High-entropy alloy coating and preparation method thereof

Abstract

The invention discloses a high-entropy alloy coating and a preparation method thereof, and relates to the technical field of preparation of high-entropy alloy coatings. The high-entropy alloy and the coating of the high-entropy alloy do not contain silicon elements, and the preparation method comprises the steps that according to the composition proportion of the high-entropy alloy, a magnetron sputtering technology is adopted, metal elementary substance targets of all components serve as sputtering target materials for sputtering, elementary substance films are sequentially deposited on a base body, and a multi-layer film precursor is formed; and then the multi-layer film precursor is subjected to vacuum annealing, so that the single-layer uniform high-entropy alloy coating is obtained. According to the method, accurate preparation of the multi-layer film precursor can be achieved by accurately controlling the sputtering rate or sputtering power of all elements, then the elements in the multi-layer film precursor are fully mixed through vacuum annealing treatment, and the uniform high-entropy alloy coating is formed. The high-entropy alloy coating prepared by the process, such as an AlCoCrFeNi high-entropy alloy coating, has excellent structural uniformity, and is suitable for the high and new technical fields of aerospace, energy engineering and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of preparing high-entropy alloy coatings, and particularly to a high-entropy alloy coating and a preparation method thereof. Background Art

[0002] High-entropy alloys are alloys composed of five or more main elements, having a unique disordered solid-solution structure or amorphous structure, and exhibiting excellent mechanical, corrosion-resistant, high-temperature-resistant and other properties. In recent years, high-entropy alloy coatings have gradually attracted the attention of researchers due to their unique structural and performance advantages. The AlCoCrFeNi high-entropy alloy coating has received extensive attention for its high strength, high hardness, excellent corrosion resistance, good high-temperature softening resistance and excellent thermal stability. Its performance can be further optimized by adjusting the composition and heat treatment process, making it show great application potential in high-tech fields such as aerospace, energy engineering, and nuclear industry. In addition, the AlCoCrFeNi high-entropy alloy also has excellent anti-irradiation performance and fatigue performance, making its application in extreme environments more reliable. These characteristics make the AlCoCrFeNi high-entropy alloy coating a hot field in materials science research.

[0003] Currently, the main methods for preparing high-entropy alloy coatings include thermal magnetron sputtering, electrochemical deposition, thermal spraying, etc. Among them, magnetron sputtering is widely used due to its mature process and high coating quality. Currently, the preparation methods disclosed by many production enterprises and research institutions directly use alloy targets for magnetron sputtering to prepare coatings, but it is difficult to prepare coatings with a thickness greater than 50 μm by this method. In addition, there is a serious problem with this preparation process, that is, it is difficult to precisely control the chemical composition of the coating. Due to the difference in sputtering ability between elements, it is difficult to keep the components of the prepared coating consistent with those of the target, and problems such as uneven element distribution and composition segregation are likely to occur, seriously affecting the performance and application of the coating. Therefore, it is necessary to develop a new preparation process to solve these problems and prepare high-entropy alloy coatings with excellent performance, especially AlCoCrFeNi high-entropy alloy coatings. Summary of the Invention

[0004] The object of the present invention is to provide a high-entropy alloy coating and a preparation method thereof for the deficiencies in the above-mentioned prior art. This method can precisely prepare a multilayer film precursor by precisely controlling the sputtering rate or sputtering power of each element, and then through vacuum annealing treatment, the elements in the multilayer film precursor are fully mixed to form a uniform high-entropy alloy coating. The high-entropy alloy coating prepared by this process, such as the AlCoCrFeNi high-entropy alloy coating, has excellent structural uniformity and is suitable for high-tech fields such as aerospace and energy engineering.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] In a first aspect, a method for preparing a high-entropy alloy coating, the high-entropy alloy and its coating do not contain silicon element, and the preparation method includes: according to the composition ratio of the high-entropy alloy, using magnetron sputtering technology, taking the metal single-element targets of each component as sputtering targets for sputtering, so as to sequentially deposit single-element films on the substrate to form a multi-layer film precursor; then vacuum annealing the multi-layer film precursor to obtain a single-layer uniform high-entropy alloy coating.

[0007] Further, the sputtering power is 100-300 w.

[0008] Further, the sputtering rate is 15-25 nm / min.

[0009] Further, the purity of the sputtering target is greater than 99.9 wt.%.

[0010] Further, the thickness of the single-element film is 0.5-20 μm;

[0011] And / or, the thickness of the high-entropy alloy coating does not exceed 500 μm.

[0012] Further, based on the multi-layer film precursor as a basic unit, the high-entropy alloy coating includes at least one of the basic units.

[0013] Further, during the vacuum annealing, the vacuum degree is lower than 5.0×10 -5 Pa; and / or, the annealing temperature is controlled below the recrystallization temperature of the substrate and ensured to be higher than 500 °C; and / or, the heating rate of annealing is 10-20 °C / s; and / or, the holding time of annealing is 2-5 h.

[0014] Further, the substrate includes steel or glass;

[0015] And / or, the high-entropy alloy includes at least one of AlCoCrFeNi high-entropy alloy, FeCoNiCuMn high-entropy alloy, FeCoNiAlMn high-entropy alloy, CoCrFeMnNi high-entropy alloy, CoCrFeNiTi high-entropy alloy, AlCoCrCuFeNi high-entropy alloy, CoCrFeNiMo high-entropy alloy, CoCrFeNiCu high-entropy alloy, CoCrFeNiNb high-entropy alloy, FeCoNiCuZr high-entropy alloy and FeCrCoZrNi high-entropy alloy;

[0016] And / or, the substrate is a clean substrate;

[0017] And / or, after the substrate is soaked in ethanol, ultrasonically cleaned to remove surface dirt, then sputtering film deposition is carried out.

