阅读说明：本技术 一种双主相稀土永磁材料及其制备方法 (Double-main-phase rare earth permanent magnetic material and preparation method thereof ) 是由 熊吉磊 陈敏 成丽春 刘星 周宏亮 于 2021-08-27 设计创作，主要内容包括：本发明提供一种双主相稀土永磁材料及其制备方法,属于钕铁硼永磁材料领域,将钕铁硼合金和所述Y2Fe14B型合金分别进行氢爆、气流粉碎制得合金细粉,取向成型后在磁场中进行第一次微波真空烧结,将所述Y2Fe14B合金坯料附着在所述钕铁硼坯料上后在磁场中进行第二次微波真空烧结,再在磁场中进行真空热处理制得；本发明以Nd2Fe14B为基体,通过工艺调整,让Y2Fe14B不进入到Nd2Fe14B主相中,只富集在主相周围,减弱了主相间磁性耦合作用,可大幅提高磁体的矫顽力,获得性能优异的新钕铁硼磁钢,实现稀土资源的高效、平衡利用,降低了生产成本。(The invention provides a double-main-phase rare earth permanent magnet material and a preparation method thereof, belonging to the field of neodymium iron boron permanent magnet materials, wherein neodymium iron boron alloy and the Y2Fe14B type alloy are respectively subjected to hydrogen explosion and airflow pulverization to prepare alloy fine powder, after orientation forming, first microwave vacuum sintering is carried out in a magnetic field, after Y2Fe14B alloy blank is attached to the neodymium iron boron blank, second microwave vacuum sintering is carried out in the magnetic field, and then vacuum heat treatment is carried out in the magnetic field to prepare the double-main-phase rare earth permanent magnet material; according to the invention, Nd2Fe14B is used as a substrate, and through process adjustment, Y2Fe14B does not enter the main phase of Nd2Fe14B and is only enriched around the main phase, so that the magnetic coupling effect between the main phases is weakened, the coercive force of the magnet can be greatly improved, new neodymium iron boron magnetic steel with excellent performance is obtained, the efficient and balanced utilization of rare earth resources is realized, and the production cost is reduced.)

1. The preparation method of the double-main-phase rare earth permanent magnetic material is characterized by comprising the following steps of:

(1) preparing Y2Fe14B type alloy;

(2) respectively carrying out hydrogen explosion on the neodymium iron boron alloy and the Y2Fe14B type alloy to respectively prepare neodymium iron boron alloy coarse powder and Y2Fe14B type alloy coarse powder, and respectively preparing neodymium iron boron alloy fine powder and Y2Fe14B type alloy fine powder by air current grinding powder;

(3) respectively carrying out orientation molding on the neodymium iron boron alloy fine powder and the Y2Fe14B type alloy fine powder in a magnetic field to prepare neodymium iron boron alloy green compacts and Y2Fe14B alloy green compacts, and respectively preparing neodymium iron boron blanks and Y2Fe14B alloy blanks after carrying out primary microwave vacuum sintering in the magnetic field;

(4) and (3) attaching the Y2Fe14B alloy blank to the neodymium iron boron blank, performing secondary microwave vacuum sintering in a magnetic field, and performing vacuum heat treatment in the magnetic field to obtain the neodymium iron boron alloy.

2. The method of claim 1, wherein the Y2Fe14B type alloy has a composition represented by the following formula:

Y₁₂Fe_82.4-x-y-zB_5.6Ag_xGa_yMo_zZr_m，

wherein x, y, z and m represent atomic percent, x is more than or equal to 0.5 and less than or equal to 0.8, y is more than or equal to 0.5 and less than or equal to 1.2, z is more than or equal to 0.4 and less than or equal to 1.0, and m is more than or equal to 0.5 and less than or equal to 1.5.

3. The method for preparing a bi-main phase rare earth permanent magnetic material according to claim 1, wherein the Y2Fe14B type alloy is prepared by the following steps: the materials are mixed according to the designed atomic percentage, and the mixture is smelted by a vacuum smelting melt-spun furnace and cast into sheet alloy with the thickness of 0.1-0.2 mm.

4. The method for preparing the double-main-phase rare earth permanent magnet material according to claim 1, wherein the process conditions of the gas flow milling powder are as follows: grinding under protective atmosphere, controlling oxygen content below 5ppm, grinding pressure at 0.60-0.62MPa, inlet temperature of protective gas at 5-10 deg.C, and external cooling circulating water at 5-10 deg.C.

