Samarium-cobalt permanent magnet material and preparation method and application thereof

Abstract

The invention discloses a samarium cobalt permanent magnet material and a preparation method and application thereof, and the preparation method comprises the following steps: 1) carrying out crushing and jet milling on an alloy ingot formed by required raw materials, and controlling the oxygen content to be less than 100 ppm during jet milling to obtain milled powder with D50 of 4-6 [mu] m; (2) the ground powder obtained in the step (1) is sieved for 0.1-2 h in air through a double-function ultrasonic experiment sieve, sieved powder with the oxygen content smaller than or equal to 0.33 wt% is obtained, and the mesh number of the double-function ultrasonic experiment sieve is smaller than or equal to 500; (3) the sieved powder obtained in the step (2) is subjected to orientation forming and isostatic pressing, and a green body is obtained; and the green body is subjected to sintering, solid solution and aging treatment, and the samarium-cobalt permanent magnet material is obtained. According to the preparation method, the samarium-cobalt permanent magnet material with relatively high coercive force can be obtained.

Description

Technical Field

[0001] The present invention relates to a samarium cobalt permanent magnet material, a preparation method and an application thereof, and in particular to a samarium cobalt permanent magnet material, a preparation method thereof, and an application of a dual-function ultrasonic test sieve in improving the coercive force of the samarium cobalt permanent magnet material. Background Art

[0002] Samarium cobalt permanent magnet materials are mainly composed of metal samarium (Sm), metal cobalt (Co), copper (Cu), iron (Fe), zirconium (Zr) and other elements. They are divided into 1:5 type and 2:17 type from the structural point of view, belonging to the first and second generation rare earth permanent magnet materials. 2:17 type samarium cobalt magnets are also called Sm2Co 17 , the maximum operating temperature can reach over 350°C. 2:17 type samarium cobalt magnets have a low temperature coefficient and good corrosion resistance. At high temperatures, their magnetic properties exceed those of neodymium iron boron magnets. Therefore, they are widely used in aerospace, military, high-temperature motors, automotive sensors, various magnetic transmissions, magnetic pumps, and microwave devices.

[0003] The coercive force of permanent magnetic materials is a key indicator to measure the material's ability to resist demagnetization. The specific numerical range is closely related to the type of material and the preparation process.

[0004] CN117457365A discloses a process for preparing a samarium-cobalt material, comprising the following steps: batching and smelting: weighing raw materials according to 15-20 parts by weight of Fe, 4-7 parts by weight of Cu, 48-52 parts by weight of Co, 2-3.5 parts by weight of Zr, and 24-27 parts by weight of Sm, and heating and smelting the raw materials to obtain an alloy melt. Strip spinning: pouring the alloy melt onto a copper roller passing cooling water to obtain a strip spinning. Powdering: pulverizing the strip spinning to obtain samarium-cobalt material powder. Molding: pressing the samarium-cobalt material powder into a shape to obtain a blank. Sintering and tempering: sintering and tempering the blank to obtain the samarium-cobalt material. The coercivity of the samarium-cobalt material obtained by this process still needs to be further improved.

[0005] CN119296941A discloses a diffusion preparation method for samarium-cobalt materials, comprising the following steps: S1. Weighing samarium-cobalt permanent magnet alloy raw materials to prepare alloy ingots; S2. Mechanically crushing the alloy particles to form alloy powder; S3. Forming the samarium-cobalt alloy powder through magnetic field orientation and cold isostatic pressing to form a green body; S4. Sintering and solution treating the green body to prepare a sintered samarium-cobalt permanent magnet blank, which is then processed into samarium-cobalt magnet slices; S5. Primary diffusion of the samarium-cobalt magnet slices with PrCu; S6. Secondary diffusion of the magnet slices with SnFe; S7. Ageing the secondary diffused slices to produce the samarium-cobalt permanent magnet material. While this method can improve the coercivity of the resulting samarium-cobalt material, it requires two diffusion steps, making it somewhat complex.

