Directional al-ni-co magnetic steel and method for manufacturing the same

Abstract

The present application relates to a kind of directional aluminum-nickel-cobalt magnetic steel and its preparation method, preparation method includes the following steps: opening temperature regulating medium, using the temperature regulating medium adjusts the temperature of directional crystallizer panel to 10-25 ℃;The molten steel liquid of smelting is cast to preheated sand mould, after casting, heat preservation is carried out, and the temperature regulating medium is closed in 5min, then continue heat preservation 20-35min after, the forming hot blank is taken out and is annealed;Then the blank after annealing is sequentially roughed, heat treated, magnetized and tempered, obtain directional aluminum-nickel-cobalt magnetic steel.The present application controls directional solidification cooling process, effectively adjusts heat exchange amount and heat exchange rate in cooling process, so as to obtain the directional aluminum-nickel-cobalt magnetic steel of excellent magnetic property and integrated crack-free, especially suitable for the preparation of large size directional aluminum-nickel-cobalt magnetic steel;Meanwhile, the preparation method of the present application is strong in operability, good repeatability, and simple and convenient.

Description

Technical Field

[0001] This invention relates to the field of permanent magnet materials technology, and in particular to a directional AlNiCo magnet and its preparation method. Background Technology

[0002] AlNiCo permanent magnets play an irreplaceable role in large electrical equipment such as nuclear power, wind power, industrial automation, and aerospace due to their good magnetic properties, temperature stability, and corrosion resistance.

[0003] Directed AlNiCo magnets are typically manufactured using a high-temperature casting method called "cold plate, hot mold." Molten steel poured into a sand mold is solidified directionally on a directional plate for a sufficient time. After cooling to room temperature, the sand mold is removed to obtain a rough ingot. Subsequent processing yields the final product. Obtaining sufficiently tall, coarse, and straight columnar crystals in the AlNiCo ingot is the only way to improve the performance of directional AlNiCo magnets. Maintaining a continuous temperature gradient between the sand mold and the directional plate during directional solidification is a necessary condition for the columnar crystals to penetrate the ingot. However, in actual production, the industry currently widely uses a process that employs low-carbon steel as the orientation plate and a cooling water column underneath to manufacture oriented AlNiCo magnets. This process leads to a contradiction between formability and magnetic properties. Generally, the higher the performance requirements of AlNiCo magnets, the taller, coarser, and straighter the internal columnar crystal structure needs to be, which inherently increases the brittleness of the AlNiCo magnets themselves. In addition, the rapid cooling during the orientation casting process and the cooling process after casting further increase the internal stress of the AlNiCo magnets, making it extremely difficult to manufacture the magnets in a crack-free, integrated manner. This is especially true for larger AlNiCo magnets, which are more prone to cracking during the preparation process to improve magnetic properties. Although the industry can also produce large oriented castings using zone melting, this process has high equipment requirements and is not economically viable. Summary of the Invention

[0004] Therefore, it is necessary to provide a directional AlNiCo magnet and its preparation method to address the above problems. The preparation method can produce an integrated, crack-free directional AlNiCo magnet with excellent magnetic properties. Moreover, the preparation method is highly operable, has good repeatability, and is simple and convenient. It is especially suitable for preparing large-size directional AlNiCo magnets.

[0005] A method for preparing oriented AlNiCo magnets includes the following steps:

[0006] Turn on the temperature regulating medium and use the temperature regulating medium to adjust the temperature of the directional crystallizer panel to 10℃-25℃;

[0007] The molten steel is poured into a preheated sand mold. After casting, the mold is kept at a certain temperature, and the temperature regulating medium is turned off within 5 minutes. Then, the mold is kept at a certain temperature for 20-35 minutes. The hot blank is then removed and annealed.

[0008] The annealed blank is then subjected to rough machining, heat treatment, magnetization and tempering in sequence to obtain oriented aluminum-nickel-cobalt magnets.

