CN108417372B - Preparation method of cerium-rich magnet for driving motor - Google Patents

Preparation method of cerium-rich magnet for driving motor Download PDF

Info

Publication number
CN108417372B
CN108417372B CN201810088550.1A CN201810088550A CN108417372B CN 108417372 B CN108417372 B CN 108417372B CN 201810088550 A CN201810088550 A CN 201810088550A CN 108417372 B CN108417372 B CN 108417372B
Authority
CN
China
Prior art keywords
cerium
hydrogen
powder
magnet
rich
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.)
Active
Application number
CN201810088550.1A
Other languages
Chinese (zh)
Other versions
CN108417372A (en
Inventor
李安华
靳朝相
邹宁
吕忠山
冯海波
邹永博
邹宇钦
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.)
Ningbo Shuoteng New Material Co ltd
Original Assignee
Ningbo Shuoteng New Material 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 Ningbo Shuoteng New Material Co ltd filed Critical Ningbo Shuoteng New Material Co ltd
Priority to CN201810088550.1A priority Critical patent/CN108417372B/en
Publication of CN108417372A publication Critical patent/CN108417372A/en
Application granted granted Critical
Publication of CN108417372B publication Critical patent/CN108417372B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F9/00—Making metallic powder or suspensions thereof
    • B22F9/02—Making metallic powder or suspensions thereof using physical processes
    • B22F9/023—Hydrogen absorption
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F9/00—Making metallic powder or suspensions thereof
    • B22F9/02—Making metallic powder or suspensions thereof using physical processes
    • B22F9/04—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling
    • 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

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Hard Magnetic Materials (AREA)
  • Powder Metallurgy (AREA)

Abstract

A preparation method of a cerium-rich magnet for a driving motor is provided, wherein the cerium-rich magnet is cerium-iron-boron alloy powder, and the chemical formula and the components of the cerium-rich magnet are (Ce) in percentage by mass1‑xRx)aFe100‑a‑b‑cMbBc. The preparation method of the cerium-rich magnet comprises the following steps: preparing a cerium-iron-boron alloy rapid-hardening sheet by adopting a rapid-hardening process; roughly crushing the cerium-iron-boron alloy quick-setting piece by using a hydrogen crushing process to prepare hydrogen crushed powder; putting the hydrogen broken powder into a mixing tank filled with inert gas and hydrogen gas, and uniformly mixing; further crushing the hydrogen broken powder into fine powder by using an airflow milling process, and supplementing hydrogen in the airflow milling process; and (3) preparing the cerium-rich magnet for the driving motor by using the fine powder after jet milling through magnetic field orientation forming, isostatic pressing, vacuum sintering and tempering heat treatment processes. According to the invention, the micro hydrogen is added in the hydrogen powder breaking and mixing step and the airflow milling step, so that the oxidation of the cerium-rich magnet alloy powder is reduced, and the performance of the prepared cerium-rich magnet is improved.

