coated by the epoxy resin into a low-temperature pulverizer for pulverizing, so that the agglomerated magnetic powder particles are completely dispersed into a single particle state.
Step 4, molding the magnetic composite material
Adding the epoxy resin/samarium-iron-nitrogen magnetic powder subjected to surface treatment and low-temperature pulverization into a forming die for pressing, and applying an electromagnetic field for orientation while pressing, wherein the strength of an orientation field is 1-3 tesla;
after the molding is finished, the magnet is solidified for 1 hour in a vacuum environment at 150-190 ℃.
Further, the chemical composition of the samarium iron nitrogen is that Sm accounts for 20-30 wt%, fe accounts for 60-80 wt%, and N accounts for 2-4 wt%; the mixed surface treating agent is prepared by diluting and dissolving phosphate coupling agent and phosphoric acid by absolute ethyl alcohol or acetone, and the dosage of the mixed surface treating agent is respectively 0.5-2% and 0.5-2% of the mass of the magnetic powder.
Further, the epoxy resin can be any one or more of E44, E55, 1003, 1004 and C704, the molding aid is a mixture of a hardener, an accelerator and a lubricant, wherein the hardener is phenolic resin and is selected from one or more of 2402, 2123, 7522E, PF-8211 and PF-8217; the accelerator is an amine compound and is selected from one or more of 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole and 1- (2-hydroxy-3-phenoxypropyl) -2-ethyl-4-methylimidazole; the lubricant is a mixture of calcium stearate, zinc stearate, ethylene bis-stearamide and oleamide. The dosage of the epoxy resin accounts for 15 to 30 percent, 1 to 10 percent and 5 to 20 percent of the mass of the epoxy resin respectively.
Further, the cold source adopted by the low-temperature crushing is one or more of liquid nitrogen, liquid argon and liquid helium, and the treatment method is one of low-temperature crushing, normal-temperature/low-temperature crushing, electric impact crushing and air expansion refrigeration low-temperature crushing.
Further: the anisotropic magnetic material is prepared by a mould pressing orientation process, the optimal ratio of the epoxy resin to the samarium iron nitrogen to the mould pressing auxiliary agent is 25:970:5, and the low-temperature crushing process is liquid nitrogen low-temperature crushing.
The present invention will be described in more detail with reference to examples. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.
Example 1.
The mass percentages of the various raw materials in this example are as follows:
bisphenol A type epoxy resin (1003) 2.5%
Samarium iron nitrogen powder 97%
Mixed molding aids 0.5%
Wherein the mass percentages of the used molding aids are calculated according to the mass percentages of the epoxy resin, and the types and the mass percentages are as follows:
2402 phenolic resin 12.5%
2% of 2-ethyl-4-methylimidazole
Ethylene bis stearamide 5.5%
The cold source used for low-temperature crushing is liquid nitrogen, and the process is a direct low-temperature crushing method
The process comprises the following steps:
step 1, samarium-iron-nitrogen magnetic powder surface treatment
The phosphate coupling agent and phosphoric acid are dissolved in absolute ethyl alcohol or methylbenzene according to a certain proportion to prepare a surface treating agent, and the dosage of the absolute ethyl alcohol or the acetone is limited by the condition that the magnetic powder can be completely coated; 100 parts of samarium-iron-nitrogen magnetic powder is added, fully stirred and uniformly mixed at 40-60 ℃, and then vacuum-dried at 80 ℃ for 6 hours, thus obtaining the surface-treated samarium-iron-nitrogen magnetic powder.
Step 2, coating with epoxy resin
The epoxy resin and the molding additive are dissolved in proper amount of ethyl acetate or acetone according to the proportion, and the dosage of the ethyl acetate or the acetone is limited by wetting magnetic powder; adding the samarium-iron-nitrogen magnetic powder subjected to surface treatment, fully stirring at 20-40 ℃, and then vacuum drying at 60 ℃ for 4 hours to obtain the epoxy resin coated samarium-iron-nitrogen magnetic powder.
Step 3, low-temperature crushing
The samarium-iron-nitrogen magnetic powder coated by epoxy resin is put into a low-temperature pulverizer, liquid nitrogen is added to reduce the temperature to-80 ℃ to-100 ℃, and the low-temperature mechanical pulverizing operation is carried out on the magnetic powder.
Step 4, orientation molding
The epoxy resin/samarium-iron-nitrogen magnetic powder subjected to surface treatment and low-temperature pulverization was put into a molding die to be pressed, and an electromagnetic field was applied to perform orientation while pressing, the strength of the orientation field was 1.0 tesla, and the magnet was cured in a vacuum environment at 180 ℃ for 1 hour after the completion of the molding, and the results were as shown in table 1 below.
