CN112820528A - Method for improving coercive force of sintered neodymium iron boron - Google Patents
Method for improving coercive force of sintered neodymium iron boron Download PDFInfo
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- CN112820528A CN112820528A CN202010373833.8A CN202010373833A CN112820528A CN 112820528 A CN112820528 A CN 112820528A CN 202010373833 A CN202010373833 A CN 202010373833A CN 112820528 A CN112820528 A CN 112820528A
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- 229910001172 neodymium magnet Inorganic materials 0.000 title claims abstract description 112
- 238000000034 method Methods 0.000 title claims abstract description 45
- QJVKUMXDEUEQLH-UHFFFAOYSA-N [B].[Fe].[Nd] Chemical compound [B].[Fe].[Nd] QJVKUMXDEUEQLH-UHFFFAOYSA-N 0.000 title claims abstract description 30
- 239000000843 powder Substances 0.000 claims abstract description 58
- 239000011812 mixed powder Substances 0.000 claims abstract description 57
- 238000010438 heat treatment Methods 0.000 claims abstract description 47
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims abstract description 40
- 238000001816 cooling Methods 0.000 claims abstract description 37
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 36
- 229910052751 metal Inorganic materials 0.000 claims abstract description 29
- 239000002184 metal Substances 0.000 claims abstract description 29
- 229910052761 rare earth metal Inorganic materials 0.000 claims abstract description 25
- 150000002910 rare earth metals Chemical class 0.000 claims abstract description 20
- 238000002156 mixing Methods 0.000 claims abstract description 19
- 239000007788 liquid Substances 0.000 claims abstract description 13
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 22
- 239000002245 particle Substances 0.000 claims description 22
- 229910052786 argon Inorganic materials 0.000 claims description 11
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 10
- 238000012545 processing Methods 0.000 claims description 9
- 229910000881 Cu alloy Inorganic materials 0.000 claims description 8
- 229910001297 Zn alloy Inorganic materials 0.000 claims description 8
- WPPDFTBPZNZZRP-UHFFFAOYSA-N aluminum copper Chemical compound [Al].[Cu] WPPDFTBPZNZZRP-UHFFFAOYSA-N 0.000 claims description 8
- FJMNNXLGOUYVHO-UHFFFAOYSA-N aluminum zinc Chemical compound [Al].[Zn] FJMNNXLGOUYVHO-UHFFFAOYSA-N 0.000 claims description 8
- 238000005496 tempering Methods 0.000 claims description 8
- 238000001035 drying Methods 0.000 claims description 6
- 239000012535 impurity Substances 0.000 claims description 6
- 229910052757 nitrogen Inorganic materials 0.000 claims description 5
- LKNRQYTYDPPUOX-UHFFFAOYSA-K trifluoroterbium Chemical compound F[Tb](F)F LKNRQYTYDPPUOX-UHFFFAOYSA-K 0.000 claims description 5
- 229910001279 Dy alloy Inorganic materials 0.000 claims description 4
- 229910001117 Tb alloy Inorganic materials 0.000 claims description 4
- 229910003440 dysprosium oxide Inorganic materials 0.000 claims description 4
- NLQFUUYNQFMIJW-UHFFFAOYSA-N dysprosium(iii) oxide Chemical compound O=[Dy]O[Dy]=O NLQFUUYNQFMIJW-UHFFFAOYSA-N 0.000 claims description 4
- 229910003451 terbium oxide Inorganic materials 0.000 claims description 4
- SCRZPWWVSXWCMC-UHFFFAOYSA-N terbium(iii) oxide Chemical compound [O-2].[O-2].[O-2].[Tb+3].[Tb+3] SCRZPWWVSXWCMC-UHFFFAOYSA-N 0.000 claims description 4
- FWQVINSGEXZQHB-UHFFFAOYSA-K trifluorodysprosium Chemical compound F[Dy](F)F FWQVINSGEXZQHB-UHFFFAOYSA-K 0.000 claims description 4
- 230000005389 magnetism Effects 0.000 abstract description 4
- 230000000052 comparative effect Effects 0.000 description 8
- 238000001764 infiltration Methods 0.000 description 8
- 230000008595 infiltration Effects 0.000 description 8
- 238000001755 magnetron sputter deposition Methods 0.000 description 7
- 229910052771 Terbium Inorganic materials 0.000 description 5
- 239000011248 coating agent Substances 0.000 description 5
- 238000000576 coating method Methods 0.000 description 5
- 230000035515 penetration Effects 0.000 description 5
- 239000012071 phase Substances 0.000 description 5
- 239000007791 liquid phase Substances 0.000 description 4
- 238000011056 performance test Methods 0.000 description 4
- GZCRRIHWUXGPOV-UHFFFAOYSA-N terbium atom Chemical compound [Tb] GZCRRIHWUXGPOV-UHFFFAOYSA-N 0.000 description 4
- 229910052692 Dysprosium Inorganic materials 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 238000004321 preservation Methods 0.000 description 3
- 239000000758 substrate Substances 0.000 description 3
- 239000013078 crystal Substances 0.000 description 2
