Anisotropic samarium iron nitride magnetic alloy powder and method for producing the same

Abstract

To provide an anisotropic samarium-iron-nitrogen magnetic alloy powder which has a matching of a satisfactory spheroidicity and a special grain size and combines a high coercive force and a high squareness without requiring screening, and a method for producing the same.SOLUTION: Provided is an anisotropic samarium-iron-nitrogen magnetic alloy powder which has a chemical formula of Sm2Fe17N3 and a Th2Zn17 crystal structure, in which the grain size of the alloy powder satisfies 0.5 μm≤D90≤5 μm and 0.1 μm≤D10≤2 μm, and the average spheroidicity of the alloy powder satisfies ≥0.7, and has a coercive force of Hcj≥10kOe and a squareness of Q≥0.5. A production method therefor has: step S1 of uniformly mixing an iron powder, a samarium oxide powder and calcium gains; step S2 of arranging the mixture at the inside of a rotating heat treatment furnace, charging it with a high temperature resistant circular ball, executing evacuation, introducing a reduction diffusion protective gas therein and heating-up a furnace body; step S3 of cooling the furnace body, executing evacuation and introducing a nitriding gas therein; and step S4 of taking out the powder and the circular ball after the cooling so as to be separated, cleaning the powder and drying the same in a vacuum environment.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to the technical field of magnetic alloy powders, and particularly to anisotropic samarium iron nitride magnetic alloy powders and a method for manufacturing the same.

Background Art

[0002] Anisotropic Sm2Fe 17 N3 material has magnetic properties comparable to those of Nd2Fe 14 B material, a higher Curie temperature, and for a long time, the price of Sm is one-tenth of that of Nd and even lower. Therefore, Sm2Fe 17 N3 material has great application potential. The well-known methods for manufacturing Sm2Fe 17 N3 material are to first manufacture a Sm2Fe 17 alloy and then nitride the Sm2Fe 17 alloy to obtain a samarium iron nitride alloy. Currently, the methods for manufacturing Sm2Fe 17 N3 material mainly include the mechanical alloying method, the hydrogenation disproportionation method, the powder metallurgy method, the chemical coprecipitation method, and the conventional reduction diffusion method, etc. Among them, the mechanical alloying method requires long-time high-energy ball milling, has low efficiency, high energy consumption, and is disadvantageous for popularization. The hydrogenation disproportionation method is mainly used for manufacturing isotropic Sm2Fe 17 N3 material and has low magnetic properties. The powder metallurgy method requires a long-time high-temperature annealing treatment for the molten SmFe alloy to remove α-Fe, and also requires fine pulverization after nitridation to obtain a powder with practical performance. The conventional reduction diffusion method is to mix raw materials, then press them into a compact and put them into a crucible for reduction diffusion, wash them, and then nitride the Sm2Fe 17 alloy powder, and finally fine pulverize it to obtain Sm2Fe 17N3 magnetic powder is obtained. All of the above methods require a fine grinding step. After the powder is finely ground and crushed, the particles exhibit an irregular shape, have many sharp corners, the integrity of the surface of the crystal grains is destroyed, and the coercivity and angularity of the magnetic powder are reduced. Also, fine grinding is usually carried out in an organic solvent, but the operation is complex and there are safety problems. The chemical coprecipitation method uses a salt solution of Sm and Fe, adds a precipitant and reacts to obtain a composite precipitate of fine particles, and then through further processes such as calcination, preliminary reduction, reduction diffusion, nitridation, and washing, finally Sm2Fe 17 is to obtain N3 magnetic powder. This method does not require fine grinding and has anisotropic Sm2Fe with practical performance 17 N3 magnetic powder can be obtained, but the process flow of this method is complex, the Sm content is difficult to control, and it is disadvantageous for large-scale popularization.

Summary of the Invention

Problems to be Solved by the Invention

[0003] Magnetic alloy powders all have a certain single-domain size. When the particle size is near the range of the single-domain size, they have good coercivity. For Sm2Fe 17 For the N3 material, the cost of reducing to the single-domain size is high. When it is reduced to the range of several microns, a coercivity that reaches the practical effect can be obtained. As is well known, Sm2Fe 17 The coercivity mechanism of the N3 material is a typical nucleation mechanism. In addition to being affected by the particle size, factors such as the particle morphology and surface state are also important factors that affect the comprehensive performance of the material. The alloy particles are fine and the powder is extremely easy to oxidize. Improving the coercivity and angularity of the material has always been a very difficult problem to solve. Based on this, patents CN100513015C, CN110662617A, and CN108701518B disclose manufacturing methods with good powder morphology by the chemical coprecipitation method, and patent CN108274016A discloses a method for Sm2Fe 17 powder with good sphericity by the spray pyrolysis reduction method. The above Sm2Fe 17The process flow of the method for controlling the morphology of N3 magnetic powder is extremely complex. The Sm content is difficult to be stably and accurately controlled, and the difficulty of large-scale production is great.

Means for Solving the Problems

[0004] The object of the present invention is to provide an anisotropic samarium iron nitride magnetic alloy powder and a manufacturing method thereof, to solve at least one of the above technical problems, without the need for sieving, and having good sphericity and a special particle size matching, and anisotropic Sm2Fe having high coercive force and high rectangularity 17 It is possible to produce N3 alloy magnetic powder.

[0005] The embodiments of the present invention are realized as follows. An anisotropic samarium iron nitride magnetic alloy powder, the chemical formula thereof is Sm2Fe 17 N3, having a Th2Zn 17 Crystal structure, the particle size of the alloy powder 0.5μm ≦ D90 ≦ 5μm, 0.1μm ≦ D10 ≦ 2μm, the average sphericity of the alloy powder ≧ 0.7, the coercive force Hcj ≧ 10 kOe, and the rectangularity Q ≧ 0.5.

[0006] In a preferred embodiment of the present invention, the anisotropic samarium iron nitride magnetic alloy powder has a particle size of the alloy powder 1μm ≦ D90 ≦ 4μm, 0.8μm ≦ D10 ≦ 2μm, the average sphericity of the alloy powder ≧ 0.8, the coercive force Hcj ≧ 13 kOe, and the rectangularity Q ≧ 0.6.

[0007] Also, the particle size of the alloy powder, the statistical value of the volume of the particles, and the statistical value of the surface area of the particles are all measured by a laser particle size analyzer.

[0008] Also, the level of the rectangularity Q value indicates the strength of the demagnetization resistance ability of the magnetic powder. Its technical effect is that when the average particle size is the same, the rectangularity value is significantly improved, whereby the magnetic powder exhibits better comprehensive magnetic performance.