[0018] Further, the atomic percentage composition of the AlCoCrFeNi high-entropy alloy is: Al 15.0-25.0 at.%, Co 15.0-25.0 at.%, Cr 15.0-25.0 at.%, Fe 15.0-25.0 at.%, Ni 15.0-25.0 at.%, and the total amount of inevitable impurities is not more than 0.5 at.%;

[0019] And / or, the atomic percentage composition of the FeCoNiAlMn high-entropy alloy is: Fe 10.0-30.0 at.%, Co 10.0-30.0 at.%, Ni 10.0-30.0 at.%, Al 10.0-30.0 at.%, Mn 10.0-30.0 at.%, and the total amount of inevitable impurities is not more than 0.5 at.%;

[0020] And / or, the atomic percentage composition of the FeCoNiCuMn high-entropy alloy is: Fe 15.0-25.0 at.%, Co 15.0-25.0 at.%, Ni 15.0-25.0 at.%, Cu 15.0-25.0 at.%, Mn 15.0-25.0 at.%, and the total amount of inevitable impurities is not more than 0.5 at.%;

[0021] And / or, in the AlCoCrFeNi high-entropy alloy, the multi-layer film precursor is arranged in the order of Ni / Cr / Co / Al / Fe elemental films, and the substrate is connected to the Fe elemental film;

[0022] And / or, in the FeCoNiAlMn high-entropy alloy, the multi-layer film precursor is arranged in the order of Ni / Mn / Co / Al / Fe elemental films, and the substrate is connected to the Fe elemental film;

[0023] And / or, in the FeCoNiCuMn high-entropy alloy, the multi-layer film precursor is arranged in the order of Ni / Cu / Co / Mn / Fe elemental films, and the substrate is connected to the Fe elemental film.

[0024] In a second aspect, a high-entropy alloy coating prepared by the preparation method according to any one of the first aspects.

[0025] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0026] The present invention provides a method for preparing a high-entropy alloy coating. This method adopts a two-step process. First, corresponding elemental targets are used to precisely deposit multiple layers of precursors through magnetron sputtering technology. Then, through rapid vacuum annealing treatment, complete diffusion and mixing of atoms are achieved, thereby preparing a high-entropy alloy coating with uniform composition and dense structure, such as an AlCoCrFeNi high-entropy alloy coating. This method can precisely control the chemical composition of the coating, ensuring the consistency and repeatability of the coating composition, which is crucial for manufacturing high-performance coating materials. In addition, this method can also flexibly regulate the microstructure and phase composition of the coating by adjusting the sputtering time and heat treatment conditions, providing broad space for further optimizing the performance of the coating. The flexibility, accuracy, and reliability of this preparation method provide strong technical support for the industrial production and application of high-entropy alloy coatings. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0028] Figure 1 Schematic diagram of the magnetron sputtering equipment used for preparing the multi-layer film precursor;

[0029] Figure 2 Schematic diagram of the preparation of the high-entropy alloy coating of the present invention;

[0030] Figure 3 AES test diagram of the high-entropy alloy coating obtained in Example 1 of the present invention;

[0031] Figure 4 AES test diagram of the high-entropy alloy coating obtained in Comparative Example 6 of the present invention;

[0032] Figure 5 AES test diagram of the high-entropy alloy coating obtained in Comparative Example 7 of the present invention;

[0033] Figure 6 AES test diagram of the high-entropy alloy coating obtained in Comparative Example 8 of the present invention;

[0034] Figure 7 AES test diagram of the high-entropy alloy coating obtained in Example 7 of the present invention;

[0035] Figure 8 AES test diagram of the high-entropy alloy coating obtained in Example 8 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] To make the objectives, technical solutions, and advantages of the present invention clearer, the following further describes the present invention with reference to embodiments. The embodiments of the present invention are implemented on the premise of the technical solutions of the present invention, and detailed implementation manners and processes are given. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention. The protection scope of the present invention is not limited to the following embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.

[0037] In the embodiments of the present invention, process parameters without specific conditions are usually carried out according to conventional conditions. Unless otherwise specified and / or described, throughout, all numerical values related to the dosage of components are "numerical values or ratios of mass". Unless otherwise specified, the raw materials used in the present invention can be obtained from commercially available products.

[0038] In the present invention, the endpoints and any values of the disclosed ranges are not limited to the exact ranges or values. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed in the present invention.

[0039] According to a first aspect of the present invention, a method for preparing a high-entropy alloy coating, wherein the high-entropy alloy and its coating do not contain silicon elements, and the preparation method includes: according to the component ratio of the high-entropy alloy, using magnetron sputtering technology, using the metal elemental targets of each component as sputtering targets for sputtering to sequentially deposit elemental films on a substrate to form a multi-layer film precursor; and then performing vacuum annealing on the multi-layer film precursor to obtain a single-layer uniform high-entropy alloy coating.

[0040] The preparation method of the high-entropy alloy coating of the present invention can precisely control the components, enabling the obtained high-entropy alloy coating to have excellent structural uniformity and being applicable to high-tech fields such as aerospace and energy engineering. This method adopts a two-step process. In the first step, a multi-layer film precursor is precisely deposited by magnetron sputtering technology using corresponding elemental targets, ensuring that the designed amounts of various elements in the high-entropy alloy can be stably and accurately deposited on the substrate, avoiding the deviation between the deposition amount and the designed amount caused by the different sputtering rates of each element under the same sputtering power when directly using a high-entropy alloy target for sputtering. It should be noted that this method is applicable to the preparation of high-entropy alloy coatings without silicon elements because, limited by the conditions of existing preparation equipment, it is difficult to prepare a single-element silicon coating with extremely high purity, and impurities such as SiO2 and SiC doped therein will seriously affect the subsequent annealing homogenization effect. Therefore, the method of the present invention is applicable to the preparation of high-entropy alloy coatings without silicon. In the second step, complete diffusion and mixing of the atoms of each metal single layer are achieved through vacuum annealing treatment, thereby preparing a single-layer high-entropy alloy coating with uniform composition and dense structure, such as an AlCoCrFeNi high-entropy alloy coating. This method can precisely control the chemical composition of the coating, ensuring the consistency and repeatability of the coating composition, which is crucial for manufacturing high-performance coating materials.

