Modified rare earth permanent magnet material and preparation method thereof

Abstract

The invention provides a modified rare earth permanent magnet material and a preparation method thereof. The modified rare earth permanent magnet material comprises a first alloy and a second alloy, the first alloy has a chemical formula shown in a formula (I): (NdxRH < 100%-x >) M < 1b > Tc < BdFe < 100%-a-b-c-d (I), x is larger than or equal to 70 wt% and smaller than 100 wt%, a is 29.5 wt%-35 wt%, b is 1 wt%-2.15 wt%, c is 0.8 wt%-1.5 wt%, and d is 1.03 wt%-1.2 wt%; the second alloy has a chemical formula as shown in a formula (II): (PryRH2 100%-y) 100%-eM2e (II), y is 0-30 wt%, and e is 0-50%; and RH1 and RH2 are the same or different. The modified rare earth permanent magnet material can meet the condition that the sum of the value of the maximum magnetic energy product (BH) max and the value of the intrinsic coercive force Hcj is larger than 80, and Hcj is larger than 40 kOe.

Description

Technical Field

[0001] The invention relates to the technical field of magnetic materials, and in particular to a modified rare earth permanent magnetic material and a preparation method thereof. Background Art

[0002] Rare earth permanent magnet materials, especially sintered NdFeB materials, are widely used in wind power generation, new energy vehicles, consumer electronics, industrial robots and other fields due to their excellent magnetic properties. At present, most sintered NdFeB magnets have high operating temperature requirements for magnets in motors, and the operating temperature reaches 220°C or even higher, and the coercivity needs to reach AH or above to meet the requirements. At present, a large amount of Dy or Tb is often added to the magnet to increase the anisotropy constant of the magnet and increase the coercive force of the magnet. However, if the amount added is too much, the remanence Br and magnetic energy product (BH) max of the magnet will be sharply reduced.

[0003] For example, an existing document (publication number CN109192424A) discloses an ultra-high coercive force sintered NdFeB magnet, wherein the high-performance sintered NdFeB magnet is obtained by isostatically pressing a compact made of NdFeB-based raw material powder in a traditional sintering process in a solution containing Dy or Tb as an isostatic pressing medium, and then undergoing a sintering process. The components and their mass fractions in the NdFeB-based raw material powder are PrNd: 25% to 28%, B: 1.0% to 1.2%, one or more of Gd, Dy, Tb, and Co: 4% to 10%, Al: 0.4% to 2.0%, Nb: 0.2% to 0.3%, Cu: 0.18% to 0.2%, and the remainder is Fe and unavoidable impurities. Although the comprehensive magnetic properties (the sum of the maximum magnetic energy product and the intrinsic coercive force) are greater than 80, the remanence (Br) and maximum magnetic energy product (BH)max of the magnet are low. In order to meet the normal use of the motor during use, the weight of the single-piece magnet needs to be larger, which makes it difficult to achieve the miniaturization and lightweight requirements of the magnet. The existing document (publication number CN114242438A) discloses a method for preparing a high-performance low-B high-Ga sintered Re-Fe-B, which prepares a high-performance low-B high-Ga sintered NdFeB magnet by adopting a segmented magnetic field orientation automatic pressing method. The diffusion process can significantly improve Hcj while keeping Br basically unchanged. However, its Hcj can only reach 12KOe.

[0004] Therefore, researching and developing a modified rare earth permanent magnet material that can simultaneously satisfy the sum of the values ​​of (BH)max and Hcj greater than 80 and Hcj greater than 40kOe is of great significance for improving its gear position and broadening its application scenarios. Summary of the invention

[0005] The main purpose of the present invention is to provide a modified rare earth permanent magnet material and a preparation method thereof, so as to solve the problem that the rare earth permanent magnet material in the prior art cannot simultaneously satisfy the sum of the maximum magnetic energy product (BH) max and the intrinsic coercive force Hcj greater than 80, and Hcj greater than 40kOe, resulting in limited application scenarios.

[0006] In order to achieve the above object, the present invention provides a modified rare earth permanent magnet material, which comprises a first alloy and a second alloy, wherein the first alloy has a chemical formula shown in formula (I): x RH 1 100％-x ) a M 1 b T c B d Fe 100％-a-b-c-d (I), where RH 1 M is a heavy rare earth element. 1 At least two selected from Cu, Ga, Al, and Co, and M 1 The invention comprises Cu and Ga, T is selected from one or more of Zr, Hf and Ti, x≥70wt% and <100wt%, a is 29.5-35wt%, b is 1-2.15wt%, c is 0.8-1.5wt%, and d is 1.03-1.2wt%; in terms of weight percentage of the first alloy, the content of Cu is 0.5-1.0wt%, and the content of Ga is 0.5-1.0wt%; the second alloy has the chemical formula shown in formula (II): (Pr y RH 2 100％-y ) 100％-e M 2 e (II): RH 2 M is a heavy rare earth element. 2 One or more selected from Cu, Ga, Al, Co, y is 0-30wt%, e is 0-50%; RH 1 With RH 2 Same or different.

[0007] Furthermore, RH 1 and RH 2 Each is independently selected from one or more of Dy, Tb, Ho, and Gd.

[0008] Further, x≥80wt% and <100wt%, a is 29.5-32wt%, b is 1.0-2.0wt%, c is 0.8-1.5wt%, d is 1.03-1.1wt%; and / or y is 0-20wt%, and e is 10-50wt%.

[0009] Furthermore, based on the weight of the modified rare earth permanent magnet material, the weight percentage of the second alloy does not exceed 20wt%; preferably, the weight ratio of the first alloy to the second alloy is (90-95):(5-10).

[0010] Furthermore, RH 1 is a combination of Tb, Dy, or Gd and Ho; RH 1 Preferably Tb; M 1 is a combination of Cu and Ga, or a combination of Cu, Ga, Al, Co, or a combination of Cu, Ga, Co; M 1 Preferably, it is a combination of Cu and Ga; M 1 More preferably, it is a combination of Cu and Ga, and the weight ratio of Cu to Ga is (16-34):(16-34); T is a combination of Zr, Hf and Ti, or a combination of Hf and Ti, or a combination of Hf and Zr; T is preferably a combination of Zr, Hf and Ti; T is more preferably a combination of Zr, Hf and Ti, and the weight ratio of Zr, Hf and Ti is (6-9):(2-5):(5-12); RH 2 is a combination of Tb, Dy, or Gd and Ho; RH 2 Preferably Tb; M 2 is a combination of Cu, Ga, Al and Co, or a combination of Cu, Ga and Co; M 2 Preferably it is a combination of Cu, Ga, Al and Co, and the weight ratio of Cu, Ga, Al to Co is (5-8):(4-7):(0.1-4):(4-8), or more preferably it is a combination of Cu, Ga and Co, and the weight ratio of Cu, Ga and Co is (5-10):(5-6):(5-9).