Description

Preparation method of cerium-rich magnet for driving motor
Technical Field
The invention belongs to the technical field of permanent magnet materials, and particularly relates to a preparation method of a cerium-rich magnet for a driving motor.
Background
Rare earth permanent magnet materials represented by neodymium iron boron are widely applied to the fields of power electronics, information communication, transportation, motors, office automation, medical instruments, aerospace and the like due to excellent magnetic properties, and application of some highly integrated high and new technology products is possible, such as hybrid electric vehicles, power generation windmills and the like. With the development of industry and the progress of society, the usage amount of neodymium iron boron is increased year by year, and a large amount of rare earth metals such as neodymium (Nd), praseodymium (Pr), dysprosium (Dy), terbium (Tb) and the like are consumed. In order to save the use of scarce rare earth, balance the utilization of rare earth and reduce the production cost, in recent years, a novel cerium-rich magnet (see patent CN 102969111A) is rapidly developed, and the market share is continuously expanded.
The expensive price of rare earth and the lack of partial rare earth resources have prompted researchers to have a long-lasting interest in Ce. However, Ce2Fe14The saturation magnetization and the anisotropy field of B are both lower than that of Nd2Fe14B phase, at the same time Ce2Fe14The B single-main-phase compound is difficult to have high remanence and coercive force at the same time. Partial substitution of Nd with Ce to form (Ce, Nd)2Fe14The compound with B phase as main phase is an effective way for preparing permanent magnetic material with practical application value, such as [ CN102800454A ]]The patent discloses (Ce, Nd) -Fe-B sintered permanent magnet materials. However, the performance of the cerium-rich magnet prepared by the traditional sintering process only reaches the level of a medium-low grade neodymium iron boron magnet, the coercive force is generally lower than 15kOe, and the requirements of high-end markets such as a driving motor and the like cannot be met.
The sintered cerium-rich magnet is produced by a production process similar to sintered neodymium iron boron, wherein a rapid hardening flake is firstly produced by a rapid hardening and flaying process, and then the rapid hardening flake is crushed into coarse powder by a hydrogen crushing process and then is produced into fine powder by an air flow milling process. Finally, the obtained fine powder is subjected to magnetic field orientation forming, vacuum sintering and tempering heat treatment to prepare the compact anisotropic sintered magnet. It is well known that the principle of the hydrogen cracking process is that after neodymium iron boron alloy contacts hydrogen, the main phase (CeNd)2Fe14The expansion coefficients of B and the hydrogen absorption crystal lattice of the rare earth-rich phase are different, so that the alloy is easy to break along the grain boundary and is finally pulverized into coarse powder. The general principle of the jet milling process is to use a continuous high-speed idlerThe gas flow of the sexual gas impacts the solid material, and the solid coarse particles collide and rub with each other in the gas flow to be further crushed into fine particles. The neodymium iron boron series alloy powder obtained by the hydrogen breaking process and the airflow milling process has high activity and is easy to oxidize, and needs inert gas protection in the processes of storage and subsequent magnet preparation processes, and because the oxygen content of the neodymium iron boron magnet is too high, the magnetic performance, particularly the coercive force, can be seriously reduced. Meanwhile, because the rare earth permanent magnet has multiple preparation process procedures and long flow, the alloy powder or the magnet blank can contact oxygen in each process link, so that oxidation occurs to a certain degree. The chemical activity of the cerium element is obviously higher than that of the neodymium element, and the cerium-rich magnet is easier to oxidize than the neodymium-iron-boron magnet in the preparation process. Therefore, in order to improve the coercive force of the cerium-rich magnet and expand the application field, it is necessary to optimize the preparation process of the cerium-rich magnet and reduce the oxygen content in the alloy.
Disclosure of Invention
In view of the above, the present invention provides a method for preparing a cerium-rich magnet for a driving motor, which prevents the cerium-rich magnet from being oxidized during the manufacturing process, so as to solve the above technical problems.
A method of preparing a cerium-rich magnet for a drive motor, comprising the steps of:
providing the powder material of the cerium-rich magnet, wherein the cerium-rich magnet comprises the following components in percentage by mass (Ce)1- xRx)aFe100-a-b-cMbBcWherein R is at least one of Nd, Pr, Dy, Tb, Ho and Gd, M is at least one of Co, Al, Cu, Ga, Nb and Zr, x is more than or equal to 0.5 and less than or equal to 0.9, a is more than or equal to 28.0 and less than or equal to 33, b is more than or equal to 0.1 and less than or equal to 5, and c is more than or equal to 0.8 and less than or equal to 1.1;
