CN109859922B - Preparation method of R-Fe-B magnet with low heavy rare earth content - Google Patents
Preparation method of R-Fe-B magnet with low heavy rare earth content Download PDFInfo
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Abstract
The invention provides a preparation method of an R-Fe-B magnet, which comprises the following steps: A) mixing an R1-Fe-B-M1 sample and an RH-M2-Q1 sample, and then carrying out hydrogen crushing to obtain coarse powder; B) performing diffusion treatment on the coarse powder, and performing hydrogen crushing on the coarse powder obtained after the diffusion treatment; C) b) carrying out airflow milling on the coarse powder obtained in the step B), and forming the obtained fine powder; D) and sintering the molded magnet to obtain the R-Fe-B magnet. In the process of preparing the R-Fe-B type magnet, the prepared magnet has the advantage that the coercive force of the magnet is obviously improved by using the extremely small amount of heavy rare earth Dy or Tb on the premise of basically keeping the remanence and the maximum energy product of a sintered magnet.
Description
Technical Field
The invention relates to the technical field of magnet materials, in particular to a preparation method of an R-Fe-B magnet with low heavy rare earth content.
Background
As is well known, an R-Fe-B-based rare earth sintered magnet having an Nd2Fe 14B-type compound as a main phase is a permanent magnet, is a magnet having the highest performance among all magnetic materials, and is widely used for a Voice Coil Motor (VCM) for hard disk drive, a servo motor, a variable frequency air conditioner motor, a motor for mounting a hybrid vehicle, a drive motor for a new energy vehicle, and the like. In the application process of the R-Fe-B rare earth sintered magnet in various motors, in order to adapt to the use environment temperature and ensure that the motor does not demagnetize in high-temperature work, the R-Fe-B rare earth sintered magnet is required to have excellent heat resistance and higher coercive force.
The traditional method for improving the coercive force of the R-Fe-B rare earth sintered magnet mainly uses heavy rare earth element RH as a raw material, and the magnet is prepared through the working procedures of smelting alloy crushing, pressing, sintering and the like. This method is characterized in that the light rare earth element RL is substituted by the heavy rare earth element RH as the rare earth element of the R2Fe14B phase of the rare earth element R, and therefore, the magnetocrystalline anisotropy (physical quantity that determines the nature of the coercive force) of the R2Fe14B phase is improved. However, since the magnetic moment of the light rare earth element RL in the Nd2Fe14B phase is higher than the magnetic moment of the heavy rare earth element RH, the more the light rare earth element RL is replaced with the heavy rare earth element RH, the lower the remanence Br. On the other hand, since the heavy rare earth element RH is a scarce resource, it is necessary to reduce the amount of use thereof. Therefore, the method of replacing all the light rare earth elements RL with the heavy rare earth elements RH by the conventional process is not ideal. In addition, due to the rapid development of new energy automobiles, magnets required by the new energy automobiles also need high coercive force and high magnetic energy product, so that how to produce high-performance magnets under the condition of low heavy rare earth is a research hotspot of neodymium iron boron permanent magnet materials in the future.
For the above problems, at present, the solution is mainly achieved by two ways: the method is characterized in that the first method is a fine crystal technology, the second method is a grain boundary diffusion technology, but the two methods have limited grain refining effect on reducing the use amount of heavy rare earth and improving the coercive force effect of a magnet, the equipment requirement is high, the process control is difficult, and the production cost is high.
At present, the grain boundary diffusion technology mainly adopts the methods of coating, depositing, plating, sputtering and the like, so that powder containing Dy/Tb metal or compounds (such as Dy203, DyF3, TbF3, DyH3, TbH3 and the like) is firstly attached to the outer surface of a magnet to be used as a diffusion source, diffusion heat treatment is carried out in a certain temperature range, rare earth elements are diffused to the surface layer of main phase grains along the grain boundary, and the Nd surface layer is replaced2Fe14Nd in the B forms a (Nd, Dy/Tb)2Fe14B shell structure, the anisotropy field of the grain surface is improved, and the grain boundary microstructure is improved, so that the coercive force of the magnet is improved.
