Preparation method of high-performance cerium-rich neodymium-iron-boron magnet
The cerium-rich neodymium iron boron magnet is prepared through the melt fast quenching method and high-energy ball milling technology. The low magnetic field diffusion heat treatment is used to solve the problems of improving the performance and weight reduction of rare earth permanent magnet materials, and the preparation of high-performance magnets is realized. It is suitable for a variety of applications .
Patent Information
- Application Number
- CN202411581429.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-07
- Publication Date
- 2024-12-20
AI Technical Summary
The prior art is difficult to effectively improve the magnetic performance and weight reduction of rare earth permanent magnet materials, and its heavy rare earth content is relatively high, which limits the performance improvement and application range of the material.
The cerium-rich neodymium iron boron thin-band amorphous alloy was prepared by melt fast quenching method, and a low-melting point Dy-Co-Al-Cu nanocrystalline alloy was prepared by high-energy ball milling technology to form a suspension and polyethylene glycol configuration, and perform low-low The diffusion heat treatment under the magnetic field achieves grain boundary diffusion and prepares high-performance cerium-rich neodymium-ferrobor magnets.
It has achieved high performance improvement of rare earth permanent magnet materials, significantly improved intrinsic coercive force and residual magnetism. It is suitable for the preparation of bonded magnets and composite magnets, and expanded the scope of application.
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of magnetic materials, and in particular to a method for preparing a high-performance cerium-rich neodymium iron boron magnet. Background Art
[0002] As a medium for converting electrical energy into mechanical energy, rare earth permanent magnet materials are currently used as core components in new energy fields such as wind power generation and electric vehicles due to their excellent magnetic properties. At the same time, with their extremely high energy density, they are constantly driving electronic equipment towards high efficiency, light weight, and miniaturization. Now the development level of permanent magnet materials has become an important indicator to measure the development level of a country.
[0003] Grain boundary diffusion technology is a new technology developed in recent years to improve the magnetic properties and reduce the weight of rare earth in sintered NdFeB materials. Under the same coercivity, its heavy rare earth content is only 20-30% of that of traditional high coercivity sintered NdFeB permanent magnets, and the remanence remains basically unchanged. To this end, the present invention discloses a new technology for grain boundary diffusion of cerium-rich NdFeB magnets using a low-melting-point Dy-Co-Al-Cu nanocrystalline alloy. First, a cerium-rich NdFeB thin ribbon amorphous alloy is prepared by melt rapid quenching method and a low-melting-point Dy-Co-Al-Cu nanocrystalline alloy is prepared by high-energy ball milling technology to obtain two alloys with different forms and structures. At the same time, the low-melting-point Dy-Co-Al-Cu nanocrystalline alloy and a polyethylene glycol dispersant are configured into a uniform suspension in anhydrous ethanol, and then the amorphous thin ribbon alloy is immersed in the suspension and subsequently diffused heat treated under a low magnetic field to obtain the final high-performance cerium-rich NdFeB magnet. The cerium-rich NdFeB thin ribbon magnet prepared by this method has a wide range of applications and can be used to prepare bonded magnets or as a hard magnetic phase to prepare composite magnets. Summary of the invention
[0004] In view of the problems existing in the prior art, the present invention aims to provide a method for preparing a high-performance cerium-rich neodymium iron boron magnet.
[0005] The method for preparing a high-performance cerium-rich neodymium iron boron magnet of the present invention comprises the following steps: (1) Preparation of Ce by atomic percentage using melt quenching method a Nd 100-a ) x (Fe 100-b M b ) 100-x-y B y Ce-rich NdFeB thin strip amorphous alloy, the copper roller speed is 35~60 m / s, where: 55≤a≤75, 2≤b≤5, 34≤x≤40, 1≤y≤2, M is one or more of Co, Ti, Cu, Nb, Hf, Al, Ga; (2) Preparation of low melting point Dy in atomic percentage using high energy ball milling technology u Co v Al w Cu 100-u-v-w Nanocrystalline alloy powder, ball milling time is 5~10 h, where: 5≤u≤10, 5≤v≤10, 5≤w≤10; then low melting point Dy u Co v Al w Cu 100-u-v-w Nanocrystalline alloy powder and polyethylene glycol dispersant are prepared into a uniform suspension in anhydrous ethanol, wherein the low melting point Dy u Co v Al w Cu 100-u-v-w The mass ratio of nanocrystalline alloy powder to dispersant is 1:0.01~0.05; (3) placing the suspension obtained in step (2) on a heating plate and heating it to 50-75°C, then immersing the amorphous thin strip alloy obtained in step (1) in the suspension for 10-50 min to form a uniform diffusion source on the surface of the amorphous thin strip alloy, then taking it out and placing it on a heating plate and heating it for 1-3 min to evaporate the anhydrous ethanol on the surface; (4) The thin strip alloy obtained in step (3) is subjected to diffusion heat treatment under a low magnetic field to obtain a final high-performance cerium-rich NdFeB magnet.
