FeCoNiMnAl high-entropy alloy modified graphene foam composite material and preparation method thereof

Abstract

The application discloses a FeCoNiMnAl high-entropy alloy modified graphene foam composite material and a preparation method thereof, wherein the preparation method comprises the following steps: S1, weighing and powdering Fe, Co, Ni, Mn and Al metal element powders according to a molar ratio of 1:1:1:0.5:0.5, ball milling the weighed and powdered metal element powders in a ball milling tank under a protective atmosphere, and uniformly mixing the metal element powders; S2, sieving the uniformly mixed powders to obtain high-entropy powders; S3, uniformly mixing the high-entropy powders and graphene in a magnetic stirrer according to a weight ratio of (1-4):1, and the mixing medium is alcohol; and S4, taking out the obtained mixed powders, and performing suction filtration, drying and sieving to obtain the graphene foam composite material. The electromagnetic wave absorbing material prepared from the FeCoNiMnAl high-entropy alloy modified graphene foam composite material can solve the problem of "impedance mismatch".

Description

Technical Field

[0001] This invention relates to the field of high-entropy alloy composite material preparation technology, specifically to FeCoNiMnAl high-entropy alloy modified graphene foam composite material and its preparation method. Background Technology

[0002] With the rapid development of electronic and electrical equipment, and considering the harm that electromagnetic waves can cause to humans and other organisms, many researchers have carried out a lot of material research and development work based on the interface impedance matching and loss mechanism of electromagnetic waves. They have confirmed that magnetically modified reduced graphene oxide (rGO) can reduce reflection loss and expand the effective absorption bandwidth, and that the absorption effect of magnetic rGO composites can be controlled by adjusting the content and morphology of magnetic materials.

[0003] High-entropy alloys generally contain five or more elements, and their content (atomic fraction, the same below) can be adjusted within the range of 5% to 35%. Therefore, there are many systems of high-entropy alloys. According to their crystal structure, high-entropy alloys can be divided into body-centered cubic (BCC), face-centered cubic (FCC), and hexagonal close-packed (HCP).

[0004] Metallic elements possess excellent comprehensive properties, including good thermal stability, chemical stability, wide bandgap, and dielectric loss. Their low manufacturing cost is also a major reason for their widespread application. However, when used as electromagnetic wave absorbing materials, pure metals do not exhibit good absorption performance due to their inherent high density, weak absorption intensity, and narrow absorption bandwidth. To improve the electromagnetic wave absorption performance of electromagnetic wave absorbing materials, it is necessary to adjust their impedance matching and enhance their conductivity loss and multipolarization relaxation loss to significantly improve their attenuation capability. Summary of the Invention

[0005] In view of this, in order to solve the above-mentioned technical problems, the purpose of this invention is to propose a FeCoNiMnAl high-entropy alloy modified graphene foam composite material and its preparation method, wherein the electromagnetic absorbing material made of the FeCoNiMnAl high-entropy alloy modified graphene foam composite material can solve the "impedance mismatch" problem.

[0006] The technical solution adopted is as follows:

[0007] The present invention discloses a method for preparing FeCoNiMnAl high-entropy alloy modified graphene foam composite material, comprising the following steps:

[0008] S1. Weigh and mix the Fe, Co, Ni, Mn and Al metal element powders according to the molar ratio of 1:1:1:0.5:0.5. Then, ball mill the weighed and mixed metal element powders in a ball mill jar under a protective atmosphere until they are homogeneous.

[0009] S2. Sift the uniformly mixed powder to obtain high-entropy powder;

[0010] S3. Mix the high-entropy powder and graphene in a magnetic stirrer at a weight ratio of (1-4):1, using alcohol as the mixing medium.

[0011] S4. The obtained mixed powder is taken out, filtered, dried and sieved to obtain FeCoNiMnAl high-entropy alloy modified graphene foam composite material with body-centered cubic structure.