[0009] In one embodiment, the temperature of the directional crystallizer panel is 12°C-25°C.

[0010] In one embodiment, the temperature difference between any two points on the directional crystallizer panel is less than or equal to 2°C.

[0011] In one embodiment, the temperature of the temperature regulating medium is 10°C-25°C.

[0012] In one embodiment, the temperature of the preheated sand mold is 1500℃-1530℃.

[0013] In one embodiment, during the annealing process, the hot blank is placed in an annealing apparatus at a temperature of 800°C-900°C, heated to 1000°C-1060°C at a rate of 60°C / h-100°C / h, held at that temperature for 3h-4h, and then cooled to ambient temperature.

[0014] In one embodiment, during the heat treatment step, the annealed blank is held at 800°C-900°C for 30-50 minutes, then solution treated at 1260°C-1300°C for 20-40 minutes, and finally the blank is removed and cooled to 800°C-900°C.

[0015] In one embodiment, during the magnetization process, the heat-treated blank is placed in a magnetic field, kept warm, and magnetized for 20-30 minutes.

[0016] In one embodiment, during the tempering process, the magnetized blank is sequentially kept at 610℃-625℃ for 3h-4h, at 580℃-595℃ for 4h-6h, and at 550℃-565℃ for 4h-6h, then cooled to 200℃-300℃ at a cooling rate of 1℃ / min-3℃ / min, and finally cooled to ambient temperature.

[0017] An oriented AlNiCo magnet prepared by the method described above.

[0018] Before casting molten steel, this invention uses a temperature regulating medium to adjust the temperature of the directional crystallizer panel, ensuring it is at a specific temperature. This allows the directional crystallizer panel to provide stable and uniform heat exchange during cooling, effectively controlling the temperature gradient between the panel and the sand mold. This is beneficial for obtaining large, straight columnar crystal structures that can penetrate the blank. Furthermore, the temperature regulating medium is turned off within 5 minutes after casting. Utilizing the relatively small heat transfer coefficient of the directional crystallizer panel, "slow cooling" is achieved during directional solidification, allowing the columnar crystals to grow in a planar manner. This improves the magnetic properties of the directional AlNiCo magnets. The "slow cooling" process also reduces cracking caused by rapid cooling, resulting in integrated, crack-free directional AlNiCo magnets.

[0019] Therefore, by controlling the directional solidification cooling process, the present invention effectively adjusts the heat exchange and heat exchange rate during the cooling process, thereby obtaining directional AlNiCo magnets with excellent magnetic properties and integrated crack-free structure, which is especially suitable for the preparation of large-size directional AlNiCo magnets. At the same time, the preparation method of the present invention is highly operable, has good repeatability, and is simple and convenient. Detailed Implementation

[0020] To facilitate understanding of the present invention, it will be described in more detail below. However, it should be understood that the present invention can be implemented in many different forms and is not limited to the embodiments or examples described herein. Rather, these embodiments or examples are provided to make the disclosure of the present invention more thorough and complete.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments or examples only and is not intended to limit the invention. The optional scope of the term "and / or" as used herein includes any one of two or more of the related listed items, as well as any and all combinations of the related listed items, including any two related listed items, any more related listed items, or a combination of all related listed items.

[0022] This invention provides a method for preparing oriented AlNiCo magnets, comprising the following steps:

[0023] S1, turn on the temperature regulating medium, and use the temperature regulating medium to adjust the temperature of the directional crystallizer panel to 10℃-25℃;

[0024] S2, pour the molten steel into the preheated sand mold, keep it at a constant temperature after casting, turn off the temperature regulating medium within 5 minutes, and then continue to keep it at a constant temperature for 20-35 minutes. Then take out the formed hot blank and anneal it.

[0025] S3, and then the annealed blank is subjected to rough machining, heat treatment, magnetization and tempering in sequence to obtain oriented aluminum nickel cobalt magnets.

