A high-entropy alloy FeCoNiCuW microwave absorbing material and its preparation method

Abstract

This invention relates to the field of microwave absorbing materials, specifically disclosing a high-entropy alloy FeCoNiCuW microwave absorbing material and its preparation method. This invention uses different porous materials as conductive substrates, and through the synergistic reduction and in-situ assembly of multiple metal ions (Fe, Co, Ni, Cu, W) during electrodeposition, forms a tightly bonded interface between the alloy layer with a high-entropy structure and the substrate. The resulting composite material combines the magnetic loss of the high-entropy alloy with the conductive network advantages of the substrate, effectively improving impedance matching and interface polarization capabilities, thereby achieving wide-bandwidth, high-efficiency, and stable electromagnetic wave absorption performance. This invention achieves in-situ bonding of the high-entropy alloy and the substrate through a low-temperature electrodeposition method. The preparation process can be completed at ambient pressure and low temperature, is simple to operate, and has good repeatability. This invention not only simplifies the preparation process and improves the bonding strength, but also provides a new technical path for the design and engineering application of high-performance electromagnetic protection materials.

Description

Technical Field

[0001] This invention relates to the field of microwave absorbing materials technology, specifically to a high-entropy alloy FeCoNiCuW microwave absorbing material and its preparation method. Background Technology

[0002] With the rapid development of electronic devices, miniaturized communication equipment, and high-speed wireless networks, electromagnetic radiation problems are becoming increasingly prominent. Excessive electromagnetic waves not only cause electromagnetic interference between devices but also adversely affect human health and the normal operation of precision instruments. Therefore, developing novel electromagnetic wave absorbing materials with lightweight, wide-bandwidth, and highly efficient absorption properties has become an important research direction in the field of electromagnetic protection and absorption. Traditional absorbing materials such as ferrites, carbides, and conductive polymers, while possessing certain absorption capabilities in some frequency bands, generally suffer from drawbacks such as high density, complex manufacturing processes, poor impedance matching, and narrow bandwidth, making it difficult to meet the needs of modern multi-band electromagnetic protection systems.

[0003] In recent years, high-entropy alloys have become important candidates for next-generation electromagnetic absorbing materials due to their multi-component design concept, complex solid solution structure, and excellent magnetic loss and conductivity properties. High-entropy systems can achieve randomization of composition and lattice at the atomic scale through multi-element inter-modulation, thereby improving magnetic anisotropy, enhancing interfacial polarization and dipole relaxation effects, which is beneficial for achieving broadband absorption characteristics. However, traditional high-entropy alloys are mostly prepared using high-temperature or vacuum methods such as melting and sputtering, which are costly and difficult to combine with flexible substrates, limiting their application in lightweight, flexible electromagnetic protection.

[0004] Porous materials can serve as ideal lightweight carriers and conductive networks, significantly improving the impedance matching characteristics and interfacial polarization intensity of microwave absorbers. If a multi-element high-entropy alloy can be uniformly deposited on the substrate surface to form an integrated composite structure, not only can a tight bond be achieved between the high-entropy phase and the substrate framework, avoiding interfacial delamination problems, but the multi-level porous structure of the substrate can also be fully utilized to enhance the multiple reflections and attenuation of electromagnetic waves, thereby obtaining efficient and stable electromagnetic wave absorption performance. Based on this, this application discloses a high-entropy alloy FeCoNiCuW microwave absorbing material and its preparation method. Summary of the Invention

[0005] This invention addresses the problems of complex preparation processes, weak bonding with substrates, insufficient flexibility, and narrow absorption bandwidth of high-entropy alloys in existing technologies. It provides a high-entropy alloy FeCoNiCuW microwave absorbing material and its preparation method, aiming to overcome the shortcomings of existing technologies.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a method for preparing a high-entropy alloy FeCoNiCuW microwave absorbing material, comprising the following steps: Step 1: Prepare the electrolyte, which includes the following components: ferrous sulfate heptahydrate, cobalt sulfate heptahydrate, copper sulfate pentahydrate, nickel sulfate hexahydrate, sodium tungstate dihydrate, complexing agent, buffer, reducing agent, and surfactant; adjust the pH of the electrolyte to 6.0~7.0; Step 2: Using an electrode rod as the anode and a conductive substrate as the cathode, electrodeposition is performed on the surface of the conductive substrate using the electrolyte prepared in Step 1 to obtain FeCoNiCuW microwave absorbing material. Step 3: Heat-treat the FeCoNiCuW microwave absorbing material prepared in Step 2.