preparing a cerium-iron-boron alloy rapid-hardening sheet by adopting a rapid-hardening process;
roughly crushing the cerium-iron-boron alloy quick-setting piece by using a hydrogen crushing process to prepare hydrogen crushed powder;
putting the hydrogen broken powder into a charging bucket filled with inert gas and hydrogen, and uniformly mixing;
breaking the powder by using the airflow milling process and further crushing the powder into fine powder, and supplementing hydrogen in the airflow milling process;
and (3) preparing the cerium-rich magnet for the driving motor by using the fine powder after jet milling through magnetic field orientation forming, isostatic pressing, vacuum sintering and tempering heat treatment processes.
Further, in the hydrogen powder breaking and mixing process, inert gas and hydrogen gas are respectively filled into the charging bucket, and the pressure of the mixed gas in the charging bucket is positive pressure.
Furthermore, in the hydrogen powder breaking and mixing process, the content of the hydrogen filled into the charging bucket is 50ppm to 300 ppm.
Further, in the hydrogen pulverizing and mixing process, the inert gas filled into the charging bucket is at least one of argon and helium.
Further, in the hydrogen powder breaking and mixing process, an antioxidant and gasoline are added as protective media.
Further, the hydrogen crushing and mixing time is 0.5-3 hours.
Further, the amount of the hydrogen supplemented in the jet milling process is not higher than 300 ppm.
Furthermore, the particle size of the fine powder prepared in the air flow milling process is 1-5 microns.
Further, the magnetic field is oriented and molded, the orientation magnetic field is 1.5-2.0T, and the pressure of the isostatic pressure is 160-250 MPa.
Further, the vacuum sintering is carried out, wherein the sintering temperature is 990-1100 ℃, and the vacuum degree is at least 1 × 10-1Pa, the time is 2-6 hours.
Further, when the temperature is between 300 and 600 ℃ in the temperature rising process, the temperature is kept for 0.5 to 3 hours to discharge the gas in the cerium-rich magnet alloy powder.
Further, the tempering heat treatment is grade 1 tempering or grade 2 tempering, wherein the tempering temperature of the grade 1 tempering is 600-700 ℃, and the time is 2-6 hours. And in the 2-level tempering, the primary tempering temperature is 800-950 ℃, the time is 1-3 hours, the secondary tempering temperature is 450-550 ℃, and the time is 2-6 hours.
Compared with the prior art, the invention adds a trace amount of hydrogen in the steps of crushing and mixing hydrogen and milling powder by airflow, on one hand, the hydrogen acts with the residual oxygen in the charging bucket, thus reducing the oxidation of cerium-rich magnet alloy powder; on the other hand, the surface of the cerium-rich magnet alloy powder can absorb certain hydrogen elements, and the cerium-rich magnet alloy powder is continuously protected in the subsequent process. Meanwhile, as the charging bucket is filled with inert gas and the pressure of the mixed gas is positive pressure, the hydrogen is uniformly distributed in the charging bucket, so that the hydrogen absorption reaction of the surfaces of all cerium-rich magnet alloy powder is ensured, and the oxidation can be avoided. The hydrogen is introduced in the preparation process of the invention, so that the oxidation of the alloy is reduced, the sintering temperature is further reduced, and the crystal grains are refined. The reduction of the oxidation amount in the cerium-rich magnet alloy powder and the refinement of the composition crystal grains are beneficial to the improvement of the coercive force, and simultaneously, the magnetic energy and the squareness and other performance indexes are also beneficial.
Drawings
Fig. 1 is a flowchart of a method for preparing a cerium-rich magnet for a driving motor according to the present invention.
Detailed Description
Specific examples of the present invention will be described in further detail below. It should be understood that the description herein of embodiments of the invention is not intended to limit the scope of the invention.
Referring to fig. 1, a flow chart of a method for preparing a cerium-rich magnet for a driving motor according to the present invention includes the following steps:
s101: providing the powder material of the cerium-rich magnet, wherein the cerium-rich magnet comprises the following components in percentage by mass (Ce)1-xRx)aFe100-a-b-cMbBcWherein R is at least one of Nd, Pr, Dy, Tb, Ho and Gd, M is at least one of Co, Al, Cu, Ga, Nb and Zr, x is more than or equal to 0.5 and less than or equal to 0.9, a is more than or equal to 28.0 and less than or equal to 33, b is more than or equal to 0.1 and less than or equal to 5, and c is more than or equal to 0.8 and less than or equal to 1.1;
s102: preparing a cerium-iron-boron alloy rapid-hardening sheet by adopting a rapid-hardening process;
s103: roughly crushing the cerium-iron-boron alloy quick-setting piece by using a hydrogen crushing process to prepare hydrogen crushed powder;
s104: putting the hydrogen broken powder into a charging bucket filled with inert gas and hydrogen, and uniformly mixing;
s105: further crushing the hydrogen broken powder into fine powder by using an airflow milling process, and supplementing hydrogen in the airflow milling process;