[0006] CN119905309A discloses a method for preparing samarium cobalt permanent magnet material, which comprises the following steps: 1) crushing and jet milling an alloy ingot formed from raw materials required for samarium cobalt permanent magnet material to obtain D 50 2) taking out 15 to 30 wt% of the first alloy fine powder, and then ball milling the taken out first alloy fine powder to obtain D 50 The method comprises the following steps: preparing a second alloy fine powder having a particle size of 0.5 to 1.2 μm; 3) mixing the remaining first alloy fine powder with the second alloy fine powder obtained in step 2) to obtain a mixed powder; 4) orienting and isostatically pressing the mixed powder to obtain a green compact; and sintering, solutionizing, and aging the green compact to obtain a samarium-cobalt permanent magnet material. This method can substantially maintain the coercivity of the obtained samarium-cobalt permanent magnet material. Summary of the Invention

[0007] One object of the present invention is to provide a method for preparing a samarium-cobalt permanent magnet material, which can produce a samarium-cobalt permanent magnet material with a high coercivity. Another object of the present invention is to provide a samarium-cobalt permanent magnet material produced according to the above-described preparation method. Yet another object of the present invention is to provide a dual-function ultrasonic test sieve for use in increasing the coercivity of a samarium-cobalt permanent magnet material.

[0008] The present invention adopts the following technical solutions to achieve the above-mentioned purpose.

[0009] In one aspect, the present invention provides a method for preparing a samarium cobalt permanent magnet material, comprising the following steps:

[0010] 1) crushing and jet milling the alloy ingot formed from the required raw materials, and controlling the oxygen content in the jet milling to be below 100 ppm to obtain D 50 The powder is 4-6μm;

[0011] 2) sieving the ground powder obtained in step 1) in air for 0.1 to 2 hours using a dual-function ultrasonic test sieve to obtain a sieved powder having an oxygen content of less than or equal to 0.33 wt %, wherein the mesh size of the dual-function ultrasonic test sieve is less than or equal to 500 mesh;

[0012] 3) Orienting and molding the sieved powder obtained in step 2) and isostatically pressing the powder to obtain a green body; sintering, solid solution treatment and aging treatment the green body to obtain a samarium cobalt permanent magnet material.

[0013] According to the preparation method of the present invention, preferably, in step 1), the required raw materials are prepared according to the composition of the samarium cobalt permanent magnet material, and then the required raw materials are formed into an alloy ingot; wherein the samarium cobalt permanent magnet material has the following composition: based on the total mass of the samarium cobalt permanent magnet material, Sm 23-27wt%, Fe 14.5-18wt%, Cu 4-6wt%, Zr 2-3.5wt%, and Co balance.

[0014] According to the preparation method of the present invention, preferably, based on the total mass of the samarium cobalt permanent magnet material, Sm is 24-25wt%, Fe is 15.2-16.8wt%, Cu is 4.3-5.3wt%, Zr is 2.5-3.3wt%, and Co is the balance.

[0015] According to the preparation method of the present invention, preferably, step 1) includes the following specific steps: melting and casting the raw materials required for the samarium cobalt permanent magnet material in a vacuum induction melting furnace to form an alloy ingot; first coarsely crushing the alloy ingot with a jaw crusher, and then finely crushing it with a medium crusher to obtain medium-crushed particles.

[0016] According to the preparation method of the present invention, preferably, after the fine crushing is completed, a lubricant and an antioxidant are added to the medium-crushed particles and mixed, and then air flow milling is performed to obtain ground powder; wherein the amount of the lubricant added is 0.02 to 0.04 wt% of the mass of the medium-crushed particles, and the amount of the antioxidant added is 0.03 to 0.05 wt% of the mass of the medium-crushed particles.

[0017] According to the preparation method of the present invention, preferably, the powders obtained by jet milling in batches are mixed in a mixer for 0.5 to 3 hours.

[0018] According to the preparation method of the present invention, preferably, in step 2), the dual-function ultrasonic experimental sieve is an experimental sieve combining a mechanical sieve and an ultrasonic vibration sieve, and its mesh size is 40 to 500 meshes.

[0019] According to the preparation method of the present invention, preferably, in step 3), the magnetic field strength during orientation molding is 1.6 to 2 T; the isostatic pressing pressure is 260 to 290 MPa; the sintering temperature is 1200 to 1250° C., and the sintering time is 1 to 3 hours; the solid solution temperature is 1170 to 1200° C., and the solid solution time is 1 to 5 hours; the aging treatment temperature is 810 to 870° C., and the aging treatment time is 12 to 20 hours.

[0020] On the other hand, the present invention also provides a samarium cobalt permanent magnet material, which is prepared according to the preparation method described above.

