A pure high-abundance rare earth rubber magnet and its preparation method

Abstract

The present invention discloses a pure high-abundance rare earth rubber magnet and a preparation method thereof. The pure high-abundance rare earth rubber magnet is composed of coupled pure high-abundance rare earth magnetic powder, rubber, and a vulcanizing agent, wherein the weight of the coupled pure high-abundance rare earth magnetic powder is 10 to 90 parts, the weight of the rubber is 10 parts, and the weight of the vulcanizing agent is 0.1 to 0.5 parts; the pure high-abundance rare earth magnetic powder has a composition of [(Ce a La 1‑a ) b Y 1‑b ] c Fe 95‑c‑d B6N d , where N is at least one of Nb, Al, Ga, Cu, Zr, Si, Ti, and Ge. This invention is the first to produce pure, high-abundance rare earth rubber magnets, which combine excellent magnetic and mechanical properties. The magnets do not contain expensive key rare earth elements such as Nd and Pr, reducing production costs. The magnets can be used for extended periods at 80°C, and the preparation process is simple, easily meeting the needs of magnet products of various sizes.

Description

Technical Field

[0001] The invention belongs to the technical field of preparation of neodymium iron boron permanent magnets, and particularly relates to a pure high-abundance rare earth rubber magnet and a preparation method thereof. Background Art

[0002] Neodymium iron boron permanent magnets, with their excellent magnetic properties, are widely used in new energy vehicles, wind power generation, office electronic equipment, smart home appliances, and other fields. However, the increasing demand for high-performance permanent magnets has led to a significant consumption of key rare earth elements such as Pr, Nd, Dy, and Tb. Furthermore, the high-abundance rare earth elements La, Ce, and Y, as associated rare earth elements during the extraction of Nd and Pr, are used in relatively low quantities, resulting in a large market backlog and a relatively low price. Numerous studies have shown that through process improvements and the construction of specialized microstructures, high-abundance rare earth permanent magnets also have the potential to serve as hard magnetic materials and possess significant application value. Therefore, the development of cost-effective magnets based on the high-abundance rare earth elements La, Ce, and Y to replace expensive Nd-Fe-B magnets in certain applications has attracted widespread attention. This approach could not only effectively alleviate the imbalance in the utilization of rare earth resources but also promote the efficient utilization and sustainable development of my country's rare earth resources.

[0003] At present, the application of high-abundance rare earths is mainly concentrated in nanocrystalline permanent magnet alloys. For nanocrystalline permanent magnet alloys, high-abundance rare earth elements are used to partially replace key rare earth elements such as Nd and Pr in Nd-Fe-B type magnets. However, due to the 14 B. La2Fe 14 B. Y2Fe 14 The low intrinsic properties of B lead to a significant decrease in magnet performance after partial substitution, and small substitutions cannot fully utilize high-abundance rare earth elements. However, preparing nanocrystalline permanent magnet alloys entirely from high-abundance rare earth elements can achieve efficient utilization of rare earth resources. Domestic invention patent CN 110534279A provides a method for preparing a pure high-abundance rare earth Ce, La, and Y-based multi-component nanocrystalline permanent magnet alloy. Although this magnet can achieve performance of 7 MGOe, due to sample heterogeneity, the magnetic energy product of the corresponding magnetic powder is only 3-5 MGOe, and the resulting rubber magnet is less than 1 MGOe. Therefore, it is necessary to adjust the alloy composition and rubber magnet preparation process to maximize magnetic performance. At the same time, pure high-abundance rare earth rubber magnets also suffer from low magnetic performance. Furthermore, due to their low Curie temperature, the operating temperature of high-abundance rare earth rubber magnets generally does not exceed 80°C.

[0004] Rubber magnets are a widely used branch of bonded magnets. They are made by mixing rubber, magnetic powder, and processing aids through kneading, pulverizing, and molding. They exhibit flexibility, elasticity, and bendability, allowing for easy punching, cutting, and pressing into a variety of complex shapes. They are primarily used in industries such as micromotors, refrigerators, disinfection cabinets, cabinets, toys, stationery, and advertising. Traditionally, rubber magnets were produced by calendaring the mixed rubber and magnetic powder between two counter-rotating rollers, or by heating and melting the mixture and then extruding it through an extrusion mold before cooling. The resulting rubber magnets typically come in sheets of uniform thickness or strips with varying cross-sectional shapes. Vulcanization is then performed as needed to produce the final rubber magnet. However, this method cannot produce rubber magnets with more complex shapes, and the magnetic powder filling ratio is relatively low, resulting in generally low magnetic properties. Compared to calendaring or extrusion, traditional compression molding can increase the magnetic powder filling ratio and, depending on the mold geometry, can produce rubber magnets with a variety of complex shapes.