[0026] In the preparation process of the directional aluminum-nickel-cobalt magnet of the present invention, the apparatus used is the same as that in the prior art. The difference is that in step S1, before the molten steel is poured, the temperature of the directional crystallizer panel is adjusted by a temperature regulating medium to make it at a specific temperature. During the casting process, the temperature regulating medium under the directional crystallizer panel is still turned on. Thus, during the cooling process, the directional crystallizer panel can continuously provide stable and uniform heat exchange, thereby effectively controlling the temperature gradient between the directional crystallizer panel and the sand mold. This is beneficial to obtaining a coarse, straight columnar crystal structure that can penetrate the blank.

[0027] It should be noted that the present invention can also flexibly control the temperature of the temperature regulating medium and the timing of its shutdown for oriented AlNiCo magnets of different sizes, thereby imparting different heat absorption capacity to the oriented crystallizer panel. This effectively controls the temperature gradient between the oriented crystallizer panel and the sand mold, resulting in AlNiCo magnets with different orientation heights. This makes the preparation method described in the present invention applicable to the preparation of large-sized oriented AlNiCo magnets.

[0028] Furthermore, before casting molten steel, the present invention ensures that the temperature of the directional crystallizer panel is within a specific range, thereby reducing the problem of unstable columnar crystal growth and limited height caused by unstable flow of the temperature regulating medium during operation, which is beneficial to obtaining a coarse and straight columnar crystal structure.

[0029] The temperature of the temperature regulating medium described in this invention is preferably between 10℃ and 25℃. This invention does not limit the specific selection of the temperature regulating medium, as long as it can effectively regulate the temperature of the directional crystallizer panel. Water is the preferred temperature regulating medium in this invention.

[0030] Preferably, the temperature of the directional crystallizer panel is adjusted to 12°C-25°C using the temperature regulating medium. This temperature is beneficial for obtaining coarse, straight columnar crystals and reduces the proportion of cracks generated during the preparation of directional AlNiCo magnets.

[0031] Preferably, the temperature difference between any two points on the directional crystallizer panel is less than or equal to 2°C, which helps to provide a more uniform temperature on the directional crystallizer panel. This further reduces the proportion of cracks caused by uneven heating at the bottom of the AlNiCo magnet and promotes the growth of columnar crystals in a planar manner, thereby further improving the magnetic properties.

[0032] In step S2, after casting is completed, the temperature regulating medium is turned off within 5 minutes. By utilizing the small heat transfer coefficient of the directional crystallizer panel itself, the purpose of "slow cooling" during directional solidification is achieved, which allows columnar crystals to grow in a planar manner. This is beneficial to improving the magnetic properties of AlNiCo magnets. Furthermore, the "slow cooling" process can reduce cracking problems caused by excessively rapid cooling, which is conducive to obtaining integrated crack-free directional AlNiCo magnets.

[0033] In addition, after the temperature regulating medium is turned off, the holding time is not more than 35 minutes, and then the hot blank is taken out and annealed immediately. Compared with the process of cooling to room temperature and then annealing (the holding time is much longer than 35 minutes), the temperature difference of the hot blank in this invention is smaller from the completion of casting to the annealing process, which is more conducive to obtaining integrated crack-free directional AlNiCo magnets.

[0034] Preferably, the molten steel can be obtained by smelting conventional raw materials used for preparing AlNiCo magnets. For example, by mass fraction, the raw materials for the molten steel include 8%-9% Al, 26%-27% Co, 2%-3% Cu, 15%-16% Ni, and 0.15%-0.3% Ti, with the balance being Fe. The raw materials are smelted at 1580℃-1700℃ until completely melted, stirred evenly, and then cast into a preheated sand mold. The preheated sand mold is preferably at a temperature of 1500℃-1530℃.

[0035] After the molten steel is poured, it is preferable to use insulating cotton to keep the sand mold warm. This means that the insulating cotton is used to keep the sides and top surface of the sand mold warm.