s106: and (3) preparing the cerium-rich magnet for the driving motor by using the fine powder after jet milling through magnetic field orientation forming, isostatic pressing, vacuum sintering and tempering heat treatment processes.
In step S101, the cerium-rich magnet is an alloy powder of cerium, iron, and boron. Cerium is a silver-grey active metal, powder is easily pyrophoric in air, is easily soluble in acid, is mainly present in monazite and bastnaesite, and is also present in fission products of uranium, thorium and plutonium. Cerium is often produced by reduction of cerium oxide with magnesium powder, or by electrolysis of molten cerium chloride. The content of the rare earth elements in the earth crust is about 0.0046 percent, which is the most abundant rare earth elements. Cerium is easily oxidized at room temperature and easily loses luster in air, and can be burnt in air by scraping with a knife. The chemical formula and the components of the cerium-rich magnet prepared by the invention are (Ce) in percentage by mass1-xRx)aFe100-a-b-cMbBcWherein R is at least one of neodymium (Nd), praseodymium (Pr), dysprosium (Dy), terbium (Tb), holmium (Ho) and gadolinium (Gd), M is at least one of cobalt (Co), aluminum (Al), copper (Cu), gallium (Ga), niobium (Nb) and zirconium (Zr), x is more than or equal to 0.5 and less than or equal to 0.9, a is more than or equal to 28.0 and less than or equal to 33, b is more than or equal to 0.1 and less than or equal to 5, and c is more than or equal to 0.8 and less than or equal to 1.1. The particle size of the cerium-iron-boron alloy powder may be 0.3 to 6 μm.
In step S104, in the hydrogen pulverizing and mixing process, the inert gas and the hydrogen gas are respectively filled into the charging bucket, the pressure of the mixed gas in the charging bucket can be positive pressure, and the content of the hydrogen gas filled into the charging bucket is 50ppm to 300 ppm. In the hydrogen powder breaking and mixing process, the inert gas filled into the charging bucket is at least one of argon and helium. In the hydrogen powder breaking and mixing process, an antioxidant and gasoline can also be added as a protective medium. In the mixing process, the hydrogen powder breaking and mixing time is 0.5 to 3 hours.
In step S105, the amount of hydrogen supplied by the jet milling process should not be higher than 300 ppm. The granularity of the prepared fine powder can be 1-5 microns through the airflow milling process.
In step S106, when the powder material of the cerium-rich magnet is subjected to magnetic field orientation molding, an orientation magnetic field of the magnetic field orientation molding is 1.5 to 2.0t, when the cerium-rich magnet is subjected to isostatic pressing, a pressure of the isostatic pressing may be 160MPa to 250MPa, when the cerium-rich magnet is subjected to vacuum sintering, a sintering temperature is 990 to 1100 ℃, and a degree of vacuum is at least 1 × 10-1Pa, the time is 2-6 hours. In order to ensure the safety risk in the magnet preparation process, when the temperature is between 300 ℃ and 600 ℃ in the temperature rise process of vacuum sintering, the temperature needs to be 0.5 to 3 hours to discharge the gas in the cerium-rich magnet alloy powder.
In step S106, the tempering heat treatment may be a grade 1 tempering or a grade 2 tempering. When the tempering heat treatment is grade 1 tempering, the tempering temperature should be 600-700 ℃ and the time should be 2-6 hours. When the tempering heat treatment is a grade 2 tempering, it should include a grade 1 tempering and a grade 2 tempering. At the moment, the grade 1 tempering temperature is 800-950 ℃, the time is 1-3 hours, the grade 2 tempering temperature is 450-550 ℃, and the time is 2-6 hours. Because the oxidation degree of the surface of the magnet blank is reduced, the shrinkage uniformity of the magnet is improved after sintering is finished, and the uniformity of magnetic performance can be improved.
In the aspect of safety, the hydrogen in the charging bucket is diluted along with the continuous supplement of inert gas in the preparation process and is removed in the vacuumizing stage of the sintering step, meanwhile, the hydrogen absorbed by the surfaces of the cerium-rich magnet alloy powder and the blank magnet is discharged in the exhaust stage when the temperature of the sintering process is 300-600 ℃, the content of the hydrogen introduced into the charging bucket is not more than 300ppm, the inert gas is used for protection, and meanwhile, most of the hydrogen is absorbed by the surfaces of the cerium-rich magnet alloy powder, so that the safety risk in the magnet preparation process is not increased.
The following examples are provided to demonstrate various properties of the cerium-rich magnet for a driving motor according to the present invention.
Example 1, which comprises the steps of:
the rapid-hardening sheet of the cerium-iron-boron alloy is prepared by a rapid-hardening process, and the components and the mass percentage of the rapid-hardening sheet are Ce6.5Nd18.4Pr7.1Fe64.6Co1.2Al0.4Cu0.15Ga0.5Nb0.2B0.95;
roughly crushing the quick-setting tablets by using a hydrogen crushing process to prepare hydrogen crushed powder;
putting the hydrogen broken powder into a material tank, filling nitrogen into the material tank to 0.2Mpa, then filling 150ppm hydrogen, adding a proper amount of antioxidant and gasoline into the material tank, and then mixing for 2 hours;
