CN111968819A - Low-heavy rare earth high-performance sintered neodymium-iron-boron magnet and preparation method thereof - Google Patents
Low-heavy rare earth high-performance sintered neodymium-iron-boron magnet and preparation method thereof Download PDFInfo
- Publication number
- CN111968819A CN111968819A CN202010943510.8A CN202010943510A CN111968819A CN 111968819 A CN111968819 A CN 111968819A CN 202010943510 A CN202010943510 A CN 202010943510A CN 111968819 A CN111968819 A CN 111968819A
- Authority
- CN
- China
- Prior art keywords
- rare earth
- heavy rare
- heat treatment
- furnace
- preparation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 229910052761 rare earth metal Inorganic materials 0.000 title claims abstract description 56
- 229910001172 neodymium magnet Inorganic materials 0.000 title claims abstract description 40
- 150000002910 rare earth metals Chemical class 0.000 title claims abstract description 33
- 238000002360 preparation method Methods 0.000 title claims abstract description 20
- 238000010438 heat treatment Methods 0.000 claims abstract description 47
- 239000000843 powder Substances 0.000 claims abstract description 32
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims abstract description 29
- 239000001257 hydrogen Substances 0.000 claims abstract description 29
- 229910052739 hydrogen Inorganic materials 0.000 claims abstract description 29
- 238000005245 sintering Methods 0.000 claims abstract description 25
- 238000009792 diffusion process Methods 0.000 claims abstract description 21
- 238000000034 method Methods 0.000 claims abstract description 18
- 230000032683 aging Effects 0.000 claims abstract description 16
- 238000005496 tempering Methods 0.000 claims abstract description 10
- 238000000465 moulding Methods 0.000 claims abstract description 7
- 238000010902 jet-milling Methods 0.000 claims abstract description 6
- 238000000227 grinding Methods 0.000 claims abstract description 5
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 50
- 238000011049 filling Methods 0.000 claims description 26
- 229910052786 argon Inorganic materials 0.000 claims description 25
- 238000001816 cooling Methods 0.000 claims description 25
- 238000010521 absorption reaction Methods 0.000 claims description 16
- 229910045601 alloy Inorganic materials 0.000 claims description 15
- 239000000956 alloy Substances 0.000 claims description 15
- QJVKUMXDEUEQLH-UHFFFAOYSA-N [B].[Fe].[Nd] Chemical compound [B].[Fe].[Nd] QJVKUMXDEUEQLH-UHFFFAOYSA-N 0.000 claims description 14
- -1 rare earth compound Chemical class 0.000 claims description 14
- 239000002994 raw material Substances 0.000 claims description 13
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 12
- 239000003963 antioxidant agent Substances 0.000 claims description 12
- 230000003078 antioxidant effect Effects 0.000 claims description 12
- 238000002156 mixing Methods 0.000 claims description 12
- 238000005266 casting Methods 0.000 claims description 8
- 238000006356 dehydrogenation reaction Methods 0.000 claims description 8
- 238000004321 preservation Methods 0.000 claims description 8
- 239000000314 lubricant Substances 0.000 claims description 6
- 229910052757 nitrogen Inorganic materials 0.000 claims description 6
- 239000002245 particle Substances 0.000 claims description 6
- 238000003756 stirring Methods 0.000 claims description 6
- 229910052692 Dysprosium Inorganic materials 0.000 claims description 5
- 229910052771 Terbium Inorganic materials 0.000 claims description 5
- 238000004519 manufacturing process Methods 0.000 claims description 4
- 229910052782 aluminium Inorganic materials 0.000 claims description 2
- 229910052802 copper Inorganic materials 0.000 claims description 2
- 229910052742 iron Inorganic materials 0.000 claims description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 2
- 239000000463 material Substances 0.000 abstract description 3
- 239000013078 crystal Substances 0.000 abstract description 2
- 239000011261 inert gas Substances 0.000 description 4
- 229920006395 saturated elastomer Polymers 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 3
- 238000002844 melting Methods 0.000 description 3
- 230000008018 melting Effects 0.000 description 3
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 238000001755 magnetron sputter deposition Methods 0.000 description 2
- 238000007740 vapor deposition Methods 0.000 description 2
- 238000003723 Smelting Methods 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000005324 grain boundary diffusion Methods 0.000 description 1
- 238000011031 large-scale manufacturing process Methods 0.000 description 1
- 238000003801 milling Methods 0.000 description 1
- 238000011056 performance test Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
- H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
- H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
- H01F1/047—Alloys characterised by their composition
- H01F1/053—Alloys characterised by their composition containing rare earth metals
- H01F1/055—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
- H01F1/057—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
- 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
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
- H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
- H01F41/0253—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing permanent magnets
- H01F41/0266—Moulding; Pressing
