CN117059356A - Neodymium-iron-boron rare earth permanent magnet and preparation method thereof - Google Patents
Neodymium-iron-boron rare earth permanent magnet and preparation method thereof Download PDFInfo
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- 229910052761 rare earth metal Inorganic materials 0.000 title claims abstract description 120
- 229910001172 neodymium magnet Inorganic materials 0.000 title claims abstract description 46
- -1 Neodymium-iron-boron rare earth Chemical class 0.000 title claims abstract description 42
- 238000002360 preparation method Methods 0.000 title abstract description 6
- 239000000956 alloy Substances 0.000 claims abstract description 191
- 229910045601 alloy Inorganic materials 0.000 claims abstract description 186
- 239000002994 raw material Substances 0.000 claims abstract description 150
- 238000000034 method Methods 0.000 claims abstract description 43
- 239000002245 particle Substances 0.000 claims abstract description 26
- 229910052796 boron Inorganic materials 0.000 claims abstract description 19
- 229910052726 zirconium Inorganic materials 0.000 claims abstract description 9
- 238000003723 Smelting Methods 0.000 claims description 18
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 14
- 229910052733 gallium Inorganic materials 0.000 claims description 14
- 229910052739 hydrogen Inorganic materials 0.000 claims description 14
- 239000001257 hydrogen Substances 0.000 claims description 14
- 229910052771 Terbium Inorganic materials 0.000 claims description 12
- 230000032683 aging Effects 0.000 claims description 12
- 238000005245 sintering Methods 0.000 claims description 12
- 229910052742 iron Inorganic materials 0.000 claims description 9
- 229910052779 Neodymium Inorganic materials 0.000 claims description 7
- 230000006698 induction Effects 0.000 claims description 6
- 210000003127 knee Anatomy 0.000 claims description 6
- 238000000465 moulding Methods 0.000 claims description 6
- 229910052727 yttrium Inorganic materials 0.000 claims description 6
- 238000010521 absorption reaction Methods 0.000 claims description 5
- 238000005266 casting Methods 0.000 claims description 5
- 238000006356 dehydrogenation reaction Methods 0.000 claims description 5
- 238000000227 grinding Methods 0.000 claims description 5
- 238000002156 mixing Methods 0.000 claims description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims 6
- 238000004519 manufacturing process Methods 0.000 claims 1
- 230000005389 magnetism Effects 0.000 abstract description 13
- 230000007547 defect Effects 0.000 abstract description 7
- 230000002349 favourable effect Effects 0.000 abstract description 3
- 230000001105 regulatory effect Effects 0.000 abstract description 3
- 230000000052 comparative effect Effects 0.000 description 17
- 150000002910 rare earth metals Chemical class 0.000 description 11
- 239000000463 material Substances 0.000 description 10
- 239000013078 crystal Substances 0.000 description 9
- 239000000203 mixture Substances 0.000 description 6
- 238000012360 testing method Methods 0.000 description 5
- 101150108611 dct-1 gene Proteins 0.000 description 3
- 238000005324 grain boundary diffusion Methods 0.000 description 3
- BGPVFRJUHWVFKM-UHFFFAOYSA-N N1=C2C=CC=CC2=[N+]([O-])C1(CC1)CCC21N=C1C=CC=CC1=[N+]2[O-] Chemical compound N1=C2C=CC=CC2=[N+]([O-])C1(CC1)CCC21N=C1C=CC=CC1=[N+]2[O-] BGPVFRJUHWVFKM-UHFFFAOYSA-N 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 239000000696 magnetic material Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000007858 starting material Substances 0.000 description 2
- 238000010998 test method Methods 0.000 description 2
- 229910000531 Co alloy Inorganic materials 0.000 description 1
- 229910052692 Dysprosium Inorganic materials 0.000 description 1
- 101100545292 Homo sapiens ZNF408 gene Proteins 0.000 description 1
- 102100023554 Zinc finger protein 408 Human genes 0.000 description 1
- QJVKUMXDEUEQLH-UHFFFAOYSA-N [B].[Fe].[Nd] Chemical compound [B].[Fe].[Nd] QJVKUMXDEUEQLH-UHFFFAOYSA-N 0.000 description 1
- 230000005347 demagnetization Effects 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 230000002427 irreversible effect Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 238000004445 quantitative analysis Methods 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
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
- H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
- H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
- H01F1/047—Alloys characterised by their composition
- H01F1/053—Alloys characterised by their composition containing rare earth metals
- H01F1/055—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
- H01F1/057—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
- H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
- 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
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- Crystallography & Structural Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Hard Magnetic Materials (AREA)
Abstract
The present disclosure relates to a neodymium-iron-boron rare earth permanent magnet and a preparation method thereof, wherein a double-alloy process is adopted, auxiliary alloy raw materials containing heavy rare earth elements and main alloy raw materials containing light rare earth elements are matched for use, the content of B in the auxiliary alloy raw materials is reasonably regulated and controlled, and simultaneously, the auxiliary alloy raw materials are controlled to contain no Zr, ti and light rare earth elements, so that the auxiliary alloy raw materials mainly form Tb 2 (FeM) 14 Phase B, tb of 2 (FeM) 14 The B phase is favorable for forming Tb on the periphery of main phase grains 2 Fe 14 And the B shell layer increases the magnetocrystalline anisotropy field between the main phase particles and reduces the proportion of heavy rare earth elements entering the main phase grains, so that the phenomenon that the coercive force of the grains is obviously lower due to grain boundary defects is improved, the great reduction of residual magnetism is avoided, and the prepared permanent magnet has high residual magnetism and high coercive force.
