CN113223847A - Preparation method of neodymium iron boron magnetic material and magnetic material prepared by adopting method - Google Patents
Preparation method of neodymium iron boron magnetic material and magnetic material prepared by adopting method Download PDFInfo
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- CN113223847A CN113223847A CN202110463517.4A CN202110463517A CN113223847A CN 113223847 A CN113223847 A CN 113223847A CN 202110463517 A CN202110463517 A CN 202110463517A CN 113223847 A CN113223847 A CN 113223847A
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- magnetic material
- iron boron
- neodymium iron
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- neodymium
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- 239000000696 magnetic material Substances 0.000 title claims abstract description 133
- 229910001172 neodymium magnet Inorganic materials 0.000 title claims abstract description 119
- QJVKUMXDEUEQLH-UHFFFAOYSA-N [B].[Fe].[Nd] Chemical compound [B].[Fe].[Nd] QJVKUMXDEUEQLH-UHFFFAOYSA-N 0.000 title claims abstract description 117
- 238000000034 method Methods 0.000 title claims abstract description 28
- 238000002360 preparation method Methods 0.000 title claims abstract description 18
- 238000003723 Smelting Methods 0.000 claims abstract description 54
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims abstract description 50
- 239000001257 hydrogen Substances 0.000 claims abstract description 49
- 229910052739 hydrogen Inorganic materials 0.000 claims abstract description 49
- 239000000843 powder Substances 0.000 claims abstract description 44
- 238000001816 cooling Methods 0.000 claims abstract description 39
- 239000002994 raw material Substances 0.000 claims abstract description 34
- 229910052751 metal Inorganic materials 0.000 claims abstract description 33
- 239000002184 metal Substances 0.000 claims abstract description 33
- 239000007788 liquid Substances 0.000 claims abstract description 28
- 238000005496 tempering Methods 0.000 claims abstract description 27
- GWXLDORMOJMVQZ-UHFFFAOYSA-N cerium Chemical compound [Ce] GWXLDORMOJMVQZ-UHFFFAOYSA-N 0.000 claims abstract description 22
- 229910052684 Cerium Inorganic materials 0.000 claims abstract description 21
- 229910000583 Nd alloy Inorganic materials 0.000 claims abstract description 21
- RKLPWYXSIBFAJB-UHFFFAOYSA-N [Nd].[Pr] Chemical compound [Nd].[Pr] RKLPWYXSIBFAJB-UHFFFAOYSA-N 0.000 claims abstract description 21
- 238000005245 sintering Methods 0.000 claims abstract description 18
- 230000005389 magnetism Effects 0.000 claims abstract description 13
- 239000000463 material Substances 0.000 claims abstract description 13
- 238000000465 moulding Methods 0.000 claims abstract description 7
- 238000005303 weighing Methods 0.000 claims abstract description 7
- 239000000155 melt Substances 0.000 claims abstract description 4
- 229910000640 Fe alloy Inorganic materials 0.000 claims description 20
- 238000010438 heat treatment Methods 0.000 claims description 20
- FPAFDBFIGPHWGO-UHFFFAOYSA-N dioxosilane;oxomagnesium;hydrate Chemical compound O.[Mg]=O.[Mg]=O.[Mg]=O.O=[Si]=O.O=[Si]=O.O=[Si]=O.O=[Si]=O FPAFDBFIGPHWGO-UHFFFAOYSA-N 0.000 claims description 19
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 18
- ZSOJHTHUCUGDHS-UHFFFAOYSA-N gadolinium iron Chemical compound [Fe].[Gd] ZSOJHTHUCUGDHS-UHFFFAOYSA-N 0.000 claims description 18
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 15
- 239000010949 copper Substances 0.000 claims description 15
- 238000010521 absorption reaction Methods 0.000 claims description 14
- 229910052802 copper Inorganic materials 0.000 claims description 14
- 238000011282 treatment Methods 0.000 claims description 13
- 229910045601 alloy Inorganic materials 0.000 claims description 11
- 239000000956 alloy Substances 0.000 claims description 11
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 claims description 10
- 239000010941 cobalt Substances 0.000 claims description 10
- 229910017052 cobalt Inorganic materials 0.000 claims description 10
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims description 10
- 239000002245 particle Substances 0.000 claims description 10
- 229910052726 zirconium Inorganic materials 0.000 claims description 10
- 229910052742 iron Inorganic materials 0.000 claims description 9
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 8
- 229910052782 aluminium Inorganic materials 0.000 claims description 6
- 238000007599 discharging Methods 0.000 claims description 5
- 238000002074 melt spinning Methods 0.000 claims description 4
- 238000003825 pressing Methods 0.000 claims description 4
- 238000006356 dehydrogenation reaction Methods 0.000 claims description 3
- 150000002431 hydrogen Chemical class 0.000 claims description 3
- 239000011261 inert gas Substances 0.000 claims description 3
- 238000002156 mixing Methods 0.000 claims description 3
- 238000000462 isostatic pressing Methods 0.000 claims description 2
- 230000002829 reductive effect Effects 0.000 abstract description 24
- 238000004321 preservation Methods 0.000 abstract description 20
- UIWYJDYFSGRHKR-UHFFFAOYSA-N gadolinium atom Chemical compound [Gd] UIWYJDYFSGRHKR-UHFFFAOYSA-N 0.000 abstract description 5
- 229910001021 Ferroalloy Inorganic materials 0.000 abstract description 3
- 229910052688 Gadolinium Inorganic materials 0.000 abstract description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 34
- 230000000052 comparative effect Effects 0.000 description 34
- 229910052786 argon Inorganic materials 0.000 description 17
- 239000000047 product Substances 0.000 description 16
- 230000009286 beneficial effect Effects 0.000 description 15
- 238000011049 filling Methods 0.000 description 14
- 238000012360 testing method Methods 0.000 description 12
- 230000000694 effects Effects 0.000 description 11
- 239000007790 solid phase Substances 0.000 description 10
- 239000012071 phase Substances 0.000 description 9
- 238000004519 manufacturing process Methods 0.000 description 8
- 230000009467 reduction Effects 0.000 description 8
- 239000013078 crystal Substances 0.000 description 7
- 229910052761 rare earth metal Inorganic materials 0.000 description 7
- 150000002910 rare earth metals Chemical class 0.000 description 7
- 241001062472 Stokellia anisodon Species 0.000 description 6
- 239000012856 weighed raw material Substances 0.000 description 6
- 239000007789 gas Substances 0.000 description 5
- 238000000227 grinding Methods 0.000 description 5
- 229910052779 Neodymium Inorganic materials 0.000 description 4
- 238000002844 melting Methods 0.000 description 4
- 230000008018 melting Effects 0.000 description 4
- QEFYFXOXNSNQGX-UHFFFAOYSA-N neodymium atom Chemical compound [Nd] QEFYFXOXNSNQGX-UHFFFAOYSA-N 0.000 description 4
- 238000010791 quenching Methods 0.000 description 4
- 238000004891 communication Methods 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 230000003247 decreasing effect Effects 0.000 description 3
- 238000004134 energy conservation Methods 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 230000001737 promoting effect Effects 0.000 description 3
- -1 Gadolinium iron Copper Chemical compound 0.000 description 2
- 229910000748 Gd alloy Inorganic materials 0.000 description 2
- 230000002411 adverse Effects 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 238000005265 energy consumption Methods 0.000 description 2
- 230000002349 favourable effect Effects 0.000 description 2
- 238000011534 incubation Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 230000000171 quenching effect Effects 0.000 description 2
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 1
- 229910000636 Ce alloy Inorganic materials 0.000 description 1
- 241000282376 Panthera tigris Species 0.000 description 1
- LAIPFIBOCSBYSV-UHFFFAOYSA-N [B].[Fe].[Ce] Chemical compound [B].[Fe].[Ce] LAIPFIBOCSBYSV-UHFFFAOYSA-N 0.000 description 1
- YWYWWXBZMKGRBW-UHFFFAOYSA-N [Fe].[Pr].[Nd] Chemical compound [Fe].[Pr].[Nd] YWYWWXBZMKGRBW-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 229910052796 boron Inorganic materials 0.000 description 1