and further crushing the mixed hydrogen broken powder by using an air flow milling process, wherein the amount of the added hydrogen is 100ppm in the air flow milling process, and the particle size distribution of the prepared fine powder is 2.1-2.8 microns.
The fine powder after the jet milling is subjected to magnetic field orientation forming, isostatic pressing, vacuum sintering and tempering heat treatment once, wherein the orientation magnetic field is 1.8T, the isostatic pressing pressure is 200MPa, the vacuum sintering temperature is 1020 ℃, and the vacuum degree is not lower than 5 × 10-2Pa, for 5 hours. And in the process of vacuum sintering and temperature rise, the temperature is respectively kept at 320 ℃ and 600 ℃ for 1 hour. And 2-stage tempering is adopted, wherein the first-stage tempering temperature is 880 ℃, the tempering time is 3 hours, the second-stage tempering temperature is 480 ℃, and the tempering time is 4 hours, so that the magnet is prepared. The performance test adopts a permanent magnet performance measuring instrument, and the test temperature is room temperature.
Example 2:
in example 2, a cerium-rich magnet was prepared using the same composition and similar preparation process as in example 1, except that: (1) hydrogen is not filled in the hydrogen powder breaking and mixing process, and (2) 250ppm hydrogen is filled in the airflow milling process. The performance test adopts a permanent magnet performance measuring instrument, and the test temperature is room temperature.
Example 3:
in example 3, a cerium-rich magnet was prepared using the same composition and similar preparation process as in example 1, except that: (1) the amount of hydrogen charged in the hydrogen crushing and mixing process is 250ppm, and (2) the hydrogen is not charged in the jet milling process. The performance test adopts a permanent magnet performance measuring instrument, the test temperature is room temperature, and the test results are shown in table 1.
Comparative example:
in a comparative example, a cerium-rich magnet was prepared using the same composition and similar preparation process as in example 1, except that: by adopting the traditional powder preparation process, hydrogen is not introduced in the hydrogen powder breaking mixing and airflow milling processes. The performance test adopts a permanent magnet performance measuring instrument, and the test temperature is room temperature.
Finally, the results are shown in the following table.
TABLE 1 magnetic Properties of sintered cerium-rich magnets prepared by different processes
Detailed description of the preferred embodiments Coercive force (kOe) Remanence (kGs) Magnetic energy product (MGOe) Hk/Hcj(％)
Example 1 17.2 12.82 40.4 95.4
Example 2 16.4 12.85 40.9 97.3
Example 3 16.7 12.75 40.1 95.1
Comparative example 14.5 12.81 39.5 93.2
As can be seen from the above examples 1-3 and comparative examples, the coercive force of the cerium permanent magnet of the present invention is significantly higher than that of the comparative examples, the magnetic energy product and squareness are also optimized to a certain extent, the remanence is equivalent to that of the comparative examples, and the comprehensive magnetic performance is significantly better than that of the cerium-rich magnet prepared by the prior art. In addition, as can be seen from comparison of examples 1 to 3, the coercive force of the magnet prepared in example 1 in which hydrogen gas was charged in both the hydrogen pulverized powder mixing and the air flow milling processes was higher than that of the magnets prepared in examples 2 and 3 in which hydrogen gas was charged only in the hydrogen pulverized powder mixing or air flow milling processes.
Compared with the prior art, the invention adds a trace amount of hydrogen in the steps of crushing and mixing hydrogen and milling powder by airflow, on one hand, the hydrogen acts with the residual oxygen in the charging bucket, thus reducing the oxidation of cerium-rich magnet alloy powder; on the other hand, the surface of the cerium-rich magnet alloy powder can absorb certain hydrogen elements, and the cerium-rich magnet alloy powder is continuously protected in the subsequent process. Meanwhile, as the charging bucket is filled with inert gas and the pressure of the mixed gas is positive pressure, the hydrogen is uniformly distributed in the charging bucket, so that the hydrogen absorption reaction of the surfaces of all cerium-rich magnet alloy powder is ensured, and the oxidation can be avoided. The hydrogen is introduced in the preparation process of the invention, so that the oxidation of the alloy is reduced, the sintering temperature is further reduced, and the crystal grains are refined. The reduction of the oxidation amount in the cerium-rich magnet alloy powder and the refinement of the composition crystal grains are beneficial to the improvement of the coercive force, and simultaneously, the magnetic energy and the squareness and other performance indexes are also beneficial.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the scope of the present invention, and any modifications, equivalents or improvements that are within the spirit of the present invention are intended to be covered by the following claims.