5. The method for preparing a bi-dominant phase rare earth permanent magnet material of claim 1, wherein the magnetic field strength of the oriented forming is 2.0T, and the compact density of the formed is 4.5 ± 0.5g/cm³。

6. The method for preparing a bi-main phase rare earth permanent magnet material as claimed in claim 1, wherein the magnetic field strength of the first microwave vacuum sintering is 4.0-5.0T, the sintering temperature is 950-1050 ℃, the sintering time is 20-30min, and the microwave power is 3.5-5.5 kW; the magnetic field intensity of the second microwave vacuum sintering is 2.0-4.0T, the sintering temperature is 850-.

7. The method for preparing a bi-main phase rare earth permanent magnetic material as claimed in claim 1, wherein the magnetic field strength of the vacuum heat treatment is 3.5T, the heat preservation temperature is 580-.

8. The method for preparing a bi-main phase rare earth permanent magnet material according to claim 1, wherein in the step (4), the adhering amount of the Y2Fe14B alloy billet is 5-25% of the total weight of the adhering product.

9. The method for preparing a bi-main phase rare earth permanent magnet material as claimed in claim 1, wherein magnetron sputtering is adopted to plate the Y2Fe14B alloy blank on the ndfeb blank, and the content of the Y2Fe14B alloy is controlled by adjusting sputtering time.

10. A bi-dominant phase rare earth permanent magnetic material prepared by the method of any one of claims 1 to 9.

Technical Field

The invention relates to the field of neodymium iron boron permanent magnet materials, in particular to a double-main-phase rare earth permanent magnet material and a preparation method thereof.

Background

Magnetic materials, especially rare earth NdFeB series permanent magnetic materials, are the best permanent magnetic materials in comprehensive performance at present, and become indispensable important material basis in modern industry and scientific technology. The sintered Nd-Fe-B permanent magnet material is rapidly industrialized due to excellent cost performance, and is widely applied to various high and new technical fields of computer hard disk drives, hard disk voice coil motors, generators, nuclear magnetic resonance instruments, sound equipment, communication equipment and the like.

However, with the continuous expansion of the application of the neodymium iron boron rare earth permanent magnet, a large amount of rare earth elements such as Pr, Nd, Dy, Tb and the like which are scarce resources are consumed in production, and a large amount of idle backlog of La, Ce, Y and the like which are abundant is accumulated; meanwhile, the raw ore contains rare earth elements of La, Ce and Y, and the separation and purification of the rare earth can cause the loss of a large amount of energy and serious ecological environment pollution. Therefore, the efficient and balanced utilization of rare earth resources becomes a problem which needs to be solved urgently in sustainable development of the rare earth industry in China. Due to the difference of resource abundance, the prices of rare earth elements La, Ce and Y are low, and in fact, in recent years, the rare earth elements with high abundance are gradually used for producing rare earth permanent magnetic materials in order to reduce the production cost. According to statistics, nearly 20% of the sintered neodymium iron boron blank products in 2016 use Ce element in different degrees; the international largest supplier of rapid-quenched magnetic powder, mcgratzs, also introduced commercial magnetic powder for bonded magnets with high Ce content. Meanwhile, in recent years, the national relevant departments also propose the development of a high-performance Ce magnet to realize the application of a high-abundance rare earth permanent magnet material in high-end fields such as motors, but the research on high-abundance rare earth Y is less, and the strong magnetism of the 2:14:1 type rare earth permanent magnet comes from the intrinsic hard magnetism of a tetragonal phase compound. The Ce2Fe14B saturated magnetic polarization strength Js is 1.17T, the magnetocrystalline anisotropy field Ha is about 26kOe, the Y2Fe14B saturated magnetic polarization strength Js is 1.41T, and the magnetocrystalline anisotropy field Ha is about 26kOe, so that the application of the high-abundance rare earth Y in the field of rare earth permanent magnet materials can be realized theoretically. However, the use of a high-abundance rare earth element Y instead of Nd in Nd2Fe14B can cause the magnetic performance of the Nd-Fe-B material to be reduced, and a remarkable magnetic dilution effect is shown. The method is also a key problem for restricting the development of the high-abundance rare earth permanent magnet material at present.