[0009] A method for manufacturing an anisotropic samarium iron nitride magnetic alloy powder, comprising the following steps. In S1, it is raw material mixing, where iron powder, samarium oxide powder, and calcium granules are uniformly mixed to obtain a mixture. In S2, it is reduction-diffusion heat treatment. The mixture is placed in a rotating heat treatment furnace, and high-temperature-resistant circular balls are added to prevent sintering of the powder. It is evacuated to below 1×10 -2 Pa, a reduction-diffusion protective gas is introduced, the furnace body is heated to 850 °C to 950 °C, and held for 1 to 3 hours.

[0010] Also, reduction-diffusion and nitridation are carried out in a rotating heat treatment furnace. By adding high-temperature-resistant circular balls to prevent lumping of the powder at the same time, the alloy powder can maintain almost the same particle size and morphology as the raw material iron powder even after high-temperature heat treatment. This greatly facilitates the control of the morphology and particle size of anisotropic Sm2Fe 17 N3 magnetic alloy powder.

[0011] Also, reduction-diffusion and nitridation heat treatment are completed in one step. After the reduction-diffusion step is completed, the temperature is directly lowered to the nitridation heat treatment temperature for nitridation, without the need to first cool the product to room temperature after the reduction-diffusion step is completed, then crush, wash, dry, and then heat up again for nitridation as in the conventional method. This not only simplifies the process but also saves energy.

[0012] In S3, it is nitridation heat treatment. The furnace body is cooled to 400 °C to 500 °C, evacuated to below 1×10 -2 Pa, a nitridation protective gas is introduced, held for 1 to 15 hours, evacuated, and cooled after 1 hour of heat treatment.

[0013] In S4, it is washing and drying. The cooled powder and circular balls are taken out and separated, the powder is washed, and dried in a vacuum environment to obtain samarium iron nitride magnetic alloy powder.

[0014] In a preferred embodiment of the present invention, in the method for manufacturing the anisotropic samarium iron nitride magnetic alloy powder, in S1, the particle size of the iron powder satisfies 0.5 μm ≤ D90 ≤ 5 μm, 0.1 μm ≤ D10 ≤ 2 μm, the sphericity of the iron powder is ≥ 0.7, the particle size of the samarium oxide satisfies 0.5 μm ≤ D90 ≤ 5 μm, and 0.1 mm ≤ the size of the calcium particles ≤ 2 mm.

[0015] In a preferred embodiment of the present invention, in the method for manufacturing the anisotropic samarium iron nitride magnetic alloy powder, in S1, the particle size of the iron powder satisfies 1 μm ≤ D90 ≤ 4 μm, 0.8 μm ≤ D10 ≤ 2 μm, the sphericity of the iron powder is ≥ 0.8, the particle size of the samarium oxide satisfies 1 μm ≤ D90 ≤ 4 μm, and 0.1 mm ≤ the size of the calcium particles ≤ 1 mm.

[0016] In a preferred embodiment of the present invention, in the method for manufacturing the anisotropic samarium iron nitride magnetic alloy powder, in S2, the high-temperature resistant circular balls account for 20% - 80% of the volume of the mixed magnetic alloy powder, and the diameter of the high-temperature resistant circular balls is 1 - 5 mm.

[0017] In a preferred embodiment of the present invention, in the method for manufacturing the anisotropic samarium iron nitride magnetic alloy powder, in S2, the high-temperature resistant circular balls account for 40% - 60% of the volume of the mixed magnetic alloy powder, and the diameter of the high-temperature resistant circular balls is 2 - 3 mm.

[0018] In a preferred embodiment of the present invention, in the method for manufacturing the anisotropic samarium iron nitride magnetic alloy powder, in S2, cemented carbide balls, zirconia balls or corundum balls are adopted as the high-temperature resistant circular balls.

[0019] In a preferred embodiment of the present invention, in the method for manufacturing the anisotropic samarium iron nitride magnetic alloy powder, in S2, the furnace body of the heat treatment furnace rotates at a speed of 5 - 20 r / min.

[0020] In a preferred embodiment of the present invention, in the method for manufacturing the anisotropic samarium iron nitride magnetic alloy powder, in S3, as the nitriding protective gas, nitrogen gas, or a mixed gas of nitrogen gas and hydrogen gas, or ammonia gas, or a mixed gas of ammonia gas and hydrogen gas is adopted.

[0021] In a preferred embodiment of the present invention, in the method for manufacturing the anisotropic samarium iron nitride magnetic alloy powder, in S4, the method for taking out and separating the cooled powder and the circular balls is Take out the cooled powder and the circular balls together, wash them with deionized water under the protection of an inert gas, and at the same time separate the high-temperature resistant circular balls with a filter net.

[0022] In a preferred embodiment of the present invention, in the method for manufacturing the anisotropic samarium iron nitride magnetic alloy powder, in S4, the method for washing the powder is Wash the powder several times. After the solution becomes clear, dissolve the remaining calcium or its compound with dilute acetic acid, and further wash with deionized water until the pH value of the washing solution reaches 7, and then wash with absolute ethanol multiple times.

Advantages of the Invention

[0023] The beneficial effects of the embodiments of the present invention are as follows: The Sm2Fe 17 N3 magnetic alloy powder provided by the present invention optimizes the particle size matching and good powder morphology. When the average particle size is the same, the squareness value is significantly improved, so that the magnetic powder exhibits better comprehensive magnetic performance. In the manufacturing method provided by the present invention, reduction diffusion and nitriding are carried out in a rotating heat treatment furnace, and at the same time, high-temperature resistant circular balls for preventing powder agglomeration are added, so that the alloy powder can still maintain almost the same particle size and morphology as the raw iron powder even after high-temperature heat treatment, and anisotropic Sm2Fe 17Greatly facilitates the control over the morphology and particle size of N3 magnetic alloy powder. In the manufacturing method provided by the present invention, reduction diffusion and nitriding heat treatment are completed in one step. After the reduction diffusion step is completed, the temperature is directly lowered to the nitriding heat treatment temperature for nitriding, without the need to first cool the product to room temperature after the reduction diffusion step is completed, crush, wash, dry, and then heat up again for nitriding as in the conventional method. This not only simplifies the process but also saves energy. The present invention employs iron powder with ultra-fine particle size and high sphericity. Since the magnetic alloy powder obtained by the manufacturing method provided by the present invention basically inherits the particle size and morphology of the iron powder, it avoids the fine crushing step that was conventionally carried out to achieve high coercivity, simplifies the process, and avoids the safety problems that are likely to occur by using organic solvents.