The coating diffusion process generally comprises two procedures, wherein the first procedure is to prepare a diffusion source, coat the heavy rare earth diffusion source on the surface of a sintered magnet and then dry the heavy rare earth diffusion source; the second procedure is that the coated product is placed in a sintering material box and then enters a vacuum sintering furnace for high-temperature heat treatment, the grain boundary diffusion technology can achieve the effect of greatly improving the coercive force of the magnet by adding a small amount of heavy rare earth element RH hydride or fluoride or alloy, and simultaneously ensure that the residual magnetism of the magnet is not greatly reduced, but the production process of the process is more complicated, the size specification of the product is limited, generally within 8 mm, the thicker the thickness of the magnet is, the poorer the diffusion effect is, in addition, the production period of a plurality of procedures is increased, the equipment and tool investment is large, the production process is complicated, the production cost is higher, and the like.
Disclosure of Invention
The invention aims to provide a preparation method of an R-Fe-B magnet, and the magnet prepared by the method can obviously improve the coercive force of the magnet on the premise of basically keeping the remanence and the maximum energy product of the magnet.
In view of the above, the present application provides a method for preparing an R-Fe-B type magnet, comprising the steps of:
A) mixing an R1-Fe-B-M1 sample and an RH-M2-Q1 sample, and then carrying out hydrogen crushing to obtain coarse powder;
r1 is selected from one or more of rare earth elements Nd, Pr, Tb, Dy, Gd, La, Ho and Ce, M1 is selected from one or more of Ti, V, Cr, Co, Ga, Cu, Mn, Si, Al, Zr, W and Mo, the content of R1 is 26-33 wt%, the content of B is 0.8-1.2 wt%, the content of M1 is 0-4 wt%, and the balance is Fe;
RH is selected from at least one of Dy and Tb, M2 is selected from Fe, Al, Cu, Zn, Ga, Ge, Nb, Ti or Zr, Q1 is selected from Zn, Sn, V, W, Ni, Ta, Mn, Cd or Mo, the content of RH is 70-100 wt%, the content of M2 is 0-30 wt%, the content of Q1 is 0-10 wt%, and the total content of RH, M2 and Q1 is 100 wt%;
B) performing diffusion treatment on the coarse powder, and performing hydrogen crushing on the coarse powder obtained after the diffusion treatment;
C) b) carrying out airflow milling on the coarse powder obtained in the step B), and forming the obtained fine powder;
D) and sintering the molded magnet to obtain the R-Fe-B magnet.
Preferably, the RH-M2-Q1 sample is 0.1 wt% to 10 wt% of the R1-Fe-B-M1 sample.
Preferably, the diffusion treatment is carried out in vacuum or inert atmosphere, the temperature of the diffusion treatment is 750-1000 ℃, and the time is 1-50 h.
Preferably, when the diffusion treatment is performed under vacuum, the vacuum degree is 1 x 10-5～9*10-1Pa; when the diffusion treatment is carried out in an inert atmosphere, the inert gas is argon, and the pressure is 500 Pa-80 KPa.
Preferably, the step B) and the step C) are carried out under strict sealing and protective atmosphere, and the oxygen increasing amount is less than 1000 ppm.
Preferably, the RH content is 80-98 wt%, the M2 content is 1-18 wt%, and the Q1 content is 0.5-6 wt%.
Preferably, the content of the R1 is 28-30 wt%, the content of the B is 0.9-1.1 wt%, and the content of the M1 is 0.5-3 wt%.
Preferably, the molding is oriented in a magnetic field of 1.2T-2.5T.
Preferably, the sintering is specifically:
and (3) preserving the heat of the molded magnet at 950-1100 ℃ for 4-25 h, preserving the heat at the highest temperature, and then carrying out aging treatment, wherein the primary aging temperature of the aging treatment is 850-920 ℃, the secondary aging temperature of the aging treatment is 450-580 ℃, and the primary aging time and the secondary aging time are both 4-6 h.
