Preparation method of magnetic high-entropy alloy composite material

Abstract

The application discloses a preparation method of a magnetic high-entropy alloy composite material, and belongs to the technical field of magnetic material preparation. The saturation magnetization intensity of the magnetic high-entropy alloy composite material can reach 153-172 emu / g, the hardness value can reach 200-233 HV, the tensile strength can reach 600-712 MPa, and the coercive force is less than 200 Oe. The preparation steps comprise the following steps: (1) high-entropy alloy powder preparation; (2) ferrite powder preparation; (3) mixing the powders obtained in the steps (1) and (2) with proper additives; (4) loading into a mold and pressure forming; (5) sintering, and the magnetic high-entropy alloy composite material is obtained. The high-entropy alloy magnetic composite material obtained by reasonably controlling the high-entropy alloy composition, the ferrite composition, the proportion of the two components and the sintering process has excellent mechanical properties and outstanding high-frequency magnetic properties.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of magnetic material preparation, in particular to a preparation method of magnetic high-entropy alloy composite material. BACKGROUND

[0002] As one of important functional materials, magnetic materials are widely used in aerospace, ocean, communication engineering, military engineering and many other fields. Magnetic materials can be divided into soft magnetic materials and hard magnetic materials according to the differences of their residual magnetism, coercive force and other parameters. The soft magnetic material has the characteristics of high saturation magnetization and low coercive force, and is widely used in electrical equipment. The metal soft magnetic material is easy to process but has low resistivity, and has large loss in use, which is not suitable for high frequency field. Although the ferrite soft magnetic material has high resistivity and good comprehensive magnetic properties, the ferrite material is brittle and not easy to process. Therefore, how to obtain a soft magnetic material with good comprehensive magnetic properties, high resistivity and easy processing is a problem to be solved by the person skilled in the art. SUMMARY

[0003] In order to solve the problems in the prior art, the present application provides a preparation method of magnetic high-entropy alloy composite material, which solves the problems mentioned in the background.

[0004] In order to achieve the above purpose, the present application provides the following technical scheme: a preparation method of magnetic high-entropy alloy composite material, the saturation magnetization of the magnetic high-entropy alloy composite material can reach 153-172emu / g, the hardness value can reach 200-233HV, the tensile strength can reach 600-712MPa, and the coercive force is <200Oe. The preparation of the magnetic high-entropy alloy composite material comprises the following steps:

[0005] S1, high-entropy alloy powder preparation;

[0006] S2, ferrite powder preparation;

[0007] S3, mixing the powders obtained in steps S1 and S2 with additives;

[0008] S4, loading the raw materials obtained in step S3 into a mold for press forming;

[0009] S5, sintering the powders obtained in step S4 to obtain the magnetic high-entropy alloy composite material.

[0010] Preferably, the high-entropy alloy powder preparation in step S1 is to proportionally mix each component raw material, then melt in a vacuum induction furnace, and then crush into powder by mechanical crushing method.

[0011] Preferably, the high-entropy alloy powder component weight ratio is: Fe 20%~30%, Co 20%~30%, Ni 20%~30%, M 20%~30%, and the balance is Al; wherein M is a rare earth element, specifically Nb, Tb, Ho or Dy.

[0012] Preferably, the high-entropy alloy powder component weight ratio is: Fe 22%~25%, Co 22%~25%, Ni 22%, M 20%~25%, and the balance is Al.

[0013] Preferably, the ferrite powder in step S2 is manganese-zinc ferrite, cobalt ferrite or nickel ferrite; and the preparation method of step S2 is ball milling or air flow milling.

[0014] Preferably, the additive in step S3 is added in an amount of 5%~20% of the total mass; and the additive is polyvinyl alcohol or paraffin wax.

[0015] Preferably, the mass ratio of the high-entropy alloy powder to the ferrite powder in step S3 is 1:1.

[0016] Preferably, the specific method of loading the mold for press forming in step S4 is rigid mold press forming or isostatic press forming.

[0017] Preferably, the specific method of sintering in step S5 is vacuum sintering or atmosphere sintering.

[0018] Preferably, the sintering temperature is 600~800℃.

[0019] The method of the present application has the advantages that: through reasonable components and process control, the soft magnetic performance of the magnetic high-entropy alloy of the present application is excellent and the mechanical properties are good, through the compounding of the magnetic high-entropy alloy and the ferrite material, a soft magnetic material with excellent comprehensive magnetic performance, high resistivity and easy subsequent processing is obtained, the saturation magnetization can reach 150emu / g, the coercive force is less than 200Oe, the saturation field is less than 500Oe, the hardness value is greater than 200HV, and the tensile strength is greater than 600MPa. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 The magnetic performance curve of the material prepared in Example 1 of the present application is shown in the figure;

[0021] Figure 2 The tensile test curve of the material prepared in Example 1 of the present application is shown in the figure; DETAILED DESCRIPTION

[0022] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0023] Embodiment 1

[0024] A method for preparing a magnetic high-entropy alloy composite material is performed according to the following steps:

[0025] Step (1): each raw material is prepared according to the following atomic percentage: Fe 25%, Co 22%, Ni 22%, Ho 25%, and the balance is Al and a small amount of impurities, then heated and melted in a vacuum induction furnace and cast into a shape, and then broken into powder using a mechanical crushing device;

[0026] Step (2): the manganese zinc ferrite powder is ground using a ball milling method;

[0027] Step (3): the powders obtained in (1) and (2) are mixed with 10% polyvinyl alcohol by mass ratio; the mass ratio of the powders in (1) and (2) is 1:1 (the same as the following embodiments).