[0012] Furthermore, the ball mill includes large balls, medium balls, and small balls; the diameter of the large balls is 8-9 mm, the diameter of the medium balls is 5-6 mm, and the diameter of the small balls is 3-4 mm; the mass ratio of the large balls, medium balls, and small balls is 1:1:2-3; the ball-to-material ratio is 3-4:1; the ball milling frequency is 800-1000 times / min; and the ball milling time is 24-30 hours.

[0013] Further, in S2, the uniformly mixed powder is passed through a 200-300 mesh sieve.

[0014] Furthermore, in S3, the stirring temperature is 15-25℃ and the stirring speed is 250-400 r / min.

[0015] The present invention relates to a FeCoNiMnAl high-entropy alloy modified graphene foam composite material, which is prepared by the preparation method described in any of the above schemes.

[0016] The present invention discloses a method for preparing FeCoNiMnAl high-entropy alloy modified graphene composite electromagnetic absorbing material, comprising the following steps: adding the above-mentioned FeCoNiMnAl high-entropy alloy modified graphene foam composite material into water for freeze-drying, and then calcining the freeze-dried product under an inert atmosphere to obtain the electromagnetic absorbing material.

[0017] Furthermore, during calcination, the temperature is increased to 500-510℃ at a heating rate of 8-10℃ / min, and held for 2-3 hours to obtain the electromagnetic absorbing material.

[0018] The present invention discloses a FeCoNiMnAl high-entropy alloy modified graphene composite electromagnetic absorbing material, which is prepared by the above-described method for preparing electromagnetic absorbing materials.

[0019] The beneficial effects of this invention are as follows:

[0020] Firstly, in preparing FeCoNiMnAl high-entropy alloys, this invention employs a physical method to prepare high-entropy alloy composite materials with a single body-centered cubic structure. The preparation utilizes purely physical techniques, reducing costs, eliminating pollution, and resulting in a high-entropy alloy with a single body-centered cubic structure.

[0021] Secondly, this invention prepares a FeCoNiMnAl high-entropy alloy modified graphene foam composite material.

[0022] Thirdly, this invention prepares a FeCoNiMnAl high-entropy alloy modified graphene composite electromagnetic absorbing material, which can solve the "impedance mismatch" problem. After preparing FeCoNiMnAl high-entropy alloy modified graphene foam composite materials with certain mechanical properties and oriented pore structure using physical methods, the dielectric properties of pure graphene alone cannot meet the impedance matching conditions, hindering its further microwave absorption applications. Furthermore, while ferromagnetic metals possess excellent permeability, their permeability decays rapidly in the microwave band. Therefore, the prepared FeCoNiMnAl high-entropy alloy modified graphene composite electromagnetic absorbing material combines the magnetic properties of the magnetic material with the excellent dielectric properties of graphene, thus solving the "impedance mismatch" problem of graphene as a novel electromagnetic absorbing material and constructing a new type of electromagnetic absorbing material. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings involved in the description of the embodiments will be briefly introduced below.

[0024] Figure 1 The image shows the XRD pattern of the pure FeCoNiMnAl high-entropy alloy sample prepared by the physical method in Example 1.

[0025] Figure 2 This is a SEM image of the pure FeCoNiMnAl high-entropy alloy powder prepared by the physical method in Example 1.

[0026] Figure 3 This is an EDS surface scan of Fe in the pure FeCoNiMnAl high-entropy alloy powder in Example 1.

[0027] Figure 4 This is an EDS surface scan of Co in the pure FeCoNiMnAl high-entropy alloy powder in Example 1.

[0028] Figure 5 This is an EDS surface scan of Ni in the pure FeCoNiMnAl high-entropy alloy powder in Example 1.

[0029] Figure 6 This is an EDS surface scan image of Mn in the pure FeCoNiMnAl high-entropy alloy powder in Example 1.