The application provides a preparation method of an R-Fe-B magnet, which comprises the steps of mixing an R1-Fe-B-M1 sample and an RH-M2-Q1 sample, and then sequentially carrying out hydrogen crushing treatment, diffusion treatment, hydrogen crushing treatment, jet milling, molding and sintering on the mixture to obtain the R-Fe-B magnet; in the preparation method, firstly, the mixture is subjected to hydrogen crushing treatment to form coarse particles with thin thickness so as to facilitate diffusion treatment, and the heavy rare earth element RH can better permeate into the R1-Fe-B-M1 alloy through the diffusion treatment to better wrap main phase grains; meanwhile, because the two samples form coarse powder, the diffusion efficiency is high, the consistency is good, and finally, the coercive force of the magnet is greatly improved while the sintered magnet ensures less residual magnetism reduction of the magnet.
Detailed Description
For a further understanding of the invention, reference will now be made to the preferred embodiments of the invention by way of example, and it is to be understood that the description is intended to further illustrate features and advantages of the invention, and not to limit the scope of the claims.
The application provides a preparation method of an R-Fe-B magnet, aiming at the problems that the coercive force of the magnet can be improved by the preparation method of the magnet in the prior art, but the residual magnetism of the magnet can not be reduced greatly, and the R-Fe-B rare earth sintered magnet which is mainly made of an R12Fe14B type compound and is prepared by the method has small residual magnetism reduction amplitude while the coercive force of the magnet is improved. Specifically, the preparation method of the R-Fe-B magnet comprises the following steps:
A) mixing an R1-Fe-B-M1 sample and an RH-M2-Q1 sample, and then carrying out hydrogen crushing to obtain coarse powder;
r1 is selected from one or more of rare earth elements Nd, Pr, Tb, Dy, Gd, La, Ho and Ce, M1 is selected from one or more of Ti, V, Cr, Co, Ga, Cu, Mn, Si, Al, Zr, W and Mo, the content of R1 is 26-33 wt%, the content of B is 0.8-1.2 wt%, the content of M1 is 0-4 wt%, and the balance is Fe;
RH is selected from at least one of Dy and Tb, M2 is selected from Fe, Al, Cu, Zn, Ga, Ge, Nb, Ti or Zr, Q1 is selected from Zn, Sn, V, W, Ni, Ta, Mn, Cd or Mo, the content of RH is 70-100 wt%, the content of M2 is 0-30 wt%, the content of Q1 is 0-10 wt%, and the total content of RH, M2 and Q1 is 100 wt%;
B) performing diffusion treatment on the coarse powder, and performing hydrogen crushing on the coarse powder obtained after the diffusion treatment;
C) b) carrying out airflow milling on the coarse powder obtained in the step B), and forming the obtained fine powder;
D) and sintering the molded magnet to obtain the R-Fe-B magnet.
In the above method of producing an R-Fe-B type magnet, the present application first mixes a sample of R1-Fe-B-M1 with a sample of RH-M2-Q1; for both samples, R1 in the R1-Fe-B-M1 sample was selected from one or more of the rare earth elements Nd, Pr, Tb, Dy, Gd, La, Ho and Ce, M1 was selected from one or more of Ti, V, Cr, Co, Ga, Cu, Mn, Si, Al, Zr, W and Mo, in particular embodiments R1 was selected from Nb, and M1 was selected from Co. 26-33 wt% of R1, 0.8-1.2 wt% of B, 0-4 wt% of M1 and the balance of Fe; in a specific embodiment, the content of R1 is 28 wt% to 30 wt%, the content of B is 0.9 wt% to 1.1 wt%, and the content of M1 is 0.5 wt% to 3 wt%.