Description
Technical Field
The present disclosure relates to the technical field of neodymium-iron-boron magnets, and in particular, to a neodymium-iron-boron rare earth permanent magnet and a preparation method thereof.
Background
The R-T-B sintered magnet is the most excellent of the known permanent magnets, and is therefore widely used in various motors and home electric appliances such as voice coil motors for hard disk drives, motors for electric vehicles, motors for industrial equipment, and the like. With the diversification of the application, the existing R-T-B sintered magnet has coercive force H at high temperature CJ The irreversible thermal demagnetization is reduced. To improve H CJ A grain boundary diffusion process is often adopted, and the coercive force of the magnet is greatly improved by a method of penetrating heavy rare earth elements such as Dy, tb and the like into a grain boundary phase, but the grain boundary diffusion treatment can lead to the reduction of residual magnetism Br of the magnet, which is unfavorable for preparing the magnet with high residual magnetism and high coercive force.
Disclosure of Invention
The invention aims to provide a neodymium-iron-boron rare earth permanent magnet and a preparation method thereof, which can reduce the proportion of heavy rare earth elements entering main phase grains, improve grain boundary defects and further improve the remanence and coercive force of a permanent magnet material.
To achieve the above object, a first aspect of the present disclosure provides a method for preparing a neodymium-iron-boron rare earth permanent magnet, the method comprising: mixing the main alloy raw material and the auxiliary alloy raw material, and performing forming treatment, sintering treatment and aging treatment on the obtained alloy raw material; the content of the auxiliary alloy raw materials is 1-10 wt% based on the total weight of the alloy raw materials;
the main alloy raw material comprises a light rare earth element RL, ga, cu, co, al, zr, B and Fe, and the light rare earth element RL is one or more selected from Y, la, ce, pr and Nd;
the auxiliary alloy raw material comprises heavy rare earth elements, M, B and Fe, wherein the content of the heavy rare earth elements in the auxiliary alloy raw material is 32-35 wt%, the content of M is 0.9-2.2 wt%, the content of B is 0.95-0.98 wt% and the balance is Fe based on the total weight of the auxiliary alloy raw material;
wherein the heavy rare earth element is Tb, M comprises Ga, cu, co and Al, and the total content of Zr, ti and light rare earth elements in the auxiliary alloy raw material is 0.
Optionally, the atomic ratio of Tb, fe and B in the auxiliary alloy raw material is (2-3): (12-15): 1, preferably (2.1 to 2.4): (13-14): 1.
optionally, taking the total weight of the auxiliary alloy raw materials as a reference, the content of Ga in the auxiliary alloy raw materials is 0.2-0.5 wt%, the content of Cu is 0.1-0.2 wt%, the content of Co is 0.5-1 wt%, and the content of Al is 0.1-0.5 wt%; the content ratio of Ga, cu, co and Al in the auxiliary alloy raw materials is (1-5): (1-2): (2-5): 1, preferably (1 to 3): (1-1.5): (3-5): 1.
optionally, based on the total weight of the main alloy raw material, the main alloy raw material contains 28.5-31 wt% of light rare earth element RL, 0.1-0.5 wt% of Ga, 0.1-0.5 wt% of Cu, 0.5-3 wt% of Co, 0.1-1 wt% of Al, 0.1-0.5 wt% of Zr, 0.9-1 wt% of B and the balance of Fe.
Optionally, the average particle size of the main alloy raw material and the auxiliary alloy raw material is below 5 μm; preferably, the average particle size of the main alloy raw material is 3.5-4.5 mu m, and the average particle size of the auxiliary alloy raw material is 3.5-4.5 mu m; more preferably, the average particle size of the master alloy raw material is 4 to 4.5 μm, and the average particle size of the slave alloy raw material is 3.5 to 4 μm.
Optionally, the forming process is an orientation forming process, and the orientation forming process is performed under the condition that the orientation magnetic induction intensity is 1.8-3.2T; the sintering treatment temperature is 1050-1085 ℃ and the sintering treatment time is 6-8 h; the aging treatment is carried out at 490-900 ℃ for 6-8 h.
Optionally, the method further comprises preparing the master alloy feedstock and the slave alloy feedstock using the steps of:
(1) According to the proportion of each element component in the main alloy raw material and the proportion of each element component in the auxiliary alloy raw material, respectively smelting the main alloy and the auxiliary alloy, and obtaining a main alloy sheet and an auxiliary alloy sheet by adopting a rapid hardening process;
(2) And respectively carrying out hydrogen crushing and micro-crushing on the main alloy sheet and the auxiliary alloy sheet to obtain the main alloy raw material and the auxiliary alloy raw material.
Optionally, in step (1), the smelting is performed in a vacuum smelting furnace having a vacuum level of 10 -2 ～10 2 Pa, wherein the smelting temperature is 1300-1500 ℃; the linear speed of the surface of the roller in the rapid hardening process is 0.5-1.5 m/s, and the casting temperature is 1300-1500 ℃; in the step (2), the hydrogen absorption pressure of the hydrogen crushing is 0.15-0.4 MPa, and the dehydrogenation temperature is 560-600 ℃; the micro-crushing is performed in an air flow mill, and the grinding pressure of the air flow mill is 0.5-0.7 MPa.
A second aspect of the present disclosure provides a neodymium-iron-boron rare earth permanent magnet produced by the method of the first aspect of the present disclosure.