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
- H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
- H01F41/0253—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing permanent magnets
- H01F41/0293—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 diffusion of rare earth elements, e.g. Tb, Dy or Ho, into permanent magnets
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Chemical & Material Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Manufacturing Cores, Coils, And Magnets (AREA)
- Hard Magnetic Materials (AREA)
- Powder Metallurgy (AREA)
Abstract
The invention discloses a low-heavy rare earth high-performance sintered neodymium-iron-boron magnet and a preparation method thereof, wherein the preparation method comprises the following steps: step one, preparing a quick-setting tablet; step two, heat treatment; step three, absorbing hydrogen and crushing; step four, jet milling; step five, orientation molding; and step six, sintering and aging. The invention relates to a preparation method of a low-heavy rare earth sintered permanent magnet material, which comprises the steps of carrying out diffusion heat treatment by using a rotary heat treatment furnace, and then carrying out the working procedures of crushing, grinding fine powder, orientation forming, diffusion sintering, multistage tempering treatment and the like to obtain a sintered neodymium-iron-boron magnet; compared with the traditional process, the cast piece heavy rare earth elements subjected to diffusion heat treatment are diffused from the surface of the magnet to the inside, so that isometric crystals can be further eliminated, an amorphous region is reduced, the heavy rare earth is more uniformly distributed after crushing, and the magnet with higher coercive force and magnetic energy product can be obtained under the condition of the same content of the heavy rare earth; compared with the diffusion heat treatment of the powder, the method has the advantages that the powder is easy to oxidize, the operation requirement is high, the requirement of the method is relatively simple, and therefore the magnet with more excellent performance can be obtained.
Description
Technical Field
The invention relates to the field of rare earth permanent magnet material preparation, in particular to a low-weight rare earth high-performance sintered neodymium iron boron magnet and a preparation method thereof.
Background
The sintered Nd-Fe-B magnet has excellent magnetic performance and is widely applied to the fields of aerospace, microwave communication technology, automobile industry, instruments and meters, medical appliances and the like. In recent years, the popularization speed and the application range of the sintered neodymium-iron-boron magnet in high-end fields such as wind power, variable frequency compressors, hybrid power and the like are rapidly expanded, and the market puts higher requirements on the performance of the sintered neodymium-iron-boron magnet.
The maximum magnetic energy product (BH) max and the coercive force Hcj are two important parameters for measuring the performance of the permanent magnet, the actual product of the current sintered Nd-Fe-B magnet reaches 59.6MGOe and reaches 93 percent of the theoretical limit, and the lifting space is limited. The coercive force of the magnet is only about 1/5 of a theoretical value, and the temperature stability is poor, so that the improvement of the coercive force of the sintered Nd-Fe-B magnet to meet the current development requirements becomes a research hotspot.
The existing method for improving the coercive force of the sintered neodymium-iron-boron magnet is mainly to add heavy rare earth elements such as Dy or Tb in the neodymium-iron-boron sintering process, and the heavy rare earth elements such as Dy or Tb are added in the raw material smelting process or added in a double-alloy mode. However, most of the heavy rare earth elements added by the methods enter the main phase of the neodymium iron boron, and only a small amount of the heavy rare earth elements are distributed in a grain boundary, and the introduction of a large amount of heavy rare earth elements such as Dy or Tb in the main phase can cause the remanence and the maximum energy product of the sintered neodymium iron boron magnet to be obviously reduced. The subsequent grain boundary diffusion is considered as an effective means for improving the coercive force, and currently, by means of magnetron sputtering, coating and vapor deposition methods, heavy rare earth elements, heavy rare earth compounds, low-melting-point heavy rare earth alloys and the like are used as diffusion sources, so that the rare earth elements are diffused into the magnet along the grain boundaries under the heat treatment condition to form a shell structure with a high magnetocrystalline anisotropy field, and further the coercive force is improved. The boundary diffusion source is mainly composed of heavy rare earth simple substance, heavy rare earth compound and heavy rare earth alloy, although the coercivity can be improved, rare earth belongs to scarce resources, and methods such as magnetron sputtering, coating, vapor deposition and the like have low utilization rate of the heavy rare earth diffusion source, so that the heavy rare earth diffusion source is greatly wasted, the production cost is further improved, and the market competition is not facilitated.