In the RH-M2-Q1 sample, RH is selected from at least one of Dy and Tb, M2 is selected from Fe, Al, Cu, Zn, Ga, Ge, Nb, Ti or Zr, Q1 is selected from Zn, Sn, V, W, Ni, Ta, Mn, Cd or Mo, in specific embodiments, RH is selected from Dy, and M2 is selected from copper; the content of RH is 70 wt% -100 wt%, the content of M2 is 0-30 wt%, the content of Q1 is 0-10 wt%, and the total content of RH, M2 and Q1 is 100 wt%, in a specific embodiment, the content of RH is 80 wt% -98 wt%, the content of M2 is 1 wt% -18 wt%, and the content of Q1 is 0.5 wt% -6 wt%. In the RH-M2-Q1 sample, when the contents of RH, M2 and Q1 are too low, the remanence of the magnet after diffusion is reduced more, the increase of coercive force is less, and when the contents of RH, M2 and Q1 are too high, hydrogen fragmentation is difficult to complete, and in addition, the required diffusion temperature is higher, so that the magnet is easy to enter a main phase, and the remanence is reduced greatly.
Of the two samples, the RH-M2-Q1 sample was 0.1 wt% to 10 wt% of the R1-Fe-B-M1 sample; more specifically, the RH-M2-Q1 sample is 0.5 wt% to 5 wt% of the R1-Fe-B-M1 sample; the addition amount of the RH-M2-Q1 sample is less than 0.1 wt%, the addition amount of heavy rare earth is less, the diffusion effect is difficult to achieve, the main phase crystal grains in the coarse powder cannot be coated, when the addition amount of the RH-M2-Q1 sample is more than 10 wt%, the remanence of the magnet is reduced more due to the larger addition amount, and in addition, the magnetic performance of the magnet is further reduced due to the fact that the content of the heavy rare earth elements is higher, the heavy rare earth elements are easy to enter the crystal grains.
The specific forms of the RH-M2-Q1 sample and the R1-Fe-B-M1 sample described herein are well known to those skilled in the art, and specifically may be in the form of a block or a cast piece, and more specifically, the RH-M2-Q1 sample is a cast piece or a block with a maximum dimension of less than 20 mm; the RH-M2-Q1 sample is small in size, the granularity is small after hydrogen crushing, waste is easily caused in the diffusion process, the powder is large in activity and easy to oxidize, the alloy is too large in size, and the alloy cannot be completely crushed after hydrogen crushing and is not easy to diffuse.
After the two raw materials are mixed, performing hydrogen crushing treatment on the obtained mixture to obtain initial coarse powder; the hydrogen fragmentation treatment is well known to those skilled in the art, and its specific embodiment is not particularly limited in this application. The particle size of the initial coarse powder is 45-355 mu m, and most of the particle size is 100-150 mu m, so that later diffusion treatment is facilitated; the initial coarse powder has too large particle size to be beneficial to later diffusion, and the initial coarse powder has too high activity and is easy to oxidize when the particle size is too small.
According to the invention, the initial meal after the hydrogen crushing is subjected to a diffusion treatment which causes the RH-M2-Q1 meal to diffuse into the R1-Fe-B-M1 main phase, providing a better encapsulation of the main phase grains. The diffusion treatment is carried out under the protection of vacuum or inert gas, and when the diffusion treatment is carried out under the vacuum, the vacuum degree is 1 to 10-5～9*10-1Pa; when the diffusion treatment is performed under an inert atmosphere, the inert gas is argon, and the pressure is 500Pa to 80kPa, and in a specific embodiment, the pressure is 15kPa to 60 kPa. The temperature of the diffusion treatment is 750-1000 ℃, and the time is 1-50 h; in a specific embodiment, the temperature of the diffusion treatment is 820-950 ℃, and the time is 3-15 h; when the temperature of the diffusion treatment is lower than 750 ℃, the diffusion driving force is reduced, and the heavy rare earth element is difficult to diffuse, so that the main phase crystal grains are difficult to coat; when the temperature is higher than 1000 ℃, heavy rare earth elements can easily enter crystal grains, and the magnetic performance of the magnet is reduced; the heat preservation time is short, the diffusion effect is poor, the consistency is poor, the coating of the main phase crystal grains cannot be well formed, in addition, the heat preservation time is long, heavy rare earth elements easily enter the main phase, the residual magnetism is obviously reduced, and the magnetic performance is poor.