[0011] In order to achieve the above-mentioned purpose, another aspect of the present invention also provides a method for preparing the above-mentioned modified rare earth permanent magnet material provided by the present application, and the method for preparing the modified rare earth permanent magnet material comprises: preparing a first alloy and a second alloy; using a grain boundary diffusion method to process the first alloy and the second alloy to obtain a modified rare earth permanent magnet material.

[0012] Furthermore, the preparation method further comprises: 1 Source, M 1 The source, T source and ferroboron are mixed and subjected to a first smelting process and a first sheeting process to obtain a first alloy casting sheet; RH 1 The source is selected from a single substance of a heavy rare earth element, or an alloy formed by a heavy rare earth element and iron; M 1 The source is selected from at least two of Cu, Ga, Al, and Co, and M 1The source includes Cu and Ga; T is selected from one or more of Zr-Fe alloy, Hf and Ti; the first alloy casting sheet is subjected to a first crushing treatment to obtain a first powder; the first powder is subjected to orientation molding and pressing treatment to obtain a green body; the green body is sintered to obtain a first alloy; preferably, the average thickness of the first alloy casting sheet is 0.2 to 0.4 mm; preferably, the average particle size of the first powder is 100 to 300 μm; preferably, the sintering treatment temperature is 40 to 1100°C and the time is 4 to 10 hours.

[0013] Furthermore, the preparation method further comprises: adding an optional Pr single substance, RH 2 Source, M 2 The source is mixed with ferroboron and subjected to a second smelting process and a second sheeting process to obtain a second alloy casting sheet; RH 2 The source is selected from a single substance of a heavy rare earth element, or an alloy formed by a heavy rare earth element and iron, 2 The source is selected from one or more of Cu, Ga, Al and Co; the second alloy casting is subjected to a second crushing process to obtain a second powder; the second powder, a solvent and a binder are mixed to obtain a slurry; the slurry is coated on the surface of the first alloy, and a modified rare earth permanent magnet material is obtained after a first heat treatment and a second heat treatment.

[0014] Furthermore, the weight ratio of the second powder, the solvent and the binder is (40-60):(40-60):(2-8); and / or the solvent is an alcohol organic solvent, preferably one or more of ethanol, ethylene glycol, and terpineol; and / or the binder is selected from one or more of polyvinyl alcohol, polyvinyl chloride resin and polyvinyl acetate.

[0015] Furthermore, the heating rate of the first heat treatment is 1-10°C / min, the temperature is 960-1020°C, and the time is 5-20h; the heating rate of the second heat treatment is 4-10°C / min, the temperature is 440-560°C, and the time is 2-6h; preferably, a cooling process is included between the first heat treatment and the second heat treatment, and the cooling process is carried out in an inert gas atmosphere; preferably, the cooling rate of the cooling process is 10-30°C / min.

[0016] The technical solution of the present invention is applied to the conventional Nd2Fe 14 Compared with the B permanent magnet material, the heavy rare earth element RH in the modified rare earth permanent magnet material provided in the present application 1 and M 1On the one hand, the introduction of elements can improve the anisotropy of modified rare earth permanent magnet materials, especially the introduction of specific contents of Cu and Ga elements can significantly improve the anisotropy, thereby improving its coercivity; on the other hand, it can also improve the temperature coefficient of intrinsic coercivity, thereby improving its high temperature resistance; in addition, the introduction of specific types and amounts of T (strictly controlling the value range of x, a, b, c and d) can be combined with the heavy rare earth element RH 1 、M 1 The elements work together to simultaneously increase the maximum magnetic energy product (BH)max and the intrinsic coercivity Hcj.

[0017] Compared with a single alloy component, the modified rare earth permanent magnet material contains both the first alloy of the specific components of the present application (strictly controlling the value range of x, a, b, c and d) and the second alloy of the specific components (strictly controlling the value range of y and e) to promote the synergistic effect of the two, which is beneficial to improving the coercive force of the modified rare earth permanent magnet material, so that the modified rare earth permanent magnet material can meet the requirements that the sum of the value of (BH)max and the value of Hcj is greater than 80, and Hcj is greater than 40kOe, so that it can meet more application scenarios (such as drive motors in new energy vehicles). Compared with other types of M 2 , using the above specific types of M 2 On the one hand, it can improve the microstructure, grain structure and grain boundary phase distribution of the material. Cu, Ga and Al are low-melting-point non-ferromagnetic elements, which mainly exist in the grain boundary phase. They can reduce the melting point of the grain boundary phase, improve the wettability of the main phase in the grain boundary phase, and can react with the rare earth element RH. 2 The reaction generates non-ferromagnetic RH 2 -Fe-Cu / Ga / Al grain boundary phase can play a good role in demagnetizing coupling, thereby better improving the intrinsic coercivity of the material without reducing the remanence of the material; on the other hand, adding the element Co can improve the high-temperature remanence temperature coefficient of the material and improve the magnetic properties of the material under high temperature conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0019] Figure 1 The SEM image of the modified rare earth permanent magnet material prepared in Example 1 of the present application is shown. DETAILED DESCRIPTION

[0020] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.

[0021] As described in the background technology, the existing rare earth permanent magnet materials cannot simultaneously satisfy the sum of the maximum magnetic energy product (BH) max and the intrinsic coercivity Hcj greater than 80, and Hcj greater than 40kOe, resulting in the problem that their application scenarios are limited. In order to solve the above technical problems, the present application provides a modified rare earth permanent magnet material, the modified rare earth permanent magnet material includes a first alloy and a second alloy, the first alloy has a chemical formula shown in formula (I): (Nd x RH 1 100％-x ) a M 1 b T c B d Fe 100％-a-b-c-d (I), where RH 1 M is a heavy rare earth element. 1 At least two selected from Cu, Ga, Al, and Co, and M 1 The invention comprises Cu and Ga, T is selected from one or more of Zr, Hf and Ti, x is ≥70wt% and <100wt%, a is 29.5-35wt%, b is 1-2.15wt%, c is 0.8-1.5wt%, and d is 1.03-1.2wt%; in terms of the weight percentage of the first alloy, the content of Cu is 0.5-1.0wt%, and the content of Ga is 0.5-1.0wt%; the second alloy has the chemical formula shown in formula (II): (Pr y RH 2 100％-y ) 100％-e M 2 e (II), where RH 2 M is a heavy rare earth element. 2 One or more selected from Cu, Ga, Al, Co, y is 0-30wt%, e is 0-50%; RH 1 With RH 2 Same or different.