Optionally, the neodymium-iron-boron rare earth permanent magnet comprises a rare earth element R, ga, cu, co, al, zr, B and Fe, and the rare earth element R comprises a light rare earth element RL and a heavy rare earth element Tb; based on the total weight of the neodymium-iron-boron rare earth permanent magnet, the content of rare earth elements R in the neodymium-iron-boron rare earth permanent magnet is 29 to 33 weight percent, the content of Ga is 0.1 to 0.5 weight percent, the content of Cu is 0.1 to 0.5 weight percent, the content of Co is 0.5 to 3 weight percent, the content of Al is 0.1 to 1 weight percent, the content of Zr is 0.1 to 0.5 weight percent, the content of B is 0.9 to 1 weight percent, and the content of Fe is 65 to 70 weight percent; wherein, the light rare earth element RL is selected from one or more of Y, la, ce, pr and Nd.
Optionally, the residual magnetism Br of the neodymium-iron-boron rare earth permanent magnet is 1.35-1.49T, preferably 1.41-1.45T; coercivity ofH CJ 960-2200 KA/m, preferably 1120-1600 KA/m; knee point coercivity H k 940-2110 KA/m, preferably 1100-1550 KA/m.
Through the technical scheme, the invention provides a neodymium-iron-boron rare earth permanent magnet and a preparation method thereof, and the method adopts a double-alloy process, and the auxiliary alloy raw material containing heavy rare earth elements and the main alloy raw material containing light rare earth elements are matched for use, the content of B in the auxiliary alloy raw material is reasonably regulated and controlled, and simultaneously the auxiliary alloy raw material is controlled to contain no Zr, ti and light rare earth elements, so that Tb is mainly formed by the auxiliary alloy raw material 2 (FeM) 14 Phase B, tb of 2 (FeM) 14 The B phase is favorable for forming Tb on the periphery of main phase grains 2 (FeM) 14 The shell layer of the B phase increases the magnetocrystalline anisotropy field between the particles of the main phase, reduces the proportion of heavy rare earth elements entering into the crystal grains of the main phase, thereby improving the phenomenon that the coercive force of the crystal grains is obviously lower due to the crystal boundary defect, avoiding the great reduction of residual magnetism and ensuring that the prepared permanent magnet has high residual magnetism and high coercive force.
Additional features and advantages of the present disclosure will be set forth in the detailed description which follows.
Detailed Description
The following describes specific embodiments of the present disclosure in detail. It should be understood that the detailed description and specific examples, while indicating and illustrating the disclosure, are not intended to limit the disclosure.
A first aspect of the present disclosure provides a method of preparing a neodymium-iron-boron rare earth permanent magnet, the method comprising: mixing the main alloy raw material and the auxiliary alloy raw material, and performing forming treatment, sintering treatment and aging treatment on the obtained alloy raw material; the content of the auxiliary alloy raw materials is 1-10 wt% based on the total weight of the alloy raw materials;
the main alloy raw material comprises a light rare earth element RL, ga, cu, co, al, zr, B and Fe, and the light rare earth element RL is one or more selected from Y, la, ce, pr and Nd;
the auxiliary alloy raw material comprises heavy rare earth elements, M, B and Fe, wherein the content of the heavy rare earth elements in the auxiliary alloy raw material is 32-35 wt%, the content of M is 0.9-2.2 wt%, the content of B is 0.95-0.98 wt% and the balance is Fe based on the total weight of the auxiliary alloy raw material;
wherein the heavy rare earth element is Tb, M comprises Ga, cu, co and Al, and the total content of Zr, ti and light rare earth elements in the auxiliary alloy raw material is 0.
The inventor of the present disclosure found in the study that when the neodymium-iron-boron rare earth permanent magnet adopts a grain boundary diffusion treatment process, heavy rare earth element Tb can enter main phase grains in the diffusion process, so that the residual magnetism of the magnet is reduced and the coercivity is improved to a limited extent. In order to avoid the diffusion of heavy rare earth elements into the main phase grains, the inventor adopts a double-alloy process, and the auxiliary alloy raw material containing the heavy rare earth elements and the main alloy raw material containing the light rare earth elements are matched for use, the content of B in the auxiliary alloy raw material is reasonably regulated and controlled, and simultaneously the auxiliary alloy raw material is controlled to contain no Zr, ti and light rare earth elements, so that the auxiliary alloy raw material mainly forms Tb 2 (FeM) 14 Phase B, tb of 2 (FeM) 14 The B phase is favorable for forming Tb on the periphery of main phase grains 2 Fe 14 And the B shell layer increases the magnetocrystalline anisotropy field between the main phase particles and reduces the proportion of heavy rare earth elements entering the main phase grains, thereby improving the phenomenon that the coercive force of the grains is obviously lower due to the grain boundary defects, avoiding the great reduction of residual magnetism and ensuring that the prepared permanent magnet has high residual magnetism and high coercive force.
In one embodiment, the heavy rare earth element content of the auxiliary alloy raw material may be 32 wt%, 32.5 wt%, 33 wt%, 33.5 wt%, 34 wt%, 34.5 wt%, 35 wt%, or a value between any two of them, preferably 32 to 33.5 wt%; the content of M may be 0.9 wt%, 1.1 wt%, 1.3 wt%, 1.5 wt%, 1.7 wt%, 1.9 wt%, 2.0 wt%, 2.2 wt%, or a value between any two thereof, preferably 0.9 to 1.8 wt%; the content of B is 0.95 wt%, 0.96 wt%, 0.97 wt%, 0.98 wt%, or a value between any two thereof, preferably 0.95 to 0.97 wt%; the neodymium-iron-boron rare earth permanent magnet further comprises O, C and N, wherein the content of O is less than 1000ppm, the content of C is less than 1000ppm, and the content of N is less than 300ppm.