[0021] In another aspect, the present invention further provides a use of a dual-function ultrasonic test sieve in improving the coercive force of samarium cobalt permanent magnet materials, comprising the steps in the preparation method described above.

[0022] The preparation method of the present invention does not introduce any other alloy elements. Only a powder screening process using a dual-function ultrasonic test sieve is added after the air flow milling to improve the coercive force of the samarium cobalt permanent magnet material. The preparation method of the present invention is applicable to industrial production. DETAILED DESCRIPTION

[0023] The present invention will be further described below with reference to specific embodiments, but the protection scope of the present invention is not limited thereto.

[0024] The inventors of this application unexpectedly discovered that sieving the powder obtained from a jet mill through a dual-function ultrasonic test sieve and controlling the oxygen content can facilitate the production of samarium-cobalt permanent magnet materials with higher coercivity. This invention eliminates the need for further refinement of the powder obtained from the jet mill and the addition of any other alloying elements.

[0025] The "coercive force" mentioned in this invention, also known as intrinsic coercive force, refers to the magnetic field strength when the magnetic field is monotonically reduced to zero and then increased in the opposite direction from the saturation magnetization state of the magnet, so that the magnetization intensity decreases to zero along the saturation hysteresis loop. The unit is Oersted (Oe) or Ampere / meter (A / m). 1Oe = 79.6A / m.

[0026] In the present invention, D 50 Also known as median diameter or median particle size, it is a statistic that represents the particle size distribution. Its specific meaning is as follows: in the particle size distribution of a particle group, the particles are sorted by particle size. The particle size value corresponding to the cumulative particle size distribution percentage reaching 50% is called D 50 That is, among all the particles, 50% of the particles have a particle size smaller than this value, and the other 50% of the particles have a particle size larger than this value.

[0027] <Preparation method of samarium cobalt permanent magnet material>

[0028] The method for preparing the samarium-cobalt permanent magnet material of the present invention comprises the following steps: (1) preparing a powder by grinding; (2) screening the powder; and (3) forming and heat treating the powder. Furthermore, the method also includes a batching step. This is described in detail below.

[0029] Ingredients and Steps

[0030] The raw materials required for the samarium cobalt permanent magnet material of the present invention only include Sm, Co, Fe, Cu, Zr and inevitable impurities.

[0031] Prepare the required raw materials according to the composition of the samarium cobalt permanent magnet material. The samarium cobalt permanent magnet material has the following composition: based on the total mass of the samarium cobalt permanent magnet material, Sm 23-27wt%, Fe 14.5-18wt%, Cu 4-6wt%, Zr 2-3.5wt%, and Co as the balance.

[0032] Based on the total mass of the samarium-cobalt permanent magnet material, the Sm content is preferably 24-26wt%, more preferably 24-25wt%, such as 24wt%, 24.3wt%, 24.5wt%, 24.7wt%, or 25wt%. The Fe content is preferably 14.5-17wt%, more preferably 15-17wt%, and even more preferably 15.2-16.8wt%. The Cu content is preferably 4.3-6wt%, more preferably 4.3-5.3wt%, and even more preferably 4.5-5.2wt%. The Zr content is preferably 2.5-3.3wt%, more preferably 2.5-3wt%. Co is the balance.

[0033] According to a specific embodiment of the present invention, based on the total mass of the samarium cobalt permanent magnet material, Sm is 24-25wt%, Fe is 15.2-17wt%, Cu is 4.5-5.3wt%, Zr is 2.5-3.3wt%, and Co is the balance.

[0034] In the present invention, the purity of each metal element used is greater than or equal to 99.9%.

[0035] Preparation steps of grinding powder

[0036] In the present invention, the alloy ingot formed from the required raw materials is crushed and jet milled, and the oxygen content is controlled below 100ppm during jet milling to obtain D 50 The powder is 4-6 μm. This is conducive to obtaining samarium cobalt permanent magnet materials with higher coercivity.

[0037] The preparation steps of the ground powder include a smelting ingot step, a crushing step and a jet mill step.

[0038] In the present invention, the step of melting and casting an ingot comprises: melting and casting the raw materials required for the samarium-cobalt permanent magnet material in a vacuum induction melting furnace to form an alloy ingot. The melting temperature and time can be those known in the art.