- RKTYLMNFRDHKIL-UHFFFAOYSA-N copper;5,10,15,20-tetraphenylporphyrin-22,24-diide Chemical compound [Cu+2].C1=CC(C(=C2C=CC([N-]2)=C(C=2C=CC=CC=2)C=2C=CC(N=2)=C(C=2C=CC=CC=2)C2=CC=C3[N-]2)C=2C=CC=CC=2)=NC1=C3C1=CC=CC=C1 RKTYLMNFRDHKIL-UHFFFAOYSA-N 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000005496 eutectics Effects 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 230000017525 heat dissipation Effects 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 229910000765 intermetallic Inorganic materials 0.000 description 1
- 230000005415 magnetization Effects 0.000 description 1
- 238000003801 milling Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000009659 non-destructive testing Methods 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 229910052623 talc Inorganic materials 0.000 description 1
- 235000012222 talc Nutrition 0.000 description 1
- 239000000454 talc Substances 0.000 description 1
Classifications
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
- H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
- H01F41/0253—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing permanent magnets
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
- H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
- H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
- H01F1/047—Alloys characterised by their composition
- H01F1/053—Alloys characterised by their composition containing rare earth metals
- H01F1/055—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
- H01F1/057—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
- H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
- H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
- H01F1/047—Alloys characterised by their composition
- H01F1/053—Alloys characterised by their composition containing rare earth metals
- H01F1/055—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
- H01F1/057—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
- H01F1/0571—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes
- H01F1/0573—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes obtained by reduction or by hydrogen decrepitation or embrittlement
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
- H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
- H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
- H01F1/047—Alloys characterised by their composition
- H01F1/053—Alloys characterised by their composition containing rare earth metals
- H01F1/055—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
- H01F1/057—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
- H01F1/0571—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes
- H01F1/0575—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes pressed, sintered or bonded together
- H01F1/0576—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes pressed, sintered or bonded together pressed, e.g. hot working
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- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
- H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
- H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
- H01F1/047—Alloys characterised by their composition
- H01F1/053—Alloys characterised by their composition containing rare earth metals
- H01F1/055—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
- H01F1/057—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
- H01F1/0571—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes
- H01F1/0575—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes pressed, sintered or bonded together
- H01F1/0577—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes pressed, sintered or bonded together sintered
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- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
- H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
- H01F41/0253—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing permanent magnets
- H01F41/0266—Moulding; Pressing
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- Engineering & Computer Science (AREA)
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- Chemical & Material Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Hard Magnetic Materials (AREA)
Abstract
The application relates to the field of magnetic materials, in particular to a preparation method of a neodymium iron boron magnetic material and the magnetic material prepared by the method. The preparation method of the neodymium iron boron magnetic material comprises the following steps: weighing raw materials; smelting, namely pre-cooling the smelting liquid, preserving heat and then throwing to obtain a throwing strip sheet; carrying out hydrogen crushing, powder making and molding orientation on the melt-spun sheet to obtain a blank; and sintering and tempering the blank to obtain the neodymium iron boron magnetic material. The neodymium iron boron magnetic material is prepared by the preparation method. And the magnet is made of the neodymium iron boron magnetic material. This application adopts metal cerium and gadolinium ferroalloy part to replace praseodymium neodymium alloy, carries out precooling and heat preservation to it before the melt is carried out the melt-spun simultaneously. Through the cooperation implementation of above-mentioned measure, not only reduced neodymium iron boron magnetism nature material's cost, guaranteed simultaneously that neodymium iron boron magnetism nature material has good performance, can satisfy the requirement of in-service use.
Description
Technical Field
The application relates to the field of magnetic materials, in particular to a preparation method of a neodymium iron boron magnetic material and the magnetic material prepared by the method.
Background
The neodymium-iron-boron magnetic material is based on a tetragonal crystal composed of neodymium, iron and boron, and has larger magnetic energy and coercive force compared with the common magnetic material. The material is widely applied to high-end industries such as communication, medical treatment, electronics and the like.
In the related art, the ndfeb magnetic material uses metallic iron, praseodymium-neodymium alloy, ferroboron alloy, etc. as basic raw materials, and adds metallic copper, metallic aluminum, metallic cobalt, metallic zirconium, etc. as auxiliary raw materials. Mixing the raw materials, and putting the mixture into a vacuum smelting furnace for smelting; and then directly carrying out melt spinning treatment on the obtained smelting liquid. And then carrying out hydrogen crushing, powder making, molding orientation, sintering, tempering and other treatments on the melt-spun product to obtain the neodymium iron boron magnetic material.
However, the demand for neodymium is rapidly increased, which leads to the continuous increase of the price of the current praseodymium-neodymium alloy, and the price reaches 722000-727000/ton, thereby greatly increasing the cost of the neodymium-iron-boron magnetic material and increasing the use pressure of the neodymium-iron-boron magnetic material.
Disclosure of Invention
In order to reduce the cost of the neodymium iron boron magnetic material, the application provides a preparation method of the neodymium iron boron magnetic material and the magnetic material prepared by the method.
In a first aspect, the present application provides a method for preparing a neodymium iron boron magnetic material, which adopts the following technical scheme:
the preparation method of the neodymium iron boron magnetic material comprises the following steps:
weighing the following raw materials in parts by weight: 367 parts of metal iron 360-116 parts, 200 parts of praseodymium-neodymium alloy 187-200 parts, 28-34 parts of ferroboron alloy, 12-20 parts of metal cerium, 6-12 parts of gadolinium-iron alloy, 0.8-1.5 parts of metal copper, 3.2-5.5 parts of metal aluminum, 2-3.5 parts of metal cobalt and 1-1.8 parts of metal zirconium;
smelting the raw materials at the temperature of at least 1400 ℃, then cooling the smelting liquid to 1300-1350 ℃, and preserving heat for at least 5 min; then, melt-spinning the melt to obtain melt-spun pieces;
carrying out hydrogen crushing, powder making and molding orientation on the melt-spun sheet to obtain a blank;
and sintering and tempering the blank to obtain the neodymium iron boron magnetic material.