Disclosure of Invention
The invention aims to provide a low-heavy rare earth high-performance sintered neodymium-iron-boron magnet and a preparation method thereof aiming at the defects in the prior art, and the purpose of improving the coercivity is achieved without increasing the use amount of heavy rare earth.
In order to achieve the purpose, the invention adopts the technical scheme that:
the first aspect of the invention provides a preparation method of a low-heavy rare earth high-performance sintered neodymium-iron-boron magnet, which comprises the following steps:
step one, preparing a quick-setting tablet: putting a neodymium iron boron raw material into a rapid hardening furnace, heating to melt the neodymium iron boron raw material, and then casting into a rapid hardening sheet;
step two, heat treatment: placing the rapid hardening sheet and the heavy rare earth compound HRE-X in a rotary heat treatment furnace, performing diffusion heat treatment under vacuum, and filling argon for cooling after the treatment is finished;
step three, hydrogen absorption and crushing: putting the quick-setting sheet subjected to the heat treatment in the second step into a hydrogen breaking furnace for hydrogen absorption and breaking, vacuumizing again after breaking, heating the hydrogen breaking furnace for dehydrogenation reaction, and then filling argon for cooling to normal temperature to obtain alloy powder;
step four, jet milling: adding an antioxidant into the alloy powder, fully mixing, and preparing into fine powder in a jet mill;
step five, orientation molding: adding a lubricant into the fine powder added with the antioxidant, mixing and fully stirring, and adding a magnetic field in a forming press for orientation under the protection of nitrogen to obtain a green body;
step six, sintering and aging: and (3) carrying out vacuum sintering on the green body, filling argon for air cooling after the vacuum sintering is finished, and then carrying out secondary tempering treatment to obtain the low-heavy rare earth high-performance sintered neodymium-iron-boron magnet.
Further, in the first step, the casting temperature is 1400-1500 ℃; the thickness of the quick-setting tablet is 200-300 mu m.
Further, in the second step, the temperature of the diffusion heat treatment is 700-750 ℃ and the time is 2-10 h.
Further, in the second step, the rotary heat treatment furnace adopted by the diffusion heat treatment comprises a furnace body and a rotating assembly, and the furnace body rotating speed of the rotary heat treatment furnace is 2-20 rpm.
Further, the HRE is any one or combination of Tb and Dy, the X is any one or combination of Fe, Cu and Al, and the addition amount of the HRE is 0.5-4 wt% of the total mass of the heavy rare earth compound HRE-X and the quick-setting tablet.
Further, in the third step, the temperature of the dehydrogenation reaction is 350-500 ℃.
Further, in the fourth step, the particle size of the fine powder after high-speed grinding is 1 to 4 μm.
Further, in the sixth step, the vacuum sintering conditions are as follows: and (3) preserving the temperature of the green body for 6-10h at the temperature of 1000-1100 ℃.
Further, in the sixth step, the conditions of the secondary tempering treatment are as follows: the temperature of the first-stage tempering treatment is 850-; the temperature of the second-stage tempering treatment is 450-580 ℃, and the heat preservation time is 1-5 h.
The second aspect of the invention provides a low-heavy rare earth high-performance sintered neodymium-iron-boron magnet prepared by the preparation method.
By adopting the technical scheme, compared with the prior art, the invention has the following technical effects:
the invention relates to a preparation method of a low-heavy rare earth sintered permanent magnet material, which comprises the steps of carrying out diffusion heat treatment by using a rotary heat treatment furnace, and then carrying out the working procedures of crushing, grinding fine powder, orientation forming, diffusion sintering, multistage tempering treatment and the like to obtain a sintered neodymium-iron-boron magnet; compared with the traditional process, the cast piece heavy rare earth elements subjected to diffusion heat treatment are diffused from the surface of the magnet to the inside, so that isometric crystals can be further eliminated, an amorphous region is reduced, the heavy rare earth is more uniformly distributed after crushing, and the magnet with higher coercive force and magnetic energy product can be obtained under the condition of the same content of the heavy rare earth; meanwhile, compared with the diffusion heat treatment of the powder, the powder is easy to oxidize and has high operation requirements, and the requirement of the invention is relatively simple, so that the magnet with excellent performance can be obtained.
Detailed Description
The present invention is further illustrated by the following examples, which are not to be construed as limiting the invention.
It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.