In one embodiment of the present disclosure, the atomic ratio of Tb, fe to B in the auxiliary alloy raw material is (2 to 3): (12-15): 1, preferably (2.1 to 2.4): (13-14): 1. in the above embodiment, the auxiliary alloy raw material has proper atomic ratio of Tb, fe and B, which is beneficial to the main formation of Tb by the auxiliary alloy raw material 2 (FeM) 14 Phase B and forming Tb around the grains of the main phase 2 Fe 14 And B shell layers are used for increasing magnetocrystalline anisotropic fields among main phase particles, so that the proportion of heavy rare earth elements entering main phase grains is reduced.
In one embodiment of the present disclosure, the content of Ga in the auxiliary alloy raw material is 0.2 to 0.5 wt%, the content of Cu is 0.1 to 0.2 wt%, the content of Co is 0.5 to 1 wt%, and the content of Al is 0.1 to 0.5 wt%, based on the total weight of the auxiliary alloy raw material; the content ratio of Ga, cu, co and Al in the auxiliary alloy raw materials is (1-5): (1-2): (2-5): 1, preferably (1 to 3): (1-1.5): (3-5): 1. in the embodiment, the auxiliary alloy raw material has a proper Ga, cu, co, al content ratio, which is beneficial to further reducing the proportion of heavy rare earth elements entering main phase grains, thereby improving the remanence and coercive force of the prepared permanent magnet material.
In a specific embodiment, the Ga content of the auxiliary alloy raw material may be 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, or a value between any two of them, preferably 0.2 to 0.3 wt%; the Cu content may be 0.1 wt%, 0.15 wt%, 0.18 wt%, 0.2 wt%, or a value between any two thereof, preferably 0.12 to 0.2 wt%; the content of Co may be 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1 wt%, or a value between any two thereof, preferably 0.5 to 0.8 wt%; the content of Al may be 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, or a value between any two thereof, preferably 0.1 to 0.4 wt%.
In one embodiment of the present disclosure, the main alloy raw material contains 28.5 to 31 wt% of light rare earth element RL, 0.1 to 0.5 wt% of Ga, 0.1 to 0.5 wt% of Cu, 0.5 to 3 wt% of Co, 0.1 to 1 wt% of Al, 0.1 to 0.5 wt% of Zr, 0.9 to 1 wt% of B, and the balance Fe, based on the total weight of the main alloy raw material. In a specific embodiment, the content of the light rare earth element RL may be 28.5 wt%, 29 wt%, 29.5 wt%, 30 wt%, 30.5 wt%, 31 wt%, or a value between any two thereof, preferably 29 to 30 wt%; the Ga content may be 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, or a value between any two thereof, preferably 0.1 to 0.3 wt%; the Cu content may be 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, or a value between any two thereof, preferably 0.1 to 0.2 wt%; the content of Co may be 0.5 wt%, 1 wt%, 1.5 wt%, 2.0 wt%, 2.5 wt%, 3 wt%, or a value between any two thereof, preferably 1 to 1.5 wt%; the content of Al may be 0.1 wt%, 0.3 wt%, 0.5 wt%, 0.7 wt%, 0.9 wt%, 1 wt%, or a value between any two thereof, preferably 0.1 to 0.5 wt%; the Zr content may be 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, or a value between any two thereof, preferably 0.2 to 0.3 wt%; the content of B may be 0.9 wt%, 0.93 wt%, 0.95 wt%, 0.97 wt%, 1 wt%, or a value between any two thereof, and is preferably 0.95 to 0.98 wt%.
In one embodiment of the present disclosure, the average particle size of the primary alloy feedstock and the secondary alloy feedstock is 5 μm or less. In a preferred embodiment, the average particle size of the master alloy raw material is 3.5 to 4.5 μm, and the average particle size of the slave alloy raw material is 3.5 to 4.5 μm; more preferably, the average particle size of the main alloy raw material is 4 to 4.5 μm, and the auxiliary alloyThe average grain size of the gold raw material is 3.5-4 mu m. In the above embodiment, the main alloy material and the auxiliary alloy material with proper granularity are selected for matching, so that Tb can be further formed on the periphery of the main phase crystal grains 2 Fe 14 And the B shell layer reduces the proportion of heavy rare earth elements entering the main phase crystal grains, optimizes the grain boundary phase of the permanent magnet material and improves the problem of grain boundary defects, thereby improving the remanence and coercive force of the permanent magnet.
In the present disclosure, the molding process, sintering process, and aging process may employ conventional apparatuses and conventional conditions in the art. In a preferred embodiment, the molding process is an orientation molding process performed under the condition that the orientation magnetic induction intensity is 1.8 to 3.2T, preferably under the condition that the orientation magnetic induction intensity is 2.5 to 3.2T; the sintering treatment temperature is 1050-1085 ℃, preferably 1060-1070 ℃; the time is 6 to 8 hours, preferably 6 to 7 hours; the aging treatment temperature is 490-900 ℃, preferably 500-900 ℃; the time is 6 to 8 hours, preferably 6 to 7 hours.