- KBQHZAAAGSGFKK-UHFFFAOYSA-N dysprosium atom Chemical compound [Dy] KBQHZAAAGSGFKK-UHFFFAOYSA-N 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000007790 solid phase Substances 0.000 description 2
- 229910052779 Neodymium Inorganic materials 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000004093 laser heating Methods 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- QEFYFXOXNSNQGX-UHFFFAOYSA-N neodymium atom Chemical compound [Nd] QEFYFXOXNSNQGX-UHFFFAOYSA-N 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
- H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
- H01F41/0253—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing permanent magnets
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- 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
Abstract
The invention discloses a method for improving the coercive force of sintered neodymium iron boron, which comprises the following steps: step one, preparing a sintered neodymium-iron-boron magnet sheet to be processed, wherein the thickness of the sintered neodymium-iron-boron magnet sheet is 1-8 mm; step two, mixing the heavy rare earth powder and the aluminum-containing metal powder uniformly to obtain mixed powder; uniformly scattering the mixed powder on the upper surface of the sintered neodymium iron boron magnet sheet to be processed, heating to 400-700 ℃ to melt the aluminum-containing metal powder into a liquid state, preserving heat for 3-20 s, and rapidly cooling to 15-23 ℃ to solidify the mixed powder into a film and adhere the film to the upper surface of the sintered neodymium iron boron magnet sheet to be processed; step four, turning the sintered NdFeB magnet slice to be processed by 180 degrees, and repeating the step three; and step five, placing the sintered neodymium iron boron magnet slice with the surface covered with the mixed powder film into a vacuum furnace for heat treatment. The method has strong practicability, and can obviously improve the coercive force on the premise of not influencing the residual magnetism and the maximum magnetic energy product of the sintered neodymium-iron-boron magnet.
Description
Technical Field
The invention relates to the technical field of neodymium iron boron magnet processing. More specifically, the invention relates to a method for improving the coercive force of sintered neodymium iron boron.
Background
Compared with the traditional permanent magnet material, the neodymium iron boron serving as the permanent magnet with the strongest magnetism has higher permanent magnet property and high cost performance. At present, neodymium iron boron is widely applied to important fields of internal combustion engines, new energy automobiles, wind power, information industry, consumer electronics, household appliances, elevators, magnetic medical technology and the like. Through development for many years, the performance of the sintered neodymium iron boron is continuously improved, the product of remanence and maximum magnetic energy is basically close to a theoretical value, and the coercive force is about 20-30% of the theoretical value. In recent years, the sintered neodymium-iron-boron magnet has increasingly increased requirements in the field of motors such as hybrid electric vehicles, and the like, and the working conditions of the motors are relatively poor, which puts higher requirements on the coercive force of the sintered neodymium-iron-boron magnet.
The method is characterized in that a layer of Tb or Dy and other heavy rare earth metals is attached to the surface of the sintered neodymium iron boron through a magnetron sputtering method, a later-stage heat treatment process is carried out, a neodymium-rich phase at a crystal boundary is heated and liquefied, so that the heavy rare earth metals attached to the surface of the magnet are diffused into the sintered neodymium iron boron along the crystal boundary until reaching the periphery of main phase particles, the anisotropy field of the sintered neodymium iron boron can be improved, and further the coercive force of the sintered neodymium iron boron is improved.
Disclosure of Invention
An object of the present invention is to solve at least the above problems and to provide at least the advantages described later.
The invention also aims to provide a method for improving the coercivity of the sintered neodymium iron boron, which utilizes the effect of aluminum on the enhancement of the fluidity of the grain boundary of the neodymium iron boron magnet to improve the permeation efficiency and the permeation depth of heavy rare earth elements so as to improve the coercivity of the sintered neodymium iron boron.