[0007] In a more optimized scheme, the steps for preparing the electrolyte in step 1 are as follows: add the buffer and complexing agent to deionized water and stir until dissolved, then add ferrous sulfate heptahydrate, cobalt sulfate heptahydrate, copper sulfate pentahydrate, nickel sulfate hexahydrate, and sodium tungstate dihydrate and stir until dissolved, and finally add the reducing agent and surfactant and continue stirring until dissolved to obtain the electrolyte.

[0008] In a more optimized scheme, the buffer is any one or more of boric acid, disodium hydrogen phosphate, phosphoric acid, acetic acid, acetic acid, and sodium carbonate in combination; the complexing agent is any one or more of citric acid monohydrate, sodium citrate, potassium pyrophosphate, oxalic acid, and sodium tripolyphosphate in combination; the reducing agent is ascorbic acid or sodium hypophosphite; and the surfactant is one or more of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, and sodium hexametaphosphate in combination.

[0009] In a more optimized scheme, the electrolyte composition in step 1 is as follows: boric acid 0.1~0.5 mol / L, citric acid monohydrate 0.1~0.4 mol / L, ferrous sulfate heptahydrate 0.01~0.1 mol / L, cobalt sulfate heptahydrate 0.01~0.1 mol / L, copper sulfate pentahydrate 0.01~0.05 mol / L, nickel sulfate hexahydrate 0.01~0.05 mol / L, sodium tungstate dihydrate 0.01~0.1 mol / L, sodium dodecyl sulfate 0.004~0.05 mol / L, and ascorbic acid 0.03~0.1 mol / L.

[0010] In a more optimized scheme, in step 2, a constant potential is used during electrodeposition, with the electrodeposition potential range being -4.5V to -2.5V, the deposition temperature being 20℃ to 80℃, and the deposition time range being 5min to 30min.

[0011] In a more optimized scheme, in step 2, the electrode rod is any one of graphite, platinum sheet, and titanium sheet; the conductive substrate is any one of copper sheet, titanium sheet, nickel foam, copper foam, aluminum sheet, stainless steel sheet, carbon cloth, and carbon foam.

[0012] In a more optimized scheme, in step 3, the heat treatment temperature is 500℃~800℃, the holding time is 1h~3h, and the heat treatment atmosphere is Ar2 or Ar2 / H2.

[0013] In a more optimized scheme, in step 2, a pretreatment step is performed before electrodeposition on the conductive substrate. The pretreatment step includes ultrasonic cleaning with acetone, anhydrous ethanol, and deionized water for 10 to 15 minutes in sequence, followed by drying.

[0014] In a more optimized scheme, the proportion of each metal element in the FeCoNiCuW microwave absorbing material is between 5% and 50%.

[0015] A more optimized solution is a high-entropy alloy FeCoNiCuW microwave absorbing material prepared by any of the above preparation methods.

[0016] Compared with the prior art, the beneficial effects achieved by the present invention are: 1. This invention uses different porous materials as conductive substrates and achieves the synergistic reduction and in-situ assembly of Fe, Co, Ni, Cu, and W multi-metal ions during electrodeposition, forming a tightly bonded interface between the alloy layer with a high-entropy structure and the substrate. The resulting composite material combines the magnetic loss of the high-entropy alloy with the conductive network advantages of the substrate, effectively improving impedance matching and interface polarization capabilities, thereby achieving wide-bandwidth, high-efficiency, and stable electromagnetic wave absorption performance. This invention achieves in-situ bonding between the high-entropy alloy and the substrate through low-temperature electrodeposition, which not only simplifies the preparation process and improves the bonding strength but also provides a new technical path for the design and engineering application of high-performance electromagnetic protection materials. The resulting composite material has excellent structural stability and wave absorption performance and can be widely used in electromagnetic protection, radar stealth, and high-frequency communication, showing good prospects for industrial application.