[0005] Pure high-abundance rare earth magnets refer to magnets containing only the three high-abundance rare earth elements La, Ce, and Y, and excluding other key rare earth elements such as Nd, Pr, Dy, and Tb. Currently, there are no public reports on the technology for producing rubber magnets using pure high-abundance rare earths. Summary of the Invention

[0006] In order to solve the shortcomings and deficiencies of the prior art, the object of the present invention is to provide a high-performance pure and high-abundance rare earth rubber magnet that can be used for a long time at 80°C.

[0007] Another object of the present invention is to provide a method for preparing the rubber magnet.

[0008] The purpose of the present invention is achieved through the following technical solutions:

[0009] A pure high-abundance rare earth rubber magnet is composed of coupled pure high-abundance rare earth magnetic powder, rubber and a vulcanizing agent, wherein the weight portion of the coupled pure high-abundance rare earth magnetic powder is 10 to 90 parts, the weight portion of the rubber is 10 parts, and the weight portion of the vulcanizing agent is 0.1 to 0.5 parts.

[0010] Preferably, the pure high-abundance rare earth magnetic powder of the present invention has a composition of [(Ce a La 1-a ) b Y 1-b ] c Fe 95-c-d B6N d, wherein N is at least one of Nb, Al, Ga, Cu, Zr, Si, Ti, and Ge, the value range of a is 0.4 to 0.9, the value range of b is 0.5 to 0.8, the value range of c is 14 to 18, and the value range of d is 0.1 to 2.

[0011] A method for preparing a pure high-abundance rare earth rubber magnet comprises the following steps:

[0012] (1) Raw material preparation: Prepare according to the atomic ratio [(Ce a La 1-a ) b Y 1-b ] c Fe 95-c-d B6N d Raw materials of each element;

[0013] (2) Alloy smelting: Alloy smelting is carried out under inert gas protection conditions to obtain a master alloy with uniform composition;

[0014] (3) Melt quenching: The master alloy obtained in step (2) is mechanically polished to remove the surface oxide layer, mechanically crushed into uniform small pieces of master alloy, and then melted. After melting, it is rapidly cooled and solidified, and finally mechanically crushed into powder to obtain magnetic powder;

[0015] (4) Magnetic powder heat treatment: heat treating the magnetic powder obtained in step (3) under the protection of argon gas with a purity of ≥99.999%;

[0016] (5) Magnetic powder coupling treatment: The magnetic powder after heat treatment in step (4) is crushed to obtain a powder passing through a 100-mesh sieve, and the powder is added to an organic solvent containing a silane coupling agent, stirred uniformly at room temperature until the organic solvent is completely volatilized, and then dried to obtain coupled magnetic powder;

[0017] (6) Mixing: The rubber is mixed on a mixing device, and the mixing temperature is controlled at room temperature. After the rubber is evenly coated on the roller, the coupled magnetic powder and the vulcanizing agent are added in sequence. After mixing evenly, the rubber is thinly passed 1 to 3 times and then cut into sheets;

[0018] (7) Compression molding: After the mixed rubber material is placed for 12 to 24 hours, it is placed in a mold, heated, and molded in a pressure device;

[0019] (8) Demolding: Demolding the molded magnet from the mold to obtain a rubber magnet.

[0020] In step (2), the inert gas is argon with a purity of ≥99.999%.

[0021] In step (2), during the smelting, each smelting is performed for 2 to 3 minutes, and after the smelting is completed, the smelting is repeated for 3 to 5 times.

[0022] In step (3), the melting process is as follows: placing a small piece of master alloy into a quartz tube with a small hole at the lower end, placing the quartz tube into a vacuum belt spinning machine, and melting the small piece of master alloy into a molten state in an argon atmosphere with a purity of ≥99.999%.

[0023] In step (3), the rapid cooling and solidification process is as follows: the molten alloy liquid is sprayed onto a water-cooled copper roller with an outer surface linear velocity of 10 to 50 m / s, and the copper roller rotates to rapidly cool and solidify the molten alloy liquid into a nanocrystalline rapid-quenching alloy with a thickness of 0.020 to 0.050 mm.

[0024] In step (4), the heat treatment temperature is 500-700° C., and the heat treatment time is 5-15 minutes.