To achieve these objects and other advantages in accordance with the present invention, there is provided a method for improving coercivity of sintered neodymium iron boron, comprising the steps of:
step one, processing the sintered neodymium-iron-boron magnet to a sheet with the thickness of 1-8 mm, removing oil and impurities, and drying to obtain a sintered neodymium-iron-boron magnet sheet to be processed;
step two, respectively taking heavy rare earth powder and aluminum-containing metal powder for mixing, and uniformly mixing to obtain mixed powder;
uniformly scattering the mixed powder on the upper surface of the sintered neodymium iron boron magnet slice to be processed, rapidly heating to 400-700 ℃ at a heating rate of 100-150 ℃/min to melt aluminum-containing metal powder into a liquid state, keeping the temperature for 3-20 s, rapidly cooling to 15-23 ℃ at a cooling rate of 80-130 ℃/min to solidify the mixed powder into a film and adhere to the upper surface of the sintered neodymium iron boron magnet slice to be processed;
turning the sintered neodymium iron boron magnet thin sheet to be processed by 180 degrees, uniformly scattering mixed powder on the turned upper surface, rapidly heating to 400-700 ℃ at a heating rate of 100-150 ℃/min to melt aluminum-containing metal powder into liquid, keeping the temperature for 3-20 s, rapidly cooling to 15-23 ℃ at a cooling rate of 80-130 ℃/min to solidify the mixed powder into a film and adhere to the turned upper surface of the sintered neodymium iron boron magnet thin sheet to be processed;
putting the sintered neodymium-iron-boron magnet sheet coated with the mixed powder film on the surface into a vacuum furnace for tempering heat treatment;
wherein, the second step, the third step and the fourth step are all carried out under the protection of nitrogen or argon;
the powder mixing process in the step two can be carried out in a three-dimensional powder mixer, and the powder mixing time is 2-4 h;
the heating mode in the third step can be laser heating.
Preferably, in the method for improving the coercivity of the sintered neodymium-iron-boron, the aluminum-containing metal powder is at least one of aluminum, aluminum-copper alloy and aluminum-zinc alloy, and the particle size of the aluminum-containing metal powder is 0.5-100 μm. The aluminum-containing metal powder is a powder particle single product or a mixture with the particle size of 0.5-100 mu m, which is prepared by processing at least one of aluminum simple substance, aluminum-copper alloy and aluminum-zinc alloy.
Preferably, in the method for improving the coercivity of the sintered neodymium-iron-boron, the aluminum content in the aluminum-copper alloy and the aluminum-zinc alloy is not less than 20%.
Preferably, in the method for improving the coercivity of the sintered neodymium-iron-boron, the heavy rare earth powder is at least one of dysprosium oxide, terbium oxide, dysprosium fluoride, terbium fluoride, dysprosium alloy and terbium alloy, and the particle size of the heavy rare earth powder is 0.5-50 μm. The heavy rare earth powder is a single product or a mixture of powder particles with the particle size of 0.5-50 mu m, which is prepared by processing at least one of dysprosium oxide, terbium oxide, dysprosium fluoride, terbium fluoride, dysprosium alloy and terbium alloy.
Preferably, in the method for improving the coercive force of the sintered neodymium iron boron, the heavy rare earth powder and the aluminum-containing metal powder are mixed according to the weight ratio of 5: 1-50: 1.
Preferably, in the method for improving the coercive force of the sintered neodymium-iron-boron magnet, the scattering amount of the mixed powder on the surface of the sintered neodymium-iron-boron magnet sheet to be processed is 2-20 mg/cm2。
Preferably, in the method for improving the coercivity of the sintered neodymium iron boron, the tempering treatment in the fifth step is as follows: heating the sintered neodymium-iron-boron magnet sheet covered with the mixed powder film on the surface to 850-950 ℃, preserving heat for 3-8 h, air-cooling to room temperature, then heating to 470-620 ℃, preserving heat for 3-8 h, and air-cooling to room temperature.
The principle of improving the coercive force of the sintered neodymium iron boron in the method is as follows: the heavy rare earth powder is surrounded after the aluminum-containing metal powder is liquefied and is uniformly distributed on the surface of the sintered neodymium iron boron, when the temperature is reduced and the heavy rare earth powder is solidified, the aluminum-containing metal is formed into a film, the heavy rare earth powder is tightly adhered to the surface of the neodymium iron boron magnet, in the heat treatment process, part of aluminum elements enter the Nd-rich liquid phase, the infiltration angle of the Nd-rich liquid phase and the Nd2Fe14B solid phase is improved, the Nd-rich phase is better and uniformly distributed along the grain boundary, meanwhile, the heavy rare earth elements are easier to diffuse into the neodymium iron boron magnet along with the improvement of the infiltration angle, so that the infiltration time is reduced, the infiltration depth is increased, the heavy rare earth elements are infiltrated into the neodymium iron boron magnet and then replace Nd on the surface of the Nd2Fe14B phase.