Brief Description of the Drawings

[0024] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. The following drawings show some embodiments of the present invention and should not be regarded as limiting the scope. For those skilled in the art, other related drawings can also be obtained based on these drawings without creative effort.

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, hereinafter, with reference to the drawings in the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Generally, the components according to the embodiments of the present invention described in this specification can be arranged and designed in various different configurations.

[0026] The anisotropic samarium iron nitride magnetic alloy powder provided by the first embodiment of the present invention has a chemical formula of Sm2Fe 17 N3 and has a Th2Zn 17 crystal structure. The particle size of the alloy powder satisfies 0.5μm ≦ D90 ≦ 5μm, 0.1μm ≦ D10 ≦ 2μm, the average sphericity of the alloy powder is ≧ 0.7, the coercive force Hcj ≧ 10 kOe, and the angularity Q ≧ 0.5.

[0027] Specifically, for the above anisotropic samarium iron nitride magnetic alloy powder, the particle size of the alloy powder satisfies 1μm ≦ D90 ≦ 4μm, 0.8μm ≦ D10 ≦ 2μm, the average sphericity of the alloy powder is ≧ 0.8, the coercive force Hcj ≧ 13 kOe, and the angularity Q ≧ 0.6.

[0028] Also, the formula for sphericity, sphericity = 4π(3V p / 4π) 2 / 3 / S p represents the sphericity of the particle, where V p is the volume of the particle and S p is the surface area of the particle.

[0029] Also, the formula for angularity, angularity Q = Hc / Hcj, where Hc is the reverse magnetic field strength corresponding to when the residual magnetism of the magnetic powder after saturation magnetization is demagnetized to 90%, and Hcj is the reverse magnetic field strength corresponding to when the residual magnetism of the magnetic powder after saturation magnetization is demagnetized to 0.

[0030] Also, the particle size of the alloy powder, the statistical value of the volume of the particle, and the statistical value of the surface area of the particle are all measured by a laser particle size analyzer.

[0031] Also, the level of the angularity Q value indicates the strength of the demagnetization resistance ability of the magnetic powder.

[0032] The technical effect is that when the average particle size is the same, the aspect ratio value is significantly improved, so that the magnetic powder exhibits better comprehensive magnetic performance.

[0033] Referring to FIG. 1, the method for manufacturing an anisotropic samarium iron nitride magnetic alloy powder provided by the second embodiment of the present invention includes the following steps: In S1, raw material mixing is performed, where iron powder, samarium oxide powder, and calcium grains are uniformly mixed to obtain a mixture.

[0034] Specifically, in S1, the particle size D90 of the iron powder is ≤5 μm, D10 ≥0.5 μm, the sphericity of the iron powder is ≥0.7, the particle size D90 of the samarium oxide is ≤5 μm, and the dimension of the calcium grains is ≤2 mm.

[0035] Specifically, in S1, the particle size D90 of the iron powder is ≤4 μm, D10 ≥0.8 μm, the sphericity of the iron powder is ≥0.8, the particle size D90 of the samarium oxide is ≤4 μm, and the dimension of the calcium grains is ≤1 mm.

[0036] In S2, reduction diffusion heat treatment is performed. The mixture is placed in a rotating heat treatment furnace, and high-temperature resistant circular balls are put in to prevent sintering of the powder. It is evacuated to below 1×10 -2 Pa, and a reduction diffusion protective gas is introduced. The reduction diffusion protective gas can adopt argon gas. The furnace body is heated to 850°C - 950°C and kept warm for 1 - 3 hours.

[0037] Specifically, in S2, the high-temperature resistant circular balls account for 20% - 80% of the volume of the mixed magnetic alloy powder, and the diameter of the high-temperature resistant circular balls is 1 - 5 mm.

[0038] Specifically, in S2, the high-temperature resistant circular balls account for 40% - 60% of the volume of the mixed magnetic alloy powder, and the diameter of the high-temperature resistant circular balls is 2 - 3 mm.

[0039] Specifically, in S2, the high-temperature resistant circular ball is made of cemented carbide ball, zirconia ball or corundum ball.

[0040] Specifically, in S2, the furnace body of the heat treatment furnace rotates at a speed of 5 - 20 r / min.

[0041] Also, reduction diffusion and nitridation are carried out in a rotating heat treatment furnace. By adding high-temperature resistant circular balls to prevent powder agglomeration at the same time, the alloy powder can still maintain almost the same particle size and morphology as the raw iron powder after high-temperature heat treatment, which greatly facilitates the control of the morphology and particle size of anisotropic Sm2Fe 17 N3 magnetic alloy powder.

[0042] In addition, reduction diffusion and nitridation heat treatment are completed in one step. After the reduction diffusion step is completed, the temperature is directly reduced to the nitridation heat treatment temperature for nitridation, without the need to cool the product to room temperature first as in the conventional method, then crush, wash, dry, and then heat up again for nitridation. This not only simplifies the process but also saves energy.

[0043] In S3, for nitridation heat treatment, the furnace body is cooled to 400°C - 500°C, evacuated to below 1×10 -2 Pa, introduce nitridation protective gas, keep warm for 1 - 15 hours, evacuate, and perform cooling after 1 hour of heat treatment.

[0044] Specifically, in S3, the nitridation protective gas is nitrogen gas, or a mixed gas of nitrogen gas and hydrogen gas, or ammonia gas, or a mixed gas of ammonia gas and hydrogen gas.

[0045] In S4, for washing and drying, the cooled powder and circular balls are taken out and separated, the powder is washed, and dried in a vacuum environment to obtain samarium iron nitrogen magnetic alloy powder.

[0046] Specifically, in S4, the method of taking out and separating the cooled powder and circular balls includes the following steps Take out the cooled powder and the circular balls together, wash them with deionized water under the protection of an inert gas, and at the same time separate the high-temperature resistant circular balls with a filter screen.

[0047] Specifically, in S4, the method for washing the powder includes the following steps: Wash the powder several times. After the solution becomes clear, dissolve the remaining calcium or its compounds with dilute acetic acid, and then wash with deionized water until the pH value of the washing solution reaches 7, and further wash with absolute ethanol multiple times.

[0048] Hereinafter, with reference to specific experimental examples and comparative examples, the beneficial effects of the present application will be further described.