[0017] 2. The innovation of this invention does not lie in simply replacing elements or changing deposition parameters, but in combining the FeCoNiCuW high-entropy alloy system with the specific functional requirement of electromagnetic wave absorption for the first time. By uniquely using porous conductive substrates such as carbon cloth, nickel foam, and copper foam, a three-dimensional composite structure is formed, which enhances interface polarization and multiple reflections of electromagnetic waves, thereby improving wave absorption performance. Compared with other inventions, it has the advantages of being lightweight, flexible, and structurally integrated.

[0018] Meanwhile, the electrodeposition process used in this invention is mild, and the preparation process can be completed at normal pressure and low temperature, making it simple to operate and highly repeatable. Secondly, the high-entropy alloy layer obtained by deposition has a dense and firm bond with the substrate, which significantly improves the problem of poor interface bonding in traditional composite systems. Thirdly, the magnetic network formed by the multi-component metals in the high-entropy alloy works synergistically with the conductive skeleton of the substrate to enhance the interfacial polarization and the ability to reflect electromagnetic waves multiple times, giving the material excellent wave absorption performance over a wide frequency range. It also has the advantages of being lightweight and having good thermal stability.

[0019] 3. This invention uses W to replace Zn. Since W has a high melting point, strong magnetism and good electromagnetic properties, it is more suitable for microwave absorbing materials. Furthermore, this invention introduces a heat treatment step under a protective atmosphere, which can effectively eliminate the internal stress of the deposited layer, promote the crystallization of high-entropy alloys, and may induce fine phase separation or nano-precipitates, thereby further controlling the electromagnetic parameters and significantly improving the microwave absorption performance and thermal stability of the material. Attached Figure Description

[0020] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 The image shown is a scanning electron microscope (SEM) image of the high-entropy alloy FeCoNiCuW microwave absorbing material prepared in Example 1 of this invention. Figure 2 The image shown is a scanning electron microscope (SEM) image of the high-entropy alloy FeCoNiCuW microwave absorbing material prepared in Example 2 of this invention. Figure 3 The image shown is a scanning electron microscope (SEM) image of the high-entropy alloy FeCoNiCuW microwave absorbing material prepared in Example 5 of this invention. Figure 4 The image shown is a scanning electron microscope (SEM) image of the high-entropy alloy FeCoNiCuW microwave absorbing material prepared in Example 6 of this invention. Figure 5 The X-ray diffraction patterns of the high-entropy alloy FeCoNiCuW microwave absorbing materials prepared in Examples 2, 5, and 6 of this invention are shown below. Figure 6 The microwave absorption performance spectrum of the high-entropy alloy FeCoNiCuW microwave absorbing material prepared in Example 1 of this invention; Figure 7 The microwave absorption performance spectrum of the high-entropy alloy FeCoNiCuW microwave absorbing material prepared in Example 6 of this invention; Figure 8 The elemental composition of the high-entropy alloy FeCoNiCuW microwave absorbing materials prepared in Examples 1 and 2 is shown in Figure 2. Detailed Implementation

[0021] 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.

[0022] Example 1 Step 1: First, heat the deionized water to 25℃ and maintain this temperature. Measure 80mL of deionized water and add 0.2mol / L boric acid and 0.2mol / L citric acid monohydrate to it in sequence, stirring until completely dissolved. Then add 0.03mol / L ferrous sulfate heptahydrate, 0.02mol / L cobalt sulfate heptahydrate, 0.01mol / L copper sulfate pentahydrate, and 0.02mol / L nickel sulfate hexahydrate, and continue stirring. Then add 0.03mol / L sodium tungstate dihydrate and 0.03mol / L ascorbic acid, stirring thoroughly until completely dissolved. Finally, add 0.005mol / L sodium dodecyl sulfate and stir evenly to obtain the electrolyte.