By adopting the technical scheme, the cerium metal is a rare earth metal with the price of 30000-31500/ton, and the cerium metal can replace part of praseodymium-neodymium alloy, so that the cost of the prepared neodymium-iron-boron magnetic material can be greatly reduced. Because the rapid growth of each group of crystal grains in the system can be inhibited, the addition of the gadolinium-iron alloy can improve the coercive force of the neodymium-iron-boron magnetic material and compensate the decrease of the coercive force of the neodymium-iron-boron magnetic material caused by the addition of cerium; meanwhile, the gadolinium-iron alloy is also a rare earth metal with a price lower than that of the praseodymium-neodymium alloy, so that part of the praseodymium-neodymium alloy can be replaced by the gadolinium-iron alloy, and the cost of the neodymium-iron-boron magnetic material is reduced. In addition, the pre-cooling and heat preservation are carried out on the smelting liquid before the strip throwing operation, so that solid phase nuclei are formed in the smelting liquid, the solid phase nuclei are beneficial to promoting the growth of the main phase of the neodymium iron boron magnetic material, the volume fraction of the main phase of the neodymium iron boron magnetic material can be improved, the residual magnetism of the neodymium iron boron magnetic material is improved, and the loss of the residual magnetism of the neodymium iron boron magnetic material caused by the addition of cerium is compensated. Therefore, through the compatibility of the raw materials and the matching selection of the preparation method, the cost of the neodymium iron boron magnetic material is greatly reduced, and the ideal magnetic performance can be still obtained.
Optionally, after sintering, the blank is tempered at the temperature of 850-930 ℃, and is subjected to heat preservation for at least 2 hours; then cooling the blank to 580-650 ℃, preserving heat for at least 1h, then cooling to 450-530 ℃, preserving heat for at least 1h, and then cooling to room temperature and discharging.
By adopting the technical scheme, tempering can be carried out through the temperature of the material during heat preservation, so that multiple tempering can be realized through one-time heating, energy consumed by heating is greatly saved, production cost is reduced, and energy conservation and emission reduction are realized. Meanwhile, the coercive force of the neodymium iron boron magnetic material can be improved through multiple times of tempering.
Optionally, the blank is vacuum sintered at a temperature of 1000-.
By adopting the technical scheme, the neodymium iron boron magnetic material obtained after the blank is sintered has ideal magnetic performance.
Optionally, the step of hydrogen breaking the melt-spun piece comprises: placing the melt-spun sheet in a hydrogen atmosphere, enabling the melt-spun sheet to absorb hydrogen for at least 1h to obtain a hydrogen breaking product, and controlling the hydrogen absorption pressure to be 0.7-0.9MPa and the hydrogen absorption temperature to be 350-500 ℃; and then heating the hydrogen-broken product to at least 550 ℃ for dehydrogenation treatment.
By adopting the technical scheme, the melt-spun sheet can be changed into a hydrogen broken product with a loose structure through hydrogen breakage, so that the efficiency of the subsequent powder making step is improved conveniently, and the production cost is reduced.
Optionally, the dehydrogenated hydrogen breaking product is introduced into an airflow mill to be broken to obtain fine powder, and the particle size of the fine powder is controlled to be 3-6 μm.
By adopting the technical scheme, the fine powder with proper particle size can reduce agglomeration among the fine powder and improve the orientation degree of the fine powder after molding orientation; meanwhile, the compactness of the pressed neodymium iron boron magnetic material can be ensured.
Optionally, talcum powder is mixed into the fine powder, and then the fine powder is placed in a magnetic field for orientation and pressing to obtain a blank; and then carrying out isostatic pressing on the blank.
By adopting the technical scheme, the talcum powder can play a role of a flow aid and improve the flowability of the fine powder, so that the fine powder has higher orientation degree after molding orientation.
Optionally, the addition amount of the talcum powder is 1-3% of the mass of the fine powder.
By adopting the technical scheme, the problem of unobvious flow aiding effect caused by insufficient talcum powder can be solved, and the problem of resistance brought to the movement of fine powder by excessive talcum powder can also be solved.
Optionally, the raw materials are protected by inert gas during smelting.
By adopting the technical scheme, the possibility of oxidizing the raw materials by oxygen is reduced and the performance of the neodymium iron boron magnetic material is ensured under the protection of inert gas.
In a second aspect, the present application provides a neodymium iron boron magnetic material, which adopts the following technical scheme:
the neodymium iron boron magnetic material is prepared by the preparation method of the neodymium iron boron magnetic material.
By adopting the technical scheme, the neodymium iron boron magnetic material has lower production cost and ideal magnetic performance.
In a third aspect, the present application provides a magnet, which adopts the following technical solution:
and the magnet is made of the neodymium iron boron magnetic material.
By adopting the technical scheme, the magnet has good magnetism and low cost, and can be applied to industries such as communication, medical treatment and electronics.
In summary, the present application has at least one of the following beneficial technical effects:
1. this application adopts metal cerium and gadolinium ferroalloy part to replace praseodymium neodymium alloy, carries out precooling and heat preservation to it before the melt is carried out the melt-spun simultaneously. Through the matching implementation of the measures, the cost of the neodymium iron boron magnetic material is reduced; meanwhile, the neodymium iron boron magnetic material is ensured to have good performance, and the actual use requirement can be met.
2. According to the tempering furnace, through the operation of multiple times of heat preservation during cooling after tempering, tempering is performed by utilizing the temperature of the material, so that the effect of one-time heating and multiple times of tempering is realized, the energy consumption caused by heating is reduced, the production cost is saved, and the realization of energy conservation and emission reduction is facilitated. Meanwhile, the operation of tempering for many times is beneficial to improving the coercive force of the neodymium iron boron magnetic material.
3. The application is favorable for reducing the movement resistance among fine powder and improving the flowability of the fine powder by adding the talcum powder, so that the orientation degree of the fine powder after molding orientation can be improved, and the remanence of the obtained neodymium-iron-boron magnetic material is favorably improved.
Detailed Description
Because the praseodymium-neodymium alloy of neodymium provided in the neodymium-iron-boron magnetic material is expensive, the cost of the neodymium-iron-boron magnetic material is increased. Therefore, how to reduce the cost of the ndfeb magnetic material is an urgent problem to be solved. The price of the metal cerium is relatively low, and the expensive praseodymium-neodymium alloy can be partially replaced, so that the raw material cost of the neodymium-iron-boron magnetic material is reduced. However, the addition of cerium can simultaneously reduce the coercive force, remanence and other magnetic properties of the neodymium iron boron magnetic material. In the research process, the applicant finds that the gadolinium-iron alloy can improve the coercive force of the neodymium-iron-boron magnetic material; and the gadolinium-iron alloy is used as a rare earth metal alloy, and the price is lower than that of the praseodymium-neodymium alloy, so that the gadolinium-iron alloy is adopted to replace part of the praseodymium-neodymium alloy, and the cost can be reduced. Meanwhile, the applicant also finds that the pre-cooling and heat preservation of the smelting liquid before the melt-spinning are beneficial to forming solid phase nuclei in the smelting liquid, and the solid phase nuclei are beneficial to promoting the growth of the main phase of the neodymium iron boron magnetic material, so that the residual magnetism of the neodymium iron boron magnetic material can be improved. Therefore, through the matching implementation of the measures, the cost of the neodymium iron boron magnetic material can be obviously reduced, and the magnetic performance of the neodymium iron boron magnetic material can be ensured not to be greatly damaged. The invention is based on this.
The present application will be described in further detail with reference to examples.
Example 1
The embodiment of the application discloses a preparation method of a neodymium iron boron magnetic material, which comprises the following steps:
(1) accurately weighing raw materials: 360kg of metallic iron, 200kg of praseodymium-neodymium alloy, 28kg of ferroboron alloy, 15kg of metallic cerium, 10kg of gadolinium-iron alloy, 0.8kg of metallic copper, 3.2kg of metallic aluminum, 2kg of metallic cobalt and 1kg of metallic zirconium.