The invention at least comprises the following beneficial effects: the method can obviously improve the coercive force of the sintered neodymium-iron-boron magnet, and has small influence on remanence and maximum magnetic energy product; the method is simple to operate, high in practicability and high in utilization rate of heavy rare earth metal; the aluminum-containing metal powder has low liquefaction temperature, the energy consumption can be reduced, and the heavy rare earth powder and the neodymium-iron-boron magnet can be firmly adhered together after being solidified and are not easy to fall off; fourthly, the aluminum element enters the Nd-rich liquid phase, so that the infiltration angle between the Nd-rich liquid phase and the Nd2Fe14B solid phase can be improved, the Nd-rich phase is better and uniformly distributed along the grain boundary, the heavy rare earth element is easier to diffuse into the neodymium iron boron magnet along with the improvement of the infiltration angle, the infiltration time can be reduced, and the infiltration depth can be increased; fifthly, the invention can simultaneously diffuse multiple heavy rare earth elements.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention.
Detailed Description
The present invention is further described in detail with reference to specific examples, so that those skilled in the art can implement the invention with reference to the description.
It will be understood that terms such as "having," "including," and "comprising," as used herein, do not preclude the presence or addition of one or more other elements or groups thereof.
It is to be noted that the experimental methods described in the following embodiments are all conventional methods unless otherwise specified, and the reagents and materials are commercially available unless otherwise specified.
Example 1
Step one, processing the sintered NdFeB base material to be processed into a sheet with the thickness of 1mm, removing oil and impurities, and drying to obtain a sintered NdFeB magnet sheet to be processed;
step two, mixing terbium oxide powder with the particle size of 0.5 mu m and aluminum powder with the particle size of 100 mu m for 2 hours in a three-dimensional powder mixer according to the weight ratio of 5:1 under the protection of nitrogen, and uniformly mixing to obtain mixed powder;
step three, uniformly scattering the mixed powder on the upper surface of the sintered neodymium-iron-boron magnet slice to be processed under the protection of argon, and ensuring that the scattering amount of the mixed powder is 2mg/cm2Then using laser at 100Rapidly heating to 400 ℃ at a heating rate of 80 ℃/min to melt the aluminum-containing metal powder into a liquid state, and rapidly cooling to 15 ℃ at a cooling rate of 80 ℃/min after heat preservation for 3s to solidify the mixed powder into a film and adhere the film to the upper surface of the sintered neodymium iron boron magnet sheet to be processed;
turning the sintered NdFeB magnet slice to be processed by 180 degrees under the protection of argon to enable the other side of the sintered NdFeB magnet slice to face upwards, and uniformly scattering mixed powder on the turned upper surface of the sintered NdFeB magnet slice to ensure that the scattering amount of the mixed powder is 2mg/cm2Rapidly heating to 400 ℃ at a heating rate of 100 ℃/min by using laser to melt the aluminum-containing metal powder into liquid, keeping the temperature for 3s, rapidly cooling to 15 ℃ at a cooling rate of 80 ℃/min to solidify the mixed powder into a film and adhere the film to the upper surface;
fifthly, putting the sintered neodymium iron boron magnet slice with the surface covered with the mixed powder film into a vacuum furnace for tempering heat treatment: heating to 850 deg.C, keeping the temperature for 3h, air cooling to room temperature, then heating to 470 deg.C, keeping the temperature for 3h, and air cooling to room temperature.
Comparative example 1
The method comprises the following steps: the same as example 1;
step two: coating terbium metal on the surface of the sintered neodymium iron boron magnet sheet to be processed by a magnetron sputtering method;
step three: the same as step five in example 1.
The magnetic performance test results of the sintered Nd-Fe-B magnet are shown in Table 1.
