CN114823114A - Preparation method of high-performance neodymium iron boron magnet - Google Patents

Preparation method of high-performance neodymium iron boron magnet Download PDF

Info

Publication number
CN114823114A
CN114823114A CN202210448995.2A CN202210448995A CN114823114A CN 114823114 A CN114823114 A CN 114823114A CN 202210448995 A CN202210448995 A CN 202210448995A CN 114823114 A CN114823114 A CN 114823114A
Authority
CN
China
Prior art keywords
iron boron
neodymium iron
magnetic field
boron magnet
magnet
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
Application number
CN202210448995.2A
Other languages
Chinese (zh)
Inventor
张锋锐
宋青松
张燕庆
张敏
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shanxi Huiqiang Magnetic Material Manufacturing Co Ltd
Original Assignee
Shanxi Huiqiang Magnetic Material Manufacturing Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Shanxi Huiqiang Magnetic Material Manufacturing Co Ltd filed Critical Shanxi Huiqiang Magnetic Material Manufacturing Co Ltd
Priority to CN202210448995.2A priority Critical patent/CN114823114A/en
Publication of CN114823114A publication Critical patent/CN114823114A/en
Pending legal-status Critical Current

Links

Images

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
    • 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

Abstract

The application relates to a preparation method of a high-performance neodymium iron boron magnet. The method comprises the step of annealing and heat treating the sintered blank of the neodymium iron boron magnet in a magnetic field environment. The magnetic field is a direct current magnetic field; preferably, the magnetic induction intensity of the direct-current magnetic field is 0.5-2T; the annealing heat treatment comprises: heating the mixture for 2-5 hours at 700-1000 ℃ in a vacuum environment, and then cooling the mixture to 300-500 ℃ and preserving the heat for 5-10 hours. According to the method, a magnetic field annealing heat treatment process is added, the blank of the sintered neodymium iron boron magnet is subjected to annealing heat treatment in a magnetic field environment, the problem that the orientation degree of the neodymium iron boron magnet is insufficient during profiling orientation is solved, and the orientation degree of the magnet can be further increased in a heat treatment stage, so that the prepared neodymium iron boron magnet has good performance.