[0025] In step (5), the mass ratio of pure high-abundance rare earth magnetic powder, silane coupling agent and organic solvent is 100:(0.5-1.5):(30-50), the silane coupling agent is one of KH550, KH560, and KH570, and the organic solvent is at least one of acetone and ethanol.

[0026] In step (5), the drying temperature is 60-120° C., and the drying time is 1-2 hours.

[0027] In step (6), the rubber is a nitrile rubber (NBR) with an acrylonitrile content of 31 to 46%; the vulcanizing agent is one of dicumyl peroxide, benzoyl peroxide, 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane, and 1,3-bis(tert-butylperoxyisopropyl)benzene.

[0028] In step (6), the mixing device is at least one of an open mixer, a calender and an internal mixer.

[0029] In step (7), the heating temperature is 130-180° C., the pressurizing time is 5-15 min, and the pressurizing pressure is 2-5 MPa.

[0030] In step (7), the pressure device is a flat-plate vulcanizing press.

[0031] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0032] (1) Pure high-abundance rare earth rubber magnets were prepared for the first time. After heat treatment, they achieved a good combination of magnetic and mechanical properties. The magnetic energy product exceeded 1.5 MGOe, and the highest magnetic energy product could reach 2.98 MGOe, which is higher than that of ferrite rubber magnets.

[0033] (2) It does not contain expensive key rare earth elements such as Nd and Pr, which greatly reduces the production cost, improves the cost performance of magnets, broadens the application range of high-abundance rare earth elements, and balances the utilization of rare earth resources;

[0034] (3) The preparation process is simple and can be formed by mold processing, which can easily meet the needs of magnet products of various sizes;

[0035] (4) The prepared pure high-abundance rare earth rubber magnet can be used for a long time at 80°C with little attenuation of magnetic properties. DETAILED DESCRIPTION

[0036] The present invention will be described in further detail below with reference to the examples, but the embodiments of the present invention are not limited thereto. The raw materials involved in the present invention can be purchased directly from the market. For process parameters not specifically noted, conventional techniques can be used.

[0037] The chemical formula of the pure high-abundance rare earth rubber magnet prepared in the following examples shows the components of the rare earth permanent magnet material and the weight percentage of each component.

[0038] Example 1

[0039] The chemical formula for the preparation of this embodiment is [(Ce 0.8 La 0.2 ) 0.7 Y 0.3 ] 17 Fe 76.5 B6N 0.5 Al 0.5 Ga 0.5 Si2 rubber magnet, where the numbers represent the weight percentages of the respective components, is composed of the following raw materials in parts by weight: 50 parts pure high-abundance rare earth magnetic powder, 10 parts nitrile rubber, 0.5 parts KH550, and 0.1 parts dicumyl peroxide.

[0040] The preparation method of the pure high-abundance rare earth rubber magnet comprises the following specific steps:

[0041] (1) Raw material configuration: According to the atomic ratio [(Ce 0.8 La 0.2 ) 0.7 Y 0.3 ] 17 Fe 76.5 B6N 0.5 Al 0.5 Ga 0.5 Si2 configuration raw materials Ce, La, Y, Fe, FeB, Nb, Al, Ga, and Si are reserved. Rare earth elements La, Ce, and Y need to be mechanically polished before configuration to remove the surface oxide layer;

[0042] (2) Alloy smelting: The raw materials of step (1) are placed in an argon arc melting furnace in the order of Ce, La, Y, Fe, FeB, Nb, Al, Ga, and Si from the bottom to the top, and smelted in argon gas with a purity of ≥99.999%. Each smelting time is 2-3 minutes. After smelting, the alloy is turned over and smelted repeatedly for 3-5 times to obtain a master alloy with uniform composition.

[0043] (3) Melt quenching: The master alloy obtained in step (2) is mechanically polished to remove the surface oxide layer, and mechanically crushed into uniform small pieces of master alloy. The master alloy is then placed in a quartz tube with a small hole at the lower end. The quartz tube is placed in a vacuum belt spinning machine. The small pieces of master alloy are melted to a molten state in an argon atmosphere with a purity of ≥99.999%. The molten alloy liquid is then sprayed onto the outer surface of a water-cooled copper roller rotating at a speed of 25 m / s. The copper roller rotates to rapidly cool and solidify the molten alloy liquid into a nanocrystalline rapid-quenching alloy with a thickness of 0.020 to 0.050 mm. Finally, the alloy is mechanically crushed into powder to obtain magnetic powder;

[0044] (4) Magnetic powder heat treatment: The magnetic powder obtained in step (3) was heat treated under argon protection with a purity of ≥99.999%, the heat treatment temperature was 500°C, and the heat treatment time was 8 minutes;

[0045] (5) Magnetic powder coupling treatment: The magnetic powder obtained after the heat treatment in step (4) is crushed to obtain a powder that passes through a 100-mesh sieve. The powder is added to acetone containing KH550 and stirred evenly at room temperature until the acetone is completely volatilized. The powder is then placed in a forced air drying oven at 80°C for 1 to 2 hours to obtain coupled magnetic powder.