TABLE 1
| Status of state | remanence/kGs | Intrinsic coercivity/kOe | Maximum magnetic energy product/MGOe | Penetration depth/mm |
| Original state | 13.25 | 17.92 | 42.75 | ～ |
| Comparative example 1 | 13.18 | 23.31 | 42.50 | 0.8 |
| Example 1 | 13.21 | 24.64 | 42.60 | 1 |
Example 2
Step one, processing a sintered neodymium-iron-boron substrate to a sheet with the thickness of 4mm, removing oil and impurities, and drying to obtain a sintered neodymium-iron-boron magnet sheet to be processed;
under the protection of nitrogen, mixing terbium fluoride powder with the particle size of 25 microns, dysprosium oxide powder with the particle size of 25 microns and dysprosium alloy powder with the particle size of 1 micron to obtain mixed powder A, mixing aluminum powder with the particle size of 50 microns and aluminum-copper alloy powder with the particle size of 50 microns to obtain mixed powder B, mixing the mixed powder A and the mixed powder B in a three-dimensional powder mixer according to the weight ratio of 28:1 for 3 hours, and uniformly mixing to obtain mixed powder;
wherein the mass fraction of aluminum in the aluminum-copper alloy is 23 percent;
step three, under the protection of argon, evenly dividing the mixed powderSpreading on the upper surface of sintered NdFeB magnet slice to be processed to ensure that the scattering amount of the mixed powder is 11mg/cm2Rapidly heating to 550 ℃ at a heating rate of 125 ℃/min by using laser to melt the aluminum-containing metal powder into liquid, keeping the temperature for 13s, rapidly cooling to 20 ℃ at a cooling rate of 105 ℃/min to solidify the mixed powder into a film and adhere the film to the upper surface of the sintered neodymium iron boron magnet slice to be processed;
turning the sintered NdFeB magnet slice to be processed by 180 degrees under the protection of argon to enable the other side of the sintered NdFeB magnet slice to face upwards, and uniformly scattering mixed powder on the turned upper surface of the sintered NdFeB magnet slice to ensure that the scattering amount of the mixed powder is 11mg/cm2Rapidly heating to 550 ℃ at a heating rate of 125 ℃/min by using laser to melt the aluminum-containing metal powder into liquid, keeping the temperature for 13s, and rapidly cooling to 20 ℃ at a cooling rate of 105 ℃/min to solidify the mixed powder into a film and adhere the film to the upper surface;
fifthly, putting the sintered neodymium iron boron magnet slice with the surface covered with the mixed powder film into a vacuum furnace for tempering heat treatment: heating to 900 deg.C, keeping the temperature for 4.5h, air cooling to room temperature, then heating to 550 deg.C, keeping the temperature for 5h, and air cooling to room temperature.
Comparative example 2
The method comprises the following steps: the same as example 2;
step two: sequentially coating terbium and dysprosium on the surface of the sintered neodymium iron boron magnet sheet to be processed by a magnetron sputtering method;
step three: the same procedure as in step five of example 2.
The magnetic performance test results of the sintered Nd-Fe-B magnet are shown in Table 2.
TABLE 2
| Status of state | remanence/kGs | Intrinsic coercivity/kOe | Maximum magnetic energy product/MGOe | Penetration depth/mm |
| Original state | 13.24 | 17.90 | 42.63 | ～ |
| Comparative example 2 | 13.17 | 24.31 | 42.37 | 0.85 |
| Example 2 | 13.20 | 27.55 | 42.49 | 2.52 |
Example 3
Step one, processing a sintered neodymium-iron-boron substrate to a sheet with the thickness of 8mm, removing oil and impurities, and drying to obtain a sintered neodymium-iron-boron magnet sheet to be processed;
mixing dysprosium fluoride powder with the particle size of 50 microns and terbium alloy powder with the particle size of 50 microns under the protection of argon to obtain mixed powder A, mixing aluminum-zinc alloy powder with the particle size of 1 micron in a three-dimensional powder mixer according to the weight ratio of 10:1 for 4 hours, and uniformly mixing to obtain mixed powder;
wherein the mass fraction of aluminum in the aluminum-zinc alloy is 30 percent;
step three, uniformly scattering the mixed powder on the upper surface of the sintered neodymium-iron-boron magnet slice to be processed under the protection of nitrogen, and ensuring that the scattering amount of the mixed powder is 20mg/cm2Rapidly heating to 700 ℃ at a heating rate of 150 ℃/min by using laser to melt the aluminum-containing metal powder into liquid, preserving heat for 20s, rapidly cooling to 23 ℃ at a cooling rate of 130 ℃/min to solidify the mixed powder into a film and adhere the film to the upper surface of the sintered neodymium iron boron magnet slice to be processed;
turning the sintered NdFeB magnet slice to be processed by 180 degrees under the protection of argon to enable the other side of the sintered NdFeB magnet slice to face upwards, and uniformly scattering mixed powder on the turned upper surface of the sintered NdFeB magnet slice to ensure that the scattering amount of the mixed powder is 20mg/cm2Rapidly heating to 700 ℃ at a heating rate of 150 ℃/min by using laser to melt the aluminum-containing metal powder into liquid, preserving heat for 20s, rapidly cooling to 23 ℃ at a cooling rate of 130 ℃/min to solidify the mixed powder into a film and adhere the film to the upper surface;
fifthly, putting the sintered neodymium iron boron magnet slice with the surface covered with the mixed powder film into a vacuum furnace for tempering heat treatment: heating to 950 deg.C, keeping the temperature for 8h, air cooling to room temperature, then heating to 620 deg.C, keeping the temperature for 8h, and air cooling to room temperature.
Comparative example 3
The method comprises the following steps: the same as in example 3;
step two: sequentially coating two metals of dysprosium and terbium on the surface of the sintered neodymium iron boron magnet sheet to be processed by a magnetron sputtering method;
step three: the same procedure as in step five of example 3.