Example 2.
The mass percentages of the various raw materials in this example are as follows:
bisphenol A type epoxy resin (1003) 2.5%
Samarium iron nitrogen powder 97%
Mixed molding aids 0.5%
Wherein the mass percentages of the plastic auxiliary agents are calculated according to the mass percentages of the epoxy resin, and the types and the mass percentages of the plastic auxiliary agents are as follows:
2402 phenolic resin 12.5%
2% of 2-ethyl-4-methylimidazole
Ethylene bis stearamide 5.5%
The cold source used for low-temperature crushing is liquid nitrogen, and the process is a direct low-temperature crushing method
The process comprises the following steps:
step 1, samarium-iron-nitrogen magnetic powder surface treatment
The phosphate coupling agent and phosphoric acid are dissolved in absolute ethyl alcohol or methylbenzene according to a certain proportion to prepare a surface treating agent, and the dosage of the absolute ethyl alcohol or the acetone is limited by the condition that the magnetic powder can be completely coated; 100 parts of samarium-iron-nitrogen magnetic powder is added, fully stirred and uniformly mixed at 40-60 ℃, and then vacuum-dried at 80 ℃ for 6 hours, thus obtaining the surface-treated samarium-iron-nitrogen magnetic powder.
Step 2, coating with epoxy resin
The epoxy resin and the molding additive are dissolved in proper amount of ethyl acetate or acetone according to the proportion, and the dosage of the ethyl acetate or the acetone is limited by wetting magnetic powder; adding the samarium-iron-nitrogen magnetic powder subjected to surface treatment, fully stirring at 20-40 ℃, and then vacuum drying at 60 ℃ for 4 hours to obtain the epoxy resin coated samarium-iron-nitrogen magnetic powder.
Step 3, low-temperature crushing
The samarium-iron-nitrogen magnetic powder coated by epoxy resin is put into a low-temperature pulverizer, liquid nitrogen is added to reduce the temperature to-80 ℃ to-100 ℃, and the low-temperature mechanical pulverizing operation is carried out on the magnetic powder.
Step 4, orientation molding
The epoxy resin/samarium-iron-nitrogen magnetic powder subjected to surface treatment and low-temperature pulverization was put into a molding die to be pressed, and an electromagnetic field was applied to perform orientation while pressing, the strength of the orientation field was 2.0 tesla, and the magnet was cured in a vacuum environment at 180 ℃ for 1 hour after the completion of the molding, and the results were as shown in table 1 below.
Example 3.
The mass percentages of the various raw materials in this example are as follows:
bisphenol A type epoxy resin (1003) 2.5%
Samarium iron nitrogen powder 97%
Mixed molding aids 0.5%
Wherein the mass percentages of the plastic auxiliary agents are calculated according to the mass percentages of the epoxy resin, and the types and the mass percentages of the plastic auxiliary agents are as follows:
2402 phenolic resin 12.5%
2% of 2-ethyl-4-methylimidazole
Ethylene bis stearamide 5.5%
The cold source used for low-temperature crushing is liquid argon, and the process is a direct low-temperature crushing method
The process comprises the following steps:
step 1, samarium-iron-nitrogen magnetic powder surface treatment
The phosphate coupling agent and phosphoric acid are dissolved in absolute ethyl alcohol or methylbenzene according to a certain proportion to prepare a surface treating agent, and the dosage of the absolute ethyl alcohol or the acetone is limited by the condition that the magnetic powder can be completely coated; 100 parts of samarium-iron-nitrogen magnetic powder is added, fully stirred and uniformly mixed at 40-60 ℃, and then vacuum-dried at 80 ℃ for 6 hours, thus obtaining the surface-treated samarium-iron-nitrogen magnetic powder.
Step 2, coating with epoxy resin
The epoxy resin and the molding additive are dissolved in proper amount of ethyl acetate or acetone according to the proportion, and the dosage of the ethyl acetate or the acetone is limited by wetting magnetic powder; adding the samarium-iron-nitrogen magnetic powder subjected to surface treatment, fully stirring at 20-40 ℃, and then vacuum drying at 60 ℃ for 4 hours to obtain the epoxy resin coated samarium-iron-nitrogen magnetic powder.
Step 3, low-temperature crushing
The samarium-iron-nitrogen magnetic powder coated by epoxy resin is put into a low-temperature pulverizer, liquid argon is added to reduce the temperature to-80 ℃ to-100 ℃, and the low-temperature mechanical pulverizing operation is carried out on the magnetic powder.