[0046] (6) Mixing: The rubber is mixed on an open mill at room temperature. After the rubber is evenly coated on the roller, the coupled magnetic powder and dicumyl peroxide are added in sequence. After mixing evenly, the rubber is thinly passed through 1 to 3 times and then sheeted.

[0047] (7) Compression molding: After the mixed rubber material is placed for 12 to 24 hours, it is placed in a mold and heated, and then molded in a flat vulcanizer at a heating temperature of 160°C, a pressing time of 12 minutes, and a pressing pressure of 2 MPa;

[0048] (8) Demolding: Demolding the molded magnet from the mold to obtain a rubber magnet;

[0049] The properties of the prepared rubber magnets are shown in Table 1.

[0050] Example 2

[0051] The difference from Example 1 is that the addition ratio of the coupled magnetic powder is changed. This example is composed of the following raw materials in parts by weight: 90 parts of pure high-abundance rare earth magnetic powder, 10 parts of nitrile rubber, 0.9 parts of KH550, and 0.1 parts of dicumyl peroxide.

[0052] The preparation method of the pure high-abundance rare earth rubber magnet comprises the following specific steps:

[0053] (1) Raw material configuration: According to the atomic ratio [(Ce 0.8 La 0.2 ) 0.7 Y 0.3 ] 17 Fe 76.5 B6N 0.5 Al 0.5 Ga 0.5 Si2 configuration raw materials Ce, La, Y, Fe, FeB, Nb, Al, Ga, and Si are reserved. Rare earth elements La, Ce, and Y need to be mechanically polished before configuration to remove the surface oxide layer;

[0054] (2) Alloy smelting: The raw materials of step (1) are placed in an argon arc melting furnace in the order of Ce, La, Y, Fe, FeB, Nb, Al, Ga, and Si from the bottom to the top, and smelted in argon gas with a purity of ≥99.999%. Each smelting time is 2-3 minutes. After smelting, the alloy is turned over and smelted repeatedly for 3-5 times to obtain a master alloy with uniform composition.

[0055] (3) Melt quenching: The master alloy obtained in step (2) is mechanically polished to remove the surface oxide layer, and mechanically crushed into uniform small pieces of master alloy. The master alloy is then placed in a quartz tube with a small hole at the lower end. The quartz tube is placed in a vacuum belt spinning machine. The small pieces of master alloy are melted to a molten state in an argon atmosphere with a purity of ≥99.999%. The molten alloy liquid is then sprayed onto the outer surface of a water-cooled copper roller rotating at a speed of 25 m / s. The copper roller rotates to rapidly cool and solidify the molten alloy liquid into a nanocrystalline rapid-quenching alloy with a thickness of 0.020 to 0.050 mm. Finally, the alloy is mechanically crushed into powder to obtain magnetic powder;

[0056] (4) Magnetic powder heat treatment: The magnetic powder obtained in step (3) was heat treated under argon protection with a purity of ≥99.999%, the heat treatment temperature was 500°C, and the heat treatment time was 8 minutes;

[0057] (5) Magnetic powder coupling treatment: The magnetic powder obtained after the heat treatment in step (4) is crushed to obtain a powder that passes through a 100-mesh sieve. The powder is added to acetone containing KH550 and stirred evenly at room temperature until the acetone is completely volatilized. The powder is then placed in a forced air drying oven at 80°C for 1 to 2 hours to obtain coupled magnetic powder.

[0058] (6) Mixing: The rubber is mixed on an open mill at room temperature. After the rubber is evenly coated on the roller, the coupled magnetic powder and dicumyl peroxide are added in sequence. After mixing evenly, the rubber is thinly passed through 1 to 3 times and then sheeted.

[0059] (7) Compression molding: After the mixed rubber material is placed for 12 to 24 hours, it is placed in a mold and heated, and then molded in a flat vulcanizer at a heating temperature of 160°C, a pressing time of 12 minutes, and a pressing pressure of 2 MPa;

[0060] (8) Demolding: Demolding the molded magnet from the mold to obtain a rubber magnet;

[0061] The properties of the prepared rubber magnets are shown in Table 1, and the high temperature resistance results are shown in Table 2.