Description

Preparation method of high-performance neodymium iron boron magnet
Technical Field
The application relates to the technical field of magnet material preparation, in particular to a preparation method of a high-performance neodymium iron boron magnet.
Background
The neodymium iron boron magnet is a permanent magnet material with the strongest magnetism so far, is widely applied to various fields such as electronics, electromechanics, instruments, medical treatment and the like, and is a permanent magnet material which is fastest in development and has the best market prospect in the world today. In recent years, with the rapid development of computer, communication equipment and automobile production, the demand of neodymium iron boron magnet materials is increased sharply; in addition, specific applications of the magnet, such as an automotive motor and the like, further requirements on miniaturization, light weight, energy conservation, environmental protection and the like are provided, and the requirements on the performance of the magnet are higher and higher.
The main magnetic performance indexes of the neodymium iron boron magnet material are remanence Br, coercive force Hc, magnetic energy product (BH) max and Curie temperature Tc. The ferroboron magnet remanence Br and the magnetic energy product (BH) max are mainly composed of: the number of main phase volumes, the degree of orientation, the relative density, and the like.
The traditional neodymium iron boron magnet is prepared into a green body through an orientation compression process, and the magnetization direction of partial magnetic powder is changed under the factors of the external magnetic field size, the magnetic field distribution uniformity, the magnetic powder stress and the like, so that the green body orientation degree is insufficient. Therefore, it is necessary to develop a technique capable of compensating for the insufficient degree of orientation of the green compact in the orientation molding.
Disclosure of Invention
In order to solve the technical problem that the green body orientation degree is insufficient in the orientation profiling in the prior art, the application provides a preparation method of a high-performance neodymium iron boron magnet.
Therefore, the first aspect of the present application provides a method for preparing a high-performance ndfeb magnet, which includes a step of annealing a sintered ndfeb magnet blank in a magnetic field environment.
According to the method, a direct-current magnetic field is introduced in the annealing heat treatment process to induce grain growth, and the action of the magnetic field mainly comprises two aspects, namely, the flowing of a melt is inhibited and electromagnetic stirring is generated through interaction with an electric field. When fluid moves in a direct-current magnetic field, induction current is generated inside the fluid, at the moment, charged particles are in the magnetic field, the particles with the moving direction not parallel to magnetic lines of force are acted by Lorentz force, and the Lorentz force F is q.V.B, wherein the charge q of the particles and the moving speed V of the particles cannot interfere due to the influence of the characteristics of the particles, so that the magnetic field strength B needs to be improved to increase the stress of the particles, the particles are more easily moved to the direction parallel to the magnetic lines of force, the orientation degree of the magnet is further increased, and the high-performance magnet neodymium iron boron is prepared.
In some embodiments, the magnetic field is a parallel magnetic field, and the direction of the magnetic lines of the magnetic field is parallel to the direction of the magnetic lines of the geomagnetic field. By using the magnetic field, the influence of the earth magnetic field can be reduced.
In some embodiments, the magnetic field is a dc magnetic field. In some preferred embodiments, the magnetic induction intensity of the DC magnetic field is 0.5-2T. In some embodiments of the present application, the magnetic induction of the dc magnetic field may be, for example, 0.5T, 0.8T, 1.0T, 1.2T, 1.5T, or 2.0T. In some more preferred embodiments of the present application, the magnetic induction of the flow magnetic field is 1-2T.
This application can effectively improve the orientation degree of magnet through the direct current magnetic field who adopts to have above-mentioned magnetic induction intensity to prepare out high performance's neodymium iron boron magnet.
In some embodiments, the annealing heat treatment comprises: heating the mixture for 2-5 hours at 700-1000 ℃ in a vacuum environment, and then cooling the mixture to 300-500 ℃ and preserving the heat for 5-10 hours.
The rate of temperature increase for the temperature increase is not specifically limited by the present application and is a matter of routine choice in the art. In some embodiments of the present application, the temperature rise rate of the temperature rise may be (10-20) ° c/min.
Likewise, the cooling rate of the cooling is not specifically limited by the present application, and is a matter of routine choice in the art. In some embodiments of the present application, the cooling rate of the cooling may be (15-25) DEG C/min.
In some embodiments, the vacuum degree of the vacuum environment is (0.5-5) x 10 -3 Pa. In some embodiments, the vacuum degree of the vacuum environment may be 1 × 10 -3 Pa。
According to the application, the microstructure of the magnet can be effectively improved through the annealing heat treatment under the conditions, and the performance of the neodymium iron boron magnet is further improved.
In some embodiments, the method specifically comprises the steps of:
s1, preparing the raw materials of the neodymium iron boron magnet into a melt-spun sheet, and then carrying out hydrogen crushing and jet milling treatment to obtain neodymium iron boron magnetic powder;
s2, carrying out orientation compression on the neodymium iron boron magnetic powder to obtain a green body of the neodymium iron boron magnet;
s3, sintering the green body of the neodymium iron boron magnet to obtain a sintered blank of the neodymium iron boron magnet;