[0022] Compared with the traditional Nd2Fe 14 Compared with the B permanent magnet material, the heavy rare earth element RH in the modified rare earth permanent magnet material provided in the present application 1 and M 1 On the one hand, the introduction of elements can improve the anisotropy of modified rare earth permanent magnet materials, especially the introduction of specific contents of Cu and Ga elements can significantly improve the anisotropy, thereby improving its coercivity; on the other hand, it can also improve the temperature coefficient of intrinsic coercivity, thereby improving its high temperature resistance; in addition, the introduction of specific types and amounts of T (strictly controlling the value range of x, a, b, c and d) can be combined with the heavy rare earth element RH 1 、M1 The elements work together to increase both (BH)max and Hcj.

[0023] Compared with a single alloy component, the modified rare earth permanent magnet material contains both the first alloy of the specific components of the present application (strictly controlling the value range of x, a, b, c and d) and the second alloy of the specific components (strictly controlling the value range of y and e) to promote the synergistic effect of the two, which is beneficial to improving the coercive force of the modified rare earth permanent magnet material, so that the modified rare earth permanent magnet material can meet the requirements that the sum of the value of (BH)max and the value of Hcj is greater than 80, and Hcj is greater than 40kOe, so that it can meet more application scenarios (such as drive motors in new energy vehicles). Compared with other types of M 2 , using the above specific types of M 2 On the one hand, it can improve the microstructure, grain structure and grain boundary phase distribution of the material. Cu, Ga and Al are low-melting-point non-ferromagnetic elements, which mainly exist in the grain boundary phase. They can reduce the melting point of the grain boundary phase, improve the wettability of the main phase in the grain boundary phase, and can react with the rare earth element RH. 2 The reaction generates non-ferromagnetic RH 2 -Fe-Cu / Ga / Al grain boundary phase can play a good role in demagnetizing coupling, thereby better improving the Hcj of the material without reducing the remanence of the material; on the other hand, adding the element Co can improve the high-temperature remanence temperature coefficient of the material and improve the magnetic properties of the material under high temperature conditions.

[0024] In a preferred embodiment, RH 1 and RH 2 Each independently includes but is not limited to one or more of Dy, Tb, Ho, and Gd. Compared with other types, the use of the above types of RH 1 and RH 2 It is beneficial to improve the anisotropy of the modified rare earth permanent magnet material, thereby improving its coercive force.

[0025] In a preferred embodiment, x≥80wt% and <100wt%, a is 29.5-32wt%, b is 1.0-2.0wt%, c is 0.8-1.5wt%, d is 1.03-1.1wt%; and / or, y is 0-20wt%, and e is 10-50wt%. Compared with other ranges, limiting the value ranges of x, y, a, b, c, d and e to the above ranges is conducive to exerting the synergistic effect of the above specific types of elements, thereby facilitating the improvement of (BH)max and Hcj of the modified rare earth permanent magnet material.

[0026] In a preferred embodiment, the weight percentage of the second alloy is no more than 20wt% based on the weight of the modified rare earth permanent magnet material. The content of the second alloy includes but is not limited to the above range, and limiting it within the above range is beneficial to further improve the (BH)max and Hcj of the modified rare earth permanent magnet material.

[0027] In order to further exert the synergistic effect of the above-mentioned specific types of elements and further improve the (BH)max and Hcj of the modified rare earth permanent magnet material, preferably, the weight ratio of the first alloy to the second alloy is (90-95):(5-10).

[0028] In a preferred embodiment, RH 1 is a combination of Tb, Dy, or Gd and Ho; RH 1 Tb is preferred. Compared with other types, the above preferred types of RH are used 1 It is beneficial to further improve the anisotropy of the modified rare earth permanent magnet material, thereby improving its coercive force.

[0029] In a preferred embodiment, M 1 is a combination of Cu and Ga, or a combination of Cu, Ga, Al, Co, or a combination of Cu, Ga, Co; M 1 Preferably, it is a combination of Cu and Ga; M 1 More preferably, it is a combination of Cu and Ga, and the weight ratio of Cu to Ga is (16 to 34): (16 to 34). Compared with other types, the use of the above preferred types of M 1 It is beneficial to further improve the coercive force and also beneficial to further improve the temperature coefficient of Hcj, thereby improving its high temperature resistance.

[0030] In a preferred embodiment, T is a combination of Zr, Hf and Ti, or a combination of Hf and Ti, or a combination of Hf and Zr; T is preferably a combination of Zr, Hf and Ti; T is more preferably a combination of Zr, Hf and Ti, and the weight ratio of Zr, Hf and Ti is (6-9): (2-5): (6-12). T includes but is not limited to the above preferred types, and limiting it within the above range is conducive to further exerting the synergistic effect of the above-mentioned various specific types of elements, thereby facilitating the improvement of (BH)max and Hcj of the modified rare earth permanent magnet material.

[0031] In a preferred embodiment, RH 2 is a combination of Tb, Dy, or Gd and Ho; RH 2 Tb is preferred. Compared with other types, the above types of RH 2 This is beneficial to further improve the anisotropy of the modified rare earth permanent magnet material, thereby helping to improve its coercive force.

[0032] In a preferred embodiment, M 2 is a combination of Cu, Ga, Al and Co, or a combination of Cu, Ga and Co; M 2 Preferably, it is a combination of Cu, Ga, Al and Co, and the weight ratio of Cu, Ga, Al to Co is (5-8): (4-7): (0.1-4): (4-8), or more preferably, it is a combination of Cu, Ga and Co, and the weight ratio of Cu, Ga and Co is (5-10): (5-6): (5-9). Compared with other types, the use of the above types of M 2 It is beneficial to further improve the microstructure, grain structure and grain boundary phase distribution of the modified rare earth permanent magnet material, thereby improving the demagnetizing coupling effect of the grain boundary phase and improving the coercive force of the material while maintaining the remanence without significantly reducing it.

[0033] The second aspect of the present application also provides a method for preparing the above-mentioned modified rare earth permanent magnet material provided by the present application, and the method for preparing the modified rare earth permanent magnet material comprises: preparing a first alloy and a second alloy; and processing the first alloy and the second alloy by a grain boundary diffusion method to obtain a modified rare earth permanent magnet material.