Wherein, the metal iron, the praseodymium-neodymium alloy and the ferroboron alloy are basic raw materials for forming the neodymium-iron-boron magnetic material. The metal cerium, gadolinium and iron alloy are rare earth metal/alloy, and the addition of the metal cerium and gadolinium and iron alloy is used for replacing part of high-price praseodymium-neodymium alloy, so that the cost of the neodymium-iron-boron magnetic material is reduced; meanwhile, the addition of the gadolinium-iron alloy is also beneficial to improving the coercive force of the neodymium-iron-boron magnetic material. The addition of the metal copper is beneficial to improving the crystal boundary microstructure and improving the coercive force of the neodymium iron boron magnetic material. The addition of the metal aluminum is beneficial to refining crystal grains and improving the overall coercive force of the material. The addition of the metal cobalt is beneficial to improving the Curie temperature and reducing the reversible temperature coefficient, thereby playing a role in improving the temperature stability of the neodymium iron boron magnetic material. The addition of the metal zirconium can play a role in inhibiting the growth of crystal grains and improving the microstructure of the material.
(2) Placing the weighed raw materials in a vacuum smelting furnace, and vacuumizing the vacuum smelting furnace to reduce the pressure in the furnace to be below 0.1 Pa; filling argon into the vacuum smelting furnace; after argon filling is finished, heating a vacuum smelting furnace to 1400 ℃ to smelt the raw materials, and fully melting the metal raw materials to obtain a smelting solution; then, pre-cooling the smelting liquid to 1300 ℃, and preserving heat for 5 min; then, the molten liquid is poured on a water-cooled copper roller rotating at the linear speed of 1.5m/s, and the melt-spun sheet with the thickness of 0.25mm is obtained after cooling.
The stable performance of the argon can protect the raw materials during smelting, so that the possibility of oxidation of the raw materials is reduced; meanwhile, the heat dissipation loss of the raw material melt before solidification can be stabilized, and the stability of the material structure is improved.
Pre-cooling the smelting liquid and preserving heat to form solid phase nuclei in the smelting liquid; in the subsequent cooling process, the solid phase nucleus is used as a base point, which is beneficial to promoting the growth of the main phase of the neodymium iron boron magnetic material, thereby being beneficial to improving the volume fraction of the finally formed main phase of the neodymium iron boron magnetic material and further being beneficial to improving the residual magnetism of the neodymium iron boron magnetic material.
(3) Putting the strip throwing sheet into a hydrogen crushing furnace, and vacuumizing the hydrogen crushing furnace to reduce the pressure in the furnace to be below 0.1 Pa; filling hydrogen into the hydrogen crushing furnace, enabling the melt-spun sheet to absorb hydrogen for 1 hour to obtain a hydrogen crushing product, and controlling the hydrogen absorption pressure to be 0.9MPa and the hydrogen absorption temperature to be 500 ℃; after the hydrogen absorption is finished, the temperature of the hydrogen crushing furnace is raised to 550 ℃, so that the hydrogen breaking product is dehydrogenated.
Because the rare earth intermetallic compound has the characteristic of hydrogen absorption, hydrogen gas can enter along the neodymium-rich phase thin layer after meeting the melt-spun piece and can expand, burst and break. Therefore, the melt-spun sheet can be changed into a loose hydrogen broken product, and a good foundation is provided for subsequent milling.
(4) Introducing the dehydrogenated hydrogen breaking product into an airflow mill, driving the hydrogen breaking product to move at a high speed by using grinding gas, and crushing the hydrogen breaking product through high-speed collision of the hydrogen breaking product to obtain fine powder with the particle size of 3-6 mu m; wherein the pressure of the grinding gas of the jet mill is controlled to be 0.5 MPa.
(5) Weighing 6.2kg of talcum powder (purchased from Mill of Tung Town Long talc powder of tiger head in Ri, Lyzhou, with the balance of 325 meshes being less than 0.5%), uniformly mixing the talcum powder and the fine powder obtained in the step (4) in a mixer, putting the mixture of the talcum powder and the fine powder into a forming magnetic field press, and under the action of an orientation magnetic field with the magnetic field intensity of 2.0T, orienting the fine powder and pressing and forming the fine powder and the talcum powder together to obtain a blank. And then, an isostatic press is used for carrying out secondary pressing on the blank under the condition that the isostatic pressure is 180MPa, so that the structure of the blank is more compact.
The talcum powder can play a role of a flow aid, improve the fluidity of the fine powder, reduce the movement resistance of the fine powder, and facilitate the distribution and arrangement of the fine powder along an oriented magnetic field, so that the orientation degree of the fine powder is improved, and the residual magnetism of the final neodymium iron boron magnetic material is improved.
(6) Placing the blank in a vacuum sintering furnace, and vacuumizing the vacuum sintering furnace to reduce the pressure in the furnace to be below 0.1 Pa; heating to 1000 ℃ and sintering for 6 h.
(7) Naturally cooling the blank to room temperature after sintering, then tempering at 850 ℃, and preserving heat for 8 hours; then introducing normal-temperature argon to quench the blank to 580 ℃, and preserving heat for 6 hours; then introducing normal temperature argon to quench the blank to 450 ℃, and preserving heat for 6 hours; and then cooling to room temperature and discharging to obtain the neodymium iron boron magnetic material.
The design of multiple times of heat preservation is adopted during temperature reduction, and the material can realize tempering treatment through the temperature of the material during heat preservation, thereby realizing the effect of one-time temperature rise and multiple times of tempering. Therefore, the coercive force of the neodymium iron boron magnetic material is favorably improved; meanwhile, because the temperature is raised for one time, energy can be greatly saved, the production cost is favorably reduced, and energy conservation and emission reduction are realized.
The embodiment of the application also discloses a neodymium iron boron magnetic material prepared by the preparation method, which has the characteristics of ideal magnetic property and lower cost.
In addition, the embodiment of the application also discloses a magnet which is made of the neodymium iron boron magnetic material and can be used in the industries of communication, medical treatment, electronics and the like.
Examples 2 to 18
As shown in Table 1, examples 2-18 are substantially the same as example 1 except that: the raw materials weighed in the step (1) have different proportions.
TABLE 1 feed proportioning in step (1) of examples 1-18
| Serial number | Iron | Praseodymium neodymium | Ferroboron | Cerium (Ce) | Gadolinium iron | Copper (Cu) | Aluminium | Cobalt | Zirconium |
| Example 1 | 360 | 200 | 28 | 15 | 10 | 0.8 | 3.2 | 2 | 1 |
| Example 2 | 362 | 196 | 30 | 15 | 10 | 0.8 | 3.2 | 2 | 1 |
| Example 3 | 364 | 192 | 32 | 15 | 10 | 0.8 | 3.2 | 2 | 1 |
| Example 4 | 367 | 187 | 34 | 15 | 10 | 0.8 | 3.2 | 2 | 1 |
| Example 5 | 364 | 195 | 32 | 12 | 10 | 0.8 | 3.2 | 2 | 1 |
| Example 6 | 364 | 190 | 32 | 17 | 10 | 0.8 | 3.2 | 2 | 1 |
| Example 7 | 364 | 187 | 32 | 20 | 10 | 0.8 | 3.2 | 2 | 1 |
| Example 8 | 364 | 196 | 32 | 15 | 6 | 0.8 | 3.2 | 2 | 1 |
| Example 9 | 364 | 194 | 32 | 15 | 8 | 0.8 | 3.2 | 2 | 1 |
| Example 10 | 364 | 190 | 32 | 15 | 12 | 0.8 | 3.2 | 2 | 1 |
| Example 11 | 363.6 | 192 | 32 | 15 | 10 | 1.2 | 3.2 | 2 | 1 |
| Example 12 | 363.3 | 192 | 32 | 15 | 10 | 1.5 | 3.2 | 2 | 1 |
| Example 13 | 362 | 192 | 32 | 15 | 10 | 1.2 | 4.8 | 2 | 1 |
| Example 14 | 361.3 | 192 | 32 | 15 | 10 | 1.2 | 5.5 | 2 | 1 |
| Example 15 | 361 | 192 | 32 | 15 | 10 | 1.2 | 4.8 | 3 | 1 |
| Example 16 | 360.5 | 192 | 32 | 15 | 10 | 1.2 | 4.8 | 3.5 | 1 |
| Example 17 | 360.5 | 192 | 32 | 15 | 10 | 1.2 | 4.8 | 3 | 1.5 |
| Example 18 | 360.2 | 192 | 32 | 15 | 10 | 1.2 | 4.8 | 3 | 1.8 |
Note: the unit of the addition of each raw material component is kg.