[0023] Add 0.5 mol / L sodium hydroxide solution to the prepared electrolyte to adjust the pH of the electrolyte to 6.0.

[0024] Step 2: Using graphite as the anode and copper sheet as the conductive substrate, electroplating was performed using a constant potential. The electrodeposition potential was controlled at -2.5V, the deposition temperature at 30℃, and the deposition time at 10min. The electroplated material was washed several times with deionized water and anhydrous ethanol, and then dried in a 60℃ oven for 24h to obtain the high-entropy alloy FeCoNiCuW microwave absorbing material.

[0025] Step 3: Place the obtained high-entropy alloy FeCoNiCuW microwave absorbing material in an Ar2 atmosphere and heat treat it at 600℃ for 2 hours.

[0026] Example 2 Step 1: Electrolyte Preparation: Heat deionized water to 30℃ and maintain the temperature. Measure 100mL of deionized water and add 0.3mol / L boric acid and 0.3mol / L citric acid monohydrate sequentially, stirring to dissolve. Add 0.04mol / L ferrous sulfate heptahydrate, 0.03mol / L cobalt sulfate heptahydrate, 0.02mol / L copper sulfate pentahydrate, and 0.03mol / L nickel sulfate hexahydrate, stirring until homogeneous. Then add 0.02mol / L sodium tungstate dihydrate and 0.04mol / L ascorbic acid, stirring until completely dissolved. Finally, add 0.007mol / L sodium dodecyl sulfate and stir until homogeneous to obtain the electrolyte. Add 2mol / L sodium hydroxide solution to the electrolyte to adjust the pH to 7.0.

[0027] Step 2: Using a platinum sheet as the anode and a titanium sheet as the conductive substrate, constant potential electroplating was performed. The electrodeposition potential was set to -3.0V, the deposition temperature to 40℃, and the deposition time to 20min. The electroplated material was washed several times with deionized water and anhydrous ethanol and dried in a 60℃ oven for 24h to obtain the high-entropy alloy FeCoNiCuW microwave absorbing material.

[0028] Step 3: Place the obtained high-entropy alloy FeCoNiCuW microwave absorbing material in an Ar2 atmosphere and heat treat it at 700℃ for 2.0h.

[0029] Example 3 Step 1: Heat deionized water to 30℃ and maintain this temperature. Measure 90 mL of deionized water and add 0.15 mol / L boric acid and 0.15 mol / L citric acid monohydrate sequentially, stirring to dissolve. Add 0.015 mol / L ferrous sulfate heptahydrate, 0.015 mol / L cobalt sulfate heptahydrate, 0.015 mol / L copper sulfate pentahydrate, and 0.025 mol / L nickel sulfate hexahydrate, stirring until homogeneous. Add 0.03 mol / L sodium tungstate dihydrate and 0.03 mol / L ascorbic acid, stirring until completely dissolved. Finally, add 0.006 mol / L sodium dodecyl sulfate and stir until homogeneous to obtain the electrolyte. Add 1 mol / L sodium hydroxide solution to the electrolyte to adjust the pH to 6.5.

[0030] Step 2: Using graphite as the anode and nickel foam as the conductive substrate, constant potential electroplating was performed. The electrodeposition potential was -3.0V, the deposition temperature was 60℃, and the deposition time was 15min. The electroplated material was washed several times with deionized water and anhydrous ethanol and dried in a 60℃ oven for 24h to obtain high-entropy alloy FeCoNiCuW microwave absorbing material.

[0031] Step 3: The obtained high-entropy alloy FeCoNiCuW microwave absorbing material is placed in an Ar2 / H2 atmosphere and heat-treated at 650℃ for 3.0h.