Example 1
A preparation method of a low-heavy rare earth high-performance sintered neodymium-iron-boron magnet comprises the following steps:
step one, preparing a quick-setting tablet: vacuumizing the rapid hardening furnace, filling inert gas, putting the neodymium iron boron raw material into the rapid hardening furnace, heating to 1450 ℃, melting the neodymium iron boron raw material, and then casting into rapid hardening sheets;
step two, heat treatment: placing the rapid hardening tablets and 1 wt% (based on the total mass of the heavy rare earth compound HRE-X and the rapid hardening tablets) heavy rare earth compound DyFe in a rotary heat treatment furnace, vacuumizing for diffusion heat treatment at 700 ℃ for 10 hours, and filling argon for cooling after the treatment is finished;
step three, hydrogen absorption and crushing: putting the quick-setting tablets processed in the second step into a hydrogen breaking furnace for hydrogen absorption and breaking, vacuumizing again after hydrogen absorption is saturated, heating the hydrogen breaking furnace to 350 ℃ for dehydrogenation reaction, and then filling argon for cooling to normal temperature to obtain alloy powder;
step four, jet milling: adding an antioxidant into the alloy powder, fully mixing, and preparing into fine powder with the average particle size of 3 mu m in a jet mill;
step five, orientation molding: adding lubricant into the fine powder added with the antioxidant, mixing and fully stirring, and adding a magnetic field in a forming press for orientation under the protection of nitrogen to obtain a green body;
step six, sintering and aging: and (3) performing vacuum sintering on the green body at 1000 ℃ for 8h, filling argon for air cooling after the heat preservation, performing primary aging treatment at 900 ℃ for 2h under vacuum, filling argon for air cooling after the heat preservation, performing secondary aging treatment at 450 ℃ for 3h under vacuum, and filling argon for air cooling after the heat preservation, thereby obtaining the low-gravity rare earth high-performance sintered neodymium-iron-boron magnet.
Example 2
A preparation method of a low-heavy rare earth high-performance sintered neodymium-iron-boron magnet comprises the following steps:
step one, preparing a quick-setting tablet: vacuumizing the rapid hardening furnace, filling inert gas, putting the neodymium iron boron raw material into the rapid hardening furnace, heating to 1500 ℃ to melt the neodymium iron boron raw material, and then casting into rapid hardening sheets;
step two, heat treatment: placing the rapid hardening tablets and 1.2 wt% (based on the total mass of the heavy rare earth compound HRE-X and the rapid hardening tablets) heavy rare earth compound Dy-Cu in a rotary heat treatment furnace, vacuumizing for diffusion heat treatment at 750 ℃ for 8 hours, and filling argon for cooling after the treatment is finished;
step three, hydrogen absorption and crushing: putting the quick-setting tablets treated in the step two into a hydrogen breaking furnace for hydrogen absorption and breaking, vacuumizing again after hydrogen absorption is saturated, heating the hydrogen breaking furnace to 450 ℃ for dehydrogenation reaction, filling argon, and cooling to normal temperature to obtain alloy powder;
step four, jet milling: adding antioxidant into the alloy powder, mixing, and making into fine powder with average particle size of 3 μm in jet mill;
step five, orientation molding: adding lubricant into the fine powder added with the antioxidant, mixing and fully stirring, and adding a magnetic field in a forming press for orientation under the protection of nitrogen to obtain a green body;
step six, sintering and aging: and (3) vacuum sintering the green body at 1000 ℃ for 6h, introducing argon for air cooling after the heat preservation, then preserving the heat at 850 ℃ for 3h under vacuum for primary aging treatment, introducing argon for air cooling after the heat preservation, preserving the heat at 580 ℃ for 3h under vacuum for secondary aging treatment, and introducing argon for air cooling after the heat preservation, thus obtaining the low-weight rare earth high-performance sintered neodymium-iron-boron magnet.