[0034] The modified rare earth permanent magnet material provided in the present application includes the first alloy and the second alloy of the above-mentioned specific type. The first alloy and the second alloy are processed by the grain boundary diffusion method to obtain a modified rare earth permanent magnet material with both higher (BH)max and higher Hcj.

[0035] In a preferred embodiment, the preparation method further comprises: 1 Source, M 1 The source, T source and ferroboron are mixed and subjected to a first smelting process and a first sheeting process to obtain a first alloy casting sheet; RH 1 The source includes but is not limited to a single substance of a heavy rare earth element, or an alloy formed by a heavy rare earth element and iron; 1 The source includes but is not limited to at least two of Cu, Ga, Al, and Co, and M 1 The source includes Cu and Ga; T includes but is not limited to one or more of Zr-Fe alloy, Hf and Ti; the first alloy casting is subjected to a first crushing treatment to obtain a first powder; the first powder is subjected to orientation molding and pressing treatment to obtain a green body; the green body is subjected to sintering treatment to obtain a first alloy.

[0036] The above raw materials are subjected to a first smelting treatment to facilitate the subsequent first sheeting treatment to obtain a first alloy casting sheet; the first alloy casting sheet is subjected to a first crushing treatment to crush it into a first powder with a smaller particle size, which is convenient for the subsequent orientation forming treatment; the orientation forming treatment refers to a treatment in which the first powder overcomes the friction and agglomeration between the powder particles under the action of an external magnetic field to form an oriented powder; the pressing treatment refers to the use of pressure to make the first powder obtain density and shape, thereby obtaining a green body; after the first powder is subjected to orientation forming and pressing treatment, a green body is obtained; the green body is sintered to obtain a modified rare earth permanent magnet material.

[0037] In a preferred embodiment, the first crushing treatment includes hydrogen crushing and air flow milling in sequence. The hydrogen crushing treatment can be divided into two stages: hydrogen absorption and dehydrogenation. The principle is to use hydrogen to react with the Nd-rich phase and the main phase to produce a hydrogenation reaction. After the hydrogen crushing treatment, a crisp powder can be obtained, which is conducive to further fine crushing. Air flow milling is a process that uses a high-pressure gas flow to accelerate the powder particles treated with hydrogen to a supersonic speed and cause the powder particles to collide with each other to crush them. In a preferred embodiment, the crushing treatment includes hydrogen crushing and air flow milling in sequence, an antioxidant is added during the air flow milling process, and a second powder is obtained after the air flow milling is completed. Adding an antioxidant during the air flow milling process is beneficial to inhibiting the first powder and the second powder from being oxidized by oxidizing substances such as oxygen in the environment, thereby preventing a sudden drop in performance due to oxidation.

[0038] In a preferred embodiment, the average thickness of the first alloy casting sheet is 0.2-0.4 mm. The average thickness of the first alloy casting sheet includes but is not limited to the above range, and limiting it to the above range is conducive to subsequent first crushing treatment and improving its machinability.

[0039] In a preferred embodiment, the average particle size of the first powder is 100-300 μm. The average particle size of the first powder includes but is not limited to the above range, which is beneficial to subsequent airflow milling, orientation molding and pressing.

[0040] In a preferred embodiment, the pressing treatment is isostatic pressing, and the pressure of the cold isostatic pressing is 160-250 MPa and the time is 10-60 seconds. The pressure and time of the cold isostatic pressing include but are not limited to the above ranges, and limiting them within the above ranges is conducive to obtaining a blank with uniform density.

[0041] In a preferred embodiment, the sintering temperature is 40-1100°C and the time is 4-10 hours. The temperature and time of the sintering process include but are not limited to the above ranges, and limiting them within the above ranges is conducive to obtaining sintered dense rare earth materials.

[0042] In a preferred embodiment, the preparation method further comprises: adding an optional Pr element, RH 2 Source, M 2 The source is mixed with ferroboron and subjected to a second smelting process and a second sheeting process to obtain a second alloy casting sheet; RH 2 The source includes but is not limited to a single substance of a heavy rare earth element, or an alloy formed by a heavy rare earth element and iron, M 2 The source includes but is not limited to one or more of Cu, Ga, Al, and Co; the second alloy casting is subjected to a second crushing process to obtain a second powder; the second powder, a solvent, and a binder are mixed to obtain a slurry; the slurry is coated on the surface of the first alloy, and a modified rare earth permanent magnet material is obtained after a first heat treatment and a second heat treatment.

[0043] The above treatment method can obtain a modified rare earth permanent magnet material with a more uniform distribution of grain boundary phase, which can improve the demagnetization coupling effect of the grain boundary phase and generate non-ferromagnetic RH 2 -Fe-Cu / Ga / Al grain boundary phase, thereby improving its (BH)max and Hcj.

[0044] In a preferred embodiment, the weight ratio of the second powder, the solvent and the binder is (40-60):(40-60):(2-8). The weight ratio of the second powder, the solvent and the binder includes but is not limited to the above range. Limiting it to the above range is beneficial to improving the dispersion uniformity of the second powder in the slurry, inhibiting the agglomeration of the second powder, and is also beneficial to the subsequent coating process.

[0045] In a preferred embodiment, the coating is performed by spraying, printing or magnetron sputtering. Compared with other methods, the coating by the above method is easier to control the coating amount of the slurry, thereby being beneficial to improving the comprehensive properties such as magnetic properties of the modified rare earth permanent magnet material.

[0046] In a preferred embodiment, the solvent is an alcohol organic solvent, preferably one or more of ethanol, ethylene glycol, and terpineol. Compared with other types, the use of the above types of solvents is conducive to further improving the dispersion uniformity of the second powder in the slurry, inhibiting the agglomeration of the second powder, and facilitating further coating processing.

[0047] In a preferred embodiment, the binder includes but is not limited to one or more of polyvinyl alcohol, polyvinyl chloride and polyvinyl acetate. The use of the above-mentioned types of binders is beneficial to improving the slurry viscosity while improving the oxidation resistance, thereby helping to reduce the impurity content of the modified rare earth permanent magnet material.

[0048] In a preferred embodiment, the heating rate of the first heat treatment is 1-10°C / min, the temperature is 960-1020°C, and the time is 5-20h; the heating rate of the second heat treatment is 4-10°C / min, the temperature is 440-560°C, and the time is 2-6h. The heating rate, temperature and time of the first heat treatment and the second heat treatment include but are not limited to the above ranges. Limiting them to the above ranges is conducive to solving the problem of difficult diffusion of magnets containing high content of Cu and Ga. Due to the presence of RH in the grain boundaries of the material before diffusion, the diffusion of the magnets is difficult to achieve. 2 -Fe-Cu / Ga / Al phase, which will hinder the Tb element in the second alloy from entering the main phase shell. By increasing the first heat treatment temperature to above 960°C, higher diffusion energy can be provided, so that the diffusion source Tb can more fully enter the main phase shell, which is beneficial to improve the (BH)max and Hcj of the modified rare earth permanent magnet material.