Examples 19 to 25
As shown in Table 2, examples 19-25 are substantially the same as example 17 except that: the control parameters in step (2) are different.
TABLE 2 different control parameters in step (2) of examples 17, 19-25
| Serial number | Melting temperature/. degree.C | Pre-cooling temperature/DEG C of smelting liquid | Holding time/min of smelting liquid |
| Example 17 | 1400 | 1300 | 5 |
| Example 19 | 1500 | 1300 | 5 |
| Example 20 | 1600 | 1300 | 5 |
| Example 21 | 1500 | 1320 | 5 |
| Example 22 | 1500 | 1350 | 5 |
| Example 23 | 1500 | 1320 | 10 |
| Example 24 | 1500 | 1320 | 12 |
| Example 25 | 1500 | 1320 | 15 |
Example 26
This example is substantially the same as example 24 except that: the control parameters in step (3) are different.
The method specifically comprises the following steps: and (3): putting the strip throwing sheet into a hydrogen crushing furnace, and vacuumizing the hydrogen crushing furnace to reduce the pressure in the furnace to be below 0.1 Pa; filling hydrogen into the hydrogen crushing furnace, enabling the melt-spun sheet to absorb hydrogen for 5 hours to obtain a hydrogen crushing product, and controlling the hydrogen absorption pressure to be 0.7MPa and the hydrogen absorption temperature to be 350 ℃; after the hydrogen absorption is finished, the temperature of the hydrogen crushing furnace is raised to 650 ℃, so that the hydrogen breaking product is dehydrogenated.
Example 27
This example is substantially the same as example 24 except that: the particle size of the fine powder in the step (4) is controlled to be 1-2.5 mu m.
Example 28
This example is substantially the same as example 24 except that: the particle size of the fine powder in the step (4) is controlled to be 6.5-8 mu m.
Example 29
This example is substantially the same as example 24 except that: the pressure of the grinding gas in the step (4) is 0.7 MPa.
Example 30
This example is substantially the same as example 24 except that: the addition amount of the talcum powder in the step (5) is 12.4 kg.
Example 31
This example is substantially the same as example 24 except that: the addition amount of the talc powder in the step (5) was 18.6 kg.
Example 32
This embodiment is substantially the same as embodiment 30 except that: the control parameters in step (6) are different.
The method specifically comprises the following steps: and (6): placing the blank in a vacuum sintering furnace, and vacuumizing the vacuum sintering furnace to reduce the pressure in the furnace to be below 0.1 Pa; heating to 1070 deg.C and sintering for 3 h.
Examples 33 to 35
As shown in Table 3, examples 33-35 are substantially the same as example 30, except that: the control parameters in step (7) are different.
TABLE 3 different control parameters in step (7) of examples 30, 33-35
| Serial number | Tempering temperature/. degree.C | Tempering time/h | The first heat preservation temperature/DEG C during temperature reduction | First heat preservation time/h during temperature reduction | The second heat preservation temperature/DEG C during temperature reduction | Second heat preservation time/h during temperature reduction |
| Example 30 | 850 | 8 | 580 | 6 | 450 | 6 |
| Example 33 | 930 | 2 | 580 | 6 | 450 | 6 |
| Example 34 | 930 | 2 | 650 | 1 | 450 | 6 |
| Example 35 | 930 | 2 | 650 | 1 | 530 | 1 |
Example 36
This embodiment is substantially the same as embodiment 30 except that: the step (7) is different.
The method specifically comprises the following steps:
and (7): naturally cooling the blank to room temperature after sintering, then heating to 850 ℃ for first tempering treatment, and keeping the temperature for 8 hours; after the heat preservation is finished, quenching the blank to room temperature through normal temperature argon, then heating to 580 ℃ for secondary tempering treatment, and preserving heat for 6 hours; after the heat preservation is finished, the blank is cooled to the room temperature again through normal-temperature argon quenching, then the temperature is raised to 450 ℃ for the third tempering treatment, and the heat preservation is carried out for 6 hours; and finally, cooling the blank to room temperature, and discharging to obtain the neodymium iron boron magnetic material.
Example 37
This embodiment is substantially the same as embodiment 30, with the following features: the step (7) is different.
The method specifically comprises the following steps:
and (7): naturally cooling the blank to room temperature after sintering, then heating to 850 ℃ for tempering treatment, and keeping the temperature for 8 hours; and cooling the blank to room temperature, and discharging to obtain the neodymium iron boron magnetic material.
Comparative example 1
This comparative example is substantially the same as example 3, with the main differences being: in step (1) of this comparative example, no cerium metal and gadolinium-iron alloy were added; in the step (2), the smelting liquid is not pre-cooled and heat-preserved.
The method specifically comprises the following steps:
(1) accurately weighing raw materials: 364kg of metallic iron, 217kg of praseodymium-neodymium alloy, 32kg of ferroboron alloy, 0.8kg of metallic copper, 3.2kg of metallic aluminum, 2kg of metallic cobalt and 1kg of metallic zirconium.
(2) Placing the weighed raw materials in a vacuum smelting furnace, and vacuumizing the vacuum smelting furnace to reduce the pressure in the furnace to be below 0.1 Pa; filling argon into the vacuum smelting furnace; after argon filling is finished, heating the vacuum smelting furnace to 1400 ℃ to smelt the raw materials; then, the molten liquid is poured on a water-cooled copper roller rotating at the linear speed of 1.5m/s, and the melt-spun sheet with the thickness of 0.25mm is obtained after cooling.
Comparative example 2
This comparative example is substantially the same as example 3, with the main differences being: in step (1) of this comparative example, no gadolinium-iron alloy was added.
The method specifically comprises the following steps:
(1) accurately weighing raw materials: 364kg of metallic iron, 202kg of praseodymium-neodymium alloy, 32kg of ferroboron alloy, 15kg of metallic cerium, 0.8kg of metallic copper, 3.2kg of metallic aluminum, 2kg of metallic cobalt and 1kg of metallic zirconium.
Comparative example 3
This comparative example is essentially the same as example 3, with the main differences being: in the step (2) of the comparative example, the molten liquid is not pre-cooled and heat-preserved.
