Preparation method of samarium-cobalt magnet

Abstract

The invention discloses a preparation method of a samarium-cobalt magnet, which comprises the following steps: S1, taking 24-27% of metal samarium, 48-58% of metal cobalt, 4-7% of pure copper, 2-5% of sponge zirconium and the balance of pure iron as smelting raw materials; s2, under the protection of inert gas, the smelting raw materials are put into a smelting furnace to be melted, and an ingot material is obtained through smelting; s3, carrying out jaw crushing on the obtained ingot, then carrying out intermediate crushing to obtain small particles, and carrying out airflow grinding to obtain powder, so as to obtain samarium cobalt powder; s4, under the protection of inert gas, the samarium cobalt powder is placed in a magnetic field for orientation forming, then isostatic pressing is conducted, and a green body is obtained; s5, performing high-temperature sintering on the green body under a vacuum condition to obtain a sintered magnet; and S6, grinding the sintered magnet according to the designed shape to obtain the samarium-cobalt magnetic steel. According to the preparation method, specific components and component proportions are adopted, so that the temperature resistance of the samarium-cobalt magnet is improved while the samarium-cobalt magnet has good magnetic performance, and the samarium-cobalt magnet can maintain magnetism at a higher temperature.

Description

Technical Field

[0001] The invention relates to the technical field of samarium cobalt magnets, and more particularly to a method for preparing a samarium cobalt magnet. Background Art

[0002] Permanent magnetic materials are currently widely used in various fields such as information, communication, aerospace, and transportation due to their energy conversion functions and various magnetic physical effects, and have become one of the important material foundations for high-tech, emerging industries, and social progress. Among them, the 2:17 type samarium cobalt permanent magnetic material, as the second-generation rare earth permanent magnetic material, has high magnetic properties, extremely low temperature coefficient, and high Curie temperature on the one hand, and good corrosion resistance and oxidation resistance on the other hand. Therefore, it plays an irreplaceable role in the field of high temperature and high stability, and is widely used in microwave tubes, gyroscopes and accelerators, high-temperature motors, magnetic bearings, sensors, drivers and other instruments and equipment.

[0003] Currently, the maximum operating temperature of existing samarium cobalt magnets is only 350°C, and the magnetism of samarium cobalt magnets will decrease when the temperature exceeds 220°C. The operating temperature in some special scenarios is usually higher, and the existing samarium cobalt magnets are difficult to use at this temperature or the use effect is poor. Therefore, it is necessary to design and develop a samarium cobalt magnet with a higher operating temperature. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a method for preparing a samarium cobalt magnet. The method for preparing the samarium cobalt magnet adopts specific components and component ratios, so that the samarium cobalt magnet has good magnetic properties and improves the temperature resistance of the samarium cobalt magnet, and can maintain magnetism at higher temperatures.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A method for preparing a samarium cobalt magnet comprises the following steps:

[0007] S1. Take 24-27% of metallic samarium, 48-58% of metallic cobalt, 4-7% of pure copper, 2-5% of sponge zirconium and the remainder of pure iron as smelting raw materials;

[0008] S2. Under the protection of inert gas, placing the smelting raw materials into a smelting furnace for melting, and smelting the resulting ingots;

[0009] S3, crushing the obtained ingot into small particles by jaw crushing, and then grinding into powder by air flow grinding to obtain samarium cobalt powder;

[0010] S4, under the protection of inert gas, placing the samarium cobalt powder in a magnetic field for orientation molding, and then isostatically pressing to obtain a green body;

[0011] S5. Sintering the green embryo at high temperature under vacuum conditions to obtain a sintered magnet;

[0012] S6. Finally, the sintered magnet is ground according to the designed shape to obtain samarium cobalt magnet.

[0013] Further, step S4 comprises:

[0014] S4.1. Take 995-998 parts of samarium cobalt powder by weight, add 1-3 parts of antioxidant and 1-2 parts of lubricant, and mix for 2 hours;

[0015] S4.2. The mixed powder is then placed in a constant magnetic field environment and pressed into a green embryo using a mold.

[0016] Furthermore, the phosphites in the antioxidant are one or more of triethyl phosphite, triisodecyl phosphite and triphenyl phosphite, and the solvent in the lubricant is turpentine or dimethylformamide.

[0017] Further, in step S1, 25.5% of metallic samarium, 55% of metallic cobalt, 5.5% of pure copper, 3.3% of sponge zirconium and the remainder of pure iron are taken as smelting raw materials.

[0018] Furthermore, the inert gas in step S2 and step S4 is argon.

[0019] Further in step S4, during magnetic field forming, the magnetic field intensity is ≥1.8T, and the isostatic pressure is ≥270MPa.

[0020] Furthermore, the sintering temperature of step S5 is 1150-1300° C., and the sintering time is 0.5-3 hours.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The preparation method of the present invention achieves the preparation of a samarium cobalt magnet with a maximum working temperature of 500°C and no negative temperature limit through raw material ratio control and subsequent process means. The samarium cobalt magnet has stable stability and chemical stability at an operating temperature of 220 degrees Celsius. This ensures that the samarium cobalt magnet has good magnetic properties while improving the temperature resistance of samarium cobalt, and can maintain magnetism at higher temperatures, thereby improving economic benefits and meeting customer needs. DETAILED DESCRIPTION

[0024] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features. Therefore, the definition of "first" and "second" features can explicitly or implicitly include one or more of the features. In the description of the present invention, "several" and "a number" mean two or more, unless otherwise clearly and specifically defined.