[0049] In a preferred embodiment, a cooling process is further included between the first heat treatment and the second heat treatment, and the cooling process is performed in an inert gas atmosphere. The above cooling process is beneficial to improving the stability of the grain boundary phase generated during the heat treatment process, making the thin layer of grain boundary phase more continuous and smooth, which is beneficial to improving the demagnetization coupling effect between the main phase grains, thereby facilitating improving the (BH)max and Hcj of the modified rare earth permanent magnet material.

[0050] In order to further make the generated non-ferromagnetic RH 2 - The Fe-Cu / Ga / Al grain boundary phase is better pinned at the grain boundary, and the preferred cooling rate during the cooling process is 10 to 30°C / min.

[0051] In a preferred embodiment, the temperatures of the first smelting treatment and the second smelting treatment process are independently included but not limited to 1400-1600° C. The temperatures of the first smelting treatment and the second smelting treatment process include but are not limited to the above ranges, and limiting them within the above ranges is conducive to sufficient melting of the raw materials and better decomposition and volatilization of impurities in the raw materials, and sufficient electromagnetic stirring to obtain a uniform alloy liquid, thereby facilitating the acquisition of a microstructure with uniform main phase size and continuous and penetrating distribution of the rare earth-rich phase.

[0052] The present application is further described in detail below in conjunction with specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in the present application.

[0053] Example 1

[0054] A method for preparing a modified rare earth permanent magnetic material, comprising:

[0055] (1) Taking Tb as RH 1 Source, with Cu and Ga as M 1Source, with ZrFe alloy, Hf and Ti as the T source, according to (Nd 90 Tb 10 ) 30 Fe bal Ga 0.9 Cu 0.6 Hf 0.2 Ti 0.4 Zr 0.4 B 1.03 Weigh Nd and RH in a stoichiometric ratio 1 Source, M 1 The source, T source and ferroboron are mixed and subjected to a first smelting treatment and a first sheeting treatment to obtain a first alloy casting sheet with a thickness of 0.28 mm; wherein the temperature of the first smelting treatment is 1500° C. and the time is 0.5 h;

[0056] (2) The first alloy casting sheet is subjected to hydrogen cracking treatment, in which the hydrogen absorption pressure is 0.1 MPa and the dehydrogenation temperature is 550°C, to obtain a powder of 150 μm; then the first alloy casting sheet is subjected to air flow milling, and 0.1 wt% of an antioxidant (Tianjin Yuesheng Magnetic and Electric Technology Co., Ltd., NdFeB special antioxidant 1#) and 0.1 wt% of a lubricant (Tianjin Yuesheng Magnetic and Electric Technology Co., Ltd., NdFeB special lubricant 6#) are added before air flow milling, and 0.15 wt% of a lubricant is added during the air flow milling process to obtain a first powder with an average particle size of 3.0 μm; the weight ratio of the first powder, the antioxidant and the lubricant is 100:0.1:0.15;

[0057] (3) Oriented in a nitrogen atmosphere, and then isostatically pressed to obtain a density of 4.5 g / cm 3 , a green body with a size of 70mm×40mm×35mm; wherein the isostatic pressing pressure is 200MPa and the time is 20s; after isostatic pressing, the green body is placed in a glove box and filled with nitrogen to exhaust oxygen to below 200ppm;

[0058] (4) sintering the green body at 1090° C. for 8 h, and then machining and pickling to obtain a first alloy sheet with a clean surface and a thickness of 4 mm;

[0059] (5) Taking Tb as RH 2 The combination of Cu, Ga, Al and Co is M 2 Source; According to Tb 70 Cu 10 Ga 10The stoichiometric ratio of Co5Al5 is as follows: Tb, Cu, Ga, Al and Co are weighed, the above single substances are mixed and subjected to a second smelting treatment and a second sheeting treatment to obtain a second alloy casting sheet with a thickness of 0.3 mm; wherein the temperature of the second smelting treatment is 1520° C. and the time is 0.5 h;

[0060] (6) crushing the second alloy casting flakes into a second powder having an average particle size of 4.0 μm;

[0061] (7) mixing the second powder, ethanol and polyvinyl alcohol (CAS No.: 9002-89-5) in a weight ratio of 50:44:6 to obtain a slurry;

[0062] (8) The slurry is coated on the surface of the first alloy sheet by spraying, and a modified rare earth permanent magnet material is obtained after a first heat treatment and a second heat treatment, wherein the temperature of the first heat treatment is 960°C and the treatment time is 16 hours, and the temperature of the second heat treatment is 500°C and the treatment time is 4 hours.

[0063] The modified rare earth permanent magnet material prepared in this embodiment is composed of a first alloy and a second alloy. The first alloy is (Nd 90 Tb 10 ) 30 Fe 66.47 Ga 0.9 Cu 0.6 Hf 0.2 Ti 0.4 Zr 0.4 B 1.03 , the second alloy is Tb 70 Cu 10 Ga 10 Co5Al5. The weight ratio of the first alloy to the second alloy is 92:8.

[0064] The above block-shaped modified rare earth permanent magnet material was sampled into a cylinder with a height of 4 mm and a diameter of 10 mm for testing.

[0065] Example 2

[0066] The difference from Example 1 is that: the amounts of Nd single substance, Tb single substance, Cu single substance, Ga single substance and ferroboron in step (1) are changed, and the sintering temperature in step (4) is 1080°C; the amounts of Tb single substance and Ga single substance in step (5) are changed; and the remaining steps are the same as Example 1.

[0067] The modified rare earth permanent magnet material prepared in this embodiment is composed of a first alloy and a second alloy. The first alloy is (Nd 87 Tb 13 ) 30 Fe 66.57 Ga0.6 Cu 0.8 Hf 0.2 Ti 0.4 Zr 0.4 B 1.03 , the second alloy is Tb 75 Cu 10 Ga5Co5Al5.

[0068] Example 3

[0069] The difference from Example 1 is that: the amounts of Nd single substance, Tb single substance, Cu single substance, Ga single substance, Ti single substance and ferroboron in step (1) are changed, and the sintering temperature in step (4) is 1080°C; the amounts of Tb single substance, Cu single substance and Ga single substance in step (5) are changed, and Al single substance is not added in this step; the remaining steps are the same as in Example 1.