[0036] After the heat preservation is completed, the insulation cotton is removed, the sand mold is quickly dismantled, and the formed hot blank is taken out. The hot blank is then quickly transferred to an annealing device for annealing treatment. Preferably, in the annealing step, the hot blank is placed in an annealing device at a temperature of 800℃-900℃, heated to 1000℃-1060℃ at a rate of 60℃ / h-100℃ / h, held at that temperature for 3h-4h, and then cooled to ambient temperature. The annealing device described in this invention is preferably an annealing furnace.

[0037] In step S3, the annealed blank is rough-machined to obtain a rough blank, for example, by wire cutting or drilling to obtain the shape of the target product.

[0038] The rough blank is then subjected to heat treatment. Preferably, the rough blank is held at 800℃-900℃ for 30-50 minutes, preferably in a box-type resistance furnace. Then, it is solution treated at 1260℃-1300℃ for 20-40 minutes, preferably in a high-temperature furnace. Finally, the blank is removed and, after the surface of the magnet has cooled to 800℃-900℃, it is transferred to a magnetic field for magnetization treatment.

[0039] Preferably, in the magnetization process, the heat-treated rough blank is covered with insulation cotton for heat preservation and placed in a magnetic field for magnetization for 20-30 minutes, then taken out for tempering.

[0040] Preferably, in the tempering process, the magnetized blank is sequentially kept at 610℃-625℃ for 3h-4h, at 580℃-595℃ for 4h-6h, and at 550℃-565℃ for 4h-6h, then cooled to 200℃-300℃ at a cooling rate of 1℃ / min-3℃ / min, and finally cooled to ambient temperature to obtain a semi-finished blank.

[0041] Preferably, after tempering, the semi-finished blank can be further processed, including fine grinding, removing surface oxide scale and other defects, cleaning, and inspection. After passing the inspection, oriented aluminum-nickel-cobalt magnets are obtained.

[0042] The present invention also provides an oriented AlNiCo magnet prepared by the method described above. The oriented AlNiCo magnet is integral, crack-free, and possesses excellent magnetic properties.

[0043] Optionally, the oriented AlNiCo magnet of the present invention can have a height of 80cm-100cm in the orientation direction and a weight of 5kg-10kg.

[0044] The following specific embodiments will further illustrate the directional AlNiCo magnet and its preparation method.

[0045] Example 1

[0046] Adjust the water temperature in the water pipe below the directional crystallizer panel to 10℃, then turn on the cooling water to cool the directional crystallizer panel so that the temperature of the directional crystallizer panel reaches 10℃ and the temperature difference between any two points on the directional crystallizer panel is 2℃.

[0047] By mass fraction, 8.2% Al, 26% Co, 2.3% Cu, 15% Ni, 0.15% Ti, and 48.35% Fe were weighed out and melted at 1620℃. After complete melting, the mixture was stirred to obtain molten steel, which was then poured into a high-temperature sand mold at 1500℃. After casting, the sand mold was quickly wrapped with insulating cotton to maintain its temperature, and the cooling water below the directional crystallizer panel was shut off. The mold was then held at this temperature for 25 minutes before being quickly removed. The formed hot blank was transferred to an annealing furnace at 900℃ and heated to 1030℃ at a heating rate of 80℃ / h, held for 3.5 hours for annealing, and then cooled to ambient temperature in the furnace. The annealed blank was then processed by wire cutting or drilling to form the shape of the target product, resulting in a rough blank.

[0048] The rough blank was placed in a box-type resistance furnace at 800℃ for 30 minutes, then transferred to a high-temperature furnace at 1260℃ for 30 minutes, and then cooled in air to 900℃. It was then transferred to a magnetic field, covered with insulation cotton, and left to stand for 30 minutes for magnetization. Afterward, it was removed and cooled to ambient temperature. The magnetized blank was then tempered, first held at 610℃ for 3 hours, then lowered to 580℃ and held for 5 hours, then lowered to 550℃ and held for 4 hours, then cooled to 200℃ at a rate of 1℃ / min, and finally air-cooled to ambient temperature to obtain a semi-finished blank. The semi-finished blank was then finely ground to remove surface oxide scale and other defects, cleaned thoroughly, and inspected to obtain oriented AlNiCo magnets.