The present application then subjects the diffusion-treated meal to a further hydrogen-fragmentation treatment, which is a technique known to those skilled in the art, the specific mode of operation of which is not particularly limited in the present application. After the hydrogen crushing treatment, performing airflow milling on the hydrogen crushed coarse powder to obtain fine powder; the jet mill is a well known technique to those skilled in the art, and its specific means of operation is not particularly limited in this application. And finally, sequentially molding and sintering the obtained fine powder to obtain the R-Fe-B magnet. In the above molding process, the molding is preferably performed in an orientation in a magnetic field of 1.2T to 2.5T. The sintering temperature is 950-1100 ℃, and the sintering time is 4-25 h. And after the sintering highest temperature heat preservation is finished, carrying out aging treatment on the magnet, wherein in the aging treatment process, the temperature of the first-stage aging is 850-920 ℃, the temperature of the second-stage aging is 450-580 ℃, and the time of the first-stage aging and the time of the second-stage aging are both 4-6 h.
The hydrogen crushing treatment, the diffusion treatment, the jet milling and the forming are all carried out under strict sealing and protective atmosphere, and the oxygen increasing amount is controlled to be less than 1000ppm so as to avoid the oxidation of the treated product.
The invention provides a preparation method of an R-Fe-B sintered magnet, which mixes an R1-Fe-B-M1 sample and an RH-M2-Q1 sample and then carries out hydrogen crushing treatment, and the crushed coarse powder is transferred into a rotary diffusion furnace to carry out diffusion treatment. Therefore, the magnet-like body prepared by the method uses a small amount of heavy rare earth to remarkably improve the coercive force of the magnet on the premise of basically keeping the remanence and the maximum energy product of a sintered magnet.
For further understanding of the present invention, the following examples are given to illustrate the preparation of R-Fe-B based magnet according to the present invention, and the scope of the present invention is not limited by the following examples.
Example 1
Smelting the configured raw materials by a vacuum smelting furnace under the protection of inert gas according to the component proportion of tables 1 and 2, respectively smelting an R1-Fe-B-M1 alloy cast sheet and an RH-M2-Q1 alloy cast sheet to form a cast sheet with the thickness of 0.1-1 mm, and adding the RH-M2-Q1 alloy cast sheet according to 1 wt% of the weight of R1-Fe-B-M1; after hydrogen crushing, transferring the two alloy casting sheets into a rotary diffusion furnace, performing diffusion treatment at the pressure of 20-40 kPa for 870 ℃/5h under inert atmosphere, performing secondary hydrogen crushing in the hydrogen crushing furnace after diffusion, and crushing SMD (surface mounted device) to 3.2 mu m by an airflow mill; and (3) adopting a magnetic field orientation of 15KOe to perform compression molding to prepare a pressed compact with the density of 3.95g/cm3(ii) a And (3) sintering the pressed compact in a sintering furnace in vacuum, sintering for 500min at 1045 ℃, aging for 180min at 890 ℃, and aging for 240min at 490 ℃ to obtain a green compact. A10 mm diameter sample column was used for the magnetic property M1.
TABLE 1 ingredient ratio Table of R1-Fe-B-M1 for R-Fe-B prepared in example 1
| Group of | Nd | B | Co | Small material | Fe |
| The content wt% | 30.6 | 0.92 | 0.5 | 0.3 | Remainder of |
TABLE 2 RH-M2-Q1 compositional proportion of R-Fe-B prepared in example 1
TABLE 3 table of performance data of R-Fe-B type magnet prepared in example 1
Example 2
Smelting the configured raw materials by a vacuum smelting furnace under the protection of inert gas according to the component proportion of tables 4 and 5, respectively smelting an R1-Fe-B-M1 alloy cast sheet and an RH-M2-Q1 alloy cast sheet to form a cast sheet with the thickness of 0.1-1 mm, and adding the RH-M2-Q1 alloy cast sheet according to 1 wt% of the weight of R1-Fe-B-M1; after hydrogen crushing, transferring the two alloy casting sheets into a rotary diffusion furnace, performing diffusion treatment at the pressure of 20-40 kPa for 870 ℃/10h under inert atmosphere, performing secondary hydrogen crushing in the hydrogen crushing furnace after diffusion, and crushing SMD (surface mounted device) to 3.2 mu m by an airflow mill; adopting 15KOe magnetic field orientation compression molding to prepare a pressed compact with the density of 3.95g/cm3(ii) a And (3) sintering the pressed compact in a sintering furnace in vacuum, sintering for 500min at 1045 ℃, aging for 180min at 890 ℃, and aging for 240min at 490 ℃ to obtain a green compact. A10 mm diameter sample column was used for the magnetic property M2.