[0062] Example 3

[0063] Different from Example 2, the chemical composition of pure high-abundance rare earth magnetic powder was changed. The chemical formula of this example is [(Ce 0.7 La 0.3 ) 0.8 Y 0.2 ] 17 Fe 76.5 B6N 0.8 Ga 0.5 Ti 1.2 Ge 0.7 A rubber magnet, wherein the numbers represent the atomic percentages of the respective components, is composed of the following raw materials in parts by weight: 90 parts of pure high-abundance rare earth magnetic powder, 10 parts of nitrile rubber, 0.9 parts of coupling agent, and 0.1 parts of dicumyl peroxide.

[0064] The preparation method of the pure high-abundance rare earth rubber magnet comprises the following specific steps:

[0065] (1) Raw material configuration: According to the atomic ratio [(Ce 0.7 La 0.3 ) 0.8 Y 0.2 ] 17 Fe 76.5 B6N 0.8 Ga 0.5 Ti 1.2 Ge 0.7 Prepare the raw materials Ce, La, Y, Fe, FeB, Nb, Al, Ga, Ti, and Ge for future use. The rare earth elements La, Ce, and Y need to be mechanically polished to remove the surface oxide layer before configuration;

[0066] (2) Alloy smelting: The raw materials of step (1) are placed in an argon arc melting furnace in the order of Ce, La, Y, Fe, FeB, Nb, Al, Ga, Ti, and Ge from the bottom to the top, and smelted in argon gas with a purity of ≥99.999%. Each smelting time is 2-3 minutes. After smelting, the raw materials are turned over and smelted repeatedly for 3-5 times to obtain a master alloy with uniform composition.

[0067] (3) Melt quenching: The master alloy obtained in step (2) is mechanically polished to remove the surface oxide layer, and mechanically crushed into uniform small pieces of master alloy. The master alloy is then placed in a quartz tube with a small hole at the lower end. The quartz tube is placed in a vacuum belt spinning machine. The small pieces of master alloy are melted to a molten state in an argon atmosphere with a purity of ≥99.999%. The molten alloy liquid is then sprayed onto the outer surface of a water-cooled copper roller rotating at a speed of 21 m / s. The copper roller rotates to rapidly cool and solidify the molten alloy liquid into a nanocrystalline rapid-quenching alloy with a thickness of 0.020 to 0.050 mm. Finally, the alloy is mechanically crushed into powder to obtain magnetic powder;

[0068] (4) Magnetic powder heat treatment: The magnetic powder obtained in step (3) was heat treated under argon protection with a purity of ≥99.999%, the heat treatment temperature was 600°C, and the heat treatment time was 12 min;

[0069] (5) Magnetic powder coupling treatment: The magnetic powder obtained after the heat treatment in step (4) is crushed to obtain a powder that passes through a 100-mesh sieve. The powder is added to acetone containing KH550 and stirred evenly at room temperature until the acetone is completely volatilized. The powder is then placed in a forced air drying oven at 80°C for 1 to 2 hours to obtain coupled magnetic powder.

[0070] (6) Mixing: The rubber is mixed on an open mill at room temperature. After the rubber is evenly coated on the roller, the coupled magnetic powder and dicumyl peroxide are added in sequence. After mixing evenly, the rubber is thinly passed through 1 to 3 times and then sheeted.

[0071] (7) Compression molding: After the mixed rubber material is placed for 12 to 24 hours, it is placed in a mold and heated, and then molded in a flat vulcanizer at a heating temperature of 160°C, a pressing time of 8 minutes, and a pressing pressure of 3 MPa;

[0072] (8) Demolding: Demolding the molded magnet from the mold to obtain a rubber magnet;

[0073] The properties of the prepared rubber magnets are shown in Table 1.

[0074] Example 4

[0075] Different from Example 2, the chemical composition of pure high-abundance rare earth magnetic powder was changed. The chemical formula of this example is [(Ce 0.9 La 0.1 )0.6 Y 0.4 ] 16 Fe 77.5 B6N 0.5 Ga 1.2 Ge 0.9 The rubber magnet, wherein the numbers represent the weight percentages of the respective components, is composed of the following raw materials in parts by weight: 90 parts of pure high-abundance rare earth magnetic powder, 10 parts of nitrile rubber, 0.9 parts of coupling agent, and 0.1 parts of dicumyl peroxide.