Claims (8)

1. A method of preparing a cerium-rich magnet for a drive motor, comprising the steps of:
providing the powder material of the cerium magnet, wherein the components and the mass percent of the cerium magnet are (Ce)1-xRx)aFe100-a-b-cMbBcWherein R is at least one of Nd, Pr, Dy, Tb, Ho and Gd, M is at least one of Co, Al, Cu, Ga, Nb and Zr, x is more than or equal to 0.5 and less than or equal to 0.9, a is more than or equal to 28.0 and less than or equal to 33, b is more than or equal to 0.1 and less than or equal to 5, and c is more than or equal to 0.8 and less than or equal to 1.1;
preparing a cerium-iron-boron alloy rapid-hardening sheet by adopting a rapid-hardening process;
roughly crushing the cerium-iron-boron alloy quick-setting piece by using a hydrogen crushing process to prepare hydrogen crushed powder;
putting the hydrogen broken powder into a material tank, respectively filling inert gas and hydrogen or nitrogen and hydrogen into the material tank, wherein the pressure of the mixed gas in the material tank is positive pressure, the content of the hydrogen filled into the material tank is 50-300 ppm, and the hydrogen are uniformly mixed;
further crushing hydrogen broken powder mixed with inert gas and hydrogen or nitrogen and hydrogen into fine powder by using an airflow milling process, wherein the granularity of the fine powder is 1-5 microns, and hydrogen is supplemented in the airflow milling process, and the quantity of the supplemented hydrogen is not higher than 300 ppm;
and (3) preparing the cerium magnet for the driving motor by using the fine powder after jet milling through magnetic field orientation forming, isostatic pressing, vacuum sintering and tempering heat treatment processes.
2. The method of preparing a cerium-rich magnet for a driving motor according to claim 1, wherein: in the hydrogen powder breaking and mixing process, the inert gas filled into the charging bucket is at least one of argon and helium.
3. The method of preparing a cerium-rich magnet for a driving motor according to claim 1, wherein: in the hydrogen powder breaking and mixing process, an antioxidant and gasoline are added as protective media.
4. The method of preparing a cerium-rich magnet for a driving motor according to claim 1, wherein: the hydrogen crushing and mixing time is 0.5 to 3 hours.
5. The method of preparing a cerium-rich magnet for a driving motor according to claim 1, wherein: the magnetic field is oriented and formed, the orientation magnetic field is 1.5-2.0T, and the pressure of the isostatic pressure is 160-250 MPa.
6. The method of claim 1, wherein the sintering is carried out under a vacuum at 990-1100 deg.C and a vacuum of at least 1 × 10-1Pa, the time is 2-6 hours.
7. The method of preparing a cerium-rich magnet for a driving motor according to claim 6, wherein: and when the temperature is between 300 and 600 ℃ in the temperature rising process, keeping the temperature for 0.5 to 3 hours to discharge the gas in the alloy powder of the cerium magnet.
8. The method of preparing a cerium-rich magnet for a driving motor according to claim 1, wherein: the tempering heat treatment is grade 1 tempering or grade 2 tempering, wherein the tempering temperature of the grade 1 tempering is 600-700 ℃, and the time is 2-6 hours; and in the 2-level tempering, the primary tempering temperature is 800-950 ℃, the time is 1-3 hours, the secondary tempering temperature is 450-550 ℃, and the time is 2-6 hours.
CN201810088550.1A 2018-01-30 2018-01-30 Preparation method of cerium-rich magnet for driving motor Active CN108417372B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201810088550.1A CN108417372B (en) 2018-01-30 2018-01-30 Preparation method of cerium-rich magnet for driving motor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201810088550.1A CN108417372B (en) 2018-01-30 2018-01-30 Preparation method of cerium-rich magnet for driving motor