TABLE 4 compositional proportion of R1-Fe-B-M1 for R-Fe-B prepared in example 4
| Group of | Nd | B | Co | Small material | Fe |
| The content wt% | 30.6 | 0.92 | 0.5 | 0.3 | Remainder of |
TABLE 5 RH-M2-Q1 compositional proportion of R-Fe-B prepared in example 2
| Group of | Dy | Cu | Mn |
| The content wt% | 92 | 7 | 1 |
TABLE 6 table of performance data of R-Fe-B type magnet prepared in example 2
As can be seen from table 6, M2 has a coercive force 0.66kOe higher than M1 and a remanence 0.05kGs lower than M1, indicating that the longer the diffusion time, the higher the coercive force of the magnet and the lower the remanence.
Example 3
Smelting the configured raw materials by a vacuum smelting furnace under the protection of inert gas according to the component proportion of tables 7 and 8, respectively smelting an R1-Fe-B-M1 alloy cast sheet and an RH-M2-Q1 alloy cast sheet to form a cast sheet with the thickness of 0.1-1 mm, and adding the RH-M2-Q1 alloy cast sheet according to 1 wt% of the weight of R1-Fe-B-M1; after hydrogen crushing, the two alloy cast pieces are transferred into a rotary diffusion furnace, diffusion treatment is carried out in an inert atmosphere at the pressure of 15-35 kPa according to the speed of 910 ℃/5h, secondary hydrogen crushing is carried out in the hydrogen crushing furnace after diffusion, and the SMD is crushed to 3.2 mu m by an airflow mill; adopting 15KOe magnetic field orientation compression molding to prepare a pressed compact with the density of 3.95g/cm3(ii) a And (3) sintering the pressed compact in a sintering furnace in vacuum, sintering for 500min at 1045 ℃, aging for 180min at 890 ℃, and aging for 240min at 490 ℃ to obtain a green compact. A10 mm diameter sample column was used for the magnetic property M3.
TABLE 7 ingredient ratio Table of R1-Fe-B-M1 for R-Fe-B prepared in example 3
| Group of | Nd | B | Co | Small material | Fe |
| The content wt% | 30.6 | 0.92 | 0.5 | 0.3 | Remainder of |
TABLE 8 RH-M2-Q1 compositional proportion of R-Fe-B prepared in example 3
| Group of | Dy | Cu | Mn |
| The content wt% | 92 | 7 | 1 |
TABLE 9 PERFORMANCE DATA TABLE FOR R-Fe-B TYPE MAGNET PREPARED IN EXAMPLE 3
As can be seen from table 9, M3 has a coercive force 0.57kOe higher than M1 and a remanence 0.07kGs lower than M1, indicating that the higher the diffusion temperature, the higher the coercive force of the magnet and the lower the remanence.