[0039] The crushing step includes coarse crushing and fine crushing steps, specifically comprising: coarsely crushing the alloy ingot using a jaw crusher, followed by fine crushing using a secondary crusher to obtain secondary crushed particles. The coarse crushed particles may have a particle size of 50 mm or less, preferably 1 to 45 mm, and more preferably 5 to 40 mm. The secondary crushed particles may have a particle size of 0.4 mm or less, for example, 0.05 to 0.4 mm.

[0040] In the present invention, the air flow milling step includes: after the fine crushing is completed, a lubricant and an antioxidant are added to the medium-crushed particles and mixed, and then air flow milling is performed to obtain a ground powder. The specific process of air flow milling can adopt those known in the art and will not be described in detail here. The lubricant can be selected from those known in the art, preferably selected from at least one of zinc stearate, calcium stearate, magnesium stearate, erucamide, oleamide, and polyethylene wax, more preferably zinc stearate. The amount of lubricant added is 0.02 to 0.04 wt% of the mass of the medium-crushed particles, preferably 0.03 to 0.04 wt%, more preferably 0.03 to 0.035 wt%. The antioxidant can be selected from those known in the art, preferably selected from one of phosphite, polyethylene oxide olefin ether, and silane, more preferably phosphite. The amount of antioxidant added is 0.03 to 0.05 wt% of the mass of the medium-crushed particles, preferably 0.04 to 0.05 wt%.

[0041] The oxygen content during air jet milling is below 100ppm. 50 In certain specific embodiments, the D 50 In other specific embodiments, the D 50 4.5~5μm.

[0042] In the present invention, the powder obtained by jet milling in batches can be mixed in a mixer for 0.5 to 3 hours, preferably 1.5 to 2 hours. This helps to enhance the uniformity of the powder particle size. The mixer can be a three-dimensional mixer. The three-dimensional mixer can be any commercially available one, and its source is not particularly limited.

[0043] Sieving steps

[0044] The obtained ground powder is sieved in air for 0.1 to 2 hours using a dual-function ultrasonic test sieve to obtain a sieved powder having an oxygen content of less than or equal to 0.33 wt %, wherein the mesh size of the dual-function ultrasonic test sieve is less than or equal to 500 mesh. The present invention has found that this method is conducive to obtaining a samarium-cobalt permanent magnet material with a higher coercive force.

[0045] The present invention uses a dual-function ultrasonic experimental sieve as an experimental sieve that combines a mechanical sieve with an ultrasonic vibration sieve. The mesh size is preferably 40 to 500 mesh, more preferably 60 to 300 mesh, more preferably 80 to 200 mesh, and further preferably 100 to 150 mesh. The aperture of a 40-mesh screen is usually 0.425 mm, and the aperture of a 500-mesh screen is usually 30 μm. Due to the large specific surface area of the ground powder and the static electricity it carries, after the ground powder is transferred to the experimental sieve, it is difficult for the ground powder to leak from the sieve without vibration. The inventor is still unclear about the principle that the use of a dual-function ultrasonic experimental sieve is beneficial for obtaining samarium cobalt permanent magnet materials with higher coercive force. It is speculated that this may be because the uniformity and consistency of the ground powder are improved.

[0046] The source and model of the dual-function ultrasonic test sieve are not particularly limited. According to a specific embodiment of the present invention, the manufacturer of the dual-function ultrasonic test sieve is Shanghai Yanyong Ultrasonic Equipment Co., Ltd., the brand is Yanyong Lansheng, and the model is YSF-150T.

[0047] In the present invention, the powder is sieved in air for preferably 0.5 to 2 hours, more preferably 0.5 to 1.5 hours, and even more preferably 0.5 to 1 hour. Sieving the powder in air can appropriately increase the oxygen content of the sieved powder, which is beneficial for obtaining a samarium cobalt permanent magnet material with a higher coercive force. The oxygen content of the sieved powder is preferably 0.22 to 0.33 wt%, more preferably 0.25 to 0.33 wt%, and even more preferably 0.27 to 0.33 wt%. If the oxygen content is not within the range of the present invention, the coercive force of the obtained samarium cobalt permanent magnet material is reduced.

[0048] Forming and heat treatment steps

[0049] The sieved powder is oriented, molded, and isostatically pressed to obtain a green compact. The green compact is then sintered, solutionized, and aged to produce a samarium-cobalt permanent magnet material. This method produces a samarium-cobalt permanent magnet material with stable and uniform magnetic properties.