and S4, annealing and heat treating the sintered blank of the neodymium iron boron magnet in a magnetic field environment to obtain the neodymium iron boron magnet.
The method is suitable for proportioning various raw materials of the neodymium iron boron, so that the raw materials of the neodymium iron boron magnet are not definitely limited by the method. In some embodiments of the present application, in step S1, the raw material of the ndfeb magnet may consist of the following components, based on the total weight of the raw material of the ndfeb magnet:
0.1 to 29.9 wt% of neodymium (Nd), 0.1 to 29.9 wt% of praseodymium (Pr), 0.1 to 5 wt% of boron (B), 0.1 to 1 wt% of cobalt (Co), 0.1 to 1 wt% of niobium (Nb), 0.01 to 0.05 wt% of magnesium (Mg), 0.01 to 0.1 wt% of calcium (Ca) and the balance of iron (Fe); wherein the sum of the weights of neodymium and praseodymium is 30 wt%.
In some preferred embodiments of the present application, in step S1, the raw material of the ndfeb magnet consists of the following components, based on the total weight of the raw material of the ndfeb magnet: 5-15 wt% of neodymium, 15-25 wt% of praseodymium, 0.5-1.5 wt% of boron, 0.1-0.5 wt% of cobalt, 0.1-0.5 wt% of niobium, 0.01-0.05 wt% of magnesium, 0.01-0.1 wt% of calcium and the balance of iron; wherein the sum of the weights of neodymium and praseodymium is 30 wt%.
In some most preferred embodiments of the present application, in step S1, the raw material of the ndfeb magnet consists of the following components, based on the total weight of the raw material of the ndfeb magnet:
10 wt% neodymium, 20 wt% praseodymium, 1 wt% boron, 0.1 wt% cobalt, 0.1 wt% niobium, 0.01 wt% magnesium, 0.01 wt% calcium and 68.78 wt% iron.
The thickness of the melt-spun piece made of the raw materials of the neodymium iron boron magnet is not definitely limited in the application. In some embodiments, the thickness of the throwing sheet can be 0.1-1 mm.
The process of hydrogen fragmentation and jet milling treatment is not specifically limited in this application and is conventional in the art. The melt-spun sheet can be processed into coarse powder through hydrogen crushing, and then the coarse powder is further prepared into fine powder with the particle size of 1-5 mu m through an air flow mill.
In this application, step S2 is right the magnetic induction intensity that neodymium iron boron magnetic powder carries out orientation die mould in-process can be 0.5~ 5T. In the present application, it is preferable that the oriented and pressed product is subjected to cold isostatic pressing to obtain a green body of the neodymium-iron-boron magnet.
In some embodiments, in step S3, the sintering process includes: in a vacuum environment, heating to 200-300 ℃, preserving heat for 2-3 h, then heating to 500-600 ℃ for dehydrogenation, finally heating to 900-1200 ℃, preserving heat for 5-6 h, and cooling.
The rate of temperature increase for the temperature increase is not specifically limited by the present application and is a matter of routine choice in the art. In some embodiments of the present application, the temperature rise rate of the temperature rise may be (5-15) ° c/min.
In the sintering treatment process, the temperature is kept at 200-300 ℃ for 2-3 h to perform exhaust degreasing on the blank; keeping the temperature for 500-600 ℃ to ensure that the dehydrogenation of the blank is completed; and preserving heat for 6 hours at 900-1200 ℃ to finish the densification sintering of the blank.
In some embodiments, the vacuum degree of the vacuum environment is (0.5-5) x 10 -3 Pa. In some embodiments of the present invention, in some embodiments,the vacuum degree of the vacuum environment can be 5 multiplied by 10 -2 Pa。
This application can effectively improve the densification degree of magnet through the sintering treatment who adopts above-mentioned condition, and then improves the performance of neodymium iron boron magnet.
In some embodiments of the present application, the method for preparing the high-performance ndfeb magnet specifically includes the following steps:
(1) preparing a raw material of a neodymium iron boron magnet into a melt-spun sheet with the thickness of 0.1-1 mm in a vacuum melt-spun furnace, and then performing hydrogen crushing and jet milling treatment to obtain neodymium iron boron magnetic powder with the particle size of 1-5 mu m;
(2) pouring the neodymium iron boron magnetic powder into an orientation forming press, carrying out orientation forming under the condition that the magnetic induction intensity is 0.5-5T, and then carrying out cold isostatic pressing treatment to obtain a green body of the neodymium iron boron magnet;
(3) transferring the green body of the neodymium-iron-boron magnet into a vacuum sintering furnace for vacuum pumping to (0.5-5) x 10 under the protection of nitrogen -3 Heating Pa to 5-15 ℃/min, keeping the temperature of 200-300 ℃ for 2-3 h, continuously heating to 500-600 ℃ for dehydrogenation, continuously heating to 900-1200 ℃, keeping the temperature for 6h, and cooling to obtain a sintered neodymium-iron-boron magnet blank;
(4) transferring the sintered blank of the neodymium iron boron magnet into a magnetic field annealing furnace with the magnetic induction intensity of 0.5-2T, and vacuumizing to (0.5-5) x 10 -3 And (4) heating Pa at the temperature of 10-20 ℃/min, heating at the temperature of 700-1000 ℃ for 2-5 h, cooling to the temperature of 300-500 ℃ at the temperature of 15-25 ℃/min, and preserving heat for 5-10 h to obtain the neodymium iron boron magnet.
A second aspect of the present application provides a high performance neodymium iron boron magnet prepared by the method as described in the first aspect of the present application.
In the application, the neodymium iron boron magnet carries out annealing heat treatment on the sintered blank of the neodymium iron boron magnet in a magnetic field environment in the preparation process, so that the orientation degree of the magnet is increased, and the performance of the magnet is better.