Example 3
A preparation method of a low-heavy rare earth high-performance sintered neodymium-iron-boron magnet comprises the following steps:
step one, preparing a quick-setting tablet: vacuumizing the rapid hardening furnace, filling inert gas, putting the neodymium iron boron raw material into the rapid hardening furnace, heating to 1450 ℃, melting the neodymium iron boron raw material, and then casting into rapid hardening sheets;
step two, heat treatment: placing the rapid hardening tablets and 0.8 wt% (based on the total mass of the heavy rare earth compound HRE-X and the rapid hardening tablets) heavy rare earth compound Tb-Cu in a rotary heat treatment furnace, vacuumizing for diffusion heat treatment at 700 ℃ for 5h, and filling argon for cooling after the treatment is finished;
step three, hydrogen absorption and crushing: putting the quick-setting sheet treated in the second step into a hydrogen breaking furnace for hydrogen absorption and breaking, vacuumizing again after hydrogen absorption is saturated, heating the hydrogen breaking furnace to 400 ℃ for dehydrogenation reaction, filling argon, and cooling to normal temperature to obtain alloy powder;
step four, jet milling: adding antioxidant into the alloy powder, mixing thoroughly, and making into fine powder with average particle size of 4 μm in jet mill;
step five, orientation molding: adding lubricant into the fine powder added with the antioxidant, mixing and fully stirring, and adding a magnetic field in a forming press for orientation under the protection of nitrogen to obtain a green body;
step six, sintering and aging: and (3) vacuum sintering the green body at 1050 ℃, keeping the temperature for 6h, filling argon for air cooling after finishing the vacuum sintering, then keeping the temperature at 950 ℃ for 2h for primary aging treatment, filling argon for air cooling after finishing the vacuum sintering, keeping the temperature at 450 ℃ for 5h for secondary aging treatment, filling argon for air cooling after finishing the vacuum sintering, and obtaining the low-heavy rare earth high-performance sintered neodymium-iron-boron magnet.
Comparative example
The preparation method of the low-heavy rare earth magnet with the specific mark comprises the following steps:
step one, preparing a quick-setting tablet: vacuumizing the rapid hardening furnace, filling inert gas, putting the neodymium iron boron raw material into the rapid hardening furnace, heating to 1450 ℃, melting the neodymium iron boron raw material, and then casting into rapid hardening sheets;
step two, hydrogen absorption and crushing: putting the quick-setting sheet into a hydrogen breaking furnace for hydrogen absorption and breaking, vacuumizing again after hydrogen absorption is saturated, heating the hydrogen breaking furnace to 400 ℃ for dehydrogenation reaction, filling argon, and cooling to normal temperature to obtain alloy powder;
step three, airflow milling: preparing the alloy powder into fine powder with the average particle size of 4 mu m in an air flow mill, and adding an antioxidant for fully mixing after the grinding is finished;
step four, orientation molding: adding lubricant into the fine powder added with the antioxidant, mixing and fully stirring, and adding a magnetic field in a forming press for orientation under the protection of nitrogen to obtain a green body;
step five, sintering and aging: and (2) vacuum sintering the green body at 1050 ℃, keeping the temperature for 6h, filling argon for air cooling after finishing the vacuum sintering, then keeping the temperature at 950 ℃ for 2h for primary aging treatment, filling argon for air cooling after finishing the vacuum sintering, keeping the temperature at 450 ℃ for 5h for secondary aging treatment, and filling argon for air cooling after finishing the secondary aging treatment to obtain the magnetic steel.
The sintered nd-fe-b magnets obtained in examples 1 to 4 and comparative example were subjected to the related performance tests, and the results are shown in table 1:
TABLE 1
| Examples of the experiments | Heavy rare earth compounds | Adding amount of | Br | Hcj | (BH)max | Hk/Hcj |
| Example 1 | DyFe | 1％ | 14.35 | 17.89 | 49.58 | 0.96 |
| Example 2 | Dy-Cu | 1.2％ | 14.28 | 18.77 | 49.42 | 0.96 |
| Example 3 | Tb-Cu | 0.8％ | 14.38 | 19.21 | 50.02 | 0.96 |
| Comparative examples | / | / | 14.50 | 14.32 | 50.97 | 0.98 |
As can be seen from the above table 1, compared with the conventional preparation method, the method provided by the invention has the advantages that the coercive force is greatly improved under the condition of low-weight rare earth, and the remanence is basically not reduced, so that the product quality is ensured, the production cost is reduced, and the method is suitable for large-scale production.
While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.
Claims (10)
1. The preparation method of the low-heavy rare earth high-performance sintered neodymium-iron-boron magnet is characterized by comprising the following steps of:
step one, preparing a quick-setting tablet: putting a neodymium iron boron raw material into a rapid hardening furnace, heating to melt the neodymium iron boron raw material, and then casting into a rapid hardening sheet;
step two, heat treatment: placing the rapid hardening sheet and the heavy rare earth compound HRE-X in a rotary heat treatment furnace, performing diffusion heat treatment in vacuum, filling argon for cooling after the treatment is finished, and removing the HRE-X;
step three, hydrogen absorption and crushing: putting the rapid hardening sheet subjected to the heat treatment in the second step into a hydrogen breaking furnace for hydrogen absorption and breaking, vacuumizing again after breaking, heating the hydrogen breaking furnace for dehydrogenation reaction, and then filling argon for cooling to normal temperature to obtain alloy powder;
step four, jet milling: adding the alloy powder into an antioxidant, fully mixing, and preparing into fine powder in a jet mill;
step five, orientation molding: adding a lubricant into the fine powder added with the antioxidant, mixing and fully stirring, and adding a magnetic field in a forming press for orientation under the protection of nitrogen to obtain a green body;
step six, sintering and aging: and (3) carrying out vacuum sintering on the green body, filling argon for air cooling after the vacuum sintering is finished, and then carrying out secondary tempering treatment to obtain the low-heavy rare earth high-performance sintered neodymium-iron-boron magnet.