Disclosure of Invention

Aiming at the problem that the magnetic property of the neodymium iron boron material is reduced because Y replaces Nd in Nd2Fe14B in the prior art, the invention provides a double-main-phase rare earth permanent magnetic material and a preparation method thereof.

The purpose of the invention is realized by adopting the following technical scheme:

a preparation method of a double-main-phase rare earth permanent magnetic material comprises the following steps:

(1) preparing Y2Fe14B type alloy;

(2) respectively carrying out hydrogen explosion on the neodymium iron boron alloy and the Y2Fe14B type alloy to respectively prepare neodymium iron boron alloy coarse powder and Y2Fe14B type alloy coarse powder, and respectively preparing neodymium iron boron alloy fine powder and Y2Fe14B type alloy fine powder by air current grinding powder;

(3) respectively carrying out orientation molding on the neodymium iron boron alloy fine powder and the Y2Fe14B type alloy fine powder in a magnetic field to prepare neodymium iron boron alloy green compacts and Y2Fe14B alloy green compacts, and respectively preparing neodymium iron boron blanks and Y2Fe14B alloy blanks after carrying out primary microwave vacuum sintering in the magnetic field;

(4) and (3) attaching the Y2Fe14B alloy blank to the neodymium iron boron blank, performing secondary microwave vacuum sintering in a magnetic field, and performing vacuum heat treatment in the magnetic field to obtain the neodymium iron boron alloy.

Preferably, the Y2Fe14B type alloy has a composition represented by the following formula:

Y₁₂Fe_82.4-x-y-zB_5.6Ag_xGa_yMo_zZr_m，

wherein x, y, z and m represent atomic percent, x is more than or equal to 0.5 and less than or equal to 0.8, y is more than or equal to 0.5 and less than or equal to 1.2, z is more than or equal to 0.4 and less than or equal to 1.0, and m is more than or equal to 0.5 and less than or equal to 1.5.

Preferably, the preparation method of the Y2Fe14B type alloy comprises the following steps: the materials are mixed according to the designed atomic percentage, and the mixture is smelted by a vacuum smelting melt-spun furnace and cast into sheet alloy with the thickness of 0.1-0.2 mm.

Preferably, the process conditions of the airflow milling powder are as follows: grinding under protective atmosphere, controlling oxygen content below 5ppm, grinding pressure at 0.60-0.62MPa, inlet temperature of protective gas at 5-10 deg.C, and external cooling circulating water at 5-10 deg.C.

Preferably, the magnetic field intensity of the orientation forming is 2.0T, and the density of the formed compact is 4.5±0.5g/cm³。

Preferably, the magnetic field intensity of the first microwave vacuum sintering is 4.0-5.0T, the sintering temperature is 950-1050 ℃, the sintering time is 20-30min, and the microwave power is 3.5-5.5 kW; the magnetic field intensity of the second microwave vacuum sintering is 2.0-4.0T, the sintering temperature is 850-.

Preferably, the magnetic field intensity of the vacuum heat treatment is 3.5T, the heat preservation temperature is 580-600 ℃, and the heat preservation time is 3 h.

Preferably, in the step (4), the adhering amount of the Y2Fe14B alloy billet is 10-50% of the total weight of the adhering product.

Preferably, the Y2Fe14B alloy blank is plated on the neodymium iron boron blank by a magnetron sputtering method, and the content of the Y2Fe14B alloy is controlled by adjusting the sputtering time.

The invention has the beneficial effects that:

aiming at the problems that the magnetic performance of the neodymium iron boron material is reduced and the obvious magnetic dilution effect is presented due to the fact that conventional vacuum sintering and aging treatment can cause the magnetic performance of the neodymium iron boron material to be reduced when high-abundance rare earth element Y is used for modifying Nd2Fe14B in the prior art, the invention takes Nd2Fe14B as a base body, reduces the magnetic coupling effect between main phases through adjustment of a sintering process, greatly improves the coercive force of a magnet, obtains new neodymium iron boron magnetic steel with excellent performance, realizes efficient and balanced utilization of rare earth resources, and reduces production cost.

Detailed Description

The invention is further described with reference to the following examples.

The embodiment of the invention relates to a preparation process of an Nd2Fe14B/Y2Fe14B type high-performance magnet, wherein the magnet comprises neodymium iron boron alloy and Y2Fe14B type alloy, the embodiment takes commercial neodymium iron boron with the trademark of N50 as an example for illustration, and the invention can also be applied to neodymium iron boron with other trademarks.