[0032] Example 4 Step 1: Heat deionized water to 50℃ and maintain the temperature. Measure 100mL of deionized water and add 0.4mol / L boric acid and 0.4mol / L citric acid monohydrate sequentially, stirring to dissolve. Add 0.03mol / L ferrous sulfate heptahydrate, 0.035mol / L cobalt sulfate heptahydrate, 0.025mol / L copper sulfate pentahydrate, and 0.035mol / L nickel sulfate hexahydrate, stirring until homogeneous. Add 0.03mol / L sodium tungstate dihydrate and 0.04mol / L ascorbic acid, stirring until completely dissolved. Finally, add 0.008mol / L sodium dodecyl sulfate and stir until homogeneous to obtain the electrolyte. Add 3mol / L sodium hydroxide solution to the electrolyte to adjust the pH to 6.0.

[0033] Step 2: Electrodeposition operation: Using a platinum sheet as the anode and copper foam as the conductive substrate, constant potential electroplating was performed. The electrodeposition potential was -4V, the deposition temperature was 40℃, and the deposition time was 20min. The electroplated material was washed several times with deionized water and anhydrous ethanol, and then dried in a 60℃ oven for 24h to obtain the high-entropy alloy FeCoNiCuW microwave absorbing material.

[0034] Step 3: Place the obtained high-entropy alloy FeCoNiCuW microwave absorbing material in an Ar2 atmosphere and heat treat it at 700℃ for 3.0h.

[0035] Example 5 Step 1: Heat deionized water to 50℃ and maintain this temperature. Measure 80 mL of deionized water and add 0.1 mol / L boric acid and 0.1 mol / L citric acid monohydrate sequentially, stirring to dissolve. Add 0.02 mol / L ferrous sulfate heptahydrate, 0.01 mol / L cobalt sulfate heptahydrate, 0.01 mol / L copper sulfate pentahydrate, and 0.015 mol / L nickel sulfate hexahydrate, stirring until homogeneous. Add 0.01 mol / L sodium tungstate dihydrate and 0.03 mol / L ascorbic acid, stirring until completely dissolved. Finally, add 0.004 mol / L sodium dodecyl sulfate and stir until homogeneous to obtain the electrolyte. Add 3 mol / L sodium hydroxide solution to the electrolyte to adjust the pH to 6.5.

[0036] Step 2: Using graphite as the anode and aluminum sheet as the conductive substrate, constant potential electroplating is performed. The electrodeposition potential is -4.5V, the deposition temperature is 60℃, and the deposition time is 20min. The electroplated material is washed several times with deionized water and anhydrous ethanol and dried in a 60℃ oven for 24h to obtain high-entropy alloy FeCoNiCuW microwave absorbing material.

[0037] Step 3: Place the obtained high-entropy alloy FeCoNiCuW microwave absorbing material in an Ar2 / H2 atmosphere and heat treat it at 800℃ for 3 hours.

[0038] Example 6 Step 1: Heat deionized water to 80℃ and maintain the temperature. Measure 100mL of deionized water and add 0.25mol / L boric acid and 0.25mol / L citric acid monohydrate sequentially, stirring to dissolve. Add 0.01mol / L ferrous sulfate heptahydrate, 0.02mol / L cobalt sulfate heptahydrate, 0.012mol / L copper sulfate pentahydrate, and 0.02mol / L nickel sulfate hexahydrate, stirring until homogeneous. Add 0.02mol / L sodium tungstate dihydrate and 0.035mol / L ascorbic acid, stirring until completely dissolved. Finally, add 0.0055mol / L sodium dodecyl sulfate and stir until homogeneous to obtain the electrolyte. Add 6mol / L sodium hydroxide solution to the electrolyte to adjust the pH to 7.0.

[0039] Step 2: Using a platinum sheet as the anode and a stainless steel sheet as the conductive substrate, constant potential electroplating is performed. The electrodeposition potential is -3.0V, the deposition temperature is 40℃, and the deposition time is 10min. The electroplated material is washed several times with deionized water and anhydrous ethanol, and then dried in a 60℃ oven for 24h to obtain a high-entropy alloy FeCoNiCuW microwave absorbing material.

[0040] Step 3: Place the obtained high-entropy alloy FeCoNiCuW microwave absorbing material in an Ar2 atmosphere and heat treat it at 700℃ for 2 hours.