In one embodiment of the present disclosure, the method further comprises preparing the master alloy feedstock and the slave alloy feedstock using the steps of: (1) According to the proportion of each element component in the main alloy raw material and the proportion of each element component in the auxiliary alloy raw material, respectively smelting the main alloy and the auxiliary alloy, and obtaining a main alloy sheet and an auxiliary alloy sheet by adopting a rapid hardening process; (2) And respectively carrying out hydrogen crushing and micro-crushing on the main alloy sheet and the auxiliary alloy sheet to obtain the main alloy raw material and the auxiliary alloy raw material.
In one embodiment of the present disclosure, in step (1), the smelting is performed in a vacuum smelting furnace having a vacuum level of 10 -2 ～10 2 Pa, preferably 10 -2 ～10 -1 Pa; the smelting temperature is 1300-1500 ℃, preferably 1350-1450 ℃; the linear speed of the surface of the roller in the rapid hardening process is 0.5-1.5 m/s, preferably 0.8-1.2 m/s; the casting temperature is 1300-1500 ℃, preferably 1350-1450 ℃; in the step (2), the hydrogen absorption pressure of the hydrogen crushing is 0.15-0.4 MPa, preferably 0.2-0.3 MPa, and the dehydrogenation temperature is 560-600 ℃, preferably 580-600 ℃; by a means ofThe micro-crushing is performed in an air-jet mill, and the grinding pressure of the air-jet mill is 0.5-0.7 MPa, preferably 0.55-0.65 MPa.
A second aspect of the present disclosure provides a neodymium-iron-boron rare earth permanent magnet produced by the method of the first aspect of the present disclosure.
In one embodiment of the present disclosure, the neodymium-iron-boron rare earth permanent magnet includes rare earth elements R, ga, cu, co, al, zr, B and Fe, and the rare earth element R includes a light rare earth element RL and a heavy rare earth element Tb; based on the total weight of the neodymium-iron-boron rare earth permanent magnet, the content of rare earth elements R in the neodymium-iron-boron rare earth permanent magnet is 29 to 33 weight percent, the content of Ga is 0.1 to 0.5 weight percent, the content of Cu is 0.1 to 0.5 weight percent, the content of Co is 0.5 to 3 weight percent, the content of Al is 0.1 to 1 weight percent, the content of Zr is 0.1 to 0.5 weight percent, the content of B is 0.9 to 1 weight percent, and the content of Fe is 65 to 70 weight percent; wherein, the light rare earth element RL is selected from one or more of Y, la, ce, pr and Nd.
In one embodiment, the rare earth element R in the neodymium-iron-boron rare earth permanent magnet may be 29 wt%, 29.5 wt%, 30 wt%, 30.5 wt%, 31 wt%, 31.5 wt%, 32 wt%, 32.5 wt%, 33 wt%, or a value between any two thereof, preferably 29 to 31 wt%; the Ga content may be 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, or a value between any two thereof, preferably 0.1 to 0.3 wt%; the Cu content may be 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, or a value between any two thereof, preferably 0.1 to 0.2 wt%, and the Co content may be 0.5 wt%, 1 wt%, 1.5 wt%, 2.0 wt%, 2.5 wt%, 3 wt%, or a value between any two thereof, preferably 0.9 to 1.5 wt%; the content of Al may be 0.1 wt%, 0.3 wt%, 0.5 wt%, 0.7 wt%, 0.9 wt%, 1 wt%, or a value between any two thereof, preferably 0.1 to 0.5 wt%; the Zr content may be 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, or a value between any two thereof, preferably 01 to 0.3 wt%; the content of B may be 0.9 wt%, 0.93 wt%, 0.95 wt%, 0.97 wt%, 1 wt%, or a value between any two thereof, and is preferably 0.95 to 0.98 wt%.
In one embodiment of the present disclosure, the remanence Br of the neodymium-iron-boron rare earth permanent magnet is 1.35 to 1.49T, preferably 1.41 to 1.45T; coercivity H CJ 960-2200 KA/m, preferably 1120-1600 KA/m; knee point coercivity H k 940-2110 KA/m, preferably 1100-1550 KA/m. The rare earth permanent magnet provided by the disclosure has larger remanence and coercivity, and has excellent knee point coercivity.
The present disclosure is further illustrated in detail by the following examples. The starting materials used in the examples are all available commercially.
The components and contents of the main alloy raw material, the auxiliary alloy raw material and the neodymium-iron-boron rare earth permanent magnet are tested by adopting an ICP component analyzer, and the average granularity of the main alloy raw material and the auxiliary alloy raw material is tested by adopting a granularity analyzer.
Example 1
S1, preparing a main alloy raw material and an auxiliary alloy raw material by adopting the following steps:
(1) According to the proportion of each element component in the main alloy raw material and the proportion of each element component in the auxiliary alloy raw material in table 1, respectively smelting the main alloy and the auxiliary alloy, and obtaining a main alloy sheet and an auxiliary alloy sheet by adopting a rapid hardening process; wherein the content of M in the auxiliary alloy raw material is 0.9 weight percent, and the atomic ratio of Tb, fe and B is 2.3:13.5:1, the content ratio of Ga, cu, co and Al is 2:1:5:1, and the total content of Zr, ti and light rare earth elements in the auxiliary alloy raw material is 0. Smelting is carried out in a vacuum smelting furnace, and the vacuum degree of the vacuum smelting furnace is 10 -2 Pa, and smelting temperature is 1350 ℃; the linear speed of the surface of the roller in the rapid hardening process is 0.8m/s, and the casting temperature is 1400 ℃;
(2) Respectively carrying out hydrogen crushing and micro-crushing on the main alloy sheet and the auxiliary alloy sheet to obtain a main alloy raw material and an auxiliary alloy raw material; the hydrogen absorption pressure of hydrogen crushing is 0.3MPa, and the dehydrogenation temperature is 600 ℃; the micro-crushing was performed in an air-jet mill at a grinding pressure of 0.55MPa.