[0049] In the following examples, the magnetic properties of the alloy magnetic powder can be detected using a vibrating sample magnetometer (VSM). The morphology of the magnetic powder particles is observed by a scanning electron microscope. The particle size distribution is measured by a laser particle size analyzer.

[0050] Table 1 Particle sizes of iron powder raw materials used in each example and comparative example, and particle sizes and properties of the correspondingly produced magnetic powder [Table 1]

[0051] Example 1 (1) Take 100 g of pure iron powder, and calculate the weight of samarium oxide based on the weight of Sm required to form the alloy, and weigh it exceeding 50%. The weight of the calcium grains is calculated based on the weight of samarium oxide according to the reduction reaction and weighed exceeding 100%. The measured particle size of the iron powder is as shown in Table 1. The D90 of the particle size of samarium oxide is 5 μm or less, and the size of the calcium grains is 2 mm or less. 17

[0052] (2) Put circular balls of cemented carbide with a diameter of 4 mm into the powder, which occupy 50% of the volume of the mixed powder in a rotary furnace, and mix with the powder at 1×10 -2 ​Evacuate to below Pa, fill with argon gas up to 0.05 MPa, rotate the furnace body at a speed of 10 r / min, then heat up to 900 °C and hold for 3 hours.

[0053] (3) Cool the furnace temperature to 420 °C, evacuate to below 1×10 -2 Pa, then introduce a mixed gas of ammonia gas and hydrogen gas with a mixing ratio of 1:1 for nitriding. After nitriding for 3 hours, evacuate and perform heat treatment for 1 hour for homogenization.

[0054] (4) After the powder is cooled, take out the material and place it in a glove box under an argon gas atmosphere. When washing the powder with deionized water, filter the circular balls with a filter net. The circular balls can be washed clean and dried for the next use. Wash the powder with deionized water until the washing liquid becomes almost clear, wash the powder with a dilute acetic acid solution for at least 10 min, further wash the powder with deionized water until the pH value of the washing liquid reaches about 7, finally wash with alcohol three times, heat the wet powder in a vacuum environment to 60 °C and dry for 2 hours, and finally obtain anisotropic Sm2Fe 17 N3 magnetic alloy powder. The measurement results of the powder particle size and magnetic properties are shown in Table 1.

[0055] Example 2 (1) Take 100 g of pure iron powder, calculate the weight of samarium oxide based on the weight of Sm required for all the iron powder to form the alloy, weigh it exceeding 50%, and the weight of calcium grains is calculated based on the weight of samarium oxide according to the reduction reaction and weighed exceeding 100%. The measured particle size of the iron powder is as shown in Table 1, the particle size D90 of samarium oxide is 5 μm or less, and the size of calcium grains is 2 mm or less. 17 (2) Place circular balls made of zirconia material with a diameter of 5 mm in the mixed powder, accounting for 30% of the volume of the mixed powder in the rotary furnace, evacuate to below 1×10

[0056] (2) Evacuate to below Pa, fill with argon gas up to 0.05 MPa, rotate the furnace body at a speed of 5 r / min, then heat up to 950 °C and hold for 1 hour. -2 Pa, fill with argon gas up to 0.05 MPa, rotate the furnace body at a speed of 5 r / min, then heat up to 950 °C and hold for 1 hour.

[0057] (3) Lower the furnace temperature to 420 °C, evacuate to below 1×10 -2 Pa, then introduce a mixed gas of ammonia gas and hydrogen gas with a mixing ratio of 1:1 for nitriding. After nitriding for 3 hours, evacuate and perform heat treatment for 1 hour for homogenization.

[0058] (4) After the powder is cooled, take out the material and place it in a glove box under an argon gas atmosphere. When washing the powder with deionized water, filter the circular balls with a filter mesh. The circular balls can be washed clean and used for the next time after drying. Wash the powder with deionized water until the washing liquid becomes almost clear, wash the powder with a dilute acetic acid solution for at least 10 min, further wash the powder with deionized water until the pH value of the washing liquid reaches about 7, and finally wash it three times with alcohol. Heat the wet powder in a vacuum environment to 60 °C and dry it for 2 hours, and finally obtain anisotropic Sm2Fe 17 N3 magnetic alloy powder. The measurement results of the powder particle size and magnetic properties are shown in Table 1.

[0059] Example 3 (1) Take 100 g of pure iron powder, calculate and obtain the weight of samarium oxide based on the weight of Sm required to form the Sm2Fe 17 alloy, weigh it exceeding 50%, and the weight of calcium grains is calculated and weighed exceeding 100% based on the weight of samarium oxide according to the reduction reaction. The measured particle size of the iron powder is as shown in Table 1, the D90 of the particle size of samarium oxide is 5 μm or less, and the dimension of the calcium grains is 2 mm or less.

[0060] (2) Occupy 70% of the volume of the mixed powder in a rotary furnace, mix circular balls made of silicon carbide material with a diameter of 2 mm into the powder, evacuate to below 1×10 -2 Pa, fill with argon gas to 0.05 MPa, rotate the furnace body at a speed of 15 r / min, then raise the temperature to 900 °C and keep it warm for 3 hours.

[0061] (3) Lower the furnace temperature to 420 °C, evacuate to 1×10 -2After evacuating to below Pa, a mixed gas of ammonia gas and hydrogen gas with a mixing ratio of 1:1 is introduced for nitridation. After nitridation for 3 hours, evacuation is performed, and heat treatment is carried out for 1 hour for homogenization.

[0062] (4) After the powder is cooled, the material is taken out and placed in a glove box under an argon gas atmosphere. When the powder is washed with deionized water, the circular balls are filtered with a filter net. The circular balls can be washed clean and dried for use in the next time. The powder is washed with deionized water until the washing liquid becomes almost clear, washed with a dilute acetic acid solution for at least 10 min, further washed with deionized water until the pH value of the washing liquid reaches about 7, and finally washed three times with alcohol. The wet powder is heated to 60 °C in a vacuum environment and dried for 2 hours. Finally, anisotropic Sm2Fe 17 N3 magnetic alloy powder is obtained. The measurement results of the particle size and magnetic properties of the powder are shown in Table 1.

[0063] Example 4 (1) Take 100 g of pure iron powder, and calculate the weight of samarium oxide based on the weight of Sm required to form the alloy with all the iron powder, and weigh it exceeding 50%. The weight of calcium grains is calculated based on the weight of samarium oxide according to the reduction reaction and weighed exceeding 100%. The measured particle size of the iron powder is as shown in Table 1. The particle size D90 of samarium oxide is 5 μm or less, and the size of calcium grains is 2 mm or less. 17

[0064] (2) Occupy 80% of the volume of the mixed powder in a rotary furnace, mix circular balls made of zirconia material with a diameter of 1 mm into the powder, evacuate to below 1×10 -2 Pa, fill with argon gas up to 0.05 MPa, rotate the furnace body at a speed of 20 r / min, then heat up to 900 °C and keep it warm for 3 hours.