[0041] Comparative Example 1 (with Example 6 as the control group, Comparative Example 1 did not undergo the heat treatment step, and the other steps remained unchanged). Step 1: Heat deionized water to 80℃ and maintain the temperature. Measure 100mL of deionized water and add 0.25mol / L boric acid and 0.25mol / L citric acid monohydrate sequentially, stirring to dissolve. Add 0.01mol / L ferrous sulfate heptahydrate, 0.02mol / L cobalt sulfate heptahydrate, 0.012mol / L copper sulfate pentahydrate, and 0.02mol / L nickel sulfate hexahydrate, stirring until homogeneous. Add 0.02mol / L sodium tungstate dihydrate and 0.035mol / L ascorbic acid, stirring until completely dissolved. Finally, add 0.0055mol / L sodium dodecyl sulfate and stir until homogeneous to obtain the electrolyte. Add 6mol / L sodium hydroxide solution to the electrolyte to adjust the pH to 7.0.

[0042] Step 2: Using a platinum sheet as the anode and a stainless steel sheet as the conductive substrate, constant potential electroplating is performed. The electrodeposition potential is -3.0V, the deposition temperature is 40℃, and the deposition time is 10min. The electroplated material is washed several times with deionized water and anhydrous ethanol, and then dried in a 60℃ oven for 24h to obtain a high-entropy alloy FeCoNiCuW microwave absorbing material.

[0043] Testing experiment: 1. Scanning electron microscope (SEM) images of the high-entropy alloy FeCoNiCuW microwave absorbing materials prepared in Examples 1-2 are shown below. Figure 1 , Figure 2 As shown; Scanning electron microscope (SEM) images of the high-entropy alloy FeCoNiCuW microwave absorbing materials prepared in Examples 5-6 are shown below. Figure 3 , Figure 4 As shown; the X-ray diffraction patterns of the high-entropy alloy FeCoNiCuW microwave absorbing materials prepared in Examples 2, 5, and 6 are as follows. Figure 5 As shown; simultaneously, the microwave absorption performance of the high-entropy alloy FeCoNiCuW microwave absorbing materials prepared in Examples 1 and 6 was tested, and the results are as follows. Figure 6 , Figure 7 As shown; the elemental composition of the absorbing materials in Examples 1-2 was tested, and the results are as follows. Figure 8As shown.

[0044] 2. The reflection loss of the circular ring within the frequency range of 2~18 GHz was measured using the coaxial method. The high-entropy FeCoNiCuW absorbing materials prepared in Examples 1 and 6 yielded the following results: Figure 6 , Figure 7 As shown, the reflection loss is below -10dB in the range of 5~18GHz, and the lowest reflection loss (1.60mm) can reach -49GHz. With a thickness of 1.50mm, it has the largest effective absorption frequency band exceeding 6GHz, which shows excellent absorption performance and provides potential for the application of this alloy in the field of electromagnetic wave absorption.

[0045] Conclusion: This invention uses different porous materials as conductive substrates and achieves synergistic reduction and in-situ assembly of multiple metal ions (Fe, Co, Ni, Cu, W) during electrodeposition, forming a tightly bonded interface between the alloy layer with a high-entropy structure and the substrate. The resulting composite material combines the magnetic loss of the high-entropy alloy with the conductive network advantages of the substrate, effectively improving impedance matching and interface polarization capabilities, thereby achieving wide-bandwidth, high-efficiency, and stable electromagnetic wave absorption performance. This invention achieves in-situ bonding of the high-entropy alloy and the substrate through low-temperature electrodeposition, which not only simplifies the preparation process and improves the bonding strength but also provides a new technical path for the design and engineering application of high-performance electromagnetic protection materials. The resulting composite material exhibits excellent structural stability and wave absorption performance and can be widely used in electromagnetic protection, radar stealth, and high-frequency communication, showing promising prospects for industrial application.