Step 4, orientation molding
The epoxy resin/samarium-iron-nitrogen magnetic powder subjected to surface treatment and low-temperature pulverization was put into a molding die to be pressed, and an electromagnetic field was applied to perform orientation while pressing, the strength of the orientation field was 1.0 tesla, and the magnet was cured in a vacuum environment at 180 ℃ for 1 hour after the completion of the molding, and the results were as shown in table 1 below.
Comparative example 4.
The mass percentages of the various raw materials in this example are as follows:
bisphenol A type epoxy resin (1003) 2.5%
Samarium iron nitrogen powder 97%
Mixed molding aids 0.5%
Wherein the mass percentages of the plastic auxiliary agents are calculated according to the mass percentages of the epoxy resin, and the types and the mass percentages of the plastic auxiliary agents are as follows:
2402 phenolic resin 12.5%
2% of 2-ethyl-4-methylimidazole
Ethylene bis stearamide 5.5%
The crushing process is normal temperature mechanical crushing method
The process comprises the following steps:
step 1, samarium-iron-nitrogen magnetic powder surface treatment
The phosphate coupling agent and phosphoric acid are dissolved in absolute ethyl alcohol or methylbenzene according to a certain proportion to prepare a surface treating agent, and the dosage of the absolute ethyl alcohol or the acetone is limited by the condition that the magnetic powder can be completely coated; 100 parts of samarium-iron-nitrogen magnetic powder is added, fully stirred and uniformly mixed at 40-60 ℃, and then vacuum-dried at 80 ℃ for 6 hours, thus obtaining the surface-treated samarium-iron-nitrogen magnetic powder.
Step 2, coating with epoxy resin
The epoxy resin and the molding additive are dissolved in proper amount of ethyl acetate or acetone according to the proportion, and the dosage of the ethyl acetate or the acetone is limited by wetting magnetic powder; adding the samarium-iron-nitrogen magnetic powder subjected to surface treatment, fully stirring at 20-40 ℃, and then vacuum drying at 60 ℃ for 4 hours to obtain the epoxy resin coated samarium-iron-nitrogen magnetic powder.
Step 3, mechanical crushing
The samarium-iron-nitrogen magnetic powder coated by epoxy resin is put into a pulverizer to be pulverized at normal temperature.
Step 4, orientation molding
The epoxy resin/samarium-iron-nitrogen magnetic powder subjected to surface treatment and mechanical crushing is added into a forming die to be pressed, and an electromagnetic field is applied to orient the epoxy resin/samarium-iron-nitrogen magnetic powder while pressing, wherein the strength of the orientation field is 1.0 Tesla, and the magnet is cured for 1 hour in a vacuum environment at 180 ℃ after the die pressing is finished, and the results are shown in the following table 1.
Comparative example 5.
The mass percentages of the various raw materials in this example are as follows:
bisphenol A type epoxy resin (1003) 2.5%
Samarium iron nitrogen powder 97%
Mixed molding aids 0.5%
Wherein the mass percentages of the plastic auxiliary agents are calculated according to the mass percentages of the polyamide resin, and the types and the mass percentages of the plastic auxiliary agents are as follows:
2402 phenolic resin 12.5%
2% of 2-ethyl-4-methylimidazole
Ethylene bis stearamide 5.5%
The crushing process is normal temperature mechanical crushing process, and the pressing process is heating orientation pressing
The process comprises the following steps:
step 1, samarium-iron-nitrogen magnetic powder surface treatment
The phosphate coupling agent and phosphoric acid are dissolved in absolute ethyl alcohol or methylbenzene according to a certain proportion to prepare a surface treating agent, and the dosage of the absolute ethyl alcohol or the acetone is limited by the condition that the magnetic powder can be completely coated; 100 parts of samarium-iron-nitrogen magnetic powder is added, fully stirred and uniformly mixed at 40-60 ℃, and then vacuum-dried at 80 ℃ for 6 hours, thus obtaining the surface-treated samarium-iron-nitrogen magnetic powder.
Step 2, coating with epoxy resin
The epoxy resin and the molding additive are dissolved in proper amount of ethyl acetate or acetone according to the proportion, and the dosage of the ethyl acetate or the acetone is limited by wetting magnetic powder; adding the samarium-iron-nitrogen magnetic powder subjected to surface treatment, fully stirring at 20-40 ℃, and then vacuum drying at 60 ℃ for 4 hours to obtain the epoxy resin coated samarium-iron-nitrogen magnetic powder.
Step 3, mechanical crushing
The samarium-iron-nitrogen magnetic powder coated by epoxy resin is put into a pulverizer to be pulverized at normal temperature.