[0050] The magnetic field intensity during orientation molding of the mixed powder can be 1.6 to 2 T, preferably 1.7 to 2 T, and more preferably 1.7 to 1.8 T. After orientation molding, a compact is obtained, which is isostatically pressed to obtain a green compact. Isostatic pressing is a cold isostatic pressing technique known in the art and will not be described in detail here. The isostatic pressing pressure can be 260 to 290 MPa, preferably 270 to 285 MPa, and more preferably 275 to 280 MPa.

[0051] The resulting green compact is placed in a vacuum sintering furnace for heat treatment to obtain a samarium-cobalt permanent magnet material. The vacuum degree during heat treatment is less than 10 Pa, preferably less than or equal to 5 Pa, more preferably less than or equal to 0.1 Pa, and even more preferably less than or equal to 0.01 Pa. Specifically, the heat treatment includes the steps of sintering, solution treatment, and aging treatment.

[0052] The sintering temperature may be 1200-1250° C., preferably 1200-1230° C., more preferably 1210-1220° C. The sintering time may be 1-3 hours, preferably 2-3 hours. After sintering, the temperature is lowered to the solution temperature.

[0053] The solution temperature can be 1170-1200°C, preferably 1180-1195°C, and more preferably 1185-1190°C. The solution time can be 1-5 hours, preferably 2-4 hours, and more preferably 2-3 hours. After the solution, it is preferably air-cooled to below 50°C, more preferably to room temperature, and then transferred to an aging furnace for aging treatment. An inert gas can be used during air cooling, and the inert gas is selected from helium, neon, and argon, and is preferably argon.

[0054] The aging treatment temperature can be 810-870°C, preferably 820-850°C, and more preferably 830-840°C. The aging treatment time can be 12-20 hours, preferably 15-18 hours, and more preferably 16-17 hours. This is conducive to obtaining samarium cobalt permanent magnet materials with uniform and stable magnetic properties.

[0055] After aging treatment, the temperature can be naturally lowered to below 50° C. in the furnace to obtain samarium cobalt permanent magnet material.

[0056] According to a specific embodiment of the present invention, the preparation method of the samarium cobalt permanent magnet material of the present invention comprises the following steps:

[0057] 1) crushing and jet milling the alloy ingot formed from the required raw materials, and controlling the oxygen content in the jet milling to be below 100 ppm to obtain D 50 The powder is 4.5-5μm;

[0058] 2) sieving the ground powder obtained in step 1) in air for 0.5 to 2 hours using a dual-function ultrasonic test sieve to obtain a sieved powder having an oxygen content of less than or equal to 0.33 wt %, wherein the mesh size of the dual-function ultrasonic test sieve is 40 to 500 mesh;

[0059] 3) Orienting and molding the sieved powder obtained in step 2) and isostatically pressing the powder to obtain a green body; sintering, solid solution treatment and aging treatment the green body to obtain a samarium cobalt permanent magnet material.

[0060] <Samarium Cobalt Permanent Magnet Material>

[0061] The coercive force of the samarium cobalt permanent magnet material obtained according to the preparation method as described above can be greater than 33 kOe, preferably greater than 34 kOe, more preferably greater than 34.5 kOe, and can reach 35.6 kOe.

[0062] <Purpose>

[0063] The present invention also provides a use of a dual-function ultrasonic test sieve in improving the coercive force of samarium cobalt permanent magnet materials, comprising the following steps:

[0064] 1) crushing and jet milling the alloy ingot formed from the required raw materials, and controlling the oxygen content in the jet milling to be below 100 ppm to obtain D 50 The powder is 4-6μm;

[0065] 2) sieving the ground powder obtained in step 1) in air for 0.1 to 2 hours using a dual-function ultrasonic test sieve to obtain a sieved powder having an oxygen content of less than or equal to 0.33 wt %, wherein the mesh size of the dual-function ultrasonic test sieve is less than or equal to 500 mesh;

[0066] 3) Orienting and shaping the sieved powder obtained in step 2) and isostatically pressing the powder to obtain a green body; sintering, solutionizing, and aging the green body to obtain a samarium-cobalt permanent magnet material. Detailed process parameters and steps are described above and are not repeated here.