[0076] The preparation method of the pure high-abundance rare earth rubber magnet comprises the following specific steps:

[0077] (1) According to the atomic ratio [(Ce 0.9 La 0.1 ) 0.6 Y 0.4 ] 16 Fe 77.5 B6N 0.5 Ga 1.2 Ge 0.9 Prepare the raw materials Ce, La, Y, Fe, FeB, Nb, Ga, and Ge for future use. The rare earth elements La, Ce, and Y need to be mechanically polished to remove the surface oxide layer before configuration;

[0078] (2) Alloy smelting: The raw materials of step (1) are placed in an argon arc melting furnace in the order of Ce, La, Y, Fe, FeB, Nb, Ga, and Ge from the bottom to the top, and smelted in argon gas with a purity of ≥99.999%. Each smelting time is 2-3 minutes. After melting, the alloy is turned over and repeated 3-5 times to obtain a master alloy with uniform composition.

[0079] (3) Melt quenching: The master alloy obtained in step (2) is mechanically polished to remove the surface oxide layer, and mechanically crushed into uniform small pieces of master alloy. The master alloy is then placed in a quartz tube with a small hole at the lower end. The quartz tube is placed in a vacuum belt spinning machine. The small pieces of master alloy are melted to a molten state in an argon atmosphere with a purity of ≥99.999%. The molten alloy liquid is then sprayed onto the outer surface of a water-cooled copper roller rotating at a speed of 21 m / s. The copper roller rotates to rapidly cool and solidify the molten alloy liquid into a nanocrystalline rapid-quenching alloy with a thickness of 0.020 to 0.050 mm. Finally, the alloy is mechanically crushed into powder to obtain magnetic powder;

[0080] (4) Magnetic powder heat treatment: The magnetic powder obtained in step (3) was heat treated under argon protection with a purity of ≥99.999%, the heat treatment temperature was 600°C, and the heat treatment time was 12 min;

[0081] (5) Magnetic powder coupling treatment: The magnetic powder obtained after the heat treatment in step (4) is crushed to obtain a powder that passes through a 100-mesh sieve. The powder is added to acetone containing KH550 and stirred evenly at room temperature until the acetone is completely volatilized. The powder is then placed in a forced air drying oven at 80°C for 1 to 2 hours to obtain coupled magnetic powder.

[0082] (6) Mixing: The rubber is mixed on an open mill at room temperature. After the rubber is evenly coated on the roller, the coupled magnetic powder and dicumyl peroxide are added in sequence. After mixing evenly, the rubber is thinly passed through 1 to 3 times and then sheeted.

[0083] (7) Compression molding: After the mixed rubber material is placed for 12 to 24 hours, it is placed in a mold and heated, and then molded in a flat vulcanizer at a heating temperature of 160°C, a pressing time of 8 minutes, and a pressing pressure of 3 MPa;

[0084] (8) Demolding: Demolding the molded magnet from the mold to obtain a rubber magnet;

[0085] The properties of the prepared rubber magnets are shown in Table 1.

[0086] Comparative Example 1

[0087] Comparative Example 1 of the present application is Example 3 in Chinese invention patent application publication number CN104505204A. The magnetic properties of the rubber magnet are shown in Table 1.

[0088] Comparative Example 2

[0089] Comparative Example 2 of the present application is Comparative Example 1 in Chinese invention patent application publication number CN104505204A. The magnetic properties of the rubber magnet are shown in Table 1.

[0090] Comparative Example 3

[0091] The difference from Example 2 is that commercial NdFeB magnetic powder with the brand name MQP-B+ was selected. 26.4 Fe 67.6 The rubber magnet of Co5B, where the numbers represent the weight percentage of each component. The rubber magnet of this comparative example is composed of the following raw materials in parts by weight: 90 parts of NdFeB magnetic powder, 10 parts of nitrile rubber, 0.9 parts of KH550, and 0.1 parts of dicumyl peroxide.

[0092] The preparation method of the NdFeB rubber magnet comprises the following specific steps:

[0093] (1) Magnetic powder coupling treatment: The powder was screened with a sieve to obtain powder that passed a 100-mesh sieve. The magnetic powder was added to acetone containing KH550, stirred evenly at room temperature until the acetone was completely volatilized, and then placed in a forced air drying oven at 80°C for 1-2 hours to obtain coupled magnetic powder;

[0094] (2) Mixing: The rubber is mixed on an open mill at room temperature. After the rubber is evenly coated on the roller, the coupled magnetic powder and dicumyl peroxide are added in sequence. After mixing evenly, the rubber is thinly passed through 1 to 3 times and then sheeted.