The magnetic performance test results of the sintered Nd-Fe-B magnet are shown in Table 3.
TABLE 3
| Status of state | remanence/kGs | Intrinsic coercivity/kOe | Maximum magnetic energy product/MGOe | Penetration depth/mm |
| Original state | 14.47 | 17.80 | 51.05 | ～ |
| Comparative example 3 | 14.38 | 24.96 | 50.46 | 0.87 |
| Example 3 | 14.40 | 29.11 | 50.53 | 2.64 |
Example 4
Step one, processing a sintered neodymium-iron-boron substrate to a sheet with the thickness of 5mm, removing oil and impurities, and drying to obtain a sintered neodymium-iron-boron magnet sheet to be processed;
mixing aluminum powder with the particle size of 50 microns and aluminum-zinc alloy powder with the particle size of 60 microns under the protection of argon to obtain mixed powder B, mixing terbium fluoride powder with the particle size of 30 microns in a three-dimensional powder mixer according to the weight ratio of 50:1 for 3 hours, and uniformly mixing to obtain mixed powder;
wherein the mass fraction of aluminum in the aluminum-copper alloy is 70 percent;
step three, uniformly scattering the mixed powder on the upper surface of the sintered neodymium-iron-boron magnet slice to be processed under the protection of argon, and ensuring that the scattering amount of the mixed powder is 12mg/cm2Rapidly heating to 600 ℃ at a heating rate of 130 ℃/min by using laser to melt the aluminum-containing metal powder into liquid, and rapidly cooling to 20 ℃ at a cooling rate of 110 ℃/min after heat preservation for 18s to solidify the mixed powder into a film and adhere the film to the upper surface of the sintered neodymium iron boron magnet slice to be processed;
turning the sintered NdFeB magnet slice to be processed by 180 degrees under the protection of argon to enable the other side of the sintered NdFeB magnet slice to face upwards, and uniformly scattering mixed powder on the turned upper surface of the sintered NdFeB magnet slice to ensure that the scattering amount of the mixed powder is 12mg/cm2Rapidly heating to 600 ℃ at a heating rate of 130 ℃/min by using laser to melt the aluminum-containing metal powder into liquid, and rapidly cooling to 20 ℃ at a cooling rate of 110 ℃/min after heat preservation for 18s to solidify the mixed powder into a film and adhere the film to the upper surface;
fifthly, putting the sintered neodymium iron boron magnet slice with the surface covered with the mixed powder film into a vacuum furnace for tempering heat treatment: heating to 910 deg.C, keeping the temperature for 5h, air cooling to room temperature, then heating to 560 deg.C, keeping the temperature for 7h, and air cooling to room temperature.
Comparative example 4
The method comprises the following steps: the same as example 4;
step two: coating terbium metal on the surface of the sintered neodymium iron boron magnet sheet to be processed by a magnetron sputtering method;
step three: the same procedure as in step five of example 4.
The magnetic performance test results of the sintered Nd-Fe-B magnet are shown in Table 4.
TABLE 4
| Status of state | remanence/kGs | Intrinsic coercivity/kOe | Maximum magnetic energy product/MGOe | Penetration depth/mm |
| Original state | 14.50 | 17.61 | 50.95 | ～ |
| Comparative example 4 | 14.39 | 24.35 | 50.44 | 0.83 |
| Example 4 | 14.43 | 28.19 | 50.57 | 2.46 |
From the test results in tables 1 to 4, the method can obviously improve the coercive force of the sintered neodymium iron boron magnet on the premise of not influencing the residual magnetism and the maximum magnetic energy product of the sintered neodymium iron boron magnet; compared with a magnetron sputtering method, the method can obviously increase the penetration depth of heavy rare earth metal in the sintered neodymium iron boron magnet, can effectively improve the coercive force of the sintered neodymium iron boron magnet, and has less influence on the residual magnetism and the maximum magnetic energy product; the method can simultaneously diffuse multiple heavy rare earth metals, has simple operation, strong practicability and high utilization rate of the heavy rare earth metals, is suitable for popularization and use, and has lower coating cost compared with a magnetron sputtering method on the surface of the sintered neodymium iron boron magnet.
The number of apparatuses and the scale of the process described herein are intended to simplify the description of the present invention. Applications, modifications and variations of the present invention will be apparent to those skilled in the art.
While embodiments of the invention have been described above, it is not limited to the applications set forth in the description and the embodiments, which are fully applicable to various fields of endeavor for which the invention may be embodied with additional modifications as would be readily apparent to those skilled in the art, and the invention is therefore not limited to the details given herein and to the embodiments shown and described without departing from the generic concept as defined by the claims and their equivalents.