[0065] (3) Cool down the furnace temperature to 420 °C, 1×10 -2After evacuating to below Pa, a mixed gas of ammonia gas and hydrogen gas with a mixing ratio of 1:1 is introduced for nitridation. After 3 hours of nitridation, evacuation is carried out, and heat treatment is performed for 1 hour for homogenization.

[0066] (4) After the powder is cooled, the material is taken out and placed in a glove box under an argon gas atmosphere. When the powder is washed with deionized water, the circular balls are filtered with a filter net. The circular balls can be washed clean and used for the next time after drying. The powder is washed with deionized water until the washing liquid becomes almost clear, the powder is washed with a dilute acetic acid solution for at least 10 min, the powder is further washed with deionized water until the pH value of the washing liquid reaches about 7, and finally the powder is washed three times with alcohol. The wet powder is heated to 60 °C in a vacuum environment and dried for 2 hours. Finally, anisotropic Sm2Fe 17 N3 magnetic alloy powder is obtained. The measurement results of the particle size and magnetic properties of the powder are shown in Table 1.

[0067] Example 5 (1) Take 100 g of pure iron powder, and calculate the weight of samarium oxide based on the weight of Sm required to form the alloy for all the iron powder, and weigh it exceeding 50%. The weight of calcium grains is calculated based on the weight of samarium oxide according to the reduction reaction and weighed exceeding 100%. The measured particle size of the iron powder is as shown in Table 1. The particle size D90 of samarium oxide is 5 μm or less, and the size of calcium grains is 2 mm or less. 17

[0068] (2) Fill 60% of the volume of the mixed powder in a rotary furnace, mix circular balls of cemented carbide with a diameter of 3 mm into the powder, evacuate to below 1×10 -2 Pa, fill with argon gas up to 0.05 MPa, rotate the furnace body at a speed of 15 r / min, then heat up to 900 °C and keep it warm for 2 hours.

[0069] (3) Cool the furnace temperature to 420 °C, evacuate to below 1×10 -2 Pa, then introduce pure ammonia gas for nitridation. After 1 hour of nitridation, evacuate and perform heat treatment for 1 hour for homogenization.

[0070] (4) After the powder is cooled, the material is taken out and placed in a glove box under an argon gas atmosphere. When the powder is washed with deionized water, the circular balls are filtered with a filter net. The circular balls can be cleaned and dried and then used for the next time. Wash the powder with deionized water until the washing liquid becomes almost clear, wash the powder with a dilute acetic acid solution for at least 10 min, further wash the powder with deionized water until the pH value of the washing liquid reaches about 7, and finally wash it three times with alcohol. Heat the wet powder in a vacuum environment to 60 °C and dry it for 2 hours. Finally, anisotropic Sm2Fe 17 N3 magnetic alloy powder is obtained. The measurement results of the particle size and magnetic properties of the powder are shown in Table 1.

[0071] Example 6 (1) Take 100 g of pure iron powder, and based on the weight of Sm required for all the iron powder to form Sm2Fe 17 alloy, calculate to obtain the weight of samarium oxide and weigh it exceeding 50%. The weight of calcium grains is calculated based on the weight of samarium oxide according to the reduction reaction and weighed exceeding 100%. The measured particle size of the iron powder is as shown in Table 1. The particle size D90 of samarium oxide is 5 μm or less, and the dimension of calcium grains is 2 mm or less.

[0072] (2) Occupy 80% of the volume of the mixed powder in a rotary furnace, mix circular balls made of zirconia material with a diameter of 1 mm into the powder, evacuate to 1×10 -2 Pa or less, fill with argon gas to 0.05 MPa, rotate the furnace body at a speed of 20 r / min, then heat up to 900 °C and keep it warm for 3 hours.

[0073] (3) Cool the furnace temperature to 500 °C, evacuate to 1×10 -2 Pa or less, then introduce pure nitrogen gas for nitriding. After nitriding for 15 hours, evacuate and perform heat treatment for 1 hour for homogenization.

[0074] (4) After the powder is cooled, the material is taken out and placed in a glove box under an argon gas atmosphere. When the powder is washed with deionized water, the circular balls are filtered with a filter screen. The circular balls can be washed clean and dried for the next use. Wash the powder with deionized water until the washing liquid becomes almost clear, wash the powder with a dilute acetic acid solution for at least 10 min, further wash the powder with deionized water until the pH value of the washing liquid reaches about 7, and finally wash it three times with alcohol. Heat the wet powder in a vacuum environment to 60 °C and dry it for 2 hours. Finally, anisotropic Sm2Fe 17 N3 magnetic alloy powder is obtained. The measurement results of the particle size and magnetic properties of the powder are shown in Table 1.

[0075] Example 7 (1) Take 100 g of pure iron powder. Based on the weight of Sm required for all the iron powder to form the Sm2Fe 17 alloy, calculate the weight of samarium oxide and weigh it exceeding 50%. The weight of calcium grains is calculated based on the weight of samarium oxide according to the reduction reaction and weighed exceeding 100%. The measured particle size of the iron powder is as shown in Table 1. The particle size D90 of samarium oxide is 5 μm or less, and the size of calcium grains is 2 mm or less.

[0076] (2) Occupy 50% of the volume of the mixed powder in a rotary furnace, mix circular balls of cemented carbide with a diameter of 4 mm into the powder, evacuate to 1×10 -2 Pa or less, fill with argon gas up to 0.05 MPa, rotate the furnace body at a speed of 10 r / min, then heat up to 880 °C and keep it warm for 2 hours.

[0077] (3) Cool the furnace temperature to 420 °C, evacuate to 1×10 -2 Pa or less, then introduce a mixed gas of ammonia gas and hydrogen gas with a mixing ratio of 1:1 for nitriding. After nitriding for 1.5 hours, evacuate and perform heat treatment for 1 hour for homogenization.