Step 4, orientation molding
The mold was heated to 180 ℃ in advance, and then the epoxy resin/samarium iron nitrogen magnetic powder subjected to surface treatment and mechanical crushing was added into the molding mold to be preheated for 1min and pressed, the orientation was performed by an external electromagnetic field while pressing, the orientation field strength was 1.0 tesla, and the magnet was cured in a vacuum environment at 180 ℃ for 1 hour after the molding was completed, and the results are shown in table 1 below.
TABLE 1 Components and test results in the examples
As can be seen from table 1, the liquid nitrogen is used as a cold source, and the magnetic powder treated by the epoxy resin is crushed by using a low-temperature crushing method, so that a molded product with higher performance can be obtained by pressing and orientation, and the application range of the epoxy resin-based composite material is widened.
Claims (9)
1. A molding method of anisotropic magnetic material is characterized in that:
step 1, performing phosphating and coupling composite treatment on the surface of samarium-iron-nitrogen magnetic powder, and coating a phosphating film and a coupling agent on the surface of the powder;
step 2, coating the samarium-iron-nitrogen magnetic powder subjected to surface treatment by adopting epoxy resin;
step 3, adding the samarium-iron-nitrogen magnetic powder coated by the epoxy resin into a low-temperature pulverizer to pulverize, so that the agglomerated magnetic powder particles are completely dispersed into a single particle state;
and 4, adding the single-particle magnetic powder into a forming die for pressing, applying an electromagnetic field for orientation while pressing, wherein the strength of the orientation field is 1-3 Tesla, and curing the magnet in a vacuum environment at 150-190 ℃ after the die pressing is finished.
2. A method of molding an anisotropic magnetic material as in claim 1, wherein: the step 1 specifically comprises the following steps:
the phosphate coupling agent and phosphoric acid are dissolved in absolute ethyl alcohol or methylbenzene according to a certain proportion to prepare a surface treating agent, and the dosage of the absolute ethyl alcohol or the acetone is limited by the condition that the magnetic powder can be completely coated;
100 parts of samarium-iron-nitrogen magnetic powder is added, fully stirred and uniformly mixed at 40-60 ℃, and then vacuum-dried to obtain the surface-treated samarium-iron-nitrogen magnetic powder.
3. A method of molding an anisotropic magnetic material as in claim 1, wherein: the step 2 is specifically as follows:
epoxy resin and a molding additive are dissolved in proper amount of ethyl acetate or acetone according to the proportion, and the dosage of the ethyl acetate or the acetone is limited by wetting magnetic powder;
adding the samarium-iron-nitrogen magnetic powder subjected to surface treatment, fully stirring at 20-40 ℃, and then vacuum drying to obtain the epoxy resin coated samarium-iron-nitrogen magnetic powder.
4. A method of molding an anisotropic magnetic material according to any of claims 1 to 3, wherein: the chemical components of samarium iron nitrogen are as follows: sm accounts for 20wt.% to 30wt.%, fe accounts for 60wt.% to 80wt.%, and N accounts for 2wt.% to 4wt.%.
5. A method of molding an anisotropic magnetic material as in claim 1, wherein: the epoxy resin has an epoxy equivalent of 100-1000, and the epoxy resin is any one or more of E44, E55, 1003, 1004 and C704.
6. A method of molding an anisotropic magnetic material as in claim 2, wherein: the phosphate coupling agent and the phosphoric acid are respectively 0.5% and 1% of the mass of the magnetic powder.
7. A method of molding an anisotropic magnetic material as in claim 3, wherein: the molding aid is a mixture of a hardener, an accelerator and a lubricant, and the dosage of the molding aid is 15-30%, 1-10% and 5-20% of the mass of the epoxy resin respectively.
8. The method for molding an anisotropic magnetic material according to claim 7, wherein: the hardener is phenolic resin and is selected from one or more of 2402, 2123, 7522E, PF-8211 and PF-8217; the accelerator is an amine compound and is selected from one or more of 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole and 1- (2-hydroxy-3-phenoxypropyl) -2-ethyl-4-methylimidazole; the lubricant is a mixture of calcium stearate, zinc stearate, oleamide, ethylene bis stearamide and polyethylene wax.
9. A method of molding an anisotropic magnetic material as in claim 1, wherein: the cold source adopted by the low-temperature crushing is one or more of liquid nitrogen, liquid argon and liquid helium, and the treatment method is one of low-temperature crushing, normal-temperature/low-temperature crushing, electric impact crushing and air expansion refrigeration low-temperature crushing.
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