[0070] The modified rare earth permanent magnet material prepared in this embodiment is composed of a first alloy and a second alloy. The first alloy is (Nd 95 Tb5) 30 Fe 66.17 Ga 0.8 Cu 0.8 Hf 0.2 Ti 0.6 Zr 0.4 B 1.03 , the second alloy is Tb 85 Cu5Ga5Co5.

[0071] Example 4

[0072] The difference from Example 1 is that the amounts of Tb, Cu and Ga in step (5) are changed, and Al is not added in this step; the remaining steps are the same as Example 1.

[0073] The modified rare earth permanent magnet material prepared in this embodiment is composed of a first alloy and a second alloy. The first alloy is (Nd 90 Tb 10 ) 30 Fe 66.47 Ga 0.9 Cu 0.6 Hf 0.2 Ti 0.4 Zr 0.4 B 1.03 , the second alloy is Tb 85 Cu5Ga5Co5.

[0074] Example 5

[0075] The difference from Example 1 is that the weight ratio of Nd single substance, Tb single substance, Cu single substance, Ga single substance, ZrFe alloy, Hf single substance and Ti single substance to ferroboron in step (1) is changed so that the first alloy in the obtained modified rare earth permanent magnet material is (Nd 90 Tb 10 ) 35 Fe 62.17 Ga 0.5 Cu 0.5 Hf 0.2 Ti 0.4 Zr 0.2 B 1.03 , wherein a is 35wt%, b is 1wt%, c is 0.8wt%, and d is 1.03wt%; the remaining steps are the same as those in Example 1.

[0076] The modified rare earth permanent magnet material prepared in this embodiment is composed of a first alloy and a second alloy. The second alloy is the same as that in embodiment 1 and is Tb 70 Cu 10 Ga 10 Co5Al5.

[0077] Example 6

[0078] The difference from Example 1 is that the weight ratio of Nd single substance, Tb single substance, Cu single substance, Ga single substance, ZrFe alloy, Hf single substance and Ti single substance to ferroboron is changed in step (1), and Co single substance is introduced as M 1 Source, so that the first alloy in the prepared modified rare earth permanent magnet material is (Nd 90 Tb 10 ) 29.5 Fe 66.47 Ga 1.0 Cu 1.0 Co 0.15 Hf 0.3 Ti 0.6 Zr 0.6 B 1.03 , wherein a is 29.5wt%, b is 2.15wt%, c is 1.5wt%, and d is 1.2wt%; the remaining steps are the same as those in Example 1.

[0079] The modified rare earth permanent magnet material prepared in this embodiment is composed of a first alloy and a second alloy. The second alloy is the same as that in embodiment 1 and is Tb 70 Cu 10 Ga 10 Co5Al5.

[0080] Example 7

[0081] The difference from Example 1 is that in step (8), the temperature of the first heat treatment is 960°C and the time is 20 hours, and the temperature of the second heat treatment is 440°C and the time is 6 hours; the remaining steps are the same as Example 1.

[0082] The modified rare earth permanent magnet material prepared in this embodiment is composed of a first alloy and a second alloy. The first alloy is the same as that in Embodiment 1 and is (Nd 90 Tb 10 ) 30 Fe 66.47 Ga 0.9 Cu 0.6 Hf 0.2 Ti 0.4 Zr 0.4 B 1.03 The second alloy is the same as that in Example 1, which is Tb 70 Cu 10 Ga 10 Co5Al5.

[0083] Example 8

[0084] The difference from Example 1 is that in step (8), the temperature of the first heat treatment is 1020°C and the time is 5 hours, and the temperature of the second heat treatment is 560°C and the time is 2 hours; the remaining steps are the same as Example 1.

[0085] The modified rare earth permanent magnet material prepared in this embodiment is composed of a first alloy and a second alloy. The first alloy is the same as that in Embodiment 1 and is (Nd 90 Tb 10 ) 30 Fe 66.47 Ga 0.9 Cu 0.6 Hf 0.2 Ti 0.4 Zr 0.4 B 1.03 The second alloy is the same as that in Example 1, which is Tb 70 Cu 10 Ga 10 Co5Al5.

[0086] Example 9

[0087] The difference from Example 1 is that the temperature of the first heat treatment in step (8) is 910° C. and the time is 10 h; the remaining steps are the same as Example 1.

[0088] Example 10

[0089] The difference from Example 1 is that the temperature of the second heat treatment in step (8) is 420° C. and the time is 4 h; the remaining steps are the same as Example 1.

[0090] Embodiment 11

[0091] The difference from Example 1 is that the weight ratio of Tb single substance, Cu single substance, Ga single substance, Al single substance and Co single substance in step (5) is changed so that the second alloy in the prepared modified rare earth permanent magnet material is Tb 50 Cu 15 Ga 15 Co 10 Al 10 , wherein e is 50wt%; the remaining steps are the same as those in Example 1.

[0092] The modified rare earth permanent magnet material prepared in this embodiment is composed of a first alloy and a second alloy. The first alloy is the same as that in Embodiment 1 and is (Nd 90 Tb 10 ) 30 Fe 66.47 Ga 0.9 Cu 0.6 Hf 0.2 Ti 0.4 Zr 0.4 B 1.03 .

[0093] Example 12

[0094] The difference from Example 1 is that the Al and Co elements in step (5) are omitted, and the weight ratio of Tb, Cu and Ga elements in this step is changed so that the second alloy in the obtained modified rare earth permanent magnet material is Tb. 50 Cu 25 Ga 25 , wherein e is 50wt%; the remaining steps are the same as those in Example 1.

[0095] The modified rare earth permanent magnet material prepared in this embodiment is composed of a first alloy and a second alloy. The first alloy is the same as that in Embodiment 1 and is (Nd 90 Tb 10 ) 30 Fe 66.47 Ga 0.9 Cu 0.6 Hf 0.2 Ti 0.4 Zr 0.4 B 1.03 .

[0096] Example 13

[0097] The difference from Example 1 is that the weight ratio of the first alloy to the second alloy is 95:5.

[0098] Embodiment 14

[0099] The difference from Example 1 is that the weight ratio of the first alloy to the second alloy is 90:10.

[0100] Embodiment 15

[0101] The difference from Example 1 is that the weight ratio of the first alloy to the second alloy is 98:2.