[0078] (4) After the powder is cooled, the material is taken out and placed in a glove box under an argon gas atmosphere. When the powder is washed with deionized water, the circular balls are filtered with a filter mesh. The circular balls can be washed cleanly and dried for the next use. Wash the powder with deionized water until the washing liquid becomes almost clear, wash the powder with a dilute acetic acid solution for at least 10 min, further wash the powder with deionized water until the pH value of the washing liquid reaches about 7, and finally wash it three times with alcohol. Heat the wet powder in a vacuum environment to 60 °C and dry it for 2 hours. Finally, anisotropic Sm2Fe 17 N3 magnetic alloy powder is obtained. The measurement results of the particle size and magnetic properties of the powder are shown in Table 1.

[0079] Example 8 (1) Take 100 g of pure iron powder. Based on the weight of Sm required for all the iron powder to form the Sm2Fe 17 alloy, calculate to obtain the weight of samarium oxide and weigh it exceeding 50%. The weight of the calcium grains is calculated based on the weight of samarium oxide according to the reduction reaction and weighed exceeding 100%. The measured particle size of the iron powder is as shown in Table 1. The particle size D90 of the samarium oxide is 5 μm or less, and the dimension of the calcium grains is 2 mm or less.

[0080] (2) Occupy 50% of the volume of the mixed powder in a rotary furnace, mix circular balls of cemented carbide with a diameter of 4 mm into the powder, evacuate to 1×10 -2 Pa or less, fill with argon gas to 0.05 MPa, rotate the furnace body at a speed of 10 r / min, then heat up to 860 °C and keep it warm for 1.5 hours.

[0081] (3) Cool the furnace temperature to 420 °C, evacuate to 1×10 -2 Pa or less, then introduce a mixed gas of ammonia gas and hydrogen gas with a mixing ratio of 1:1 for nitriding. After nitriding for 1.5 hours, evacuate and perform heat treatment for 1 hour for homogenization.

[0082] (4) After the powder is cooled, the material is taken out and placed in a glove box under an argon gas atmosphere. When the powder is washed with deionized water, the circular balls are filtered with a filter screen. The circular balls can be cleaned and dried and then used for the next time. The powder is washed with deionized water until the washing liquid becomes almost clear, washed with a dilute acetic acid solution for at least 10 min, further washed with deionized water until the pH value of the washing liquid reaches about 7, and finally washed three times with alcohol. The wet powder is heated to 60 °C in a vacuum environment and dried for 2 hours. Finally, anisotropic Sm2Fe 17 N3 magnetic alloy powder is obtained. The measurement results of the particle size and magnetic properties of the powder are shown in Table 1.

[0083] Example 9 (1) Take 100 g of pure iron powder. Based on the weight of Sm required for all the iron powder to form the Sm2Fe 17 alloy, calculate to obtain the weight of samarium oxide and weigh it exceeding 50%. The weight of the calcium grains is calculated based on the weight of samarium oxide according to the reduction reaction and weighed exceeding 100%. The measured particle size of the iron powder is as shown in Table 1. The particle size D90 of the samarium oxide is 5 μm or less, and the size of the calcium grains is 2 mm or less.

[0084] (2) Occupy 50% of the volume of the mixed powder in a rotary furnace, mix circular balls of cemented carbide with a diameter of 4 mm into the powder, evacuate to 1×10 -2 Pa or less, fill with argon gas up to 0.05 MPa, rotate the furnace body at a speed of 10 r / min, then heat up to 850 °C and keep it warm for 2 hours.

[0085] (3) Cool the furnace temperature to 400 °C, evacuate to 1×10 -2 Pa or less, then introduce a mixed gas of ammonia gas and hydrogen gas with a mixing ratio of 1:1 for nitriding. After nitriding for 2 hours, evacuate and perform heat treatment for 1 hour for homogenization.

[0086] (4) After the powder is cooled, the material is taken out and placed in a glove box under an argon gas atmosphere. When the powder is washed with deionized water, the circular balls are filtered with a filter screen. The circular balls can be cleaned and dried and then used for the next time. The powder is washed with deionized water until the washing liquid becomes almost clear, washed with a dilute acetic acid solution for at least 10 min, further washed with deionized water until the pH value of the washing liquid reaches about 7, and finally washed three times with alcohol. The wet powder is heated to 60 °C in a vacuum environment and dried for 2 hours. Finally, anisotropic Sm2Fe 17 N3 magnetic alloy powder is obtained. The measurement results of the particle size and magnetic properties of the powder are shown in Table 1.

[0087] Example 10 (1) Take 100 g of pure iron powder. Based on the weight of Sm required for all the iron powder to form the Sm2Fe 17 alloy, calculate the weight of samarium oxide and weigh it exceeding 50%. The weight of calcium grains is calculated based on the weight of samarium oxide according to the reduction reaction and weighed exceeding 100%. The measured particle size of the iron powder is as shown in Table 1. The particle size D90 of samarium oxide is 5 μm or less, and the dimension of calcium grains is 2 mm or less.

[0088] (2) Occupy 50% of the volume of the mixed powder in a rotary furnace, mix circular balls of cemented carbide with a diameter of 4 mm into the powder, evacuate to 1×10 -2 Pa or less, fill with argon gas up to 0.05 MPa, rotate the furnace body at a speed of 10 r / min, then heat up to 870 °C and keep it warm for 1 hour.

[0089] (3) Lower the furnace temperature to 420 °C, evacuate to 1×10 -2 Pa or less, then introduce a mixed gas of ammonia gas and hydrogen gas with a mixing ratio of 1:1 for nitriding. After nitriding for 1.5 hours, evacuate and perform heat treatment for 1 hour for homogenization.

[0090] (4) After the powder is cooled, the material is taken out and placed in a glove box under an argon gas atmosphere. When the powder is washed with deionized water, the circular balls are filtered with a filter mesh. The circular balls can be cleaned and dried and then used for the next time. Wash the powder with deionized water until the washing liquid becomes almost clear, wash the powder with a dilute acetic acid solution for at least 10 min, further wash the powder with deionized water until the pH value of the washing liquid reaches about 7, and finally wash it three times with alcohol. Heat the wet powder in a vacuum environment to 60 °C and dry it for 2 hours to finally obtain anisotropic Sm2Fe17N3 magnetic alloy powder. The measurement results of the particle size and magnetic properties of the powder are shown in Table 1.

[0091] Comparative proportion 1 (1) Take 100 g of pure iron powder, and calculate the weight of samarium oxide based on the weight of Sm required to form the alloy, and weigh it exceeding 50%. The weight of calcium grains is calculated based on the weight of samarium oxide according to the reduction reaction and weighed exceeding 100%. The measured particle size of the iron powder is as shown in Table 1. The particle size D90 of samarium oxide is 5 μm or less, and the size of calcium grains is 2 mm or less. 17

[0092] (2) Occupy 50% of the volume of the mixed powder in a rotary furnace, mix circular balls of cemented carbide with a diameter of 4 mm into the powder, evacuate to below 1×10 -2 Pa, fill with argon gas to 0.05 MPa, rotate the furnace body at a speed of 10 r / min, then heat up to 900 °C and keep it warm for 3 hours.