[0049] The magnetic properties of the directional AlNiCo magnet in this embodiment were tested, and the results are shown in Table 1.

[0050] Example 2

[0051] Adjust the water temperature in the water pipe below the directional crystallizer panel to 15℃, then turn on the cooling water to cool the directional crystallizer panel so that the temperature of the directional crystallizer panel reaches 15℃, and the temperature difference between any two points on the directional crystallizer panel is 1℃.

[0052] By mass fraction, 8.5% Al, 26.2% Co, 2.5% Cu, 15.5% Ni, 0.2% Ti, and 47.1% Fe were weighed out and melted at 1650℃. After complete melting, the mixture was stirred to obtain molten steel, which was then poured into a high-temperature sand mold at 1510℃. After casting, the sand mold was quickly wrapped with insulating cotton for 2 minutes to maintain its temperature. Then, the cooling water under the directional crystallizer panel was turned off, and the temperature was maintained for another 28 minutes. The sand mold was then quickly removed, and the formed hot blank was transferred to an annealing furnace at 900℃. The furnace was heated to 1020℃ at a heating rate of 70℃ / h and held for 3.0 hours for annealing. The blank was then cooled to ambient temperature in the furnace. The annealed blank was then processed by wire cutting or drilling to form the shape of the target product, resulting in a rough blank.

[0053] The rough blank was placed in a box-type resistance furnace at 800℃ for 30 minutes, then transferred to a high-temperature furnace at 1260℃ for 30 minutes, and then cooled in air to 900℃. It was then transferred to a magnetic field, covered with insulation cotton, and left to stand for 30 minutes for magnetization. Afterward, it was removed and cooled to ambient temperature. The magnetized blank was then tempered, first held at 610℃ for 3 hours, then lowered to 580℃ and held for 5 hours, then lowered to 550℃ and held for 4 hours, then cooled to 300℃ at a rate of 1℃ / min, and finally air-cooled to ambient temperature to obtain a semi-finished blank. The semi-finished blank was then finely ground to remove surface oxide scale and other defects, cleaned thoroughly, and inspected to obtain oriented AlNiCo magnets.

[0054] The magnetic properties of the directional AlNiCo magnet in this embodiment were tested, and the results are shown in Table 1.

[0055] Example 3

[0056] Adjust the water temperature in the water pipe below the directional crystallizer panel to 20℃, then turn on the cooling water to cool the directional crystallizer panel, so that the temperature of the directional crystallizer panel reaches 20℃, and the temperature difference between any two points on the directional crystallizer panel is 0.5℃.

[0057] By mass fraction, 8.6% Al, 26.5% Co, 2.5% Cu, 15.8% Ni, 0.2% Ti, and 45.4% Fe were weighed out and melted at 1680℃. After complete melting, the mixture was stirred to obtain molten steel, which was then poured into a high-temperature sand mold at 1530℃. After casting, the sand mold was quickly wrapped with insulating cotton for 4 minutes to maintain its temperature. The cooling water below the directional crystallizer panel was then turned off, and the temperature was maintained for another 30 minutes. The sand mold was then quickly removed, and the formed hot blank was transferred to an annealing furnace at 900℃. The furnace was heated to 1050℃ at a heating rate of 90℃ / h and held for 3.2 hours for annealing. The blank was then cooled to ambient temperature in the furnace. The annealed blank was then processed by wire cutting or drilling to form the shape of the target product, resulting in a rough blank.