[0006] Furthermore, the diffusion heat treatment under low magnetic field described in step (4) is divided into a primary grain boundary diffusion heat treatment and a secondary annealing heat treatment. The magnetic field intensity of the primary grain boundary diffusion heat treatment is 0.3~0.6 T, the temperature is 800~950 °C, the holding time is 30~50 min, and then it is rapidly cooled to room temperature; the magnetic field intensity of the secondary annealing heat treatment is 0.1~0.3 T, the temperature is 500~600 °C, the holding time is 10~20 min, and then it is rapidly cooled to room temperature.
[0007] Compared with the existing technology, the present invention has the following advantages and beneficial effects: the present invention discloses a new technology for grain boundary diffusion of cerium-rich NdFeB magnets using low-melting-point Dy-Co-Al-Cu nanocrystalline alloys, and prepares two alloys of different forms and structures of cerium-rich NdFeB thin ribbon amorphous alloy and low-melting-point Dy-Co-Al-Cu nanocrystalline alloy respectively by melt rapid quenching and high-energy ball milling technology, and then immerses the cerium-rich NdFeB thin ribbon amorphous alloy in a uniform suspension prepared by low-melting-point Dy-Co-Al-Cu nanocrystalline alloy and polyethylene glycol dispersant in anhydrous ethanol, and the suspension is heated to a certain temperature in a heating plate to form a uniform diffusion source on the surface of the amorphous thin ribbon alloy; then the thin ribbon alloy is subjected to diffusion heat treatment under a low magnetic field to obtain the final high-performance cerium-rich NdFeB magnet. The cerium-rich NdFeB thin ribbon magnet prepared by this method has a wide range of applications, and can be used to prepare bonded magnets or as a hard magnetic phase to prepare composite magnets. DETAILED DESCRIPTION
[0008] The present invention will be further described in detail below with reference to the embodiments, but the present invention is not limited to the following embodiments.
[0009] Example 1 (1) Preparation of Ce by atomic percentage using melt quenching method 55 Nd 45 ) 36 (Fe 98 Co2) 63 B is a cerium-rich NdFeB thin ribbon amorphous alloy, and the copper roller speed is 35 m / s; (2) Preparation of low melting point Dy5Co5Al7Cu by atomic percentage using high energy ball milling technology 83 Nanocrystalline alloy powder, ball milling time is 5 h; then low melting point Dy5Co5Al7Cu 83 Nanocrystalline alloy powder and polyethylene glycol dispersant are prepared into a uniform suspension in anhydrous ethanol, in which low melting point Dy5Co5Al7Cu 83 The mass ratio of nanocrystalline alloy powder to dispersant is 1:0.01; (3) placing the suspension obtained in step (2) on a heating plate and heating it to 50°C, then immersing the amorphous thin strip alloy obtained in step (1) in the suspension for 10 min to form a uniform diffusion source on the surface of the amorphous thin strip alloy, then taking it out and placing it on a heating plate and heating it for 3 min to evaporate the anhydrous ethanol on the surface; (4) The thin strip alloy obtained in step (3) is subjected to diffusion heat treatment under a low magnetic field. The diffusion heat treatment under a low magnetic field is divided into a primary grain boundary diffusion heat treatment and a secondary annealing heat treatment. The magnetic field intensity of the primary grain boundary diffusion heat treatment is 0.3 T, the temperature is 850 ° C, the holding time is 50 min, and then it is rapidly cooled to room temperature; the magnetic field intensity of the secondary annealing heat treatment is 0.3 T, the temperature is 600 ° C, the holding time is 10 min, and then it is rapidly cooled to room temperature, and finally the final high-performance cerium-rich NdFeB magnet is obtained.
[0010] The cerium-rich NdFeB magnet prepared by the present invention has an intrinsic coercive force of 15.61 kOe, a remanence of 11.21 kG, and a magnetic energy product of 18.91 MGOe through magnetic property testing.
[0011] Example 2 (1) Preparation of Ce by atomic percentage using melt quenching method 60 Nd 40 ) 38 (Fe 97 Ti1Cu2) 60.5 B 1.5 Ce-rich NdFeB thin strip amorphous alloy, the copper roller speed is 45 m / s; (2) Preparation of low melting point Dy7Co7Al8Cu by atomic percentage using high energy ball milling technology 78 Nanocrystalline alloy powder, ball milling time is 7 h; then low melting point Dy7Co7Al8Cu 78 Nanocrystalline alloy powder and polyethylene glycol dispersant are prepared into a uniform suspension in anhydrous ethanol, in which low melting point Dy7Co7Al8Cu 78 The mass ratio of nanocrystalline alloy powder to dispersant is 1:0.03; (3) placing the suspension obtained in step (2) on a heating plate and heating it to 60°C, then immersing the amorphous thin strip alloy obtained in step (1) in the suspension for 30 min, so that a uniform diffusion source is formed on the surface of the amorphous thin strip alloy, then taking it out and placing it on a heating plate and heating it for 3 min to evaporate the anhydrous ethanol on the surface; (4) The thin strip alloy obtained in step (3) is subjected to diffusion heat treatment under low magnetic field. The diffusion heat treatment under low magnetic field is divided into primary grain boundary diffusion heat treatment and secondary annealing heat treatment. The magnetic field intensity of the primary grain boundary diffusion heat treatment is 0.5 T, the temperature is 900 °C, the holding time is 40 min, and then it is rapidly cooled to room temperature; the magnetic field intensity of the secondary annealing heat treatment is 0.2 T, the temperature is 550 °C, the holding time is 15 min, and then it is rapidly cooled to room temperature, and finally the final high-performance cerium-rich NdFeB magnet is obtained.