[0028] Step (4): the raw material obtained in (3) is loaded into a rigid mold and pressure formed;

[0029] Step (5): the powder obtained in (4) is sintered under vacuum, and the sintering temperature is 600°C, thereby obtaining the magnetic high-entropy alloy composite material.

[0030] The magnetic properties (hysteresis loop) of the material prepared in this embodiment are shown in Figure 1 , and the tensile test curve is shown in Figure 2 . The saturation magnetization of the material can reach 153emu / g, the coercivity is about 60Oe, the saturation field is less than 500Oe, the hardness value is greater than 200HV, and the tensile strength is greater than 600MPa.

[0031] Embodiment 2

[0032] A method for preparing a magnetic high-entropy alloy composite material is performed according to the following steps:

[0033] Step (1): each raw material is prepared according to the following atomic percentage: Fe 25%, Co 22%, Ni 22%, Tb 25%, and the balance is Al and a small amount of impurities, then heated and melted in a vacuum induction furnace and cast into a shape, and then broken into powder using a mechanical crushing device;

[0034] Step (2): Grind nickel ferrite powder using ball milling;

[0035] Step (3): Mix the powder obtained in (1) and (2) with polyvinyl alcohol at a mass ratio of 15%;

[0036] Step (4): Load the raw material obtained in (3) into an isostatic pressing device and press it into shape;

[0037] Step (5): The powder obtained in (4) is sintered in a vacuum environment at a temperature of 700℃ to obtain a magnetic high-entropy alloy composite material.

[0038] The magnetic properties of the material prepared in this embodiment are as follows: saturation magnetization up to 172 emu / g, coercivity about 180 Oe, saturation field about 475 Oe, hardness value 233 HV, and tensile strength about 712 MPa.

[0039] Example 3

[0040] A method for developing a magnetic high-entropy alloy composite material is carried out according to the following steps:

[0041] Step (1): Mix the raw materials according to the following atomic percentages: Fe 22%, Co 25%, Ni 22%, Nb 20%, with the balance being Al and a small amount of impurities. Then heat and melt them in a vacuum induction furnace and cast them into shape. After that, use a mechanical crushing device to crush them into powder.

[0042] Step (2): Grind manganese-zinc ferrite powder using an air jet mill;

[0043] Step (3): Mix the powder obtained in (1) and (2) with paraffin wax at a mass ratio of 10%;

[0044] Step (4): Load the raw material obtained in (3) into a rigid mold and press it into shape;

[0045] Step (5): The powder obtained in (4) is sintered in an argon atmosphere at a temperature of 800°C to obtain a magnetic high-entropy alloy composite material.

[0046] The magnetic properties of the material prepared in this embodiment are as follows: saturation magnetization up to 164 emu / g, coercivity about 110 Oe, saturation field about 335 Oe, hardness 211 HV, and tensile strength about 664 MPa.

[0047] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a magnetic high-entropy alloy composite material, characterized in that, The magnetic high-entropy alloy composite material has a saturation magnetization of 153–172 emu / g, a hardness of 200–233 HV, a tensile strength of 600–712 MPa, and a coercivity of <200 Oe. The preparation of the magnetic high-entropy alloy composite material includes the following steps: S1. Preparation of high-entropy alloy powder; The weight ratio of the high-entropy alloy powder components is: Fe 20%–30%, Co 20%–30%, Ni 20%–30%, M 20%–30%, with the balance being Al; where M is a rare earth element, specifically Nb, Tb, Ho, or Dy; S2, preparation of ferrite powder; S3. Mix the powder obtained in steps S1 and S2 with the additive; S4. Load the raw material obtained in step S3 into the mold and press it into shape; S5. Sinter the powder obtained in step S4 to obtain the magnetic high-entropy alloy composite material.

2. The method for preparing the magnetic high-entropy alloy composite material according to claim 1, characterized in that: The preparation of high-entropy alloy powder in step S1 involves mixing the raw materials of each component in a certain proportion, then melting them in a vacuum induction furnace, and finally crushing them into powder using a mechanical pulverizing method.

3. The method for preparing the magnetic high-entropy alloy composite material according to claim 1, characterized in that: The high-entropy alloy powder composition by weight ratio is: Fe 22%–25%, Co 22%–25%, Ni 22%, M 20%–25%, with the balance being Al.

4. The method for preparing the magnetic high-entropy alloy composite material according to claim 1, characterized in that: In step S2, the ferrite powder is manganese-zinc ferrite, cobalt ferrite, or nickel ferrite; the preparation method of step S2 is ball milling or air jet milling.

5. The method for preparing the magnetic high-entropy alloy composite material according to claim 1, characterized in that: In step S3, the amount of additive added accounts for 5-20% of the total mass; the additive is polyvinyl alcohol or paraffin.

6. The method for preparing the magnetic high-entropy alloy composite material according to claim 1, characterized in that: In step S3, the mass ratio of high-entropy alloy powder to ferrite powder is 1:

1.

7. The method for preparing the magnetic high-entropy alloy composite material according to claim 1, characterized in that: The specific method for loading the mold and pressing it in step S4 is rigid molding or isostatic pressing.

8. The method for preparing the magnetic high-entropy alloy composite material according to claim 1, characterized in that: The specific sintering method in step S5 is vacuum sintering or atmosphere sintering.

9. The method for preparing the magnetic high-entropy alloy composite material according to claim 8, characterized in that: The sintering temperature is 600–800°C.

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