[0041] In addition, this method can also flexibly control the microstructure and phase composition of the coating by adjusting the sputtering time and heat treatment conditions, providing a broad space for further optimizing the performance of the coating. The flexibility, accuracy, and reliability of this preparation method provide a solid technical foundation and strong technical support for the industrial / commercial production of high-entropy alloy coatings and their applications in multiple fields.

[0042] As an optional implementation mode of the preparation method of the present invention, the sputtering power is 100 - 300 w; and / or, the sputtering rate is 15 - 25 nm / min.

[0043] In the present invention, the sputtering power can be controlled within 100 - 300 W to measure the sputtering rate. By ensuring that the sputtering rate of each elemental metal target is within 15 - 25 nm / min, a uniform and dense elemental layer can be obtained. Generally, different sputtering powers result in different sputtering rates. Moreover, for different instruments and equipment, even with the same sputtering power, the sputtering rate of each instrument is different. To ensure accuracy, it is generally necessary to first measure the sputtering rate (depositing a thin film of a certain thickness at a certain sputtering power within a certain time, and the thickness of the thin film deposited per unit time can be obtained, which is the sputtering rate). Since the sputtering rate has a certain relationship with the density and surface roughness of the thin film, to ensure the density and surface roughness of the elemental metal thin film, its sputtering rate is controlled within 15 - 25 nm / min, not too fast, in order to obtain a dense and uniform thin film. The sputtering rate can typically but not exclusively be selected as 16 nm / min, 18 nm / min, 20 nm / min, 22 nm / min, 24 nm / min, etc.

[0044] In addition, the sputtering rate can also be controlled by controlling the sputtering power. The sputtering power is 100 - 300 W, and can typically but not exclusively be selected as 110 W, 130 W, 150 W, 170 W, 190 W, 210 W, 230 W, 250 W, 270 W, 290 W, etc. When the sputtering power is too high, the surface temperature of the target will rise sharply, which may cause the target to overheat or even melt. In addition, too high a power may also cause an insulating layer to form on the surface of the target, thereby affecting the deposition rate and the quality of the thin film. While too low a power will lead to a significant reduction in the deposition rate, prolong the time for preparing the thin film, and may also affect the production efficiency.

[0045] As an alternative embodiment of the preparation method of the present invention, the purity of the sputtering target is greater than 99.9 wt.%.

[0046] And / or, the thickness of the elemental film is 0.5 - 20 μm;

[0047] And / or, the thickness of the high-entropy alloy coating does not exceed 500 μm.

[0048] In the present invention, according to the element ratio of the high-entropy alloy, the thickness of the single-element film corresponding to each element is determined, and a multi-layer film precursor conforming to the expected composition is designed. Using the magnetron sputtering technique, each metal single-element target with a purity greater than 99.9 wt.% such as Al, Co, Cr, Fe, and Ni metal targets is used as the sputtering target material. By precisely controlling the sputtering time and sputtering power (rate) of each metal single-element target (element), a single-element film with the required thickness (content) is obtained, and the single-element films are sequentially deposited on the substrate to form a multi-layer film precursor. Among them, the thickness of any single-element film is controlled within 0.5 - 20 μm, typically but not limited to 1 μm, 2 μm, 4 μm, 6 μm, 8 μm, 10 μm, 12 μm, 14 μm, 16 μm, 18 μm, etc. This avoids the situation that if the single-element film is too small, it will affect the preparation efficiency and multiple repeated preparations are required to obtain a multi-layer film with the required thickness; it also avoids the situation that if the single-element film is too large, it may lead to insufficient interlayer diffusion under the same annealing conditions and a high-entropy alloy cannot be formed.

[0049] Preferably, the prepared multi-layer film precursor is placed in a vacuum rapid annealing furnace for vacuum rapid annealing treatment to obtain a high-entropy alloy coating with uniform composition. For vacuum rapid annealing, its heating rate is faster than that of ordinary vacuum annealing, which can shorten the time used in the annealing process to a certain extent and minimize the influence of the residual oxygen in the vacuum furnace on the film.

[0050] More preferably, the multi-layer film precursor is used as a basic unit for repeated stacking to prepare a high-entropy alloy coating with a total thickness exceeding 50 μm and up to 500 μm. Therefore, as an optional implementation scheme, based on the multi-layer film precursor as the basic unit, the high-entropy alloy coating includes at least one such basic unit.

[0051] In the present invention, the substrate can be steel or glass. For example, materials such as 45# steel and quartz glass can be used as the substrate. However, it should be noted that the substrate before sputtering the film layer should be a substrate with a clean surface to avoid the influence of the dirt on the surface of the substrate on the performance of the sputtered film layer. Specifically, the substrate can be cleaned in the following ways before sputtering the film layer: such as soaking the substrate in ethanol and ultrasonic cleaning the substrate to remove the surface dirt.