Example 1

A process for preparing Nd2Fe14B/Y2Fe14B type high-performance magnet, the process for preparing Nd2Fe14B/Y2Fe14B type high-performance magnet comprises the following steps:

(1) compounding, Y2Fe14B type powderMixing according to the following atomic ratio of Y₁₂Fe_82.4-x-y-zB_5.6Ag_xGa_yMo_zZr_mWherein x is 0.5, y is 0.5, z is 0.4, and m is 0.5; the neodymium iron boron alloy adopts a commercial N50 neodymium iron boron alloy sheet;

(2) smelting by using a vacuum smelting furnace, starting smelting when the smelting melt-spun furnace is pumped into an environment with the vacuum degree of less than 0.5Pa, starting casting when the smelting temperature reaches 1600-1650 ℃, then adjusting the rotating speed of a water-cooling copper roller to be 45rpm, controlling the water inlet temperature to be 10-15 ℃ and starting casting to obtain a sheet alloy, and controlling the thickness of the prepared Y2Fe14B sheet alloy to be 0.10-0.20 mm;

(3) respectively loading the N50 alloy sheet and the Y2Fe14B sheet alloy into a reaction kettle of a rotary hydrogen explosion furnace for vacuumizing treatment, filling argon to normal pressure when the vacuum degree reaches below 0.5Pa, vacuumizing to fill high-purity industrial hydrogen (the purity is 99.99%), absorbing saturated hydrogen, finishing hydrogen absorption when the pressure loss of the hydrogen absorption is less than or equal to 0.01Mpa/5min, using water cooling and using an infrared thermometer for temperature measurement in the hydrogen absorption process to ensure that the temperature in the hydrogen absorption process is controlled below 100 ℃, heating the furnace to 600 ℃ after the hydrogen absorption is finished, performing dehydrogenation when the vacuum degree reaches below 40Pa, finishing dehydrogenation, finally performing water cooling treatment, reducing the temperature to below 30 ℃, discharging the furnace into a mixing tank protected by argon gas, and obtaining hydrogen explosion powder;

(4) adopting QLMR-400G type airflow milling equipment, respectively putting the hydrogen blasting powder mixed in the step (3) into an airflow milling machine, controlling the oxygen content in the milling process to be below 5ppm, operating the whole airflow milling machine under the protection of nitrogen, controlling the milling pressure to be between 0.60 and 0.62MPa, controlling the inlet temperature of nitrogen to be between 5 and 10 ℃, and controlling the temperature of cooling circulating water outside a milling chamber to be between 5 and 10 ℃; obtaining a fine powder having a particle size distribution of X10 ═ 0.40 μm, X50 ═ 1.02 μm, and X90 ═ 2.52 μm;

(5) magnetic field forming: respectively putting the fine powder obtained in the step (4) into a fully-sealed magnetic field forming press with the oxygen content of less than 10ppm, and performing orientation forming, wherein the magnetic field intensity is 2.0T, and the formed green compact density is 4.5 +/-0.5 g/cm³；

(6) Magnetic field microwave sintering: performing high-intensity magnetic field microwave sintering on the product obtained in the step (5), wherein the microwave sintering temperature is 950 ℃, the temperature is kept for 30min, the microwave frequency is 5.5kW, and the intensity of the magnetic field applied in the process is 5.0T; after heat preservation is finished, air cooling is carried out to below 30 ℃ under the protection of argon, discharging is carried out, Y2Fe14B blanks and N50 pre-sintering blanks are obtained, and surface grinding polishing and appearance processing are carried out on the formed Y2Fe14B blanks, so that Y2Fe14B type target materials are obtained;

(7) plating a Y2Fe14B type target alloy on the N50 pre-sintering blank by adopting magnetron sputtering, and controlling the content of the Y2Fe14B alloy by controlling the sputtering time to make the weight of the alloy respectively account for 5%, 10%, 15%, 20% and 25% of the total weight to obtain a sputtered mixed neodymium-iron-boron magnet;

besides magnetron sputtering, other possible attachment means, such as coating, electrophoresis, etc., can be used by those skilled in the art;

(8) secondary magnetic field microwave sintering: performing high-intensity magnetic field microwave sintering on the product obtained in the step (7), wherein the microwave sintering temperature is 850 ℃, the heat preservation time is 20min, the microwave frequency is 2.0kW, and the intensity of the magnetic field applied in the process is 4.0T;

(9) magnetic field heat treatment: and (3) putting the product obtained in the step (8) into a vacuum magnetic field heat treatment furnace with the vacuum degree of less than 0.7Pa for magnetic field heat treatment, heating to 600 ℃, preserving heat for 3 hours, keeping the magnetic field strength for 3.5T, and after heat preservation is finished, carrying out air cooling to below 30 ℃ under the protection of argon gas to obtain the Nd2Fe14B/Y2Fe14B type high-performance magnet.