The beneficial technical effects are as follows: according to the method, a magnetic field annealing heat treatment process is added, the blank of the sintered neodymium iron boron magnet is subjected to annealing heat treatment in a magnetic field environment, the problem that the orientation degree of the neodymium iron boron magnet is insufficient during profiling orientation is solved, and the orientation degree of the magnet can be further increased in a heat treatment stage, so that the prepared neodymium iron boron magnet has good performance.
Drawings
Fig. 1 is an SEM image of a neodymium iron boron magnet prepared in example 1 of the present application.
Fig. 2 is an SEM image of the neodymium iron boron magnet prepared in comparative example 1.
Detailed Description
In order to make the present application more easily understandable, the present application will be further described in detail with reference to examples, which are only illustrative and not limiting to the application scope of the present application. The starting materials or components used in the present application may be commercially or conventionally prepared unless otherwise specified.
Example 1
The embodiment provides a preparation method of a neodymium iron boron magnet, which comprises the following steps:
step one, according to nominal composition Nd 10 Pr 20 Fe 68.78 Co 0.1 Nb 0.1 Mg 0.01 Ca 0.01 B 1 (the number in each element subscript represents the weight percentage content of the raw materials, the unit is wt%, the same below) 1kg of materials are prepared, a vacuum rapid hardening melt-spun furnace is used for preparing a melt-spun sheet with the average thickness of 0.3mm, the melt-spun sheet is subjected to hydrogen crushing treatment to prepare coarse powder, and neodymium iron boron magnetic powder with the particle size of 3.2-3.7 mu m is prepared through an air flow mill;
step two, pouring the neodymium iron boron magnetic powder obtained in the step one into an orientation forming press, carrying out orientation forming under the magnetic induction intensity of 1.5T, and then carrying out cold isostatic pressing treatment to obtain a green body of the neodymium iron boron magnet;
step three, transferring the green body obtained in the step two into a vacuum sintering furnace under the protection of nitrogen, wherein the pressure is 5 multiplied by 10 under the vacuum environment -2 pa, heating to 250 ℃ at a speed of 10 ℃/min, keeping the temperature for 2h, exhausting and degreasing, continuously heating to 575 ℃ to ensure that dehydrogenation is completed, then heating to 1030 ℃ and keeping the temperature for 6h to complete densification and sintering, and introducing argon for rapid coolingBut, obtaining a blank of the sintered neodymium iron boron magnet;
step four, transferring the sintered blank of the neodymium iron boron magnet obtained in the step three into a direct-current magnetic field annealing furnace with the magnetic induction intensity of 0.5T, and vacuumizing to 1 multiplied by 10 -3 And (3) heating Pa at 15 ℃/min, heating at 900 ℃ for 3.5h, cooling at 20 ℃/min to 470 ℃, and preserving heat for 6h to obtain the neodymium-iron-boron magnet. The magnet was subjected to electron microscope scanning, and its SEM image is shown in fig. 1. As can be seen from fig. 1, the main phase of the neodymium-iron-boron magnet obtained in example 1 has uniform grains and clear grain boundaries, which indicates that the magnetic field can induce the grain growth to be uniform, and the neodymium-rich phase can also uniformly coat the main phase to achieve a good antiferromagnetic coupling effect, so as to improve the magnetic performance.
Example 2
The embodiment provides a preparation method of a neodymium iron boron magnet, which comprises the following steps:
step one, according to nominal composition Nd 10 Pr 20 Fe 68.78 Co 0.1 Nb 0.1 Mg 0.01 Ca 0.01 B 1 1kg of ingredients are mixed, a vacuum rapid hardening melt-spun furnace is used for preparing a melt-spun sheet with the average thickness of 0.3mm, the melt-spun sheet is subjected to hydrogen crushing treatment to prepare coarse powder, and neodymium iron boron magnetic powder with the particle size of 3.2-3.7 mu m is prepared through air flow grinding;
step two, pouring the neodymium iron boron magnetic powder obtained in the step one into an orientation forming press, carrying out orientation forming under the magnetic induction intensity of 2T, and then carrying out cold isostatic pressing treatment to obtain a green body of the neodymium iron boron magnet;
step three, transferring the green body obtained in the step two into a vacuum sintering furnace under the protection of nitrogen, wherein the pressure is 5 multiplied by 10 under the vacuum environment -2 pa, heating to 250 ℃ at a speed of 10 ℃/min, preserving heat for 2h, exhausting and degreasing, continuously heating to 575 ℃ to ensure that dehydrogenation is completed, then heating to 1030 ℃ and preserving heat for 6h to complete densification and sintering, and introducing argon to rapidly cool to obtain a sintered blank of the neodymium iron boron magnet;
step four, transferring the sintered blank of the neodymium iron boron magnet obtained in the step three into a direct-current magnetic field annealing furnace with the magnetic induction intensity of 1T, and vacuumizing to 1 multiplied by 10 -3 Pa starts to rise at 15 ℃/min, is heated at 900 ℃ for 3.5h, then is cooled to 470 ℃ at 20 ℃/min and is kept warm for 6hAnd obtaining the neodymium iron boron magnet.
Example 3
The process was substantially the same as in example 2, except that the magnetic induction intensity of the DC magnetic field annealing furnace in the fourth step was 1.5T.
Example 4
The process was substantially the same as in example 2, except that the magnetic induction intensity of the DC magnetic field annealing furnace in the fourth step was 1.2T.
Example 5
The process was substantially the same as in example 2, except that the magnetic induction intensity of the DC magnetic field annealing furnace in the fourth step was 0.8T.
Example 6
The process was substantially the same as in example 2, except that the magnetic induction intensity of the DC magnetic field annealing furnace in the fourth step was 2T.
Comparative example 1
The comparative example provides a preparation method of a neodymium iron boron magnet, which comprises the following steps:
step one, according to nominal composition Nd 10 Pr 20 Fe 68.78 Co 0.1 Nb 0.1 Mg 0.01 Ca 0.01 B 1 1kg of ingredients are mixed, a vacuum rapid hardening melt-spun furnace is used for preparing a melt-spun sheet with the average thickness of 0.3mm, the melt-spun sheet is subjected to hydrogen crushing treatment to prepare coarse powder, and neodymium iron boron magnetic powder with the particle size of 3.2-3.7 mu m is prepared through air flow grinding;
step two, pouring the neodymium iron boron magnetic powder obtained in the step one into an orientation forming press, carrying out orientation forming under the magnetic induction intensity of 1.5T, and then carrying out cold isostatic pressing treatment to obtain a green body of the neodymium iron boron magnet;
step three, transferring the green body obtained in the step two into a vacuum sintering furnace under the protection of nitrogen, wherein the pressure is 5 multiplied by 10 under the vacuum environment -2 pa, heating to 250 ℃ at a speed of 10 ℃/min, preserving heat for 2h, exhausting and degreasing, continuously heating to 575 ℃ to ensure that dehydrogenation is completed, then heating to 1030 ℃ and preserving heat for 5.5h to complete densification and sintering, and introducing argon to rapidly cool to obtain a blank of the sintered neodymium-iron-boron magnet; then carrying out secondary tempering treatment on the blank, wherein the primary tempering temperature is 900 ℃, preserving heat for 3.5h, introducing argon for rapid cooling, and then heating to 470 ℃ for secondary temperingAnd performing secondary tempering, and keeping the temperature for 6 hours to obtain the neodymium iron boron magnet. The magnet was subjected to electron microscope scanning, and its SEM image is shown in fig. 2. As can be seen from fig. 2, the neodymium-iron-boron magnet obtained in comparative example 1 has non-uniform main phase grains, unclear grain boundaries, larger grains, and agglomerated neodymium-rich phases at the grain boundaries, and does not uniformly coat the main phase grains.
Comparative example 2
The embodiment provides a preparation method of a neodymium iron boron magnet, which comprises the following steps:
step one, according to nominal composition Nd 10 Pr 20 Fe 68.78 Co 0.1 Nb 0.1 Mg 0.01 Ca 0.01 B 1 1kg of ingredients are mixed, a vacuum rapid hardening melt-spun furnace is used for preparing a melt-spun sheet with the average thickness of 0.3mm, the melt-spun sheet is subjected to hydrogen crushing treatment to prepare coarse powder, and neodymium iron boron magnetic powder with the particle size of 3.2-3.7 mu m is prepared through air flow grinding;
step two, pouring the neodymium iron boron magnetic powder obtained in the step one into an orientation forming press, carrying out orientation forming under the magnetic induction intensity of 2T, and then carrying out cold isostatic pressing treatment to obtain a green body of the neodymium iron boron magnet;
step three, transferring the green body obtained in the step two into a vacuum sintering furnace under the protection of nitrogen, wherein the pressure is 5 multiplied by 10 under the vacuum environment -2 pa, heating to 250 ℃ at a speed of 10 ℃/min, preserving heat for 2h, exhausting and degreasing, continuously heating to 575 ℃ to ensure that dehydrogenation is completed, then heating to 1030 ℃ and preserving heat for 6h to complete densification and sintering, and introducing argon to rapidly cool to obtain a sintered blank of the neodymium iron boron magnet;
step four, transferring the sintered blank of the neodymium iron boron magnet obtained in the step three into a direct-current magnetic field annealing furnace with the magnetic induction intensity of 0.2T, and vacuumizing to 1 multiplied by 10 -3 And (3) heating Pa at 15 ℃/min, heating at 900 ℃ for 3.5h, cooling at 20 ℃/min to 470 ℃, and preserving heat for 6h to obtain the neodymium-iron-boron magnet.
Test example 1
The ndfeb magnets prepared in examples 1 to 6 and comparative examples 1 to 2 were prepared into 10 × 3mm samples in which the 3mm direction was the orientation direction, and the magnetic properties of the samples were tested using an AMH-500 permanent magnetic hysteresis loop tester. The average magnetic property indexes measured are shown in table 1.
TABLE 1
Remanence (kGs) Coercive force (kOe) Magnetic energy product (MGOe)
Example 1 13.5 14.5 44.8
Example 2 14.2 11.5 46.2
Example 3 14.5 11.3 45.2
Example 4 14.2 11.6 46.5
Example 5 13.9 12.1 43.9
Example 6 14.3 12.3 45.3
Comparative example 1 12.5 12.2 43.5
Comparative example 2 13.1 12.9 43.4
As can be seen from table 1, the ndfeb magnet obtained in example 1 has better remanence, coercive force and magnetic energy product than comparative example 1, and thus it can be seen that the ndfeb magnet obtained by the method described in the present application has better magnetic properties. Comparing the magnetic performance indexes of the ndfeb magnets prepared in the comparative example 2 and the examples 2 to 5 shows that the ndfeb magnets prepared in the examples 2 to 5 have better remanence and magnetic energy product compared with the comparative example 2, which shows that the orientation degree of the prepared ndfeb magnets can be effectively improved only when the magnetic induction intensity of the adopted direct current magnetic field is within the range of 0.5 to 2T, and further the magnetic performance of the magnets is improved.
It should be noted that the above-mentioned embodiments are only for explaining the present application and do not constitute any limitation to the present application. The present application has been described with reference to exemplary embodiments, but the words which have been used herein are words of description and illustration, rather than words of limitation. Modifications may be made to the invention as specified within the scope of the claims and modifications may be made without departing from the scope and spirit of the invention. Although the present application has been described herein with reference to particular means, materials and embodiments, the present application is not intended to be limited to the particulars disclosed herein, but rather the present application extends to all other methods and applications having the same functionality.