[0025] A method for preparing a samarium cobalt magnet comprises the following steps:

[0026] S1. Take 24-27% of metallic samarium, 48-58% of metallic cobalt, 4-7% of pure copper, 2-5% of sponge zirconium and the remainder of pure iron as smelting raw materials;

[0027] S2. Under the protection of inert gas, placing the smelting raw materials into a smelting furnace for melting, and smelting the resulting ingots;

[0028] S3, crushing the obtained ingot into small particles by jaw crushing, and then grinding into powder by air flow grinding to obtain samarium cobalt powder;

[0029] S4, under the protection of inert gas, placing the samarium cobalt powder in a magnetic field for orientation molding, and then isostatically pressing to obtain a green body;

[0030] S5. Sintering the green embryo at high temperature under vacuum conditions to obtain a sintered magnet;

[0031] S6. Finally, the sintered magnet is ground according to the designed shape to obtain samarium cobalt magnet.

[0032] Preferably, step S4 comprises:

[0033] S4.1. Take 995-998 parts by weight of samarium cobalt powder, add 1-3 parts of antioxidant and 1-2 parts of lubricant, and mix for 2 hours to prevent oxidation and increase powder fluidity;

[0034] S4.2. The mixed powder is then placed in a constant magnetic field environment and pressed into a green embryo using a mold.

[0035] Preferably, the phosphites in the antioxidant are one or more of triethyl phosphite, triisodecyl phosphite and triphenyl phosphite, and the solvent in the lubricant is turpentine or dimethylformamide.

[0036] Preferably, in step S1, 25.5% of metallic samarium, 55% of metallic cobalt, 5.5% of pure copper, 3.3% of sponge zirconium and the remainder of pure iron are taken as smelting raw materials.

[0037] Preferably, the inert gas in step S2 and step S4 is argon, and the argon is used to protect the smelting raw materials and samarium cobalt powder.

[0038] Preferably, in step S4, during magnetic field forming, the magnetic field intensity is ≥1.8T, and the isostatic pressure is ≥270MPa.

[0039] Preferably, the sintering temperature of step S5 is 1150-1300° C., and the sintering time is 0.5-3 h.

[0040] The preparation method of the present invention achieves the preparation of a samarium cobalt magnet with a maximum working temperature of 500°C and no negative temperature limit through raw material ratio control and subsequent process means. The samarium cobalt magnet has stable stability and chemical stability at an operating temperature of 220 degrees Celsius. This ensures that the samarium cobalt magnet has good magnetic properties while improving the temperature resistance of samarium cobalt, and can maintain magnetism at higher temperatures, thereby improving economic benefits and meeting customer needs.

[0041] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A method for preparing a samarium cobalt magnet, characterized in that: The steps include: S1. Take 24-27% of metallic samarium, 48-58% of metallic cobalt, 4-7% of pure copper, 2-5% of sponge zirconium and the remainder of pure iron as smelting raw materials; S2. Under the protection of inert gas, placing the smelting raw materials into a smelting furnace for melting, and smelting the resulting ingots; S3, crushing the obtained ingot into small particles by jaw crushing, and then grinding into powder by air flow grinding to obtain samarium cobalt powder; S4, under the protection of inert gas, placing the samarium cobalt powder in a magnetic field for orientation molding, and then isostatically pressing to obtain a green body; S5. Sintering the green embryo at high temperature under vacuum conditions to obtain a sintered magnet; S6. Finally, the sintered magnet is ground according to the designed shape to obtain samarium cobalt magnet.

2. The method for preparing a samarium cobalt magnet according to claim 1, characterized in that: The step S4 comprises: S4.

1. Take 995-998 parts of samarium cobalt powder by weight, add 1-3 parts of antioxidant and 1-2 parts of lubricant, and mix for 2 hours; S4.

2. The mixed powder is then placed in a constant magnetic field environment and pressed into a green embryo using a mold.

3. The method for preparing a samarium cobalt magnet according to claim 2, characterized in that: The phosphites in the antioxidant are one or more of triethyl phosphite, triisodecyl phosphite and triphenyl phosphite, and the solvent in the lubricant is turpentine or dimethylformamide.

4. The method for preparing a samarium cobalt magnet according to claim 1, characterized in that: In step S1, 25.5% of metallic samarium, 55% of metallic cobalt, 5.5% of pure copper, 3.3% of sponge zirconium and the remainder of pure iron are taken as smelting raw materials.

5. The method for preparing a samarium cobalt magnet according to claim 1, characterized in that: The inert gas in step S2 and step S4 is argon.

6. The method for preparing a samarium cobalt magnet according to claim 1, characterized in that: In the step S4, during magnetic field forming, the magnetic field intensity is ≥1.8T, and the isostatic pressure is ≥270MPa.

7. The method for preparing a samarium cobalt magnet according to claim 1, characterized in that: The sintering temperature of step S5 is 1150-1300° C., and the sintering time is 0.5-3 hours.