[0095] (3) Compression molding: After the mixed rubber material is placed for 12 to 24 hours, it is placed in a mold and heated, and then molded in a flat vulcanizer at a heating temperature of 160°C, a pressing time of 15 minutes, and a pressing pressure of 3 MPa;

[0096] (4) Demolding: Demolding the molded magnet from the mold to obtain a rubber magnet.

[0097] The high temperature resistance results of the rubber magnets are shown in Table 2.

[0098] Comparative Example 4

[0099] The difference from Example 2 is that commercial NdLaCeFeB magnetic powder with the brand name MQP-9-6.5HD was selected. The chemical formula of the prepared powder in this comparative example is Nd6Pr2La 6.7 Ce 13.4 Fe 67.3 Zr 1.5 B 1.1 The rubber magnet of the comparative example is composed of the following raw materials in parts by weight: 90 parts of NdLaCeFeB magnetic powder, 10 parts of nitrile rubber, 0.9 parts of KH550, and 0.1 parts of dicumyl peroxide.

[0100] The preparation method of the lanthanum-cerium-containing neodymium iron boron rubber magnet comprises the following specific steps:

[0101] (1) Magnetic powder coupling treatment: The powder was screened with a sieve to obtain powder passing through a 100-mesh sieve. The magnetic powder was added to acetone containing KH550 and stirred evenly at room temperature until the acetone was completely volatilized. The mixture was then placed in a forced air drying oven at 80°C for 1 to 2 hours.

[0102] (2) Mixing: The rubber is mixed on an open mill at room temperature. After the rubber is evenly coated on the roller, the coupled magnetic powder and dicumyl peroxide are added in sequence. After mixing evenly, the rubber is thinly passed through 1 to 3 times and then sheeted.

[0103] (3) Compression molding: After the mixed rubber material is placed for 12 to 24 hours, it is placed in a mold and heated, and then molded in a flat vulcanizer at a heating temperature of 160°C, a pressing time of 15 minutes, and a pressing pressure of 3 MPa;

[0104] (4) Demolding: Demolding the molded magnet from the mold to obtain a rubber magnet.

[0105] The high temperature resistance results of the rubber magnets are shown in Table 2.

[0106] Table 1 Comparison of magnetic properties and mechanical properties

[0107]

[0108] Magnetic properties: Measured using a comprehensive physical property measurement system (PPMS9) in accordance with GB-T 3217-2013 Test methods for magnetic properties of permanent magnetic (hard magnetic) materials.

[0109] Mechanical properties: According to GB / T 1040-1992 Plastics Tensile Test Method, a vertical electronic universal testing machine was used for mechanical property testing.

[0110] As can be seen from Table 1, the pure, high-abundance rare earth rubber magnets of the present invention exhibit excellent hard magnetic properties, with maximum magnetic energy products exceeding 1.5 MGOe, exceeding those of existing ferrite rubber magnets. The magnetic powder filling ratio of Example 1, 83%, is lower than the 91.5% and 91% magnetic powder filling ratios of Comparative Example 1 and Comparative Example 2, yet exhibits superior magnetic and mechanical properties. Examples 2-4, with a filling ratio of 90%, achieve a maximum magnetic energy product of 2.98 MGOe and an increased tensile strength of 8.67 MPa, demonstrating excellent magnetic and mechanical properties.

[0111] Table 2 Comparison of high temperature resistance

[0112]

[0113] The high temperature resistance test refers to placing the rubber magnet in a blast drying oven at 80°C for baking, taking out the rubber magnet at regular intervals for performance testing, recording the magnetic energy product of the magnet, and comparing it with the magnetic energy product of the initial magnet.

[0114] As can be seen from Table 2, compared to Nd-containing rubber magnets, the pure high-abundance rare earth rubber magnets of the present invention exhibit lower magnetic performance loss and higher thermal stability after prolonged baking at 80°C. In contrast, Nd-based rubber magnets experience a greater than 10% loss in magnetic performance after prolonged baking at 80°C.