[0052] In the present invention, the high-entropy alloy includes AlCoCrFeNi high-entropy alloy, FeCoNiCuMn high-entropy alloy, FeCoNiAlMn high-entropy alloy, CoCrFeMnNi high-entropy alloy, CoCrFeNiTi high-entropy alloy, AlCoCrCuFeNi high-entropy alloy, CoCrFeNiMo high-entropy alloy, CoCrFeNiCu high-entropy alloy, CoCrFeNiNb high-entropy alloy, FeCoNiCuZr high-entropy alloy, FeCrCoZrNi high-entropy alloy, etc. Among them, the atomic percentage composition of the AlCoCrFeNi high-entropy alloy is: Al 15.0-25.0 at.%, Co 15.0-25.0 at.%, Cr 15.0-25.0 at.%, Fe 15.0-25.0 at.%, Ni 15.0-25.0 at.%, and the total amount of inevitable impurities is not more than 0.5 at.%. In its high-entropy alloy coating, the multilayer film is arranged in the order of Ni / Cr / Co / Al / Fe elemental films, and the substrate is connected to the Fe elemental film.

[0053] The atomic percentage composition of the FeCoNiAlMn high-entropy alloy is: Fe 10.0-30.0 at.%, Co 10.0-30.0 at.%, Ni 10.0-30.0 at.%, Al 10.0-30.0 at.%, Mn 10.0-30.0 at.%, and the total amount of inevitable impurities is not more than 0.5 at.%. In its high-entropy alloy coating, the multilayer film is arranged in the order of Ni / Mn / Co / Al / Fe elemental films, and the substrate is connected to the Fe elemental film.

[0054] The atomic percentage composition of the FeCoNiCuMn high-entropy alloy is: Fe 15.0-25.0 at.%, Co 15.0-25.0 at.%, Ni 15.0-25.0 at.%, Cu 15.0-25.0 at.%, Mn 15.0-25.0 at.%, and the total amount of inevitable impurities is not more than 0.5 at.%. In its high-entropy alloy coating, the multilayer film is arranged in the order of Ni / Cu / Co / Mn / Fe elemental films, and the substrate is connected to the Fe elemental film.

[0055] As an alternative implementation of the preparation method of the present invention, during the vacuum annealing, the vacuum degree is lower than 5.0×10 -5 Pa; and / or, the annealing temperature is controlled below the recrystallization temperature of the substrate and ensured to be higher than 500 °C; and / or, the heating rate of annealing is 10-20 °C / s; and / or, the holding time of annealing is 2-5 h.

[0056] In the present invention, the prepared multilayer film precursor is subjected to vacuum annealing. While preventing the oxidation of each elemental layer by oxygen, the elemental layers are mixed and diffused with each other under heating, thereby obtaining a single-layer and uniformly mixed consistent high-entropy alloy coating. Specifically, the vacuum degree during vacuum annealing is controlled to be lower than 5.0×10 -5 Pa. It should be noted that the multilayer film precursor is attached to the substrate for vacuum annealing. Therefore, when controlling the annealing temperature and heating rate, the situation of the substrate should also be considered in addition to the multilayer film precursor. Thus, the annealing temperature is controlled below the recrystallization temperature of the substrate to avoid deformation of the substrate or reaction with the multilayer film precursor due to too high annealing temperature. At the same time, it is necessary to ensure that the annealing temperature is higher than 500 °C to avoid insufficient interlayer diffusion of the multilayer film precursor and inability to form a high-entropy alloy. Specifically, the annealing temperature can be not higher than 900 °C, and typically but not limitedly, it can be selected as 510 °C, 550 °C, 600 °C, 700 °C, 800 °C, 900 °C, etc.

[0057] Regarding the control of the heating rate, the heating rate can be controlled at 10-20 °C / s. Typically but not limitedly, it can be selected as 11 °C / s, 12 °C / s, 13 °C / s, 14 °C / s, 15 °C / s, 16 °C / s, 17 °C / s, 18 °C / s, 19 °C / s, etc. This can not only take into account the different thermal conductivities and specific heat capacities of different materials and avoid defects such as cracking between the coating and the substrate or cracks in the coating itself, but also can shorten the time used for the annealing process to a certain extent and minimize the influence of the residual oxygen in the vacuum furnace on the film.

[0058] In addition, the holding time is controlled to be 2-5 h. Typically but not limitedly, it can be selected as 2.5 h, 3 h, 3.5 h, 4 h, 4.5 h, etc. Specifically, it can be selected according to the basic unit amount of the multilayer film precursor in the high-entropy alloy coating to ensure that the elemental films in the high-entropy alloy coating with the required thickness are diffused and mixed with each other sufficiently.

[0059] According to the second aspect of the present invention, a high-entropy alloy coating prepared by the preparation method as described in the first aspect.

[0060] Optionally, the high-entropy alloy coating is an AlCoCrFeNi high-entropy alloy coating, the substrate is 45# steel, and the atomic percentage composition of the high-entropy alloy is: Al 15.0-25.0 at.%, Co 15.0-25.0 at.%, Cr 15.0-25.0 at.%, Fe 15.0-25.0 at.%, Ni 15.0-25.0 at.%, and the total amount of inevitable impurities is not more than 0.5 at.%.

[0061] The high-entropy alloy coating of the present invention, such as the AlCoCrFeNi high-entropy alloy coating, is prepared by a two-step method combining magnetron sputtering and rapid annealing. It can quickly and accurately regulate the chemical composition of the coating, ensuring the consistency and reproducibility of the coating components during the production process, which is crucial for the production of high-performance coatings. At the same time, by adjusting the sputtering parameters and heat treatment conditions, the microstructure and phase composition of the coating can be regulated, providing a broad space for further optimizing the performance of the coating.

[0062] The high-entropy alloy coating of the present invention, such as the AlCoCrFeNi high-entropy alloy coating, has excellent structural uniformity and is applicable to high-tech fields such as aerospace and energy engineering.

[0063] The following further describes the present invention in detail with specific embodiments.