Example 4
Smelting the configured raw materials by a vacuum smelting furnace under the protection of inert gas according to the component proportion of the components shown in the table 10 and the table 11, respectively smelting R1-Fe-B-M1 and RH-M2-Q1 alloy cast pieces to form cast pieces with the thickness of 0.1-1 mm, and adding RH-M2-Q1 alloy according to 1 wt% of the weight of R1-Fe-B-M1Casting a sheet; after hydrogen crushing, the two alloy cast pieces are transferred into a rotary diffusion furnace, diffusion treatment is carried out in an inert atmosphere at the pressure of 30-50 kPa according to 870 ℃/5h, secondary hydrogen crushing is carried out in the hydrogen crushing furnace after diffusion, and the SMD is crushed to 3.2 mu m by an airflow mill; adopting 15KOe magnetic field orientation compression molding to prepare a pressed compact with the density of 3.95g/cm3(ii) a And (3) sintering the pressed compact in a sintering furnace in vacuum, sintering for 500min at 1045 ℃, aging for 180min at 890 ℃, and aging for 240min at 490 ℃ to obtain a green compact. A10 mm diameter sample column was used for the magnetic property M4.
TABLE 10 compositional proportion of R1-Fe-B-M1 for R-Fe-B prepared in example 4
| Group of | Nd | B | Co | Small material | Fe |
| The content wt% | 30.6 | 0.92 | 0.5 | 0.3 | Remainder of |
TABLE 11 RH-M2-Q1 compositional proportion of R-Fe-B prepared in example 4
| Group of | Dy | Cu | Mn |
| The content wt% | 85 | 12 | 3 |
TABLE 12 table of performance data of R-Fe-B type magnet prepared in example 4
As can be seen from table 12, M4 has a coercive force 0.8kOe lower than that of M1 and a remanence 0.11kGs lower than that of M1, indicating that as the content of heavy rare earth decreases, the content of metal M2 increases and both the coercive force and remanence of the magnet decrease.
Comparative example 1
Smelting the configured raw materials by a vacuum smelting furnace under the protection of inert gas according to the component proportion of tables 1 and 2, respectively smelting an R1-Fe-B-M1 alloy cast sheet and an RH-M2-Q1 alloy cast sheet to form a cast sheet with the thickness of 0.1-1 mm, and adding the RH-M2-Q1 alloy cast sheet according to 1 wt% of the weight of R1-Fe-B-M1; hydrogen crushing in a hydrogen crushing furnace to obtain coarse powder, and airflow milling to break SMD to 3.2 micron; adopting 15KOe magnetic field orientation to perform compression molding to prepare a pressed compact, wherein the density of the pressed compact is 4.05g/cm 3; and (3) sintering the pressed compact in a sintering furnace in vacuum for 500min at 1045 ℃. Then aging at 890 deg.C for 180min, and at 490 deg.C for 240min to obtain green compact. A10 mm diameter sample column was used for the magnetic property D1.
TABLE 13 table of performance data of R-Fe-B type magnet prepared in comparative example
The above description of the embodiments is only intended to facilitate the understanding of the method of the invention and its core idea. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (8)
1. A preparation method of an R-Fe-B magnet is characterized by comprising the following steps:
A) mixing an R1-Fe-B-M1 sample and an RH-M2-Q1 sample, and then carrying out hydrogen crushing to obtain coarse powder;
r1 is selected from one or more of rare earth elements Nd, Pr, Tb, Dy, Gd, La, Ho and Ce, M1 is selected from one or more of Ti, V, Cr, Co, Ga, Cu, Mn, Si, Al, Zr, W and Mo, the content of R1 is 26-33 wt%, the content of B is 0.8-1.2 wt%, the content of M1 is 0-4 wt%, and the balance is Fe;
RH is selected from at least one of Dy and Tb, M2 is selected from Fe, Al, Cu, Zn, Ga, Ge, Nb, Ti or Zr, Q1 is selected from Zn, Sn, V, W, Ni, Ta, Mn, Cd or Mo, the content of RH is 80-98 wt%, the content of M2 is 1-18 wt%, the content of Q1 is 0.5-6 wt%, and the total content of RH, M2 and Q1 is 100 wt%;
B) performing diffusion treatment on the coarse powder, and performing hydrogen crushing on the coarse powder obtained after the diffusion treatment;
C) b) carrying out airflow milling on the coarse powder obtained in the step B), and forming the obtained fine powder;
D) and sintering the molded magnet to obtain the R-Fe-B magnet.