Publications (2)

Publication Number Publication Date
CN108417372A CN108417372A (en) 2018-08-17
CN108417372B true CN108417372B (en) 2020-09-11

Family

ID=63127361

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201810088550.1A Active CN108417372B (en) 2018-01-30 2018-01-30 Preparation method of cerium-rich magnet for driving motor

Country Status (1)

Country Link
CN (1) CN108417372B (en)

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61238938A (en) * 1985-04-16 1986-10-24 Hitachi Metals Ltd Sintering method for permanent magnet alloy
CN1442258A (en) * 2002-03-05 2003-09-17 赵宇靖 Hydrogen blasting furnace for breaking rare earth permanent magnetic material and hydrogen blasting technology
CN101051544A (en) * 2007-05-10 2007-10-10 浙江大学 Method for preparing high performance sintered neodymium-iron-boron air stream millby hydrogenation
CN103996522B (en) * 2014-05-11 2016-06-15 沈阳中北通磁科技股份有限公司 A kind of manufacture method of the Fe-B rare-earth permanent magnet containing Ce
CN104900360B (en) * 2015-05-28 2017-07-25 钢铁研究总院 A kind of permanent-magnet alloy for adding compound low price rare earth and preparation method thereof
CN105405563B (en) * 2015-12-18 2018-05-01 京磁材料科技股份有限公司 A kind of hydrogen breaking method of neodymium iron boron magnetic body
CN107146674B (en) * 2017-05-27 2018-11-09 浙江大学 From the cerium-rich rare earth permanent magnet and its production method of heat treatment

Also Published As

Publication number Publication date
CN108417372A (en) 2018-08-17

Similar Documents

Publication Publication Date Title
JP6419869B2 (en) Cerium-containing neodymium iron boron magnet and method for producing the same
JP6366666B2 (en) Method for producing sintered Nd-Fe-B magnetic body containing no heavy rare earth element
CN110853856B (en) High-coercivity cerium-containing magnet and preparation method thereof
TWI421885B (en) Manufacture method of rare earth metal permanent magnet material
CN102610347B (en) RE permanent magnetic alloy material and preparation technology thereof
EP1900462B1 (en) Process for producing rare-earth permanent magnet material
EP3355319B1 (en) Corrosion-resistant sintered neodymium-iron-boron magnet rich in lanthanum and cerium, and manufacturing method
JP2015023285A (en) R-t-m-b-based sintered magnet and production method therefor
CN108281246B (en) High-performance sintered neodymium-iron-boron magnet and preparation method thereof
CN104036945A (en) Method for manufacturing high-temperature stable regenerated sintered neodymium-iron-boron magnet by waste permanent-magnet motor magnet steel
CN104036947A (en) Method for manufacturing high-coercivity regenerated sintered neodymium-iron-boron magnet by waste permanent-magnet motor magnet steel
JP4179973B2 (en) Manufacturing method of sintered magnet
JP2012079796A (en) Alloy material for r-t-b based rare-earth permanent magnet, production method of r-t-b based rare-earth permanent magnet, and motor
CN113223807B (en) Neodymium-iron-boron permanent magnet and preparation method and application thereof
JP2005209932A (en) Rare-earth magnet and manufacturing method thereof, and manufacturing apparatus
CN108172390B (en) Preparation method for improving performance uniformity of cerium-rich magnet for driving motor
CN111341515B (en) Cerium-containing neodymium-iron-boron magnetic steel and preparation method thereof
JP2005285859A (en) Rare-earth magnet and its manufacturing method
CN108417372B (en) Preparation method of cerium-rich magnet for driving motor
JP5743458B2 (en) Alloy material for RTB-based rare earth permanent magnet, method for manufacturing RTB-based rare earth permanent magnet, and motor
CN111755191A (en) High-abundance rare earth Ce/Y/Nd/La substituted samarium-iron-nitrogen-based magnetic powder with high maximum magnetic energy product
CN113871120B (en) Mixed rare earth permanent magnet material and preparation method thereof
CN108777228B (en) Method for improving magnetic property of cerium-rich magnet through mixed material hydrogenation
CN110289161B (en) Preparation method of neodymium iron boron magnet with low rare earth content
CN112053824B (en) Sintered NdFeB permanent magnet and preparation method 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
GR01 Patent grant
GR01 Patent grant