[0102] Comparative Example 1

[0103] The difference from Example 1 is that the amount of Cu and Ga in step (1) is changed so that the first alloy in the obtained modified rare earth permanent magnet material is (Nd 80 Tb 20 ) 30 Fe 67.77 Ga 0.1 Cu 0.1 Hf 0.2 Ti 0.4 Zr 0.4 B 1.03 , wherein a is 30wt%, b is 0.2wt%, c is 1.0wt% and d is 1.03wt%; the time of the first heat treatment in step (8) is 10h; the remaining steps are the same as in Example 1.

[0104] The modified rare earth permanent magnet material prepared in this embodiment is composed of a first alloy and a second alloy. The second alloy is the same as that in embodiment 1 and is Tb 70 Cu 10 Ga 10 Co5Al5.

[0105] Comparative Example 2

[0106] The difference from Example 1 is that the dosage ratio of Tb single substance, Cu single substance, Ga single substance, Al single substance and Co single substance is changed so that the second alloy in the prepared modified rare earth permanent magnet material is Tb 60 Cu 15 Ga 15 Co5Al5, wherein e is 60wt%; the remaining steps are the same as those in Example 1.

[0107] The modified rare earth permanent magnet material prepared in this embodiment is composed of a first alloy and a second alloy. The first alloy is the same as that in Embodiment 1 and is (Nd 90 Tb 10 ) 30 Fe 66.47 Ga 0.9 Cu 0.6 Hf 0.2 Ti 0.4 Zr 0.4 B 1.03 .

[0108] Comparative Example 3

[0109] The difference from Example 1 is that steps (5) to (8) are omitted, that is, the second alloy is not prepared, and grain boundary diffusion is not performed. The modified rare earth permanent magnet material obtained is only composed of the first alloy, which is the same as that in Example 1 and is (Nd 90 Tb 10 ) 30 Fe 66.47 Ga 0.9 Cu 0.6 Hf 0.2 Ti 0.4 Zr 0.4 B 1.03 .

[0110] Comparative Example 4

[0111] The difference from Example 1 is that the weight ratio of Tb single substance, Cu single substance, Ga single substance, Al single substance and Co single substance in step (5) is changed so that the second alloy in the prepared modified rare earth permanent magnet material is Tb 50 Cu 15 Ga 15 Co 10 Al 10 , wherein e is 50wt%; the remaining steps are the same as those in Example 1.

[0112] The modified rare earth permanent magnet material prepared in this embodiment is composed of a first alloy and a second alloy. The first alloy is the same as that in Embodiment 1 and is (Nd 90 Tb 10 ) 30 Fe 66.47 Ga 0.9 Cu 0.6 Hf 0.2 Ti 0.4 Zr 0.4 B 1.03 .

[0113] Comparative Example 5

[0114] Using traditional sintered Nd2Fe 14 B permanent magnet material, the preparation method thereof comprises the following steps: the difference from Example 1 is that according to the final composition of Example 1, the weight ratio of the first alloy to the second alloy is 92:8, that is, (Nd 74.8 Tb 25.2 ) 33.2 Fe 66.4 7Ga 1.63 Cu 1.35 Al 0.4 Hf 0.18 Ti 0.37 Zr 0.37 B0.95 A single alloy is smelted to obtain an alloy sheet with a thickness of 0.3μm. The alloy sheet is pulverized by hydrogen crushing and air flow grinding to obtain a fine powder of 3μm. The fine powder is formed and isostatically pressed to obtain a 70mm×40mm×35mm green body, which is sintered and subjected to two-stage heat treatment to obtain a dense rare earth material.

[0115] The block-shaped modified rare earth permanent magnet material or sintered Nd2Fe 14 The B permanent magnetic material was prepared into a cylinder with a height of 4 mm and a diameter of 10 mm. The magnetic properties were tested under closed-circuit test conditions using the magnetic properties tester NIM-62000 of the China Institute of Metrology at room temperature of 20±3°C. The test results are shown in Table 1.

[0116] Table 1

[0117] Br(kGs) (BH)max(MGOe) Hcj(kOe) The sum of the values ​​of (BH)max+Hcj Example 1 13.10 42.30 41.2 83.5 Example 2 13.21 42.70 40.8 83.5 Example 3 13.30 43.90 40.2 84.1 Example 4 13.12 42.40 40.8 83.2 Example 5 13.18 42.68 40.4 83.08 Example 6 13.10 42.24 41.0 83.24 Example 7 13.16 42.60 41.6 84.2 Example 8 13.04 42.12 42.2 84.32 Example 9 13.02 40.80 40.50 81.3 Example 10 13.10 40.56 40.8 81.36 Embodiment 11 13.14 42.60 41.0 83.6 Example 12 13.24 43.10 40.2 83.3 Example 13 13.18 42.70 40.6 83.3 Embodiment 14 13.04 42.10 42.8 84.9 Embodiment 15 13.20 42.60 40.1 82.7 Comparative Example 1 12.84 40.90 38.50 79.4 Comparative Example 2 12.76 40.20 38.8 79.0 Comparative Example 3 13.42 43.42 30.2 73.62 Comparative Example 4 13.18 42.40 37.2 79.6 Comparative Example 5 11.42 28.04 48.2 76.24

[0118] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0119] By comparing Example 1 with Comparative Examples 1 to 3, and Examples 1, 11, 12 with Comparative Example 4, it can be seen that compared with a single alloy component, making the modified rare earth permanent magnet material simultaneously contain the first alloy of the specific components of the present application (strictly controlling the value range of x, a, b, c and d) and the second alloy of the specific components (strictly controlling the value range of y and e) is beneficial to exerting the synergistic effect of the two, which is beneficial to improving the coercive force of the modified rare earth permanent magnet material, so that the modified rare earth permanent magnet material can meet the requirements that the sum of the value of (BH)max and the value of Hcj is greater than 80, and Hcj is greater than 40kOe.

[0120] Comparing Example 1 with Comparative Example 5, it can be seen that compared with the traditional Nd2Fe 14 Compared with the B permanent magnet material, the heavy rare earth element RH in the modified rare earth permanent magnet material provided in the present application 1 and M 1 On the one hand, the introduction of elements can improve the anisotropy of modified rare earth permanent magnet materials, especially the introduction of specific contents of Cu and Ga elements can significantly improve the anisotropy, thereby improving its coercivity; on the other hand, it can also improve the temperature coefficient of intrinsic coercivity, thereby improving its high temperature resistance; in addition, the introduction of specific types and amounts of T (strictly controlling the value range of x, a, b, c and d) can be combined with the heavy rare earth element RH 1 、M 1 The elements work together to simultaneously improve the maximum magnetic energy product (BH)max and the intrinsic coercive force Hcj of the modified rare earth permanent magnet material.