2. The method as claimed in claim 1, wherein the casting temperature is 1400-1500 ℃ in the first step; the thickness of the main phase rapid hardening piece is 200-300 mu m.
3. The method as claimed in claim 1, wherein the temperature of the diffusion heat treatment in the second step is 700-750 ℃ for 2-10 h.
4. The preparation method according to claim 1, wherein in the second step, the rotary heat treatment furnace used for the diffusion heat treatment comprises a furnace body and a rotating assembly, and the rotating speed of the furnace body of the rotary heat treatment furnace is 2-20 rpm.
5. The preparation method according to claim 1, wherein in the heavy rare earth compound HRE-X, the HRE is any one or combination of two of Tb and Dy, the X is any one or combination of several of Fe, Cu and Al, and the addition amount of the HRE-X is 0.5-4 wt.% of the total mass of the heavy rare earth compound HRE-X and the rapid hardening tablet.
6. The method as claimed in claim 1, wherein the dehydrogenation reaction is carried out at a temperature of 350-500 ℃ in the third step.
7. The method according to claim 1, wherein in the fourth step, the fine powder after high-speed grinding has a particle size of 1 to 4 μm.
8. The production method according to claim 1, wherein in the sixth step, the vacuum sintering conditions are: and (3) preserving the temperature of the green body for 6-10h at the temperature of 1000-1100 ℃.
9. The manufacturing method according to claim 1, wherein in the sixth step, the conditions of the secondary tempering treatment are as follows: the temperature of the first-stage tempering treatment is 850-; the temperature of the second-stage tempering treatment is 450-580 ℃, and the heat preservation time is 1-5 h.
10. A low-heavy rare earth high-performance sintered neodymium-iron-boron magnet prepared according to the preparation method of claims 1-9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010943510.8A CN111968819A (en) | 2020-09-09 | 2020-09-09 | Low-heavy rare earth high-performance sintered neodymium-iron-boron magnet and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010943510.8A CN111968819A (en) | 2020-09-09 | 2020-09-09 | Low-heavy rare earth high-performance sintered neodymium-iron-boron magnet and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111968819A true CN111968819A (en) | 2020-11-20 |
Family
ID=73392810
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010943510.8A Pending CN111968819A (en) | 2020-09-09 | 2020-09-09 | Low-heavy rare earth high-performance sintered neodymium-iron-boron magnet and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111968819A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113851320A (en) * | 2021-10-13 | 2021-12-28 | 中国科学院宁波材料技术与工程研究所 | Preparation method of light rare earth alloy grain boundary diffusion-enhanced heavy rare earth-free sintered neodymium-iron-boron magnet |
| CN114864264A (en) * | 2022-05-16 | 2022-08-05 | 安徽吉华新材料有限公司 | Preparation process of low-heavy rare earth high-coercivity rare earth neodymium-iron-boron permanent magnet |
| CN114974869A (en) * | 2022-06-01 | 2022-08-30 | 北京工业大学 | Method for efficiently regenerating high-performance neodymium iron boron magnet by using waste sintered neodymium iron boron blocks |
| CN115274286A (en) * | 2022-09-27 | 2022-11-01 | 宁波科宁达工业有限公司 | Rare earth permanent magnet and preparation method thereof |
| WO2024066029A1 (en) * | 2022-09-30 | 2024-04-04 | 杭州永磁集团有限公司 | Samarium-cobalt magnet and preparation method therefor |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101958171A (en) * | 2010-04-14 | 2011-01-26 | 无锡南理工科技发展有限公司 | Method for preparing corrosion-resistant sintered neodymium iron boron (NdFeB) magnet |
| CN103757586A (en) * | 2014-01-13 | 2014-04-30 | 赣州诚正有色金属有限公司 | Method of infiltrating metal infiltrating agent to cerium-containing neodymium iron boron magnetic material |