[0115] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A pure high-abundance rare earth rubber magnet, characterized by: Composed of coupled pure high-abundance rare earth magnetic powder, rubber and a vulcanizing agent, wherein the weight portion of the coupled pure high-abundance rare earth magnetic powder is 50-90 parts, the weight portion of the rubber is 10 parts, and the weight portion of the vulcanizing agent is 0.1-0.5 parts; The pure high-abundance rare earth magnetic powder has a composition of [(Ce a La 1-a ) b Y 1-b ] c Fe 95-c-d B6N d , wherein N is at least one of Nb, Al, Ga, Cu, Zr, Si, Ti, and Ge, the value range of a is 0.7 to 0.9, the value range of b is 0.6 to 0.8, the value range of c is 16 to 18, and the value range of d is 0.5 to 2; The preparation of the high-abundance rare earth rubber magnet comprises the following steps: (1) Raw material preparation; (2) Alloy smelting; (3) Melt quenching: The master alloy obtained in step (2) is mechanically polished to remove the surface oxide layer, and then mechanically crushed into uniform small pieces of master alloy and melted. After melting, it is rapidly cooled and solidified into nanocrystalline rapid quenching alloy, and finally mechanically crushed into powder to obtain magnetic powder; (4) heat treatment of magnetic powder; the heat treatment temperature is 500-700°C and the heat treatment time is 5-15 minutes; (5) Magnetic powder coupling treatment; (6) Mixing; (7) Pressing and molding; (8) Demolding.

2. The pure high-abundance rare earth rubber magnet according to claim 1, characterized in that: The preparation steps are specifically as follows: (1) Raw material preparation: Prepare according to the atomic ratio [(Ce a La 1-a ) b Y 1-b ] c Fe 95-c-d B6N d Raw materials of each element; (2) Alloy smelting: Alloy smelting is carried out under inert gas protection conditions to obtain a master alloy with uniform composition; (3) Rapid quenching of the melt; (4) Magnetic powder heat treatment: The magnetic powder obtained in step (3) is heat treated under the protection of argon gas with a purity of ≥99.999%; (5) Magnetic powder coupling treatment: The magnetic powder after heat treatment in step (4) is crushed to obtain a powder passing through a 100-mesh sieve, and the powder is added to an organic solvent containing a silane coupling agent, stirred evenly at room temperature until the organic solvent is completely volatilized, and then dried to obtain coupled magnetic powder; (6) Mixing: The rubber is mixed on the mixing device, and the mixing temperature is controlled at room temperature. After the rubber is evenly coated on the roller, the coupled magnetic powder and the vulcanizer are added in sequence. After mixing evenly, the rubber is thinly passed 1 to 3 times and then cut into sheets; (7) Compression molding: After the mixed rubber material is placed for 12 to 24 hours, it is placed in a mold, heated, and molded in a pressure device; (8) Demolding: Demolding the molded magnet from the mold to obtain a rubber magnet.

3. The pure high-abundance rare earth rubber magnet according to claim 2, characterized in that: In step (2), the inert gas is argon with a purity of ≥99.999%; In step (2), during the smelting, each smelting is performed for 2 to 3 minutes, and after the smelting is completed, the smelting is performed over, and the smelting is repeated 3 to 5 times.

4. The pure high-abundance rare earth rubber magnet according to claim 2, characterized in that: In step (3), the melting process is as follows: placing a small piece of master alloy into a quartz tube with a small hole at the lower end, placing the quartz tube into a vacuum belt spinning machine, and melting the small piece of master alloy into a molten state in an argon atmosphere with a purity of ≥99.999%; In step (3), the rapid cooling and solidification process is as follows: the molten alloy liquid is sprayed onto a water-cooled copper roller with an outer surface linear velocity of 10 to 50 m / s, and the copper roller rotates to rapidly cool and solidify the molten alloy liquid into a nanocrystalline rapid-quenching alloy with a thickness of 0.020 to 0.050 mm.

5. The pure high-abundance rare earth rubber magnet according to claim 2, characterized in that: In step (5), the mass ratio of pure high-abundance rare earth magnetic powder, silane coupling agent and organic solvent is 100: (0.5-1.5): (30-50); The silane coupling agent is one of KH550, KH560 and KH570; The organic solvent is at least one of acetone and ethanol; The drying temperature is 60-120° C., and the drying time is 1-2 hours.

6. The pure high-abundance rare earth rubber magnet according to claim 2, characterized in that: In step (6), the mixing device is at least one of an open mill, a calender and an internal mixer; The rubber is a nitrile rubber (NBR) with an acrylonitrile content of 31 to 46%; The vulcanizing agent is one of dicumyl peroxide, benzoyl peroxide, 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane, and 1,3-bis(tert-butylperoxyisopropyl)benzene.

7. The pure high-abundance rare earth rubber magnet according to claim 2, characterized in that: In step (7), the heating temperature is 130-180° C., the pressurizing time is 5-15 min, and the pressurizing pressure is 2-5 MPa; and the pressure device is a flat plate vulcanizing press.

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