[0121] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those described herein, for example.

[0122] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A modified rare earth permanent magnet material, characterized in that: The modified rare earth permanent magnet material comprises a first alloy and a second alloy, wherein the first alloy has a chemical formula shown in formula (I): x RH 1 100％-x ) a M 1 b T c B d Fe 100％-a-b-c-d (I), where RH 1 M is a heavy rare earth element. 1 At least two selected from Cu, Ga, Al, and Co, and the M 1 The invention comprises Cu and Ga, T is selected from one or more of Zr, Hf and Ti, x≥70wt% and <100wt%, a is 29.5-35wt%, b is 1-2.15wt%, c is 0.8-1.5wt%, and d is 1.03-1.2wt%; in terms of weight percentage of the first alloy, the content of Cu is 0.5-1.0wt%, and the content of Ga is 0.5-1.0wt%; The second alloy has a chemical formula shown in formula (II): (Pr y RH 2 100％-y ) 100％-e M 2 e (II), where RH 2 M is a heavy rare earth element. 2 One or more selected from Cu, Ga, Al, Co, y>0 and ≤30wt%, e is 0-50%; the RH 1 With the RH 2 Same or different.

2. The modified rare earth permanent magnet material according to claim 1, characterized in that: The RH 1 and the RH 2 Each is independently selected from one or more of Dy, Tb, Ho, and Gd.

3. The modified rare earth permanent magnetic material according to claim 1 or 2, characterized in that: The x is ≥80wt% and <100wt%, the a is 29.5-32wt%, the b is 1.0-2.0wt%, the c is 0.8-1.5wt%, the d is 1.03-1.1wt%; and / or, the y is 0-20wt%, and the e is 10-50wt%.

4. The modified rare earth permanent magnetic material according to claim 1 or 2, characterized in that: The weight percentage of the second alloy is no more than 20wt% based on the weight of the modified rare earth permanent magnet material; Preferably, the weight ratio of the first alloy to the second alloy is (90-95):(5-10).

5. The modified rare earth permanent magnetic material according to any one of claims 1 to 4, characterized in that: The RH 1 is a combination of Tb, Dy, Gd and Ho; the RH 1 Preferably Tb; The M 1 is a combination of Cu and Ga, or a combination of Cu, Ga, Al, Co, or a combination of Cu, Ga, Co; the M 1 Preferably, it is a combination of Cu and Ga; 1 More preferably, it is a combination of Cu and Ga, and the weight ratio of Cu to Ga is (16-34): (16-34); The T is a combination of Zr, Hf and Ti, or a combination of Hf and Ti, or a combination of Hf and Zr; the T is preferably a combination of Zr, Hf and Ti; the T is more preferably a combination of Zr, Hf and Ti, and the weight ratio of the Zr, the Hf and the Ti is (6-9):(2-5):(5-12); The RH 2 is a combination of Tb, Dy, Gd and Ho; the RH 2 Preferably Tb; The M 2 is a combination of Cu, Ga, Al and Co, or a combination of Cu, Ga and Co; the M 2 Preferably it is a combination of Cu, Ga, Al and Co, and the weight ratio of Cu, Ga, Al and Co is (5-8):(4-7):(0.1-4):(4-8), or more preferably it is a combination of Cu, Ga and Co, and the weight ratio of Cu, Ga and Co is (5-10):(5-6):(5-9).

6. A method for preparing the modified rare earth permanent magnetic material according to any one of claims 1 to 5, characterized in that: The preparation method of the modified rare earth permanent magnetic material comprises: preparing a first alloy and a second alloy; The first alloy and the second alloy are processed by a grain boundary diffusion method to obtain the modified rare earth permanent magnet material.

7. The method for preparing the modified rare earth permanent magnetic material according to claim 6, characterized in that: The preparation method further comprises: Nd single substance, RH 1 Source, M 1 The RH source, the T source and the ferroboron are mixed and subjected to a first smelting process and a first sheeting process to obtain a first alloy casting sheet; the RH 1 The source is selected from a single substance of a heavy rare earth element, or an alloy formed by a heavy rare earth element and iron; the M 1 The source is selected from at least two of Cu, Ga, Al, and Co, and the M 1 The source includes Cu and Ti; the T is selected from one or more of Zr-Fe alloy, Hf and Ti; Performing a first crushing process on the first alloy casting sheet to obtain a first powder; Performing orientation molding and pressing treatment on the first powder to obtain a green body; sintering the green compact to obtain the first alloy; Preferably, the average thickness of the first alloy casting sheet is 0.2-0.4 mm; Preferably, the average particle size of the first powder is 100 to 300 μm; Preferably, the sintering treatment is carried out at a temperature of 40 to 1100° C. and for a time of 4 to 10 hours.

8. The method for preparing the modified rare earth permanent magnetic material according to claim 7, characterized in that: The preparation method further comprises: The optional Pr single substance, RH 2 Source, M 2 The RH is mixed with ferroboron and subjected to a second smelting process and a second sheeting process to obtain a second alloy casting sheet; 2 The source is selected from a single substance of a heavy rare earth element, or an alloy formed by a heavy rare earth element and iron, wherein the M 2 The source is selected from one or more of Cu, Ga, Al and Co; performing a second crushing process on the second alloy casting flakes to obtain a second powder; mixing the second powder, a solvent and a binder to obtain a slurry; The slurry is coated on the surface of the first alloy, and the modified rare earth permanent magnet material is obtained after a first heat treatment and a second heat treatment.

9. The method for preparing the modified rare earth permanent magnetic material according to claim 8, characterized in that: The weight ratio of the second powder, the solvent and the binder is (40-60):(40-60):(2-8); and / or, The solvent is an alcohol organic solvent, preferably one or more of ethanol, ethylene glycol, and terpineol; and / or, The binder is selected from one or more of polyvinyl alcohol, polyvinyl chloride resin and polyvinyl acetate.

10. The method for preparing the modified rare earth permanent magnetic material according to claim 8, characterized in that: The heating rate of the first heat treatment is 1-10°C / min, the temperature is 960-1020°C, and the time is 5-20h; the heating rate of the second heat treatment is 4-10°C / min, the temperature is 440-560°C, and the time is 2-6h; Preferably, a cooling process is further included between the first heat treatment and the second heat treatment, and the cooling process is performed in an inert gas atmosphere; preferably, the cooling rate of the cooling process is 10 to 30° C. / min.

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