S2, preparing the neodymium-iron-boron rare earth permanent magnet by adopting the prepared main alloy raw material and auxiliary alloy raw material:
the main alloy raw material and the auxiliary alloy raw material are mixed according to the proportion of 29:1 to obtain an alloy raw material, wherein the content of the auxiliary alloy raw material is 3.3 weight percent based on the total weight of the alloy raw material; the obtained alloy raw material was subjected to forming treatment, sintering treatment and aging treatment, and finally a neodymium-iron-boron rare earth permanent magnet 1, which was denoted as CT-1, was obtained, and the composition thereof was shown in Table 2. Wherein the forming treatment is an orientation forming treatment which is carried out under the condition that the orientation magnetic induction intensity is 3.1T, the sintering treatment temperature is 1060 ℃ and the time is 7h; the aging treatment temperature is 900 ℃ and the aging treatment time is 7 hours.
Microstructure test is carried out on the prepared neodymium-iron-boron rare earth permanent magnet 1, and analysis of test results shows that Tb is arranged outside the main phase grains of CT-1 2 Fe 14 B shell layer, and the proportion of heavy rare earth element in main phase crystal grain is only 0.12%, indicating that Tb is outside main phase crystal grain 2 Fe 14 The formation of the B shell layer effectively reduces the proportion of heavy rare earth elements diffused into main phase grains, thereby improving the phenomenon that the coercive force of the grains is obviously lower due to the grain boundary defect and improving the remanence of the permanent magnet material. The specific microstructure test method comprises the following steps: and carrying out scanning electron microscope analysis on different fields of the permanent magnet material, determining the content of each element in the grain boundary phase of the material through single-point quantitative analysis, determining the phase of an inter-grain triangular area through element measurement, and further calculating the area occupation ratio of the phase.
Example 2
This embodiment is identical to embodiment 1, except that: the content of M in the auxiliary alloy raw material is 1.8 wt% and the content of Fe is 65.22 wt%, wherein M comprises 0.4 wt% Ga, 0.2 wt% Cu, 1 wt% Co and 0.2 wt% Al, so that the auxiliary alloy raw material satisfies that the atomic ratio of Tb, fe and B is 2.2:12.9:1, finally obtaining the NdFeB rare earth permanent magnet 2, which is marked as CT-2. Wherein, the components and average particle size of the main alloy raw material and the auxiliary alloy raw material are shown in Table 1, and the components of CT-2 are shown in Table 2.
Example 3
This embodiment is identical to embodiment 1, except that: the content of Ga in the auxiliary alloy raw material is 0.5 wt%, the content of Cu is 0.1 wt%, the content of Co is 0.1 wt%, and the content of Al is 0.2 wt%, so that the auxiliary alloy raw material satisfies the content ratio of Ga, cu, co and Al being 2.5:0.5:0.5:1, finally obtaining the NdFeB rare earth permanent magnet 3, which is marked as CT-3. Wherein, the proportion and average particle size of each element of the main alloy raw material and the auxiliary alloy raw material are shown in Table 1, and the composition of CT-3 is shown in Table 2.
Example 4
This embodiment is identical to embodiment 1, except that: in the step (1), the proportion and average particle size of the elements of the main alloy raw material and the auxiliary alloy raw material are shown in table 1, the auxiliary alloy raw material satisfies that the content of M is 1.5 weight percent, and the atomic ratio of Tb, fe and B is 2.3:12.7:1, the content ratio of Ga, cu, co and Al is 4:2:8:1, the vacuum degree of the vacuum melting furnace is 10 2 Pa, and smelting temperature is 1400 ℃; the linear speed of the surface of the roller in the rapid hardening process is 1.5m/s, and the casting temperature is 1300 ℃; in the step (2), the hydrogen absorption pressure of hydrogen crushing is 0.2MPa, and the dehydrogenation temperature is 560 ℃; the micro-crushing was performed in an air-jet mill at a grinding pressure of 0.7MPa.
In the step S2, the main alloy raw material and the auxiliary alloy raw material are mixed according to 90:10 weight ratio, the orientation molding treatment is carried out under the condition that the orientation magnetic induction intensity is 2T, the sintering treatment temperature is 1050 ℃ and the time is 8h; the aging treatment temperature is 800 ℃ and the aging treatment time is 8 hours; finally, a neodymium-iron-boron rare earth permanent magnet 4 is obtained and is marked as CT-4, and the composition of the neodymium-iron-boron rare earth permanent magnet is shown in Table 2.
Comparative example 1
This embodiment is identical to embodiment 3, except that: the content of B in the auxiliary alloy raw material is 1 weight percent, and the content of Fe is 66.1 weight percent, so that the auxiliary alloy raw material satisfies that the atomic ratio of Tb, fe and B is 2.2:12.8:1, finally obtaining a comparative rare earth permanent magnet 1, which is marked as DCT-1. Wherein, the proportion and average particle size of each element of the main alloy raw material and the auxiliary alloy raw material are shown in Table 1, and the composition of DCT-1 is shown in Table 2.