[0064] Examples 1-6

[0065] Examples 1-6 all provide an AlCoCrFeNi high-entropy alloy coating, and their specific alloy atomic percentage components are shown in Table 1:

[0066] Table 1 Alloy atomic percentage components of AlCoCrFeNi high-entropy alloy coatings in Examples 1-6

[0067]

[0068]

[0069] To obtain the above AlCoCrFeNi high-entropy alloy coating, the following method is specifically used for preparation, including:

[0070] S1. According to the composition, use the Figure 1 shown device and the corresponding elemental targets of Fe, Al, Co, Cr, and Ni for sputtering respectively, control the sputtering power between 150 and 250 w, and the sputtering time for each is 60 min.

[0071] Among them, the magnetron sputtering parameters include: the substrate is 45# steel, the substrate temperature is 25 °C, the base vacuum is less than 5.0×10 - 5 Pa, the sputtering gas pressure is 8.0×10 -1 Pa, the sputtering gas is argon, and the argon flow rate is 3 sccm.

[0072] S2. Use a step instrument to measure the thickness of the five elemental films respectively, calculate the sputtering rate (sputtering rate = elemental film thickness / total time used to sputter the film of this thickness), and the sputtering power and sputtering rate corresponding to the five targets are shown in Table 2:

[0073] Table 2. Sputtering parameters of Al, Co, Cr, Fe, and Ni targets for the preparation of Examples 1-6

[0074]

[0075] S3. Design the multilayer film precursors for each example according to the ratios in Table 1, as Figure 2 shown. Specifically, according to the coating element ratios, determine the thickness of the single-element film corresponding to each element, and design a multilayer film precursor that meets the expected composition; in the multilayer film precursor, the single-element films are arranged in the order of Ni / Cr / Co / Al / Fe, and the thickness of the single-element film is controlled within 0.5 - 20 μm. In addition, the substrate is connected to the Fe single-element film in the multilayer film precursor, and the Ni / Cr / Co / Al / Fe multilayer film precursor can be repeatedly stacked and prepared multiple times as a basic unit, thereby obtaining high-entropy alloy coatings with different total thicknesses;

[0076] The thicknesses of the single-element films in the multilayer film precursor, the number of times of preparing the basic unit, and the total thickness of the obtained high-entropy alloy coatings in the preparation of Examples 1 - 6 are shown in Table 3:

[0077] Table 3. Thicknesses of the single-element films, the number of times of preparing the basic unit, and the total thickness of the obtained high-entropy alloy coatings in the preparation of Examples 1 - 6

[0078]

[0079] S4. Soak the substrate (45# steel) in ethanol and ultrasonically clean it to remove the dirt on the substrate surface, obtaining a clean substrate.

[0080] S5. Adopt the magnetron sputtering technology obtained in the aforementioned steps S1 and S2 (the substrate is 45# steel, the substrate temperature is 25°C, the background vacuum is less than 5.0×10 -5 Pa, the sputtering gas pressure is 8.0×10 -1 Pa, the sputtering gas is argon, and the argon gas flow rate is 3 sccm), accurately control the sputtering time and sputtering power / rate of each target according to Table 2, adjust the position of the sample stage, and sequentially deposit single-element films on the clean substrate obtained in step S4 to obtain a multilayer film precursor that meets the expected design thickness and composition in step S3.

[0081] S6. Place the multilayer film precursor prepared in step S5 in a vacuum annealing furnace for vacuum annealing. The vacuum degree is lower than 5.0×10 -5 Pa, the annealing temperature is set at 600°C, which is both below the recrystallization temperature of the substrate (the recrystallization temperature of 45# steel is about 1160°C) and higher than 500°C. The heating rate is 10 - 20°C / s, and the holding time is 2 - 5 h to obtain an AlCoCrFeNi high-entropy alloy coating.

[0082] Among them, the annealing systems used in Examples 1 to 6 are shown in Table 4:

[0083] Table 4 Annealing systems used in the preparation of Examples 1 to 6

[0084]

[0085]

[0086] Example 7

[0087] Example 7 provides an FeCoNiAlMn high-entropy alloy coating, and the atomic percentage composition of the alloy is: Fe 25 at.%, Co 20 at.%, Ni 30 at.%, Al 15 at.%, Mn 10 at.%, and the total amount of inevitable impurities is not more than 0.5 at.%.

[0088] The FeCoNiAlMn high-entropy alloy coating is prepared by the following method, including:

[0089] S1. According to the composition, the corresponding elemental targets of Fe, Co, Ni, Al, and Mn are used for sputtering respectively, and the sputtering power is controlled between 150 and 250 w, and the sputtering time for each is 60 min.

[0090] Among them, the magnetron sputtering parameters include: the substrate is 45# steel, the substrate temperature is 25 °C, the background vacuum is less than 5.0×10 - 5 Pa, the sputtering gas pressure is 8.0×10 -1 Pa, the sputtering gas is argon, and the argon gas flow rate is 3 sccm.

[0091] S2. Use a step instrument to measure the thickness of the five elemental films respectively, and calculate the sputtering rate (sputtering rate = elemental film thickness / total time used to sputter the film of this thickness). The sputtering power and sputtering rate corresponding to the five targets are shown in Table 5:

[0092] Table 5 Sputtering parameters of elemental targets used in the preparation of Example 7

[0093]

[0094] S3. Design a multilayer film precursor according to the ratio. Specifically, according to the coating element ratio, determine the thickness of the elemental film corresponding to each element (Al 1.25 μm, Co 1.0 μm, Cr 0.75 μm, Fe 1.0 μm, Mn 1.0 μm). The elemental film sequence in the multilayer film precursor is arranged in the order of Ni / Mn / Co / Al / Fe, and the substrate is connected to the Fe elemental film in the multilayer film precursor. The total thickness of the multilayer film is 5.0 μm;

[0095] S4. The substrate (45# steel) is soaked in ethanol and ultrasonically cleaned to remove the dirt on the substrate surface, obtaining a clean substrate.