The method specifically comprises the following steps:
(2) placing the weighed raw materials in a vacuum smelting furnace, and vacuumizing the vacuum smelting furnace to reduce the pressure in the furnace to be below 0.1 Pa; filling argon into the vacuum smelting furnace; after argon filling is finished, heating the vacuum smelting furnace to 1400 ℃ to smelt the raw materials; then, the molten liquid is poured on a water-cooled copper roller rotating at the linear speed of 1.5m/s, and the melt-spun sheet with the thickness of 0.25mm is obtained after cooling.
Comparative example 4
This comparative example is essentially the same as example 19, with the main differences being: in step (2) of this comparative example, the molten liquid was pre-cooled to 1200 ℃.
The method specifically comprises the following steps:
step (2): placing the weighed raw materials in a vacuum smelting furnace, and vacuumizing the vacuum smelting furnace to reduce the pressure in the furnace to be below 0.1 Pa; filling argon into the vacuum smelting furnace; after argon filling is finished, heating the vacuum smelting furnace to 1500 ℃ to smelt the raw materials; then, pre-cooling the smelting liquid to 1200 ℃, and preserving heat for 5 min; then, the molten liquid is poured on a water-cooled copper roller rotating at the linear speed of 1.5m/s, and the melt-spun sheet with the thickness of 0.25mm is obtained after cooling.
Comparative example 5
This comparative example is essentially the same as example 19, with the main differences being: in step (2) of this comparative example, the molten liquid was pre-cooled to 1400 ℃.
The method specifically comprises the following steps:
step (2): placing the weighed raw materials in a vacuum smelting furnace, and vacuumizing the vacuum smelting furnace to reduce the pressure in the furnace to be below 0.1 Pa; filling argon into the vacuum smelting furnace; after argon filling is finished, heating the vacuum smelting furnace to 1500 ℃ to smelt the raw materials; then, pre-cooling the smelting liquid to 1400 ℃, and preserving heat for 5 min; then, the molten liquid is poured on a water-cooled copper roller rotating at the linear speed of 1.5m/s, and the melt-spun sheet with the thickness of 0.25mm is obtained after cooling.
Comparative example 6
This comparative example is essentially the same as example 21, with the main differences being: in the step (2) of the comparative example, the molten metal was cooled to 1300 ℃ and then kept at the temperature for 2 min.
The method specifically comprises the following steps:
step (2): placing the weighed raw materials in a vacuum smelting furnace, and vacuumizing the vacuum smelting furnace to reduce the pressure in the furnace to be below 0.1 Pa; filling argon into the vacuum smelting furnace; after argon filling is finished, heating the vacuum smelting furnace to 1500 ℃ to smelt the raw materials; then, pre-cooling the smelting liquid to 1300 ℃, and preserving heat for 2 min; then, the molten liquid is poured on a water-cooled copper roller rotating at the linear speed of 1.5m/s, and the melt-spun sheet with the thickness of 0.25mm is obtained after cooling.
Performance detection
The neodymium iron boron magnetic materials obtained in the embodiments 1-37 and the comparative examples 1-6 are taken, and the magnetic performance of the neodymium iron boron magnetic materials is tested by adopting an NIM-10000H rare earth permanent magnet nondestructive testing system at the temperature of 20 ℃ according to the reference standard GB/T3217-2013.
The test results are given in the following table:
TABLE 4 magnetic Properties of the NdFeB magnetic materials obtained in examples 1-37 and comparative examples 1-6
| Serial number | Maximum magnetic energy product/MGOe | remanence/KGs | Coercive force/KOe | Intrinsic coercivity/KOe | Curie temperature/. degree.C |
| Example 1 | 38.87 | 13.11 | 14.32 | 34.89 | 357 |
| Example 2 | 38.75 | 12.98 | 14.21 | 34.66 | 357 |
| Example 3 | 39.01 | 13.20 | 14.58 | 34.93 | 358 |
| Example 4 | 38.69 | 13.01 | 14.29 | 34.74 | 357 |
| Example 5 | 39.06 | 13.26 | 14.63 | 34.99 | 358 |
| Example 6 | 38.96 | 13.16 | 14.53 | 34.87 | 357 |
| Example 7 | 38.73 | 12.95 | 14.25 | 34.60 | 356 |
| Example 8 | 39.04 | 13.26 | 14.37 | 34.69 | 358 |
| Example 9 | 39.01 | 13.24 | 14.49 | 34.82 | 358 |
| Example 10 | 38.89 | 13.08 | 14.60 | 34.96 | 357 |
| Example 11 | 38.97 | 13.16 | 14.83 | 35.12 | 358 |
| Example 12 | 38.90 | 13.07 | 14.86 | 35.17 | 357 |
| Example 13 | 38.92 | 13.09 | 14.98 | 35.30 | 358 |
| Example 14 | 38.80 | 12.92 | 15.02 | 35.39 | 357 |
| Example 15 | 38.86 | 13.02 | 14.87 | 35.21 | 363 |
| Example 16 | 38.76 | 12.88 | 14.69 | 35.12 | 366 |
| Example 17 | 38.82 | 12.97 | 14.99 | 35.36 | 363 |
| Example 18 | 38.74 | 12.88 | 15.03 | 35.40 | 363 |
| Example 19 | 38.86 | 12.98 | 14.96 | 35.37 | 363 |
| Example 20 | 38.89 | 12.99 | 14.98 | 35.43 | 363 |
| Example 21 | 39.11 | 13.10 | 15.11 | 35.40 | 364 |
| Example 22 | 39.09 | 13.06 | 15.06 | 35.36 | 364 |
| Example 23 | 39.18 | 13.21 | 15.16 | 35.45 | 364 |
| Example 24 | 39.23 | 13.35 | 15.20 | 35.50 | 364 |
| Example 25 | 39.25 | 13.38 | 15.21 | 35.49 | 364 |
| Example 26 | 39.25 | 13.34 | 15.24 | 35.49 | 364 |
| Example 27 | 38.67 | 13.03 | 14.83 | 35.07 | 360 |
| Example 28 | 38.92 | 13.21 | 15.10 | 35.26 | 361 |
| Example 29 | 39.26 | 13.39 | 15.20 | 35.54 | 363 |
| Example 30 | 39.37 | 13.66 | 15.24 | 35.55 | 364 |
| Example 31 | 39.31 | 13.62 | 15.20 | 35.53 | 364 |
| Example 32 | 39.35 | 13.68 | 15.23 | 35.52 | 364 |
| Example 33 | 39.31 | 13.65 | 15.22 | 35.55 | 364 |
| Example 34 | 39.28 | 13.67 | 15.20 | 35.55 | 364 |
| Example 35 | 39.32 | 13.62 | 15.20 | 35.52 | 364 |
| Example 36 | 39.39 | 13.69 | 15.24 | 35.58 | 364 |
| Example 37 | 39.32 | 13.55 | 14.78 | 35.02 | 362 |
| Comparative example 1 | 39.11 | 13.25 | 14.65 | 35.05 | 358 |
| Comparative example 2 | 39.03 | 13.21 | 14.15 | 34.48 | 357 |
| Comparative example 3 | 38.10 | 12.32 | 14.60 | 34.91 | 355 |
| Comparative example 4 | 38.48 | 12.62 | 14.97 | 35.25 | 360 |
| Comparative example 5 | 35.29 | 12.48 | 14.94 | 35.23 | 359 |
| Comparative example 6 | 35.30 | 12.52 | 15.03 | 35.34 | 360 |
Referring to table 4, examples 1 to 4 compare different ratios of metallic iron, praseodymium-neodymium alloy and ferroboron alloy in step (1) of the method for preparing a neodymium-iron-boron magnetic material. Through the detection and comparison of the overall magnetic performance of the obtained neodymium iron boron magnetic material, the proportion of the embodiment 3 is relatively excellent.