Comparative example 2
This embodiment is identical to embodiment 2, except that: the secondary alloy raw material also included 4 wt% Ti such that the content of Fe in the secondary alloy raw material was 61.22 wt% and the secondary alloy raw material satisfied an atomic ratio of Tb, fe, and B of 2.2:12.1:1, finally obtaining a comparative rare earth permanent magnet 2, which is marked as DCT-2. Wherein, the proportion and average particle size of each element of the main alloy raw material and the auxiliary alloy raw material are shown in Table 1, and the composition of DCT-2 is shown in Table 2.
Comparative example 3
This embodiment is identical to embodiment 1, except that: the content of M in the auxiliary alloy raw material was 2.7 wt% and the content of Fe was 64.35 wt%, wherein M includes 0.6 wt% Ga, 0.3 wt% Cu, 1.5 wt% Co, 0.3 wt% Al, so that the auxiliary alloy raw material satisfies an atomic ratio of Tb, fe to B of 2.3:13.1:1, the content ratio of Ga, cu, co and Al is 2:1:5:1, finally obtaining a comparative rare earth permanent magnet 3, which is marked as DCT-3. Wherein, the proportion and average particle size of each element of the main alloy raw material and the auxiliary alloy raw material are shown in table 1, and the DCT-3 component is shown in table 2.
Comparative example 4
This comparative example is identical to example 4, except that: the secondary alloy material also contained 10 wt% Nd such that the content of Fe in the secondary alloy material was 54.52 wt% and the secondary alloy material satisfied an atomic ratio of Tb, fe to B of 2.3:10.8:1, finally obtaining a comparative rare earth permanent magnet 4, which is marked as DCT-4. Wherein, the proportion and average particle size of each element of the main alloy raw material and the auxiliary alloy raw material are shown in table 1, and the DCT-4 component is shown in table 2.
TABLE 1 composition and average particle size of Main alloy raw Material and auxiliary alloy raw Material
TABLE 2 Components of NdFeB rare earth permanent magnets
Test case
The magnetic property test is carried out on the magnetic materials prepared in the examples and the comparative examples, and the magnetic property test method comprises the following steps: the residual magnetism Br and the coercive force H of the magnet material are measured by using a PFM14.CN type ultra-high coercive force permanent magnetic material tester of China measuring institute for testing CJ And knee point coercivity H k The data are shown in table 3:
TABLE 3 Performance data for magnet materials
From the above table data, compared with the comparative magnet materials DCT-1 to DCT-4 obtained in comparative examples 1 to 4, the residual magnetism, coercive force and knee point coercive force of the neodymium-iron-boron rare earth permanent magnets CT-1 to CT-4 obtained in examples 1 to 4 are obviously improved, which indicates that the rare earth permanent magnets prepared by the method of the present disclosure can effectively form Tb outside the main phase grains 2 Fe 14 And the B shell layer reduces the proportion of heavy rare earth elements entering the main phase crystal grains, thereby improving the crystal boundary defect and improving the remanence and coercive force of the rare earth permanent magnet material.
As can be seen from a comparison of the data of example 2 and example 1, example 1 uses a preferred co-alloy starting material having an atomic ratio of Tb, fe to B of (2.1 to 2.4): (13-14): in the embodiment of 1, the prepared neodymium-iron-boron rare earth permanent magnet has higher coercive force, and the residual magnetism is hardly reduced.
As can be seen from the comparison of the data of example 3 and example 1, the content ratio of Ga, cu, co and Al in the auxiliary alloy raw materials adopted in example 1 is (1-5): (1-2): (2-5): in the embodiment of 1, the prepared neodymium-iron-boron rare earth permanent magnet has higher coercivity.
As can be seen from the comparison of the data of the comparative example 1 and the data of the example 3, the example 3 satisfies that the content of B in the auxiliary alloy raw material is 0.95-0.98 wt%, and the prepared neodymium-iron-boron rare earth permanent magnet has higher coercivity.
As can be seen from the comparison of the data of the comparative example 2 and the data of the example 2, when the total content of Zr, ti and light rare earth elements in the auxiliary alloy raw material of the example 2 is 0, the prepared neodymium-iron-boron rare earth permanent magnet has higher remanence and coercivity, and the coercivity of the prepared comparative rare earth permanent magnet is not obviously improved when the auxiliary alloy raw material of the comparative example 2 contains Ti.
As can be seen from comparison of the data of example 3 and example 1, in example 1, when the embodiment in which the content of M in the auxiliary alloy raw material is 0.9-2.2 wt% is adopted, the remanence and coercivity of the produced neodymium-iron-boron rare earth permanent magnet are greatly improved.
As can be seen from the comparison of the data of the comparative example 4 and the data of the example 4, the prepared neodymium-iron-boron rare earth permanent magnet has higher coercivity when the total content of Zr, ti and light rare earth elements in the auxiliary alloy raw material is 0 in the example 4.
The preferred embodiments of the present disclosure have been described in detail above, but the present disclosure is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solutions of the present disclosure within the scope of the technical concept of the present disclosure, and all the simple modifications belong to the protection scope of the present disclosure.
In addition, the specific features described in the foregoing embodiments may be combined in any suitable manner, and in order to avoid unnecessary repetition, the present disclosure does not further describe various possible combinations.
Moreover, any combination between the various embodiments of the present disclosure is possible as long as it does not depart from the spirit of the present disclosure, which should also be construed as the disclosure of the present disclosure.