[0096] S5. Using the magnetron sputtering technology obtained in the aforementioned steps S1 and S2 (the substrate is 45# steel, the substrate temperature is 25 °C, the background vacuum is less than 5.0×10 -5 Pa, the sputtering pressure is 8.0×10 -1 Pa, the sputtering gas is argon, and the argon gas flow rate is 3 sccm), accurately control the sputtering time and sputtering power / rate of each target according to Table 5, adjust the position of the sample stage, and sequentially deposit elemental films on the clean substrate obtained in step S4 to obtain a multilayer film precursor that meets the expected design thickness and composition in step S3.

[0097] S6. Place the multilayer film precursor prepared in step S5 in a vacuum annealing furnace for vacuum annealing. The vacuum degree is lower than 5.0×10 -5 Pa, the annealing temperature is set at 600 °C, the heating rate is 20 °C / s, and the holding time is 2 h to obtain a FeCoNiAlMn high-entropy alloy coating.

[0098] Example 8

[0099] Example 8 provides a FeCoNiCuMn high-entropy alloy coating, and its alloy atomic percentage composition is: Fe 25 at.%, Co 25 at.%, Ni 15 at.%, Cu 15 at.%, Mn 20 at.%, and the total amount of inevitable impurities is not more than 0.5 at.%.

[0100] The FeCoNiAlMn high-entropy alloy coating is prepared by the following method, including:

[0101] S1. According to the composition, use the corresponding elemental targets of Fe, Co, Ni, Cu, and Mn for sputtering respectively, control the sputtering power between 150 and 250 w, and the sputtering time for each is 60 min.

[0102] Among them, the magnetron sputtering parameters include: the substrate is 45# steel, the substrate temperature is 25 °C, the background vacuum is less than 5.0×10 - 5 Pa, the sputtering pressure is 8.0×10 -1 Pa, the sputtering gas is argon, and the argon gas flow rate is 3 sccm.

[0103] S2. Use a step instrument to measure the thickness of the five elemental films respectively, calculate the sputtering rate (sputtering rate = elemental film thickness / total time used to sputter the film of this thickness), and the sputtering power and sputtering rate corresponding to the five targets are shown in Table 6:

[0104] Table 6. Sputtering parameter table of elemental targets for preparation in Example 8

[0105]

[0106]

[0107] S3. Design the multi-layer film precursor according to the ratio. Specifically, according to the coating element ratio, determine the thickness of the single-element film corresponding to each element (Al 1.25 μm, Co 1.0 μm, Cr 0.75 μm, Fe 1.0 μm, Mn 1.0 μm). The single-element films in the multi-layer film precursor are arranged in the order of Ni / Cu / Co / Mn / Fe. The substrate is connected to the Fe single-element film in the multi-layer film precursor. The total thickness of the multi-layer film is 5.0 μm.

[0108] S4. Immerse the substrate (45# steel) in ethanol, ultrasonically clean it to remove the dirt on the substrate surface, and obtain a clean substrate.

[0109] S5. Adopt the magnetron sputtering technology obtained in the aforementioned steps S1 and S2 (the substrate is 45# steel, the substrate temperature is 25 °C, the background vacuum is less than 5.0×10 -5 Pa, the sputtering gas pressure is 8.0×10 -1 Pa, the sputtering gas is argon, and the argon gas flow rate is 3 sccm). Accurately control the sputtering time and sputtering power / rate of each target according to Table 6, adjust the position of the sample stage, and sequentially deposit single-element films on the clean substrate obtained in step S4 to obtain a multi-layer film precursor that meets the expected design thickness and composition in step S3.

[0110] S6. Place the multi-layer film precursor prepared in step S5 in a vacuum annealing furnace for vacuum annealing. The vacuum degree is lower than 5.0×10 -5 Pa, the annealing temperature is set at 600 °C, the heating rate is 20 °C / s, and the holding time is 2 h to obtain an FeCoNiCuMn high-entropy alloy coating.

[0111] Comparative Example 1

[0112] This comparative example is a comparative experiment of Example 1, providing an AlCoCrFeNi high-entropy alloy coating. The atomic percentage composition of the alloy is: Al 25 at.%, Co 20 at.%, Cr 15 at.%, Fe 20 at.%, Ni 20 at.%, and the total amount of inevitable impurities is not more than 0.5 at.%.

[0113] The preparation method of the above AlCoCrFeNi high-entropy alloy coating is as follows:

[0114] S1. Weigh each raw material according to the designed ratio.

[0115] S2. Put the raw materials into an induction melting furnace, heat and melt them to obtain a high-entropy alloy melt.

[0116] S3. Pour the obtained high-entropy alloy melt into a Φ60 mold to prepare a high-entropy alloy casting.

[0117] S4. Further process the casting to obtain a high-entropy alloy target with a diameter of 50.8 mm and a thickness of 3 mm.

[0118] S5. Use the alloy target for sputtering, control the sputtering power at 200 w and the sputtering time at 200 min. The thickness of the obtained AlCoCrFeNi high-entropy alloy coating is 5.0 μm.

[0119] Specifically, the magnetron sputtering parameters are: the substrate is 45# steel, the substrate temperature is 25 °C, the base vacuum is less than 5.0×10 - 5 Pa, the sputtering gas pressure is 8.0×10 -1 Pa, the sputtering gas is argon, and the argon gas flow rate is 3 sccm.