[0067] <Analysis Method>

[0068] Coercive force test: Use Hirst permanent magnet pulse measuring instrument to test the coercive force of magnetic properties.

[0069] Oxygen content test: Use an oxygen, nitrogen and hydrogen analyzer to measure the oxygen content of the material.

[0070] In the following examples and comparative examples,

[0071] The lubricant used is zinc stearate, and the antioxidant used is phosphite.

[0072] The manufacturer of the dual-function ultrasonic test sieve used is Shanghai Yanyong Ultrasonic Equipment Co., Ltd., the brand is Yanyong Lansheng, and the model is YSF-150T.

[0073] Example 1

[0074] The raw materials required for the samarium cobalt permanent magnet material are prepared according to the following specific composition: based on the total mass of the samarium cobalt permanent magnet material, Sm 24.3wt%, Fe 15.7wt%, Cu 4.9wt%, Zr 2.7wt%, and Co balance (i.e., 52.4wt%).

[0075] The prepared raw materials are melted and cast in a vacuum induction melting furnace to obtain alloy ingots.

[0076] The alloy ingot formed from the required raw materials is first coarsely crushed using a jaw crusher, and then finely crushed using a medium crusher to obtain medium-sized particles with a particle size of less than 0.4 mm. After the fine crushing is completed, 0.03 wt% lubricant and 0.04 wt% antioxidant are added to the material tank containing the medium-sized particles and mixed evenly using a mixer. Then, the mixture is jet milled, and the oxygen content of the jet mill is controlled below 100 ppm to obtain particles with a particle size of D 50 Grind the powder to 4.5-5μm. Mix the powder ground by air jet mill in batches for 2 hours in a three-dimensional mixer to enhance the uniformity of powder particle size.

[0077] The mixed ground powder was sieved in air for 0.5 h using a dual-function ultrasonic test sieve with a mesh size of 100 meshes to obtain a sieved powder with an oxygen content of 0.27 wt%.

[0078] The resulting sieved powder was pressed into 55mm×48mm×50mm cubes in an orienting press with a magnetic field strength of 1.8T to produce compacts. The compacts were then cold isostatically pressed at a pressure of 280MPa to produce green compacts. The cold isostatically pressed green compacts were placed in a vacuum sintering furnace and sintered at 1210°C for 2 hours. After sintering, the temperature was lowered to 1190°C over approximately 30 minutes. Solution treatment was then performed at 1190°C for 3 hours. After solution treatment, the compacts were rapidly air-cooled to room temperature and then transferred to an aging furnace, where the temperature was raised to 830°C. The solutionized compacts were aged at 830°C for 17 hours before being removed from the furnace and cooled to below 50°C. This resulted in the samarium-cobalt permanent magnet material.

[0079] The coercive force of the samarium cobalt permanent magnet material obtained in this embodiment is 35.47 kOe.

[0080] Example 2

[0081] Except for the following parameters and settings, the rest are the same as Example 1:

[0082] The mixed ground powder was sieved in air using a dual-function ultrasonic experimental sieve for 1 hour to obtain a sieved powder with an oxygen content of 0.29 wt%.

[0083] The coercive force of the samarium cobalt permanent magnet material obtained in this embodiment is 35.60 kOe.

[0084] Example 3

[0085] Except for the following parameters and settings, the rest are the same as Example 1:

[0086] The mixed ground powder was sieved in air for 1.5 hours using a dual-function ultrasonic experimental sieve to obtain a sieved powder with an oxygen content of 0.31 wt%.

[0087] The coercive force of the samarium cobalt permanent magnet material obtained in this embodiment is 35.32 kOe.

[0088] Example 4

[0089] Except for the following parameters and settings, the rest are the same as Example 1:

[0090] The mixed ground powder was sieved in air for 2 hours using a dual-function ultrasonic experimental sieve to obtain a sieved powder with an oxygen content of 0.33 wt%.

[0091] The coercive force of the samarium cobalt permanent magnet material obtained in this embodiment is 34.58 kOe.

[0092] Comparative Example 1

[0093] Except for the following parameters and settings, the rest are the same as Example 1:

[0094] The mixed ground powder was sieved in air for 2.5 hours using a dual-function ultrasonic experimental sieve to obtain a sieved powder with an oxygen content of 0.35 wt%.

[0095] The coercive force of the samarium cobalt permanent magnet material obtained in this embodiment is 32.53 kOe.