Claims (7)
1. The method for improving the coercive force of the sintered neodymium iron boron is characterized by comprising the following steps of:
step one, processing the sintered neodymium-iron-boron magnet to a sheet with the thickness of 1-8 mm, removing oil and impurities, and drying to obtain a sintered neodymium-iron-boron magnet sheet to be processed;
step two, respectively taking heavy rare earth powder and aluminum-containing metal powder for mixing, and uniformly mixing to obtain mixed powder;
uniformly scattering the mixed powder on the upper surface of the sintered neodymium iron boron magnet slice to be processed, rapidly heating to 400-700 ℃ at a heating rate of 100-150 ℃/min to melt aluminum-containing metal powder into a liquid state, keeping the temperature for 3-20 s, rapidly cooling to 15-23 ℃ at a cooling rate of 80-130 ℃/min to solidify the mixed powder into a film and adhere to the upper surface of the sintered neodymium iron boron magnet slice to be processed;
turning the sintered neodymium iron boron magnet thin sheet to be processed by 180 degrees, uniformly scattering mixed powder on the turned upper surface, rapidly heating to 400-700 ℃ at a heating rate of 100-150 ℃/min to melt aluminum-containing metal powder into liquid, keeping the temperature for 3-20 s, rapidly cooling to 15-23 ℃ at a cooling rate of 80-130 ℃/min to solidify the mixed powder into a film and adhere to the turned upper surface of the sintered neodymium iron boron magnet thin sheet to be processed;
putting the sintered neodymium-iron-boron magnet sheet coated with the mixed powder film on the surface into a vacuum furnace for tempering heat treatment;
and the second step, the third step and the fourth step are all carried out under the protection of nitrogen or argon.
2. The method for improving the coercivity of sintered neodymium-iron-boron as claimed in claim 1, wherein the metal powder containing aluminum is at least one of aluminum, aluminum-copper alloy and aluminum-zinc alloy, and the particle size of the metal powder containing aluminum is 0.5-100 μm.
3. The method for improving the coercivity of sintered neodymium-iron-boron as claimed in claim 2, wherein the aluminum content in the aluminum-copper alloy and the aluminum-zinc alloy is not less than 20%.
4. The method for improving the coercivity of sintered neodymium-iron-boron according to claim 1, wherein the heavy rare earth powder is at least one of dysprosium oxide, terbium oxide, dysprosium fluoride, terbium fluoride, dysprosium alloy and terbium alloy, and the particle size of the heavy rare earth powder is 0.5-50 μm.
5. The method for improving the coercivity of sintered neodymium-iron-boron as claimed in claim 1, wherein the heavy rare earth powder and the aluminum-containing metal powder are mixed according to a weight ratio of 5:1 to 50: 1.
6. The method for improving coercivity of sintered NdFeB magnet as claimed in claim 1, wherein the scattering amount of the mixed powder on the surface of the sintered NdFeB magnet sheet to be processed is 2-20 mg/cm2。
7. The method for improving the coercivity of the sintered neodymium-iron-boron as claimed in claim 1, wherein the tempering treatment mode in the fifth step is as follows: heating the sintered neodymium-iron-boron magnet sheet covered with the mixed powder film on the surface to 850-950 ℃, preserving heat for 3-8 h, air-cooling to room temperature, then heating to 470-620 ℃, preserving heat for 3-8 h, and air-cooling to room temperature.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115954202A (en) * | 2023-02-22 | 2023-04-11 | 宁波恒盛磁业有限公司 | Method for preparing neodymium-iron-boron magnet from neodymium-iron-boron reclaimed material |
Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0249973A1 (en) * | 1986-06-16 | 1987-12-23 | Tokin Corporation | Permanent magnetic material and method for producing the same |
| CN101178963A (en) * | 2007-12-03 | 2008-05-14 | 中国石油大学(华东) | Method for preparing high coercitive force and high corrosion resistance magnetic body by nanometer powdered aluminium crystal boundary modified |
| JP2012248828A (en) * | 2011-05-02 | 2012-12-13 | Shin Etsu Chem Co Ltd | Rare earth permanent magnet and method for producing the same |