The permanent magnet performance of different Y2Fe14B type alloy contents is measured by taking a sample with 0% of Y2Fe14B type alloy content as a reference, and the measurement results are shown in the following table:

example 2

A process for preparing Nd2Fe14B/Y2Fe14B type high-performance magnet, the process for preparing Nd2Fe14B/Y2Fe14B type high-performance magnet comprises the following steps:

(1) mixing Y2Fe14B type powder at the following atomic ratio₁₂Fe_82.4-x-y-zB_5.6Ag_xGa_yMo_zZr_mWherein x ═0.8, y is 1.2, z is 1.0, and m is 1.5; the neodymium iron boron alloy adopts a commercial N50 neodymium iron boron alloy sheet;

(2) smelting by using a vacuum smelting furnace, starting smelting when the smelting melt-spun furnace is pumped into an environment with the vacuum degree of less than 0.5Pa, starting casting when the smelting temperature reaches 1600-1650 ℃, then adjusting the rotating speed of a water-cooling copper roller to be 45rpm, controlling the water inlet temperature to be 10-15 ℃ and starting casting to obtain a sheet alloy, and controlling the thickness of the prepared Y2Fe14B sheet alloy to be 0.10-0.20 mm;

(3) loading the N50 alloy sheet and the Y2Fe14B sheet alloy into a reaction kettle of a rotary hydrogen explosion furnace for vacuumizing treatment, filling argon to normal pressure when the vacuum degree reaches below 0.5Pa, vacuumizing to fill high-purity industrial hydrogen (the purity is 99.99%), absorbing saturated hydrogen, finishing hydrogen absorption when the pressure loss of the hydrogen absorption is less than or equal to 0.01Mpa/5min, using water cooling and using an infrared thermometer to measure the temperature in the hydrogen absorption process to ensure that the temperature in the hydrogen absorption process is controlled below 100 ℃ after the hydrogen absorption is finished, heating the furnace to 600 ℃ after the hydrogen absorption is finished, performing dehydrogenation until the vacuum degree reaches below 40Pa, finishing the dehydrogenation, finally performing water cooling treatment, reducing the temperature to below 30 ℃, discharging the furnace into a mixing tank protected by argon gas, and obtaining hydrogen explosion powder;

(4) adopting QLMR-400G type airflow milling equipment, respectively putting the hydrogen blasting powder mixed in the step (3) into an airflow milling machine, controlling the oxygen content in the milling process to be below 5ppm, operating the whole airflow milling machine under the protection of nitrogen, controlling the milling pressure to be between 0.60 and 0.62MPa, controlling the inlet temperature of nitrogen to be between 5 and 10 ℃, and controlling the temperature of cooling circulating water outside a milling chamber to be between 5 and 10 ℃; obtaining a fine powder having a particle size distribution of X10 ═ 0.50 μm, X50 ═ 1.1 μm, and X90 ═ 2.7 μm;

(5) magnetic field forming: respectively putting the fine powder obtained in the step (4) into a fully-sealed magnetic field forming press with the oxygen content of less than 10ppm, and performing orientation forming, wherein the magnetic field intensity is 2.0T, and the formed green compact density is 4.5 +/-0.5 g/cm³；

(6) Magnetic field microwave sintering: performing high-intensity magnetic field microwave sintering on the product obtained in the step (5), wherein the microwave sintering temperature is 1050 ℃, the temperature is kept for 20min, the microwave frequency is 3.5kW, and the intensity of the magnetic field applied in the process is 4.0T; after heat preservation is finished, air cooling is carried out to below 30 ℃ under the protection of argon, discharging is carried out, Y2Fe14B blanks and N50 pre-sintering blanks are obtained, and surface grinding polishing and appearance processing are carried out on the formed Y2Fe14B blanks, so that Y2Fe14B type target materials are obtained;