Claims (11)
1. A method of making a neodymium-iron-boron rare earth permanent magnet, the method comprising: mixing the main alloy raw material and the auxiliary alloy raw material, and performing forming treatment, sintering treatment and aging treatment on the obtained alloy raw material; the content of the auxiliary alloy raw materials is 1-10 wt% based on the total weight of the alloy raw materials;
the main alloy raw material comprises a light rare earth element RL, ga, cu, co, al, zr, B and Fe, and the light rare earth element RL is one or more selected from Y, la, ce, pr and Nd;
the auxiliary alloy raw material comprises heavy rare earth elements, M, B and Fe, wherein the content of the heavy rare earth elements in the auxiliary alloy raw material is 32-35 wt%, the content of M is 0.9-2.2 wt%, the content of B is 0.95-0.98 wt% and the balance is Fe based on the total weight of the auxiliary alloy raw material;
wherein the heavy rare earth element is Tb, M comprises Ga, cu, co and Al, and the total content of Zr, ti and light rare earth elements in the auxiliary alloy raw material is 0.
2. The method according to claim 1, wherein the atomic ratio of Tb, fe to B in the auxiliary alloy raw material is (2 to 3): (12-15): 1, preferably (2.1 to 2.4): (13-14): 1.
3. the method according to claim 1, wherein the content of Ga in the auxiliary alloy raw material is 0.2 to 0.5 wt%, the content of Cu is 0.1 to 0.2 wt%, the content of Co is 0.5 to 1 wt%, and the content of Al is 0.1 to 0.5 wt%, based on the total weight of the auxiliary alloy raw material;
the content ratio of Ga, cu, co and Al in the auxiliary alloy raw materials is (1-5): (1-2): (2-5): 1, preferably (1 to 3): (1-1.5): (3-5): 1.
4. the method according to claim 1, wherein the main alloy raw material contains 28.5 to 31 wt% of light rare earth element RL, 0.1 to 0.5 wt% of Ga, 0.1 to 0.5 wt% of Cu, 0.5 to 3 wt% of Co, 0.1 to 1 wt% of Al, 0.1 to 0.5 wt% of Zr, 0.9 to 1 wt% of B, and the balance of Fe, based on the total weight of the main alloy raw material.
5. The method of claim 1, wherein the average particle size of the primary alloy feedstock and the secondary alloy feedstock are each 5 μιη or less;
preferably, the average particle size of the main alloy raw material is 3.5-4.5 mu m, and the average particle size of the auxiliary alloy raw material is 3.5-4.5 mu m; more preferably, the average particle size of the master alloy raw material is 4 to 4.5 μm, and the average particle size of the slave alloy raw material is 3.5 to 4 μm.
6. The method according to claim 1, wherein the molding process is an orientation molding process performed under a condition that an orientation magnetic induction is 1.8 to 3.2T; the sintering treatment temperature is 1050-1085 ℃ and the sintering treatment time is 6-8 h; the aging treatment is carried out at 490-900 ℃ for 6-8 h.
7. The method of claim 1, further comprising preparing the master alloy feedstock and the slave alloy feedstock using the steps of:
(1) According to the proportion of each element component in the main alloy raw material and the proportion of each element component in the auxiliary alloy raw material, respectively smelting the main alloy and the auxiliary alloy, and obtaining a main alloy sheet and an auxiliary alloy sheet by adopting a rapid hardening process;
(2) And respectively carrying out hydrogen crushing and micro-crushing on the main alloy sheet and the auxiliary alloy sheet to obtain the main alloy raw material and the auxiliary alloy raw material.
8. The method according to claim 7, wherein in step (1), the smelting is performed in a vacuum smelting furnace having a vacuum degree of 10 -2 ～10 2 Pa, wherein the smelting temperature is 1300-1500 ℃; the linear speed of the surface of the roller in the rapid hardening process is 0.5-1.5 m/s, and the casting temperature is 1300-1500 ℃;
in the step (2), the hydrogen absorption pressure of the hydrogen crushing is 0.15-0.4 MPa, and the dehydrogenation temperature is 560-600 ℃; the micro-crushing is performed in an air flow mill, and the grinding pressure of the air flow mill is 0.5-0.7 MPa.
9. A neodymium iron boron rare earth permanent magnet produced by the method of any one of claims 1 to 8.
10. The neodymium-iron-boron rare earth permanent magnet according to claim 9, wherein said neodymium-iron-boron rare earth permanent magnet comprises rare earth elements R, ga, cu, co, al, zr, B and Fe, and said rare earth element R comprises a light rare earth element RL and a heavy rare earth element Tb; based on the total weight of the neodymium-iron-boron rare earth permanent magnet, the content of rare earth elements R in the neodymium-iron-boron rare earth permanent magnet is 29 to 33 weight percent, the content of Ga is 0.1 to 0.5 weight percent, the content of Cu is 0.1 to 0.5 weight percent, the content of Co is 0.5 to 3 weight percent, the content of Al is 0.1 to 1 weight percent, the content of Zr is 0.1 to 0.5 weight percent, the content of B is 0.9 to 1 weight percent, and the content of Fe is 65 to 70 weight percent;
wherein, the light rare earth element RL is selected from one or more of Y, la, ce, pr and Nd.
11. The neodymium-iron-boron rare earth permanent magnet according to claim 9, characterized in that the remanence Br of the neodymium-iron-boron rare earth permanent magnet is 1.35-1.49T, preferably 1.41-1.45T; coercivity H CJ 960-2200 KA/m, preferably 1120-1600 KA/m; knee point coercivity H k 940-2110 KA/m, preferably 1100-1550 KA/m.
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