[0046] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0047] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. 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 high-entropy alloy FeCoNiCuW microwave absorbing material, characterized in that: Includes the following steps: Step 1: Prepare the electrolyte, which includes the following components: ferrous sulfate heptahydrate, cobalt sulfate heptahydrate, copper sulfate pentahydrate, nickel sulfate hexahydrate, sodium tungstate dihydrate, complexing agent, buffer, reducing agent, and surfactant; adjust the pH of the electrolyte to 6.0~7.0; Step 2: Using an electrode rod as the anode and a conductive substrate as the cathode, electrodeposition is performed on the surface of the conductive substrate using the electrolyte prepared in Step 1 to obtain FeCoNiCuW microwave absorbing material. Step 3: Heat-treat the FeCoNiCuW microwave absorbing material prepared in Step 2.

2. The preparation method of a high-entropy alloy FeCoNiCuW microwave absorbing material according to claim 1, characterized in that: In step 1, the steps for preparing the electrolyte are as follows: add the buffer and complexing agent to deionized water and stir until dissolved, then add ferrous sulfate heptahydrate, cobalt sulfate heptahydrate, copper sulfate pentahydrate, nickel sulfate hexahydrate, and sodium tungstate dihydrate and stir until dissolved, and finally add the reducing agent and surfactant and continue stirring until dissolved to obtain the electrolyte.

3. The preparation method of a high-entropy alloy FeCoNiCuW microwave absorbing material according to claim 2, characterized in that: The buffer is any one or more of boric acid, disodium hydrogen phosphate, phosphoric acid, acetic acid, acetic acid, and sodium carbonate; the complexing agent is any one or more of citric acid monohydrate, sodium citrate, potassium pyrophosphate, oxalic acid, and sodium tripolyphosphate; the reducing agent is ascorbic acid or sodium hypophosphite; and the surfactant is any one or more of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, and sodium hexametaphosphate.

4. The preparation method of a high-entropy alloy FeCoNiCuW microwave absorbing material according to claim 1, characterized in that: In step 1, the electrolyte composition is as follows: boric acid 0.1~0.5 mol / L, citric acid monohydrate 0.1~0.4 mol / L, ferrous sulfate heptahydrate 0.01~0.1 mol / L, cobalt sulfate heptahydrate 0.01~0.1 mol / L, copper sulfate pentahydrate 0.01~0.05 mol / L, nickel sulfate hexahydrate 0.01~0.05 mol / L, sodium tungstate dihydrate 0.01~0.1 mol / L, sodium dodecyl sulfate 0.004~0.05 mol / L, and ascorbic acid 0.03~0.1 mol / L.

5. The method for preparing a high-entropy alloy FeCoNiCuW microwave absorbing material according to claim 1, characterized in that: In step 2, a constant potential is used during electrodeposition, with the electrodeposition potential range being -4.5V to -2.5V, the deposition temperature being 20℃ to 80℃, and the deposition time range being 5min to 30min.

6. The preparation method of a high-entropy alloy FeCoNiCuW microwave absorbing material according to claim 1, characterized in that: In step 2, the electrode rod is any one of graphite, platinum sheet, and titanium sheet; the conductive substrate is any one of copper sheet, titanium sheet, nickel foam, copper foam, aluminum sheet, stainless steel sheet, carbon cloth, and carbon foam.

7. The method for preparing a high-entropy alloy FeCoNiCuW microwave absorbing material according to claim 1, characterized in that: In step 3, the heat treatment temperature is 500℃~800℃, the holding time is 1h~3h, and the heat treatment atmosphere is Ar2 or Ar2 / H2.

8. The method for preparing a high-entropy alloy FeCoNiCuW microwave absorbing material according to claim 1, characterized in that: In step 2, a pretreatment step is performed before electrodeposition on the conductive substrate. The pretreatment step includes ultrasonic cleaning with acetone, anhydrous ethanol, and deionized water for 10 to 15 minutes in sequence, followed by drying.

9. The method for preparing a high-entropy alloy FeCoNiCuW microwave absorbing material according to claim 1, characterized in that: The proportions of each metal element in the FeCoNiCuW microwave absorbing material are between 5% and 50%.

10. A high-entropy alloy FeCoNiCuW microwave absorbing material prepared by the preparation method according to any one of claims 1 to 9.

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