[0120] S6. Place the coating prepared in step S5 in a vacuum annealing furnace for vacuum annealing. The vacuum degree is lower than 5.0×10 -5 Pa, the annealing temperature is set at 600 °C, the heating rate is 20 °C / s, and the holding time is 2 h to obtain the AlCoCrFeNi high-entropy alloy coating.

[0121] Comparative Example 2

[0122] This comparative example is a comparative experiment of Example 2, providing an AlCoCrFeNi high-entropy alloy coating. The atomic percentage composition of the alloy is: Al 20 at.%, Co 20 at.%, Cr 20 at.%, Fe 20 at.%, Ni 20 at.%, and the total amount of inevitable impurities is not more than 0.5 at.%.

[0123] The preparation method of the above AlCoCrFeNi high-entropy alloy coating is as follows:

[0124] S1. Weigh each raw material according to the designed ratio.

[0125] S2. Put the raw materials into an induction melting furnace, heat and melt them to obtain a high-entropy alloy melt.

[0126] S3. Pour the obtained high-entropy alloy melt into a Φ60 mold to prepare a high-entropy alloy casting.

[0127] S4. Further process the casting to obtain a high-entropy alloy target with a diameter of 50.8 mm and a thickness of 3 mm.

[0128] S5. Sputtering is carried out using an alloy target, controlling the sputtering power at 200 w and the sputtering time at 12000 min, and the thickness of the obtained coating is 300.0 μm.

[0129] Specifically, the magnetron sputtering parameters are as follows: the substrate is 45# steel, the substrate temperature is 25 °C, the base vacuum is less than 5.0×10 - 5 Pa, the sputtering gas pressure is 8.0×10 -1 Pa, the sputtering gas is argon, and the argon gas flow rate is 3 sccm.

[0130] S6. The coating prepared in step S5 is placed in a vacuum annealing furnace for vacuum annealing. The vacuum degree is lower than 5.0×10 -5 Pa, the annealing temperature is set at 600 °C, the heating rate is 20 °C / s, and the holding time is 4 h to obtain an AlCoCrFeNi high-entropy alloy coating.

[0131] Comparative Example 3

[0132] This comparative example is a comparative experiment of Example 4, providing an AlCoCrFeNi high-entropy alloy coating. The atomic percentage composition of the alloy is as follows: Al 15 at.%, Co 15 at.%, Cr 20 at.%, Fe 25 at.%, Ni 25 at.%, and the total amount of inevitable impurities is not more than 0.5 at.%.

[0133] The preparation method of the above AlCoCrFeNi high-entropy alloy coating is as follows:

[0134] S1. Weigh each raw material according to the designed ratio.

[0135] S2. Put the raw materials into an induction melting furnace for heating and melting to obtain a high-entropy alloy melt.

[0136] S3. Pour the obtained high-entropy alloy melt into a mold with a diameter of Φ60 to prepare a high-entropy alloy casting.

[0137] S4. The casting is further processed to obtain a high-entropy alloy target with a diameter of 50.8 mm and a thickness of 3 mm.

[0138] S5. Sputtering is carried out using the alloy target, controlling the sputtering power at 200 w and the sputtering time at 200 min, and the thickness of the obtained AlCoCrFeNi high-entropy alloy coating is 5.0 μm.

[0139] Specifically, the magnetron sputtering parameters are as follows: the substrate is 45# steel, the substrate temperature is 25 °C, the base vacuum is less than 5.0×10 - 5 Pa, the sputtering gas pressure is 8.0×10 -1Pa, the sputtering gas is argon, and the argon gas flow rate is 3 sccm.

[0140] S6. Place the coating prepared in step S5 in a vacuum annealing furnace for vacuum annealing. The vacuum degree is lower than 5.0×10 -5 Pa, the annealing temperature is set at 600 °C, the heating rate is 20 °C / s, and the holding time is 2 h to obtain an AlCoCrFeNi high-entropy alloy coating.

[0141] Comparative Example 4

[0142] This comparative example is a comparative experiment of Example 5, providing an AlCoCrFeNi high-entropy alloy coating. The atomic percentage composition of the alloy is: Al 25 at.%, Co 25 at.%, Cr 20 at.%, Fe 15 at.%, Ni 15 at.%, and the total amount of inevitable impurities is not more than 0.5 at.%.

[0143] The preparation method of the above AlCoCrFeNi high-entropy alloy coating is as follows:

[0144] S1. Weigh each raw material according to the designed ratio.

[0145] S2. Put the raw materials into an induction melting furnace and heat them to melt to obtain a high-entropy alloy melt.

[0146] S3. Pour the obtained high-entropy alloy melt into a mold with a diameter of Φ60 to prepare a high-entropy alloy casting.

[0147] S4. The casting is further processed to obtain a high-entropy alloy target with a diameter of 50.8 mm and a thickness of 3 mm.

[0148] S5. Use the alloy target for sputtering, control the sputtering power at 200 w, the sputtering time at 200 min, and the thickness of the obtained AlCoCrFeNi high-entropy alloy coating is 5.0 μm.

[0149] Specifically, the magnetron sputtering parameters are: the substrate is 45# steel, the substrate temperature is 25 °C, the base vacuum is less than 5.0×10 - 5 Pa, the sputtering gas pressure is 8.0×10 -1 Pa, the sputtering gas is argon, and the argon gas flow rate is 3 sccm.

[0150] S6. Place the coating prepared in step S5 in a vacuum annealing furnace for vacuum annealing. The vacuum degree is lower than 5.0×10 -5 Pa, the annealing temperature is set at 600 °C, the heating rate is 20 °C / s, and the holding time is 2 h to obtain an AlCoCrFeNi high-entropy alloy coating.