| WO2016086397A1 (en) * | 2014-12-04 | 2016-06-09 | 浙江大学 | Method for improving coercive force of sintered neodymium iron boron magnet by adding dysprosium hydrogen compound and product |
| JP2016122862A (en) * | 2015-08-28 | 2016-07-07 | ティアンヘ （パオトウ） アドヴァンスト テック マグネット カンパニー リミテッド | Rare earth permanent magnet material and manufacturing method therefor |
| CN106373688A (en) * | 2016-08-31 | 2017-02-01 | 浙江东阳东磁稀土有限公司 | Method for preparing rare earth permanent magnet material |
| CN106409497A (en) * | 2016-08-31 | 2017-02-15 | 浙江东阳东磁稀土有限公司 | Grain boundary diffusion method for neodymium-iron-boron magnet |
| CN108417376A (en) * | 2018-02-05 | 2018-08-17 | 宁波松科磁材有限公司 | A kind of Sintered NdFeB magnet preparation method without heavy rare earth |
| CN109732046A (en) * | 2018-12-24 | 2019-05-10 | 浙江东阳东磁稀土有限公司 | A kind of Sintered NdFeB magnet and preparation method thereof |
| CN109859922A (en) * | 2019-04-01 | 2019-06-07 | 江西金力永磁科技股份有限公司 | A kind of preparation method of the R-Fe-B magnet of low heavy rare earth content |
| CN110021467A (en) * | 2018-01-10 | 2019-07-16 | 中国科学院宁波材料技术与工程研究所 | A kind of preparation method of Sintered NdFeB magnet |
-
2020
- 2020-09-09 CN CN202010943510.8A patent/CN111968819A/en active Pending
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101958171A (en) * | 2010-04-14 | 2011-01-26 | 无锡南理工科技发展有限公司 | Method for preparing corrosion-resistant sintered neodymium iron boron (NdFeB) magnet |
| CN103757586A (en) * | 2014-01-13 | 2014-04-30 | 赣州诚正有色金属有限公司 | Method of infiltrating metal infiltrating agent to cerium-containing neodymium iron boron magnetic material |
| WO2016086397A1 (en) * | 2014-12-04 | 2016-06-09 | 浙江大学 | Method for improving coercive force of sintered neodymium iron boron magnet by adding dysprosium hydrogen compound and product |
| JP2016122862A (en) * | 2015-08-28 | 2016-07-07 | ティアンヘ （パオトウ） アドヴァンスト テック マグネット カンパニー リミテッド | Rare earth permanent magnet material and manufacturing method therefor |
| CN106373688A (en) * | 2016-08-31 | 2017-02-01 | 浙江东阳东磁稀土有限公司 | Method for preparing rare earth permanent magnet material |
| CN106409497A (en) * | 2016-08-31 | 2017-02-15 | 浙江东阳东磁稀土有限公司 | Grain boundary diffusion method for neodymium-iron-boron magnet |
| CN110021467A (en) * | 2018-01-10 | 2019-07-16 | 中国科学院宁波材料技术与工程研究所 | A kind of preparation method of Sintered NdFeB magnet |
| CN108417376A (en) * | 2018-02-05 | 2018-08-17 | 宁波松科磁材有限公司 | A kind of Sintered NdFeB magnet preparation method without heavy rare earth |
| CN109732046A (en) * | 2018-12-24 | 2019-05-10 | 浙江东阳东磁稀土有限公司 | A kind of Sintered NdFeB magnet and preparation method thereof |
| CN109859922A (en) * | 2019-04-01 | 2019-06-07 | 江西金力永磁科技股份有限公司 | A kind of preparation method of the R-Fe-B magnet of low heavy rare earth content |
Non-Patent Citations (3)
| Title |
|---|
| YUKUN LIU: "Magnetic properties and microstructure evolution of in-situ Tb-Cu diffusion treated hot-deformed Nd-Fe-B magnets", 《JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS》, vol. 504 * |
| 宋小朋: "晶界添加Dy79.73Fe20. 27对烧结钕铁硼微观结构和磁性能的影响", 《稀土》, vol. 41, no. 3, pages 11 * |
| 饶先发: "低重稀土、高矫顽力烧结钕铁硼磁体研究进展", 《广东化工》, vol. 42, no. 17 * |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113851320A (en) * | 2021-10-13 | 2021-12-28 | 中国科学院宁波材料技术与工程研究所 | Preparation method of light rare earth alloy grain boundary diffusion-enhanced heavy rare earth-free sintered neodymium-iron-boron magnet |
| CN114864264A (en) * | 2022-05-16 | 2022-08-05 | 安徽吉华新材料有限公司 | Preparation process of low-heavy rare earth high-coercivity rare earth neodymium-iron-boron permanent magnet |
| CN114864264B (en) * | 2022-05-16 | 2023-06-30 | 安徽吉华新材料有限公司 | Preparation process of low-weight rare earth high-coercivity rare earth neodymium-iron-boron permanent magnet |
| CN114974869A (en) * | 2022-06-01 | 2022-08-30 | 北京工业大学 | Method for efficiently regenerating high-performance neodymium iron boron magnet by using waste sintered neodymium iron boron blocks |