[0030] Figure 7 This is an EDS surface scan image of Al in the pure FeCoNiMnAl high-entropy alloy powder in Example 1. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] Example 1

[0033] A method for preparing a FeCoNiMnAl high-entropy alloy involves weighing and mixing raw material powders of Fe, Co, Ni, Mn, and Al in a molar ratio of 1:1:1:0.5:0.5, where Fe is 7.8130 g, Co is 8.2450 g, Ni is 8.2115 g, Mn is 3.8430 g, and Al is 1.8874 g. All weighed powders are then added to a ball mill jar. The ball milling process includes large, medium, and small balls; the diameter of the large balls is 8-9 mm, the diameter of the medium balls is 5-6 mm, and the diameter of the small balls is 3-4 mm; the mass ratio of the large, medium, and small balls is 1:1:2; the ball-to-material ratio is 3:1; the ball milling frequency is 1000 times / min; and the ball milling time is 24 h.

[0034] The uniformly mixed powder is passed through an 800-1000 mesh sieve to obtain FeCoNiMnAl high-entropy alloy powder.

[0035] The powder was placed in a sample bag, and Ar gas was introduced to prevent the metal from being oxidized.

[0036] The FeCoNiMnAl high-entropy alloy powder of Example 1 was tested, and the test results are shown in [reference needed]. Figures 1-7 .

[0037] Example 2

[0038] A method for preparing FeCoNiMnAl high-entropy alloy modified graphene foam composite material: FeCoNiMnAl high-entropy alloy powder (after being sieved through a 200-mesh sieve) from Example 1 is uniformly mixed with graphene at a weight ratio of 1:1 in a magnetic stirrer. The mixing medium is 20 ml of alcohol, the stirring temperature is 15℃, and the stirring speed is 250 r / min. The resulting mixed powder is then removed, filtered, dried, and sieved. Through the above steps, a FeCoNiMnAl high-entropy alloy modified graphene foam composite material with a body-centered cubic structure is obtained.

[0039] Example 3

[0040] A FeCoNiMnAl high-entropy alloy modified graphene composite electromagnetic absorbing material is obtained by adding the FeCoNiMnAl high-entropy alloy modified graphene foam composite material of Example 2 into water for freeze-drying, then placing the freeze-dried product in an inert atmosphere for calcination, heating it to 500-510℃ at a heating rate of 8-10℃ / min, and holding it at that temperature for 2-3 hours.

[0041] Tests revealed that it has good absorption performance in the 2-20GHz frequency range.

[0042] This demonstrates that the magnetic properties of the magnetic material in the FeCoNiMnAl high-entropy alloy-modified graphene composite electromagnetic absorbing material are combined with the excellent dielectric properties of graphene, which can solve the "impedance mismatch" problem of graphene as a novel electromagnetic absorbing material, thereby constructing a novel electromagnetic absorbing material.

[0043] The detailed descriptions listed above are merely specific illustrations of feasible embodiments of the present invention and are not intended to limit the scope of protection of the present invention. All equivalent embodiments or modifications made without departing from the spirit of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a FeCoNiMnAl high-entropy alloy modified graphene composite electromagnetic absorbing material, wherein... The feature is that it includes the following steps: S1. Mix Fe, Co, Ni, Mn, and Al metal powders in a molar ratio of 1:1:1:0.5:0.

5. The metal element powder was weighed and prepared, and then ball-milled in a ball mill jar under a protective atmosphere. Mix thoroughly; S2. Sift the uniformly mixed powder to obtain high-entropy powder; S3. Mix the high-entropy powder and graphene evenly in a magnetic stirrer at a weight ratio of (1-4):

1. The mixture is made up of alcohol. S4. Take out the resulting mixed powder, filter, dry, and sieve it to obtain a body-centered cubic structure. FeCoNiMnAl high-entropy alloy modified graphene foam composite material; S5. After freeze-drying the FeCoNiMnAl high-entropy alloy-modified graphene foam composite material in water, the following steps were taken: The freeze-dried product was calcined under an inert atmosphere to obtain an electromagnetic absorbing material. During calcination, the temperature was increased to 500-510℃ at a rate of 8-10℃ / min and held for 2-3 hours.

2. A FeCoNiMnAl high-entropy alloy modified graphene composite electromagnetic absorbing material, which is derived from the rights holder The sample obtained by the preparation method described in Question 1.

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