[0058] The rough blank was placed in a box-type resistance furnace at 800℃ for 30 minutes, then transferred to a high-temperature furnace at 1260℃ for 30 minutes. After removal, it was cooled to 900℃ in air, transferred to a magnetic field, covered with insulation cotton, and left to stand for 30 minutes for magnetization. It was then removed and cooled to ambient temperature. The magnetized blank was then tempered, first held at 610℃ for 3 hours, then lowered to 580℃ for 5 hours, then lowered to 550℃ for 4 hours, and then cooled to 200℃ at a cooling rate of 2℃ / min. Finally, it was air-cooled to ambient temperature to obtain a semi-finished blank. The semi-finished blank was then finely ground to remove surface oxide scale and other defects, cleaned, and inspected to obtain oriented AlNiCo magnets.

[0059] The magnetic properties of the directional AlNiCo magnet in this embodiment were tested, and the results are shown in Table 1.

[0060] Example 4

[0061] Adjust the water temperature in the water pipe below the directional crystallizer panel to 25℃, then turn on the cooling water to cool the directional crystallizer panel until the temperature of the directional crystallizer panel reaches 25℃, and the temperature difference between any two points on the directional crystallizer panel is 0℃.

[0062] By mass fraction, 9% Al, 27% Co, 2.5% Cu, 16% Ni, 0.25% Ti, and 45.25% Fe were weighed out and melted at 1700℃. After complete melting, the mixture was stirred to obtain molten steel, which was then poured into a high-temperature sand mold at 1480℃. After casting, the sand mold was quickly wrapped with insulating cotton for 5 minutes. Then, the cooling water under the directional crystallizer panel was turned off, and the mold was kept at that temperature for another 32 minutes. The sand mold was then quickly removed, and the formed hot blank was transferred to an annealing furnace at 900℃. The furnace was heated to 1000℃ at a heating rate of 100℃ / h and held for 4.0 hours for annealing. The blank was then cooled to ambient temperature in the furnace. The annealed blank was then processed by wire cutting or drilling to form the shape of the target product, resulting in a rough blank.

[0063] The rough blank was placed in a box-type resistance furnace at 800℃ for 30 minutes, then transferred to a high-temperature furnace at 1260℃ for 30 minutes, and then cooled in air to 900℃. It was then transferred to a magnetic field, covered with insulation cotton, and left to stand for 30 minutes for magnetization. Afterward, it was removed and cooled to ambient temperature. The magnetized blank was then tempered, first held at 610℃ for 3 hours, then lowered to 580℃ and held for 5 hours, then lowered to 550℃ and held for 4 hours, then cooled to 200℃ at a rate of 3℃ / min, and finally air-cooled to ambient temperature to obtain a semi-finished blank. The semi-finished blank was then finely ground to remove surface oxide scale and other defects, cleaned thoroughly, and inspected to obtain oriented AlNiCo magnets.

[0064] The magnetic properties of the directional AlNiCo magnet in this embodiment were tested, and the results are shown in Table 1.

[0065] Comparative Example 1

[0066] The difference between Comparative Example 1 and Example 3 is that the water temperature in the water pipe below the panel of the directional crystallizer was adjusted to 15°C, and then the cooling water was turned on before casting began. Furthermore, the cooling water remained on until the formed blank was transferred to the annealing furnace.

[0067] The magnetic properties of the oriented AlNiCo magnets in this comparative example were tested, and the results are shown in Table 1.

[0068] Comparative Example 2

[0069] The difference between Comparative Example 2 and Example 3 is that after casting is completed, the cooling water under the panel of the directional crystallizer is turned off after the temperature is maintained for 10 minutes.

[0070] The magnetic properties of the oriented AlNiCo magnets in this comparative example were tested, and the results are shown in Table 1.

[0071] Comparative Example 3

[0072] The difference between Comparative Example 3 and Example 3 is that after turning off the cooling water, the sand mold was removed after it cooled to room temperature.

[0073] The magnetic properties of the oriented AlNiCo magnets in this comparative example were tested, and the results are shown in Table 1.

[0074] The performance test results of the oriented AlNiCo magnets in the above embodiments and comparative examples are shown in Table 1.