Because the price of the praseodymium-neodymium alloy is 722000-727000/ton, and the price of the metal cerium is 30000-31500/ton, the raw material cost of the embodiment 3 adopting the metal cerium to replace part of the praseodymium-neodymium alloy is obviously reduced compared with the comparative example 1. And as can be seen from the test results in table 4, the magnetic performance of the neodymium iron boron magnetic material obtained in example 3 is not significantly reduced compared to that of comparative example 1. This is due to: by comparing the embodiment 3 with the comparative example 2, the coercive force and the intrinsic coercive force of the neodymium iron boron magnetic material can be improved by adding the gadolinium-iron alloy; meanwhile, the comparison between the example 3 and the comparative example 3 can show that pre-cooling and heat preservation of the raw material smelting liquid before the strip throwing are beneficial to improving the performances of the residual magnetism and the like of the neodymium iron boron magnetic material. Therefore, in the embodiment 3, the decrease of the magnetic performance caused by the addition of cerium can be compensated by the addition of the gadolinium-iron alloy and the pre-cooling and heat preservation of the smelting liquid, so that the neodymium-iron-boron magnetic material obtained in the embodiment 3 has the advantages that the raw material cost is reduced, the magnetic performance is not obviously decreased compared with that of the neodymium-iron-boron magnetic material obtained in the comparative example 1, and the neodymium-iron-boron magnetic material still has ideal magnetic performance. In addition, the gadolinium-iron alloy is used as a rare earth metal alloy, and the price is about 380000/ton, so that the cost of the neodymium-iron-boron magnetic material can be further reduced by adding the gadolinium-iron alloy.
Examples 3, 5-7 are compared for the amount of cerium metal added. As a result, the saturated magnetization and the anisotropy field of the cerium-iron-boron phase are lower than those of the neodymium-iron-boron as the addition amount of the metal cerium is increased, so that the magnetic properties of the obtained neodymium-iron-boron magnetic material are reduced. Further, when the amount of metallic cerium added exceeds 3wt% of the total amount of the raw materials (example 7), the magnetic properties are remarkably decreased.
Examples 3, 8-10 are compared with respect to the addition of gadolinium ferroalloy. As a result, the coercive force and the intrinsic coercive force of the obtained neodymium iron boron magnetic material are improved along with the increase of the addition of the gadolinium-iron alloy, because the rapid growth of crystal grains is favorably inhibited. At the same time, however, the volume fraction of the main phase of the neodymium iron boron magnetic material is reduced due to the increase of the addition of the gadolinium-iron alloy, so that the remanence of the obtained neodymium iron boron magnetic material is slightly reduced. The comprehensive analysis shows that the embodiment 3 is relatively better.
Examples 11 to 12 of the present application examined the effect of the amount of copper added in combination with example 3. Through test results, the fact that the coercive force and the intrinsic coercive force of the neodymium iron boron magnetic material can be improved by adding copper can be found, but the remanence of the neodymium iron boron magnetic material can be reduced to a certain extent. Overall, example 11 is preferred.
Examples 13 to 14 of the present application examined the effect of the amount of aluminum added in combination with example 11. Through test results, the coercive force and the intrinsic coercive force of the neodymium iron boron magnetic material are all increased, and the remanence is slightly reduced along with the increase of the adding amount of the aluminum. Overall, example 13 is preferred.
Examples 15 to 16 of the present application examined the effect of the amount of cobalt added in combination with example 13. According to the test result, the Curie temperature of the neodymium iron boron magnetic material can be improved by adding the cobalt, so that the temperature stability of the neodymium iron boron magnetic material is improved. However, the addition of cobalt can reduce the coercive force, remanence and other magnetic properties of the neodymium iron boron magnetic material.
Examples 17 to 18 of the present application examined the effect of the amount of added zirconium in combination with example 15. According to the test results, the crystal grain growth can be inhibited, the microstructure of the material is improved, and the magnetic properties such as the coercive force of the neodymium iron boron magnetic material are improved due to the addition of the zirconium. However, the addition of zirconium also has a certain negative effect on the remanence and the maximum energy product of the neodymium iron boron magnetic material.
Examples 17 and 19 to 20 examined the influence of the melting temperature in step (2) of the method for producing a neodymium-iron-boron magnetic material. From the test results, it can be found that the magnetic property of the obtained neodymium iron boron magnetic material is improved along with the increase of the smelting temperature, because the higher smelting temperature is beneficial to more fully melting the metal raw materials, so that the final product with better performance is obtained.
Examples 19, 21 to 22 were compared with comparative examples 4 to 5 in terms of the temperature of the molten metal precooling. As a result, it was found that as the pre-cooling temperature decreases, the remanence of the resulting ndfeb magnetic material gradually increases and then falls back. This is because the pre-cooling temperature is too high, far from the eutectic point, and solid phase nuclei are difficult to form. The pre-cooling temperature is too low, and the good formation of solid phase nuclei is also not favorable due to the long cooling process.
Examples 21, 23-25 are compared to comparative example 6 for the incubation time after pre-cooling. From the results, it is understood that comparative example 4 has a low residual magnetism of the resulting magnetic material due to the short incubation time and the formation of imperfect solid phase nuclei, which affects the promotion of the growth of the main phase. And with the extension of the heat preservation time, the formed solid phase core becomes perfect, so that the residual magnetism and other magnetic properties of the prepared neodymium iron boron magnetic material are obviously improved.
Example 26 the control parameters associated with step (3) of the ndfeb magnetic material preparation method were adjusted compared to example 24. According to test results, when hydrogen is broken, the hydrogen absorption time of the melt-spun sheet is adjusted to 5h, the hydrogen absorption pressure is adjusted to 0.7MPa, the hydrogen absorption temperature is adjusted to 500 ℃, the dehydrogenation temperature is adjusted to 650 ℃, and the neodymium iron boron magnetic material with ideal magnetic performance can still be obtained.
Examples 27-28 the range of control of the fine powder particle size in step (4) of the ndfeb magnetic material preparation method was varied compared to example 24. From the test results, it can be known that the magnetic performance of the finally formed neodymium iron boron magnetic material is affected by the particle size of the fine powder being too small or too large. Wherein, the particle size of the fine powder is too small, which is easy to agglomerate, thereby influencing the orientation of the fine powder and further causing the magnetic property of the neodymium iron boron magnetic material to be damaged. The excessive particle size of the fine powder can influence the compactness of the neodymium iron boron magnetic material and also can adversely influence the performance of the final material.
Example 29 the pressure of the grinding gas was changed compared to example 24. According to the test results, the pressure of the grinding gas is increased to 0.7MPa, so that the magnetic property of the final neodymium iron boron magnetic material cannot be damaged.
Examples 30 to 31 the effect of the amount of talc added in step (5) of the method for producing a neodymium-iron-boron magnetic material was examined in combination with example 24. Through comparison test results, the remanence of the obtained neodymium iron boron magnetic material is increased and then decreased along with the increase of the addition of the talcum powder. The right amount of talcum powder is beneficial to reducing the resistance between fine powder and improving the fluidity of the fine powder, so that the orientation degree of the fine powder is improved, and the residual magnetism of the neodymium iron boron magnetic material can be improved. However, excessive talc powder increases the resistance between fine powders, which adversely affects the magnetic properties of the ndfeb magnetic material.