(7) plating a Y2Fe14B type target alloy on the N50 pre-sintering blank by adopting magnetron sputtering, and controlling the content of the Y2Fe14B alloy by controlling the sputtering time to make the weight of the alloy respectively account for 5%, 10%, 15%, 20% and 25% of the total weight to obtain a sputtered mixed neodymium-iron-boron magnet;

(8) secondary magnetic field microwave sintering: performing high-intensity magnetic field microwave sintering on the product obtained in the step (7), wherein the microwave sintering temperature is 950 ℃, the temperature is kept for 30min, the microwave frequency is 3.0kW, and the intensity of the magnetic field applied in the process is 2.0T;

(9) magnetic field heat treatment: and (3) putting the product obtained in the step (8) into a vacuum magnetic field heat treatment furnace with the vacuum degree of less than 0.7Pa for magnetic field heat treatment, heating to 580 ℃, preserving heat for 3 hours, keeping the magnetic field strength for 3.5T, and after heat preservation is finished, carrying out air cooling to below 30 ℃ under the protection of argon gas to obtain the Nd2Fe14B/Y2Fe14B type high-performance magnet.

The permanent magnet performance of different Y2Fe14B type alloy contents is measured by taking a sample with 0% of Y2Fe14B type alloy content as a reference, and the measurement results are shown in the following table:

comparative example 1

A preparation process of an Nd2Fe14B/Y2Fe14B type permanent magnet comprises the following steps:

steps (1) to (4) are the same as in example 1;

(5) mixing powder: respectively adding 0-25% of Y2Fe14B type alloy fine powder into an N50 flailing fine powder tank, then mixing the fine powder for 60min under the protection of argon, cooling for 2h after the powder mixing is finished, and sieving the mixed fine powder by using a 100-mesh sieve under the protection of argon;

(6) magnetic field forming: placing the mixed fine powder in the step (5) into a fully-sealed magnetic field forming press with the oxygen content of less than 10ppm for magnetic field orientation forming, wherein the magnetic field orientation preferably adopts a positive and negative pulse magnetic field for multiple orientations, the magnetic field strength is 4.0T, and the density of the formed pressed compact isIs 4.2 to 4.3g/cm³；

(7) Cold isostatic pressing: putting the pressed blank obtained in the step (6) into cold isostatic pressing equipment for further pressing and forming to improve the density, and obtaining a green blank under the isostatic pressing pressure of 250 MPa;

(8) and (3) vacuum sintering: putting the green body in the step (7) into a normal vacuum sintering furnace under the protection of argon gas for high-temperature sintering, wherein the specific process is that the green body is put into the sintering furnace, is vacuumized to 0.5Pa, is heated to 450 ℃ at a speed of 7 ℃/min, is subjected to heat preservation for 30min, is heated to 870 ℃ at a speed of 6 ℃/min from 450 ℃, is subjected to heat preservation for 60min, is heated to 1070 ℃ at a speed of 5 ℃/min, and is subjected to heat preservation for 180 min; after the heat preservation is finished, the furnace is discharged after the air cooling is carried out to below 30 ℃ under the protection of argon;

(9) aging heat treatment: heating the product in the step (8) to 895 ℃ at the temperature of 7 ℃/min, and keeping the temperature for 2.5 h; after the heat preservation is finished, air cooling is carried out to below 200 ℃, then the temperature is raised to 495 ℃ of the second heat treatment temperature, the heat preservation is carried out for 5 hours, after the heat preservation is finished, the air cooling is carried out to below 30 ℃ under the protection of argon, and then the Nd2Fe14B/Y2Fe14B type permanent magnet is prepared.

The permanent magnet performance of different Y2Fe14B type alloy contents is measured by taking a sample with 0% of Y2Fe14B type alloy content as a reference, and the measurement results are shown in the following table:

comparative example 2

A preparation process of an Nd2Fe14B/Y2Fe14B type permanent magnet comprises the following steps:

steps (1) to (4) are the same as in example 2; steps (5) to (9) were the same as in comparative example 1.

The permanent magnet performance of different Y2Fe14B type alloy contents is measured by taking a sample with 0% of Y2Fe14B type alloy content as a reference, and the measurement results are shown in the following table:

finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the protection scope of the present invention, although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.