[0093] (3) Lower the furnace temperature to 420 °C, evacuate to below 1×10 -2 Pa, then introduce a mixed gas of ammonia gas and hydrogen gas with a mixing ratio of 1:1 for nitriding. After nitriding for 3 hours, evacuate and perform heat treatment for 1 hour for homogenization.

[0094] (4) After the powder has cooled, the material is taken out and placed in a glove box under an argon gas atmosphere. The powder is washed with deionized water and the circular balls are filtered through a filter net. The circular balls are cleaned and can be used again after drying. The powder is washed with deionized water until the washing liquid is almost clear, then washed with dilute acetic acid solution for at least 10 min, then washed with deionized water until the washing liquid pH value is about 7, and finally washed with alcohol three times. The wet powder is heated to 60 °C in a vacuum environment and dried for 2 hours, and finally the anisotropic Sm2Fe 17 Obtain N3 magnetic alloy powder.

[0095] (5) The obtained magnetic alloy powder is placed in a ball milling pot and ball milled for 20 hours under the conditions of a ball material ratio of 30:1, anhydrous ethanol as a medium, and a rotation speed of 300 r / min. The powder and the solvent are separated in a glove box and vacuum dried to obtain the final anisotropic SmFe 17 Obtain N3 magnetic alloy powder. The particle size and magnetic properties of the powder are shown in Table 1.

[0096] Comparison 2 (1) Take 100g of pure iron powder. All the iron powder is SmFe. 17 Based on the weight of Sm required to produce the alloy, the weight of samarium oxide is calculated and weighed out to be more than 50%, and the weight of calcium particles is calculated and weighed out to be more than 100% based on the weight of samarium oxide according to the reduction reaction. The measured particle size of the iron powder is as shown in Table 1, the particle size D90 of samarium oxide is 5 μm or less, and the size of the calcium particles is 2 mm or less.

[0097] (2) The powder is mixed in a rotary kiln with a diameter of 4 mm, and the powder is mixed with a round ball of cemented carbide with a diameter of 1 × 10 -2 The furnace is evacuated to a pressure of 0.05 Pa or less, and then filled with argon gas up to 0.05 MPa. The furnace body is rotated at a speed of 10 r / min, and then the temperature is raised to 900°C and maintained at that temperature for 3 hours.

[0098] (3) The furnace temperature is lowered to 420°C and 1×10 -2After evacuating to below Pa, a mixed gas of ammonia gas and hydrogen gas with a mixing ratio of 1:1 is introduced for nitridation. After 3 hours of nitridation, evacuation is performed, and heat treatment is carried out for 1 hour for homogenization.

[0099] (4) After the powder is cooled, the material is taken out and placed in a glove box under an argon gas atmosphere. When the powder is washed with deionized water, the circular balls are filtered with a filter mesh. The circular balls can be washed clean and dried for use in the next time. The powder is washed with deionized water until the washing liquid becomes almost clear, washed with a dilute acetic acid solution for at least 10 min, further washed with deionized water until the pH value of the washing liquid reaches about 7, and finally washed three times with alcohol. The wet powder is heated to 60 °C in a vacuum environment and dried for 2 hours. Finally, anisotropic Sm2Fe 17 N3 magnetic alloy powder is obtained.

[0100] (5) The obtained magnetic alloy powder is put into a ball milling pot, ball-milled for 20 hours under the conditions that the ball material ratio is 30:1, absolute ethanol is used as the medium, and the rotation speed is 300 r / min. The powder and the solvent are separated in a glove box and vacuum dried. Finally, anisotropic Sm2Fe 17 N3 magnetic alloy powder is obtained. The measurement results of the particle size and magnetic properties of the powder are shown in Table 1.

[0101] Comparative Example 3 (1) Take 100 g of pure iron powder, calculate the weight of samarium oxide based on the weight of Sm required for all the iron powder to form the alloy, and weigh it exceeding 50%. The weight of calcium grains is calculated based on the weight of samarium oxide according to the reduction reaction and weighed exceeding 100%. The measured particle size of the iron powder is as shown in Table 1. The D90 of the particle size of samarium oxide is 5 μm or less, and the size of calcium grains is 2 mm or less. 17

[0102] (2) Occupy 50% of the volume of the mixed powder in a rotary furnace, mix circular balls of cemented carbide with a diameter of 4 mm into the powder, 1×10 (2) Occupy 50% of the volume of the mixed powder in a rotary furnace, mix circular balls of cemented carbide with a diameter of 4 mm into the powder, 1×10 -2Evacuate to below Pa, fill with argon gas up to 0.05 MPa, rotate the furnace body at a speed of 10 r / min, then heat up to 860 °C and hold for 1.5 hours.

[0103] (3) Cool the furnace temperature to 420 °C, evacuate to below 1×10 -2 Pa, then introduce a mixed gas of ammonia gas and hydrogen gas with a mixing ratio of 1:1 for nitriding. After nitriding for 1.5 hours, evacuate and perform heat treatment for 1 hour for homogenization.

[0104] (4) After the powder is cooled, take out the material and place it in a glove box under an argon gas atmosphere. When washing the powder with deionized water, filter the circular balls with a filter net. The circular balls can be washed clean and used for the next time after drying. Wash the powder with deionized water until the washing liquid becomes almost clear, wash the powder with dilute acetic acid solution for at least 10 min, further wash the powder with deionized water until the pH value of the washing liquid reaches about 7, and finally wash with alcohol three times. Heat the wet powder in a vacuum environment to 60 °C and dry for 2 hours. Finally, anisotropic Sm2Fe 17 N3 magnetic alloy powder is obtained.

[0105] (5) Put the obtained magnetic alloy powder into a ball milling pot, perform ball milling for 20 hours under the conditions that the ball material ratio is 30:1, anhydrous ethanol is used as the medium, and the rotation speed is 300 r / min. Separate the powder and the solvent in a glove box and perform vacuum drying to finally obtain anisotropic Sm2Fe 17 N3 magnetic alloy powder. The measurement results of the particle size and magnetic properties of the powder are shown in Table 1.