Example 32 the control parameters for sintering in step (6) of the ndfeb magnetic material preparation method were varied compared to example 30. According to the test results, the sintering temperature is increased to 1070 ℃ and sintered for 3h, and the neodymium iron boron magnetic material with ideal magnetic performance can be obtained.
Examples 33-35 the control parameters in step (7) of the ndfeb magnetic material preparation method were adjusted compared to example 30. From the results, it is understood that under the different control parameters of examples 33-35, the Nd-Fe-B magnetic material with ideal magnetic performance can be obtained.
Example 36 compared to example 30, three separate tempers were used. From the results, it is clear that the magnetic properties of the neodymium-iron-boron magnetic material obtained in example 30 are not inferior to those of example 36. Therefore, the design of once heating and multiple times of heat preservation during cooling is adopted, the effect is similar to that of multiple times of independent tempering, and the purpose of once heating and multiple times of tempering is achieved. The mode of once heating and multiple tempering can reduce the energy consumption and the production cost.
Example 37 compared to example 30, a single tempering treatment was used. From the results, it is clear that the magnetic properties such as the coercive force of the neodymium iron boron magnetic material obtained in example 30 are better than those of example 37, which shows that the magnetic properties of the magnetic material are improved by tempering for a plurality of times.
The present embodiment is only for explaining the present application, and it is not limited to the present application, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present application.
Claims (10)
1. The preparation method of the neodymium iron boron magnetic material is characterized by comprising the following steps: the method comprises the following steps:
weighing the following raw materials in parts by weight: 367 parts of metal iron 360-116 parts, 200 parts of praseodymium-neodymium alloy 187-200 parts, 28-34 parts of ferroboron alloy, 12-20 parts of metal cerium, 6-12 parts of gadolinium-iron alloy, 0.8-1.5 parts of metal copper, 3.2-5.5 parts of metal aluminum, 2-3.5 parts of metal cobalt and 1-1.8 parts of metal zirconium;
smelting the raw materials at the temperature of at least 1400 ℃, then cooling the smelting liquid to 1300-1350 ℃, and preserving heat for at least 5 min; then, melt-spinning the melt to obtain melt-spun pieces;
carrying out hydrogen crushing, powder making and molding orientation on the melt-spun sheet to obtain a blank;
and sintering and tempering the blank to obtain the neodymium iron boron magnetic material.
2. The method for preparing neodymium iron boron magnetic material according to claim 1, characterized in that: tempering the blank at the temperature of 850-930 ℃ after sintering, and preserving heat for at least 2 h; then cooling the blank to 580-650 ℃, preserving heat for at least 1h, then cooling to 450-530 ℃, preserving heat for at least 1h, and then cooling to room temperature and discharging.
3. The method for preparing neodymium iron boron magnetic material according to claim 2, characterized in that: the blank is subjected to vacuum sintering at a temperature of 1000-1070 ℃.
4. The method for preparing neodymium iron boron magnetic material according to claim 1, characterized in that: the step of carrying out hydrogen breaking on the melt-spun piece comprises the following steps: placing the melt-spun sheet in a hydrogen atmosphere, enabling the melt-spun sheet to absorb hydrogen for at least 1h to obtain a hydrogen breaking product, and controlling the hydrogen absorption pressure to be 0.7-0.9MPa and the hydrogen absorption temperature to be 350-500 ℃; and then heating the hydrogen-broken product to at least 550 ℃ for dehydrogenation treatment.
5. The method for preparing neodymium iron boron magnetic material according to claim 4, characterized in that: and introducing the dehydrogenated hydrogen breaking product into an airflow mill for breaking to obtain fine powder, wherein the particle size of the fine powder is controlled to be 3-6 microns.
6. The method for preparing neodymium iron boron magnetic material according to claim 5, characterized in that: mixing talcum powder into the fine powder, then placing the fine powder in a magnetic field for orientation and pressing to obtain a blank; and then carrying out isostatic pressing on the blank.
7. The method for preparing neodymium iron boron magnetic material according to claim 6, characterized in that: the addition amount of the talcum powder is 1-3% of the mass of the fine powder.
8. The method for preparing neodymium iron boron magnetic material according to claim 1, characterized in that: the raw materials are protected by inert gas during smelting.
9. Neodymium iron boron magnetism nature material, its characterized in that: the neodymium iron boron magnetic material is prepared by the preparation method of the neodymium iron boron magnetic material according to any one of claims 1 to 8.
10. Magnet, its characterized in that: the neodymium-iron-boron magnetic material of claim 9.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114918416A (en) * | 2022-04-19 | 2022-08-19 | 中国科学院宁波材料技术与工程研究所 | Method for manufacturing rare earth metal powder or rare earth alloy powder |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106653268A (en) * | 2016-12-14 | 2017-05-10 | 中国工程物理研究院材料研究所 | Preparation method of high-performance sintered Nd-Fe-B magnet with multi-layer grain boundary structure and prepared product |
| CN108389710A (en) * | 2018-01-05 | 2018-08-10 | 宁波招宝磁业有限公司 | A kind of preparation method of high-performance neodymium-iron-boron magnet |
| CN111403163A (en) * | 2020-01-07 | 2020-07-10 | 浙江凯文磁业有限公司 | Preparation method of high-corrosion-resistance sintered neodymium-iron-boron magnet |
| CN111681868A (en) * | 2020-07-09 | 2020-09-18 | 福建省长汀金龙稀土有限公司 | Method for treating neodymium iron boron alloy sheet after smelting |
| CN112562952A (en) * | 2020-11-20 | 2021-03-26 | 宁波合力磁材技术有限公司 | Neodymium-iron-boron permanent magnet material and preparation method thereof |
-
2021
- 2021-04-28 CN CN202110463517.4A patent/CN113223847A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106653268A (en) * | 2016-12-14 | 2017-05-10 | 中国工程物理研究院材料研究所 | Preparation method of high-performance sintered Nd-Fe-B magnet with multi-layer grain boundary structure and prepared product |
| CN108389710A (en) * | 2018-01-05 | 2018-08-10 | 宁波招宝磁业有限公司 | A kind of preparation method of high-performance neodymium-iron-boron magnet |
| CN111403163A (en) * | 2020-01-07 | 2020-07-10 | 浙江凯文磁业有限公司 | Preparation method of high-corrosion-resistance sintered neodymium-iron-boron magnet |
| CN111681868A (en) * | 2020-07-09 | 2020-09-18 | 福建省长汀金龙稀土有限公司 | Method for treating neodymium iron boron alloy sheet after smelting |
| CN112562952A (en) * | 2020-11-20 | 2021-03-26 | 宁波合力磁材技术有限公司 | Neodymium-iron-boron permanent magnet material and preparation method thereof |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114918416A (en) * | 2022-04-19 | 2022-08-19 | 中国科学院宁波材料技术与工程研究所 | Method for manufacturing rare earth metal powder or rare earth alloy powder |
| CN114918416B (en) * | 2022-04-19 | 2024-05-10 | 中国科学院宁波材料技术与工程研究所 | Method for producing rare earth metal powder or rare earth alloy powder |
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Application publication date: 20210806 |