[0075] Table 1

[0076]

[0077]

[0078] As can be seen from Examples 1-4 and Comparative Examples 1-3, the preparation process of the directional AlNiCo magnets provided by the present invention not only effectively reduces the problem of easy cracking during the directional solidification of AlNiCo magnets, but also greatly enhances the magnetic properties of AlNiCo magnets.

[0079] Furthermore, as can be seen from Example 3 and Comparative Example 1, casting begins immediately after the cooling water is turned on. During the casting of molten steel and subsequent cooling of the molten steel, the heat exchange of the directional crystallizer panel is too fast, and the heat exchange is fastest at the point where the water column impacts the crystallizer panel. This results in the columnar crystals not being thick and straight enough, and the heat exchange at the bottom of the large casting is uneven, which increases the proportion of cracks in the directional AlNiCo magnet products.

[0080] As can be seen from Example 3 and Comparative Example 2, the cooling water was turned off after 10 minutes, which delayed the timing of "slow cooling". The high-temperature solidification stage is the main stage of cracking and stress concentration, which increases the proportion of cracks in directional AlNiCo magnets.

[0081] As can be seen from Example 3 and Comparative Example 3, when the hot blank is cooled to room temperature and then annealed, large blanks are very prone to cracks due to the inconsistent heating and cooling rates inside and outside during repeated heating and cooling processes.

[0082] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0083] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for preparing oriented AlNiCo magnets, characterized in that, Includes the following steps: Turn on the temperature regulating medium and use the temperature regulating medium to adjust the temperature of the directional crystallizer panel to 10℃-25℃; The molten steel is poured into a preheated sand mold. After casting, the mold is kept at a certain temperature, and the temperature regulating medium is turned off within 5 minutes. Then, the mold is kept at a certain temperature for 20-35 minutes. The hot blank is then removed and annealed. The annealed blank is then subjected to rough machining, heat treatment, magnetization and tempering in sequence to obtain oriented aluminum-nickel-cobalt magnets.

2. The method for preparing oriented AlNiCo magnets according to claim 1, characterized in that, The temperature of the directional crystallizer panel is 12℃-25℃.

3. The method for preparing oriented AlNiCo magnets according to claim 1, characterized in that, The temperature difference between any two points on the directional crystallizer panel is less than or equal to 2°C.

4. The method for preparing oriented AlNiCo magnets according to claim 1, characterized in that, The temperature of the temperature regulating medium is 10℃-25℃.

5. The method for preparing oriented AlNiCo magnets according to claim 1, characterized in that, The temperature of the preheated sand mold is 1500℃-1530℃.

6. The method for preparing oriented AlNiCo magnets according to claim 1, characterized in that, In the annealing process, the hot blank is placed in an annealing apparatus at a temperature of 800℃-900℃, heated to 1000℃-1060℃ at a rate of 60℃ / h-100℃ / h, held at that temperature for 3h-4h, and then cooled to ambient temperature.

7. The method for preparing oriented AlNiCo magnets according to claim 1, characterized in that, In the heat treatment process, the annealed blank is held at 800℃-900℃ for 30min-50min, then solution treated at 1260℃-1300℃ for 20min-40min, and finally the blank is taken out and cooled to 800℃-900℃.

8. The method for preparing oriented AlNiCo magnets according to claim 1, characterized in that, In the magnetization process, the heat-treated blank is placed in a magnetic field, kept at a constant temperature, and magnetized for 20-30 minutes.

9. The method for preparing oriented AlNiCo magnets according to claim 1, characterized in that, In the tempering process, the magnetized blank is held in an environment of 610℃-625℃ for 3-4 hours, 580℃-595℃ for 4-6 hours, and 550℃-565℃ for 4-6 hours in sequence. Then, it is cooled to 200℃-300℃ at a cooling rate of 1℃ / min-3℃ / min, and finally cooled to ambient temperature.

10. An oriented AlNiCo magnet prepared by the method of any one of claims 1-9.

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