[0106] As can be seen from Examples 1 to 10 in Table 1, by the manufacturing method provided by the present invention, the powder characteristics of the raw material iron powder can be effectively maintained, thereby obtaining a large coercive force and a high squareness. As can be seen from the examples and the comparative examples, the anisotropic Sm2Fe 17 N3 magnetic powder having a good particle size distribution and morphology has better performance.

[0107] Embodiments of the present invention seek protection for anisotropic samarium iron nitride magnetic alloy powder and its manufacturing method, and have the following effects: 1. The Sm2Fe 17 N3 magnetic alloy powder provided by the present invention optimizes the particle size matching and good powder morphology. When the average particle size is the same, the squareness value is significantly improved. As a result, the magnetic powder exhibits better comprehensive magnetic performance.

[0108] 2. In the manufacturing method provided by the present invention, reduction diffusion and nitridation are carried out in a rotating heat treatment furnace, and at the same time, high-temperature-resistant circular balls that prevent powder agglomeration are added. Thus, the alloy powder can still maintain a particle size and morphology similar to those of the raw iron powder even after high-temperature heat treatment, greatly facilitating the control of the morphology and particle size of the anisotropic Sm2Fe 17 N3 magnetic alloy powder.

[0109] 3. In the manufacturing method provided by the present invention, reduction diffusion and nitridation heat treatment are completed in one step. After the reduction diffusion step is completed, the temperature is directly lowered to the nitridation heat treatment temperature for nitridation, without the need to first cool the product to room temperature after the reduction diffusion step is completed, then crush, wash, dry, and then heat up again for nitridation as in the conventional method. This not only simplifies the process but also saves energy.

[0110] 4. The present invention employs iron powder with ultra-fine particle size and high sphericity. Since the magnetic alloy powder obtained by the manufacturing method provided by the present invention basically inherits the particle size and morphology of the iron powder, the step of fine grinding that was conventionally carried out to achieve high coercivity is avoided, simplifying the process and avoiding safety problems that are likely to occur by using organic solvents.

[0111] It should be understood that the above specific embodiments of the present invention are merely for illustrative explanation or for explaining the principles of the present invention, and do not limit the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present invention should all be included within the protection scope of the present invention. Furthermore, it is intended that the scope be defined by the claims and include all changes within the meaning and scope equivalent to the claims.

Claims

1. The chemical formula is Sm ２ Fe １７ N ３ And Th ２ Zinc １７ The alloy powder has a crystal structure, the grain size of the alloy powder is 1 μm≦D90≦4 μm, 0.8 μm≦D10≦2 μm, the average sphericity of the alloy powder is ≧0.8, and the coercive force H ｃｊ ≧13 kOe, and squareness Q≧0.

6.

2. A method for producing anisotropic samarium iron nitrogen magnetic alloy powder, comprising the steps of: In S1, raw material mixing is performed by uniformly mixing iron powder, samarium oxide powder, and calcium particles to obtain a mixture, the particle size of the iron powder being 0.5 μm≦D90≦5 μm, 0.1 μm≦D10≦2 μm, the sphericity of the iron powder being ≧0.7, the particle size of the samarium oxide being 0.5 μm≦D90≦5 μm, and 0.1 mm≦calcium particle size≦2 mm; In S2, a reduction diffusion heat treatment is performed by placing the mixture in a rotating heat treatment furnace, placing a high-temperature resistant circular ball therein, and distributing the mixture in a 1×10 －２ The furnace is evacuated to a pressure of 0.1 Pa or less, a reducing and diffusing protective gas is introduced, the furnace body is heated to 850°C to 950°C, and kept at that temperature for 1 to 3 hours. In S3, a nitriding heat treatment is performed by cooling the furnace body to 400°C to 500°C and －２ The chamber is evacuated to a pressure of 0.1 Pa or less, a nitriding protective gas is introduced, the chamber is kept warm for 1 to 15 hours, the chamber is evacuated, the chamber is heat-treated for 1 hour, and then cooled. In step S4, the method for producing anisotropic samarium iron nitrogen magnetic alloy powder is characterized in that the cooled powder and the circular balls are taken out and separated, the powder is washed, and dried in a vacuum environment to obtain samarium iron nitrogen magnetic alloy powder.

3. The method for producing anisotropic samarium iron nitrogen magnetic alloy powder according to claim 2, characterized in that in S1, the particle size of the iron powder is 1 μm≦D90≦4 μm, 0.8 μm≦D10≦2 μm, the sphericity of the iron powder is ≧0.8, the particle size of the samarium oxide is 1 μm≦D90≦4 μm, and 0.1 mm≦calcium particle size≦1 mm.

4. In S2, the high-temperature resistant circular balls account for 20% to 80% of the volume of the mixed magnetic alloy powder, and the diameter of the high-temperature resistant circular balls is 1 to 5 mm. The method for manufacturing anisotropic samarium iron nitride magnetic alloy powder according to claim 2, characterized in that.

5. In S2, the high-temperature resistant circular balls account for 40% to 60% of the volume of the mixed magnetic alloy powder, and the diameter of the high-temperature resistant circular balls is 2 to 3 mm. The method for manufacturing anisotropic samarium iron nitride magnetic alloy powder according to claim 2, characterized in that.

6. In S2, the high-temperature resistant circular balls are made of cemented carbide balls, zirconia balls or corundum balls. The method for manufacturing anisotropic samarium iron nitride magnetic alloy powder according to claim 2, characterized in that.

7. In S2, the furnace body of the heat treatment furnace rotates at a speed of 5 to 20 r / min. The method for manufacturing anisotropic samarium iron nitride magnetic alloy powder according to claim 2, characterized in that.

8. In S3, the nitriding protective gas is nitrogen gas, or a mixed gas of nitrogen gas and hydrogen gas, or ammonia gas, or a mixed gas of ammonia gas and hydrogen gas. The method for manufacturing anisotropic samarium iron nitride magnetic alloy powder according to claim 2, characterized in that.

9. In S4, the method for taking out and separating the cooled powder and circular balls is taking out the cooled powder and circular balls together, washing them with deionized water under the protection of inert gas, and simultaneously separating the high-temperature resistant circular balls with a filter screen. The method for manufacturing anisotropic samarium iron nitride magnetic alloy powder according to claim 2, characterized in that.

10. In S4, the method for washing the powder is The method for manufacturing anisotropic samarium iron nitride magnetic alloy powder according to claim 2, comprising washing the powder several times, after the solution becomes clear, dissolving the remaining calcium or its compound with dilute acetic acid, further washing with deionized water until the pH value of the washing liquid reaches 7, and further washing with absolute ethanol multiple times.

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