Claims (9)

1. The preparation method of the high-performance neodymium iron boron magnet is characterized by comprising the step of carrying out annealing heat treatment on a sintered blank of the neodymium iron boron magnet in a magnetic field environment.
2. The method of claim 1, wherein the magnetic field is a parallel magnetic field, and the direction of the magnetic field lines is parallel to the direction of the magnetic field lines of the earth magnetic field.
3. The method according to claim 1 or 2, wherein the magnetic field is a direct current magnetic field; preferably, the magnetic induction intensity of the direct current magnetic field is 0.5-2T.
4. The method of claim 1 or 2, wherein the annealing heat treatment comprises: heating the mixture for 2-5 hours at 700-1000 ℃ in a vacuum environment, and then cooling the mixture to 300-500 ℃ and preserving the heat for 5-10 hours.
5. The method according to claim 4, wherein the vacuum degree of the vacuum environment is (0.5-5) x 10 -3 Pa。
6. The method according to claim 1 or 2, characterized in that it comprises in particular the steps of:
s1, preparing the raw materials of the neodymium iron boron magnet into a melt-spun sheet, and then performing hydrogen crushing and jet milling treatment to obtain neodymium iron boron magnetic powder;
s2, carrying out orientation compression on the neodymium iron boron magnetic powder to obtain a green body of the neodymium iron boron magnet;
s3, sintering the green body of the neodymium iron boron magnet to obtain a sintered blank of the neodymium iron boron magnet;
and S4, annealing the sintered blank of the neodymium iron boron magnet in a magnetic field environment to obtain the neodymium iron boron magnet.
7. The method according to claim 6, wherein in step S3, the sintering process comprises: in a vacuum environment, heating to 200-300 ℃, preserving heat for 2-3 h, then heating to 500-600 ℃ for dehydrogenation, finally heating to 900-1200 ℃, preserving heat for 5-6 h, and cooling.
8. The method according to claim 7, wherein the vacuum degree of the vacuum environment is (0.5 to 5) x 10 -3 Pa。
9. A high performance neodymium iron boron magnet prepared by the method of any one of claims 1 to 8.
CN202210448995.2A 2022-04-26 2022-04-26 Preparation method of high-performance neodymium iron boron magnet Pending CN114823114A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210448995.2A CN114823114A (en) 2022-04-26 2022-04-26 Preparation method of high-performance neodymium iron boron magnet