[0012] The cerium-rich NdFeB magnet prepared by the present invention has an intrinsic coercive force of 16.89 kOe, a remanence of 11.25 kG, and a magnetic energy product of 19.25 MGOe through magnetic property testing.
[0013] Example 3 (1) Preparation of Ce by atomic percentage using melt quenching method 68 Nd 32 ) 40 (Fe 96 Co2Ga2) 58 B2 Ce-rich NdFeB thin strip amorphous alloy, the copper roller speed is 55 m / s; (2) Using high-energy ball milling technology to prepare low-melting-point Dy in atomic percentage 10 Co 10 Al9Cu 71 Nanocrystalline alloy powder, ball milling time is 10 h; then low melting point Dy 10 Co 10 Al9Cu 71 Nanocrystalline alloy powder and polyethylene glycol dispersant are prepared into a uniform suspension in anhydrous ethanol, wherein the low melting point Dy 10 Co 10 Al9Cu 71 The mass ratio of nanocrystalline alloy powder to dispersant is 1:0.05; (3) placing the suspension obtained in step (2) on a heating plate and heating it to 70°C, then immersing the amorphous thin strip alloy obtained in step (1) in the suspension for 50 min to form a uniform diffusion source on the surface of the amorphous thin strip alloy, then taking it out and placing it on a heating plate and heating it for 3 min to evaporate the anhydrous ethanol on the surface; (4) The thin strip alloy obtained in step (3) is subjected to diffusion heat treatment under a low magnetic field. The diffusion heat treatment under a low magnetic field is divided into a primary grain boundary diffusion heat treatment and a secondary annealing heat treatment. The magnetic field intensity of the primary grain boundary diffusion heat treatment is 0.6 T, the temperature is 950 ° C, the holding time is 30 min, and then it is rapidly cooled to room temperature; the magnetic field intensity of the secondary annealing heat treatment is 0.1 T, the temperature is 500 ° C, the holding time is 20 min, and then it is rapidly cooled to room temperature, and finally the final high-performance cerium-rich NdFeB magnet is obtained.
[0014] The cerium-rich NdFeB magnet prepared by the present invention is tested for magnetic properties, and the intrinsic coercive force is 17.99 kOe, the remanence is 12.05 kG, and the magnetic energy product is 19.08 MGOe.
Claims
1. A method for preparing a high-performance cerium-rich neodymium iron boron magnet, characterized in that The steps include: (1) Preparation of Ce by atomic percentage using melt quenching method a Nd 100-a ) x (Fe 100-b M b ) 100-x-y B y Ce-rich NdFeB thin strip amorphous alloy, the copper roller speed is 35~60 m / s, where: 55≤a≤75, 2≤b≤5, 34≤x≤40, 1≤y≤2, M is one or more of Co, Ti, Cu, Nb, Hf, Al, Ga; (2) Using high-energy ball milling technology to prepare low-melting-point Dy in atomic percentage u Co v Al w Cu 100-u-v-w Nanocrystalline alloy powder, ball milling time is 5~10 h, where: 5≤u≤10, 5≤v≤10, 5≤w≤10; then low melting point Dy u Co v Al w Cu 100-u-v-w Nanocrystalline alloy powder and polyethylene glycol dispersant are prepared into a uniform suspension in anhydrous ethanol, wherein the low melting point Dy u Co v Al w Cu 100-u-v-w The mass ratio of nanocrystalline alloy powder to dispersant is 1:0.01~0.05; (3) placing the suspension obtained in step (2) on a heating plate and heating it to 50-75°C, then immersing the amorphous thin strip alloy obtained in step (1) in the suspension for 10-50 min to form a uniform diffusion source on the surface of the amorphous thin strip alloy, then taking it out and placing it on a heating plate and heating it for 1-3 min to evaporate the anhydrous ethanol on the surface; (4) The thin strip alloy obtained in step (3) is subjected to diffusion heat treatment under a low magnetic field to obtain a final high-performance cerium-rich NdFeB magnet.
2. The method for preparing a high performance cerium-rich NdFeB magnet according to claim 1, characterized in that: The diffusion heat treatment under low magnetic field described in step (4) is divided into a primary grain boundary diffusion heat treatment and a secondary annealing heat treatment. The magnetic field intensity of the primary grain boundary diffusion heat treatment is 0.3~0.6 T, the temperature is 800~950 °C, the holding time is 30~50 min, and then it is rapidly cooled to room temperature; the magnetic field intensity of the secondary annealing heat treatment is 0.1~0.3 T, the temperature is 500~600 °C, the holding time is 10~20 min, and then it is rapidly cooled to room temperature.