| CN115274286A (en) * | 2022-09-27 | 2022-11-01 | 宁波科宁达工业有限公司 | Rare earth permanent magnet and preparation method thereof |
| CN115274286B (en) * | 2022-09-27 | 2022-12-27 | 宁波科宁达工业有限公司 | Rare earth permanent magnet and preparation method thereof |
| WO2024066029A1 (en) * | 2022-09-30 | 2024-04-04 | 杭州永磁集团有限公司 | Samarium-cobalt magnet and preparation method therefor |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111968819A (en) | Low-heavy rare earth high-performance sintered neodymium-iron-boron magnet and preparation method thereof | |
| EP3975212A1 (en) | A method for preparation of a sintered type ndfeb permanent magnet with an adjusted grain boundary | |
| CN104681268A (en) | Processing method for improving coercive force of sintered neodymium-iron-boron magnet | |
| CN109859922B (en) | Preparation method of R-Fe-B magnet with low heavy rare earth content | |
| CN113223807B (en) | Neodymium-iron-boron permanent magnet and preparation method and application thereof | |
| CN113851320A (en) | Preparation method of light rare earth alloy grain boundary diffusion-enhanced heavy rare earth-free sintered neodymium-iron-boron magnet | |
| CN111540557B (en) | Neodymium-iron-boron magnet material, raw material composition, preparation method and application | |
| CN104464997B (en) | A kind of preparation method of high-coercivity neodymium-iron-boronpermanent-magnet permanent-magnet material | |
| CN112582121B (en) | Preparation method of ultrahigh-performance sintered samarium-cobalt magnet | |
| CN112216460B (en) | Nanocrystalline neodymium-iron-boron magnet and preparation method thereof | |
| CN114210976B (en) | Method for sintering neodymium-iron-boron double alloy and combining grain boundary diffusion | |
| CN113948303B (en) | Sintered NdFeB radiation ring and preparation method thereof | |
| EP4152348B1 (en) | Preparation method for heavy rare earth-free high-performance neodymium-iron-boron permanent magnet material | |
| CN112750586B (en) | Mixed rare earth sintered NdFeB permanent magnet and preparation method thereof | |
| WO2021218699A1 (en) | Neodymium-iron-boron magnet material, raw material composition, preparation method, and application | |
| CN109545491B (en) | Neodymium-iron-boron permanent magnet material and preparation method thereof | |
| CN112750614A (en) | Neodymium iron boron preparation method for improving utilization rate of rare earth elements | |
| CN111477446A (en) | Neodymium-iron-boron sintered magnet and preparation method thereof | |
| CN114597043A (en) | Preparation method of cerium-containing samarium cobalt permanent magnet material | |
| CN114914048A (en) | High-remanence high-coercivity heavy-rare-earth-free sintered neodymium-iron-boron magnet and preparation method thereof | |
| CN107026002A (en) | The preparation method of Nd Fe B alloys magnet | |
| CN111292912B (en) | High-performance rare earth double-alloy magnet and preparation method thereof | |
| CN112053824A (en) | Sintered neodymium-iron-boron permanent magnet and preparation method thereof | |
| CN115240943B (en) | High-Wen-resistant iron-boron material, preparation method thereof and neodymium-iron-boron sheet | |
| CN111968850B (en) | Method for preparing high-coercivity neodymium-iron-boron permanent magnet material by discharge plasma sintering |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| CB02 | Change of applicant information |
Address after: 315035 West Gate of Cicheng Town, Jiangbei District, Ningbo City, Zhejiang Province Applicant after: Ningbo Ketian Magnetic Industry Co.,Ltd. Address before: 315034, Zhejiang, Ningbo province Jiangbei District mercy town west door Applicant before: NINGBO KETIAN MAGNET Co.,Ltd. |
|
| CB02 | Change of applicant information | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20201120 |
|
| RJ01 | Rejection of invention patent application after publication |