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210448995.2A CN114823114A (en) 2022-04-26 2022-04-26 Preparation method of high-performance neodymium iron boron magnet

Publications (1)

Publication Number Publication Date
CN114823114A true CN114823114A (en) 2022-07-29

Family

ID=82507875

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210448995.2A Pending CN114823114A (en) 2022-04-26 2022-04-26 Preparation method of high-performance neodymium iron boron magnet

Country Status (1)

Country Link
CN (1) CN114823114A (en)

Similar Documents

Publication Publication Date Title
CN103985533B (en) Eutectic alloy Hydride Doped improves the coercitive method of Sintered NdFeB magnet
CN102903472A (en) Sintered neodymium-iron-boron magnet and preparation method thereof
JP7101448B2 (en) Manufacturing method of sintered magnetic material
CN111326306B (en) R-T-B series permanent magnetic material and preparation method and application thereof
CN111326304B (en) Rare earth permanent magnetic material and preparation method and application thereof
CN112562952A (en) Neodymium-iron-boron permanent magnet material and preparation method thereof
CN101246771B (en) Method for manufacturing high-performance Nd-Fe-B permanent-magnetic material
CN111243812B (en) R-T-B series permanent magnetic material and preparation method and application thereof
CN112086255A (en) High-coercivity and high-temperature-resistant sintered neodymium-iron-boron magnet and preparation method thereof
CN111446055A (en) High-performance neodymium iron boron permanent magnet material and preparation method thereof
CN104575899A (en) Sintered neodymium iron boron magnet and preparation method thereof
CN111312462B (en) Neodymium-iron-boron material and preparation method and application thereof
CN111243811B (en) Neodymium-iron-boron material and preparation method and application thereof
CN111312463B (en) Rare earth permanent magnetic material and preparation method and application thereof
CN109326404B (en) Neodymium-iron-boron magnetic material and preparation method thereof
CN116612956A (en) Cerium-containing neodymium-iron-boron magnet with core-shell structure and preparation method and application thereof
CN114823114A (en) Preparation method of high-performance neodymium iron boron magnet
CN114823027A (en) High-boron neodymium-iron-boron permanent magnet material and preparation method thereof
CN110957094B (en) Sintering method of neodymium iron boron magnet
CN113593802A (en) Corrosion-resistant high-performance neodymium iron boron sintered magnet and preparation method and application thereof
CN114171276A (en) Magnetostatic coupling high-strength composite neodymium iron boron magnet and preparation method thereof
CN111261356A (en) R-T-B series permanent magnetic material and preparation method and application thereof
CN106205921A (en) A kind of high energy product sintered Nd-Fe-B permanent magnetic material and preparation method
CN111968813A (en) NdFeB system magnetic powder, NdFeB system sintered magnet and preparation method
CN111312464A (en) Rare earth permanent magnetic material and preparation method and application thereof

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