| CN104681225A (en) * | 2013-12-03 | 2015-06-03 | 湖南稀土金属材料研究院 | Treating method for improving performance of sintered NdFeB (neodymium iron boron) materials |
| CN105655075A (en) * | 2016-01-14 | 2016-06-08 | 北京科技大学 | Method for obtaining high-magnetism sintered neodymium iron boron by means of hot isostatic pressure |
| US20160203892A1 (en) * | 2015-01-09 | 2016-07-14 | Hyundai Motor Company | Rare earth permanent magnet and method for manufacturing thereof |
| CN107093516A (en) * | 2017-04-14 | 2017-08-25 | 华南理工大学 | A kind of grain boundary decision method for improving neodymium iron boron magnetic body coercivity and heat endurance |
| CN107424825A (en) * | 2017-07-21 | 2017-12-01 | 烟台首钢磁性材料股份有限公司 | A kind of neodymium iron boron magnetic body coercivity improves method |
| CN108183021A (en) * | 2017-12-12 | 2018-06-19 | 安泰科技股份有限公司 | Rare earth permanent-magnetic material and preparation method thereof |
| CN108565105A (en) * | 2018-03-05 | 2018-09-21 | 华南理工大学 | A kind of high-coercive force neodymium iron boron magnetic body and preparation method thereof |
| CN108831658A (en) * | 2018-08-28 | 2018-11-16 | 中国计量大学 | A kind of method that grain boundary decision prepares high-coercive force neodymium iron boron magnetic body under Constant charge soil |
| JP2019062156A (en) * | 2017-09-28 | 2019-04-18 | 日立金属株式会社 | Method for manufacturing r-t-b based sintered magnet |
| CN110400691A (en) * | 2019-08-07 | 2019-11-01 | 泮敏翔 | A kind of preparation method improving neodymium iron boron magnetic body coercivity and heat-resisting quantity |
| CN110415960A (en) * | 2019-07-19 | 2019-11-05 | 浙江东阳东磁稀土有限公司 | A method of improving Sintered NdFeB magnet magnetic property |
-
2020
- 2020-05-06 CN CN202010373833.8A patent/CN112820528A/en active Pending
Patent Citations (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0249973A1 (en) * | 1986-06-16 | 1987-12-23 | Tokin Corporation | Permanent magnetic material and method for producing the same |
| CN101178963A (en) * | 2007-12-03 | 2008-05-14 | 中国石油大学(华东) | Method for preparing high coercitive force and high corrosion resistance magnetic body by nanometer powdered aluminium crystal boundary modified |
| JP2012248828A (en) * | 2011-05-02 | 2012-12-13 | Shin Etsu Chem Co Ltd | Rare earth permanent magnet and method for producing the same |
| CN104681225A (en) * | 2013-12-03 | 2015-06-03 | 湖南稀土金属材料研究院 | Treating method for improving performance of sintered NdFeB (neodymium iron boron) materials |
| US20160203892A1 (en) * | 2015-01-09 | 2016-07-14 | Hyundai Motor Company | Rare earth permanent magnet and method for manufacturing thereof |
| CN105655075A (en) * | 2016-01-14 | 2016-06-08 | 北京科技大学 | Method for obtaining high-magnetism sintered neodymium iron boron by means of hot isostatic pressure |
| CN107093516A (en) * | 2017-04-14 | 2017-08-25 | 华南理工大学 | A kind of grain boundary decision method for improving neodymium iron boron magnetic body coercivity and heat endurance |
| CN107424825A (en) * | 2017-07-21 | 2017-12-01 | 烟台首钢磁性材料股份有限公司 | A kind of neodymium iron boron magnetic body coercivity improves method |
| JP2019062156A (en) * | 2017-09-28 | 2019-04-18 | 日立金属株式会社 | Method for manufacturing r-t-b based sintered magnet |
| CN108183021A (en) * | 2017-12-12 | 2018-06-19 | 安泰科技股份有限公司 | Rare earth permanent-magnetic material and preparation method thereof |
| CN108565105A (en) * | 2018-03-05 | 2018-09-21 | 华南理工大学 | A kind of high-coercive force neodymium iron boron magnetic body and preparation method thereof |
| WO2019169875A1 (en) * | 2018-03-05 | 2019-09-12 | 华南理工大学 | High-coercivity neodymium iron boron magnet and preparation method therefor |
| CN108831658A (en) * | 2018-08-28 | 2018-11-16 | 中国计量大学 | A kind of method that grain boundary decision prepares high-coercive force neodymium iron boron magnetic body under Constant charge soil |
| CN110415960A (en) * | 2019-07-19 | 2019-11-05 | 浙江东阳东磁稀土有限公司 | A method of improving Sintered NdFeB magnet magnetic property |
| CN110400691A (en) * | 2019-08-07 | 2019-11-01 | 泮敏翔 | A kind of preparation method improving neodymium iron boron magnetic body coercivity and heat-resisting quantity |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115954202A (en) * | 2023-02-22 | 2023-04-11 | 宁波恒盛磁业有限公司 | Method for preparing neodymium-iron-boron magnet from neodymium-iron-boron reclaimed material |
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