[0096] Comparative Example 2

[0097] Except for the following parameters and settings, the rest are the same as Example 1:

[0098] The mixed ground powder was sieved in air using a dual-function ultrasonic experimental sieve for 3 hours to obtain a sieved powder with an oxygen content of 0.37 wt%.

[0099] The coercive force of the samarium cobalt permanent magnet material obtained in this embodiment is 29.71 kOe.

[0100] Table 1

[0101]

[0102] From the comparison between the embodiment and the comparative example, it can be seen that the use of the dual-function ultrasonic test sieve in the present invention is conducive to obtaining samarium cobalt permanent magnet materials with higher coercivity.

[0103] The present invention is not limited to the above-mentioned embodiments. Any modification, improvement, or substitution that can be conceived by those skilled in the art without departing from the essential content of the present invention shall fall within the scope of the present invention.

Claims

1. A method for preparing a samarium cobalt permanent magnet material, characterized in that: The steps include: 1) crushing and jet milling the alloy ingot formed from the required raw materials, and controlling the oxygen content in the jet milling to be below 100 ppm to obtain D 50 The powder is 4-6μm; 2) sieving the ground powder obtained in step 1) in air for 0.1 to 2 hours using a dual-function ultrasonic test sieve to obtain a sieved powder having an oxygen content of less than or equal to 0.33 wt %, wherein the mesh size of the dual-function ultrasonic test sieve is less than or equal to 500 mesh; 3) Orienting and molding the sieved powder obtained in step 2) and isostatically pressing the powder to obtain a green body; sintering, solid solution treatment and aging treatment the green body to obtain a samarium cobalt permanent magnet material.

2. The preparation method according to claim 1, characterized in that In step 1), the required raw materials are prepared according to the composition of the samarium cobalt permanent magnet material, and then the required raw materials are formed into an alloy ingot; wherein the samarium cobalt permanent magnet material has the following composition: based on the total mass of the samarium cobalt permanent magnet material, Sm 23-27wt%, Fe 14.5-18wt%, Cu 4-6wt%, Zr 2-3.5wt%, and Co balance.

3. The preparation method according to claim 2, characterized in that Based on the total mass of the samarium cobalt permanent magnet material, Sm is 24-25wt%, Fe is 15.2-16.8wt%, Cu is 4.3-5.3wt%, Zr is 2.5-3.3wt%, and Co is the balance.

4. The preparation method according to claim 2, characterized in that Step 1) includes the following specific steps: melting and casting the raw materials required for samarium cobalt permanent magnet material in a vacuum induction melting furnace to form an alloy ingot; first coarsely crushing the alloy ingot with a jaw crusher, and then finely crushing it with a medium crusher to obtain medium-crushed particles.

5. The preparation method according to claim 4, characterized in that After the fine crushing is completed, a lubricant and an antioxidant are added to the medium-crushed particles and mixed, and then subjected to airflow milling to obtain ground powder; wherein the amount of the lubricant added is 0.02-0.04wt% of the mass of the medium-crushed particles, and the amount of the antioxidant added is 0.03-0.05wt% of the mass of the medium-crushed particles.

6. The preparation method according to claim 5, characterized in that The powders obtained by jet milling in batches were mixed in a mixer for 0.5 to 3 hours.

7. The preparation method according to claim 1, characterized in that In step 2), the dual-function ultrasonic test sieve is a test sieve that combines a mechanical sieve with an ultrasonic vibration sieve, and its mesh size is 40 to 500 meshes.

8. The preparation method according to claim 1, characterized in that In step 3), the magnetic field strength during orientation molding is 1.6 to 2 T; the isostatic pressing pressure is 260 to 290 MPa; the sintering temperature is 1200 to 1250° C., and the sintering time is 1 to 3 hours; the solution temperature is 1170 to 1200° C., and the solution time is 1 to 5 hours; the aging treatment temperature is 810 to 870° C., and the aging treatment time is 12 to 20 hours.

9. A samarium cobalt permanent magnet material, characterized in that: The invention relates to a novel novel nanostructured carbon foam prepared by the preparation method according to any one of claims 1 to 8.

10. Use of a dual-function ultrasonic test sieve in improving the coercivity of samarium cobalt permanent magnet materials, characterized in that: The method comprises the steps of the preparation method as claimed in claim 1.

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