2. The method of claim 1, wherein the RH-M2-Q1 sample is 0.1 wt% to 10 wt% of the R1-Fe-B-M1 sample.
3. The method according to claim 1, wherein the diffusion treatment is performed under vacuum or an inert atmosphere, and the temperature of the diffusion treatment is 750 to 1000 ℃ and the time is 1 to 50 hours.
4. The method according to claim 3, wherein the diffusion treatment is carried out under vacuum at a vacuum degree of 1 x 10-5～9*10-1Pa; when the diffusion treatment is carried out in an inert atmosphere, the inert gas is argon, and the pressure is 500 Pa-80 KPa.
5. The method for preparing the water-soluble polymer according to claim 1, wherein the steps B) and C) are carried out under a strictly sealed and protective atmosphere, and the oxygen increasing amount is less than 1000 ppm.
6. The method according to claim 1, wherein the R1 content is 28-30 wt%, the B content is 0.9-1.1 wt%, and the M1 content is 0.5-3 wt%.
7. The method according to claim 1, wherein the molding is performed in an orientation in a magnetic field of 1.2T to 2.5T.
8. The method according to claim 1, wherein the sintering is in particular:
and (3) preserving the heat of the molded magnet at 950-1100 ℃ for 4-25 h, preserving the heat at the highest temperature, and then carrying out aging treatment, wherein the primary aging temperature of the aging treatment is 850-920 ℃, the secondary aging temperature of the aging treatment is 450-580 ℃, and the primary aging time and the secondary aging time are both 4-6 h.
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| CN111446055A (en) * | 2020-05-08 | 2020-07-24 | 中国科学院宁波材料技术与工程研究所 | High-performance neodymium iron boron permanent magnet material and preparation method thereof |
| CN113751713B (en) * | 2020-06-05 | 2024-02-09 | 江西金力永磁科技股份有限公司 | Neodymium iron boron ultrafine powder recovery method |
| CN111968819A (en) * | 2020-09-09 | 2020-11-20 | 宁波科田磁业有限公司 | Low-heavy rare earth high-performance sintered neodymium-iron-boron magnet and preparation method thereof |
| CN113643892B (en) * | 2021-08-19 | 2024-03-22 | 太原开元智能装备有限公司 | Preparation method of RFeB sintered magnet |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104733148A (en) * | 2015-03-31 | 2015-06-24 | 安徽省瀚海新材料有限公司 | High-performance Re-TM-B permanent magnetic material manufacturing method |
| CN108922708A (en) * | 2018-07-11 | 2018-11-30 | 董开 | A kind of preparation method and the broken all-in-one oven of rotary diffusible hydrogen of sintered rare-earth permanent magnetic body |
| CN109102976A (en) * | 2018-08-10 | 2018-12-28 | 浙江东阳东磁稀土有限公司 | A method of improving rare-earth Nd-Fe-B magnetic property |
| CN109192495A (en) * | 2018-11-07 | 2019-01-11 | 安徽大地熊新材料股份有限公司 | A kind of preparation method of recycled sinter Nd-Fe-B permanent magnet |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104681268B (en) * | 2013-11-28 | 2018-02-23 | 湖南稀土金属材料研究院 | One kind improves the coercitive processing method of Sintered NdFeB magnet |
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104733148A (en) * | 2015-03-31 | 2015-06-24 | 安徽省瀚海新材料有限公司 | High-performance Re-TM-B permanent magnetic material manufacturing method |
| CN108922708A (en) * | 2018-07-11 | 2018-11-30 | 董开 | A kind of preparation method and the broken all-in-one oven of rotary diffusible hydrogen of sintered rare-earth permanent magnetic body |
| CN109102976A (en) * | 2018-08-10 | 2018-12-28 | 浙江东阳东磁稀土有限公司 | A method of improving rare-earth Nd-Fe-B magnetic property |
| CN109192495A (en) * | 2018-11-07 | 2019-01-11 | 安徽大地熊新材料股份有限公司 | A kind of preparation method of recycled sinter Nd-Fe-B permanent magnet |
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