[0151] Comparative Example 5

[0152] This comparative example is a comparative experiment of Example 6, providing an AlCoCrFeNi high-entropy alloy coating. The atomic percentage composition of the alloy is: Al 15 at.%, Co 20 at.%, Cr 25 at.%, Fe 20 at.%, Ni 20 at.%, and the total amount of inevitable impurities is not more than 0.5 at.%.

[0153] The preparation method of the above AlCoCrFeNi high-entropy alloy coating is as follows:

[0154] S1. Weigh each raw material according to the designed ratio.

[0155] S2. Put the raw materials into an induction melting furnace and heat them to melt, obtaining a high-entropy alloy melt.

[0156] S3. Pour the obtained high-entropy alloy melt into a Φ60 mold to prepare a high-entropy alloy casting.

[0157] S4. The casting is further processed to obtain a high-entropy alloy target with a diameter of 50.8 mm and a thickness of 3 mm.

[0158] S5. Use the alloy target for sputtering, control the sputtering power at 200 w and the sputtering time at 200 min. The thickness of the obtained AlCoCrFeNi high-entropy alloy coating is 5.0 μm.

[0159] Specifically, the magnetron sputtering parameters are: the substrate is 45# steel, the substrate temperature is 25 °C, the base vacuum is less than 5.0×10 - 5 Pa, the sputtering gas pressure is 8.0×10 -1 Pa, the sputtering gas is argon, and the argon gas flow rate is 3 sccm.

[0160] S6. Place the coating prepared in step S5 in a vacuum annealing furnace for vacuum annealing. The vacuum degree is lower than 5.0×10 -5 Pa, the annealing temperature is set at 600 °C, the heating rate is 20 °C / s, and the holding time is 2 h to obtain the AlCoCrFeNi high-entropy alloy coating.

[0161] Comparative Examples 6 - 8

[0162] Comparative Examples 6 to 8 are comparative experiments of Example 1, and the difference from Example 1 is only the annealing control, as shown in Table 7 specifically:

[0163] Table 7 Annealing systems used in the preparation of Comparative Examples 6 - 8

[0164]

[0165] Testing and Results

[0166] (1) For the AlCoCrFeNi high-entropy alloy coatings prepared in Examples 1-6 and Comparative Examples 1-5, the FeCoNiAlMn high-entropy alloy coating prepared in Example 7, and the FeCoNiCuMn high-entropy alloy coating prepared in Example 8, their elemental compositions were measured using SEM-EDS, and the test results are shown in Table 8.

[0167] Table 8 Chemical Composition of Coatings (at.%)

[0168]

[0169]

[0170] From the results in the above table, it can be seen that for the AlCoCrFeNi high-entropy alloy coating, FeCoNiAlMn high-entropy alloy coating, and FeCoNiCuMn high-entropy alloy coating obtained by the method of the present invention, their actual components are closer to the designed components. In particular, by comparing the AlCoCrFeNi high-entropy alloy coatings obtained in Examples 1-6 and Comparative Examples 1-5, it can be seen that for the AlCoCrFeNi high-entropy alloy coating obtained by the method of the present invention, the deviation of its single-element component does not exceed ±0.3 at.%, and the deviation rate does not exceed 1.2%. For the AlCoCrFeNi high-entropy alloy coating prepared using an alloy target, the deviation of its single-element component is as high as 3.1 at.%, and the deviation rate can reach 15.5%. Thus, it can be seen that the preparation method of the present invention can more accurately control the components.

[0171] (2) For the AlCoCrFeNi high-entropy alloy coatings prepared in Example 1 and Comparative Examples 6-8, the FeCoNiAlMn high-entropy alloy coating prepared in Example 7, and the FeCoNiCuMn high-entropy alloy coating prepared in Example 8, AES tests were conducted, and the test results are as Figures 3 to 8 shown. It can be seen that the high-entropy alloy coatings prepared by the method of the present invention have uniform compositions and no compositional segregation, achieving complete diffusion and mixing of atoms. In particular, by comparing Example 1 with Comparative Examples 6-8, it can be seen that the method of the present invention avoids the situations where insufficient interlayer diffusion of the multilayer film precursor leads to the inability to form a high-entropy alloy (such as Comparative Examples 6 and 7) or compositional segregation (such as Comparative Example 8) caused by non-annealing or too high or too low annealing temperature.

[0172] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention are within the scope of protection of the pending claims of the present invention.

Claims

1. A preparation method of a high-entropy alloy coating, wherein the high-entropy alloy and its coating do not contain silicon element, characterized in that, The preparation method includes: according to the component ratio of the high-entropy alloy, using magnetron sputtering technology, taking the metal elemental targets of each component as sputtering targets for sputtering, so as to sequentially deposit elemental films on the substrate to form a multi-layer film precursor; then performing vacuum annealing on the multi-layer film precursor to obtain a single-layer and uniform high-entropy alloy coating.

2. The preparation method according to claim 1, characterized in that, The power of the sputtering is 100-300 w.

3. The preparation method according to claim 1, wherein The rate of the sputtering is 15-25 nm / min.

4. The preparation method according to claim 1, characterized in that, The purity of the sputtering target is greater than 99.9 wt.%.

5. The preparation method according to claim 1, characterized in that, The thickness of the elemental film is 0.5-20 μm; and / or, the thickness of the high-entropy alloy coating does not exceed 500 μm.

6. The preparation method according to claim 1, characterized in that, Based on the multi-layer film precursor as the basic unit, the high-entropy alloy coating includes at least one of the basic units.

7. According to the preparation method described in claim 1, characterized in that, During the vacuum annealing, the vacuum degree is lower than 5.0×10 - 5 Pa; and / or, the annealing temperature is controlled below the matrix recrystallization temperature and ensured to be higher than 500 °C; and / or, the heating rate of annealing is 10-20 °C / s; and / or, the holding time of annealing is 2-5 h.

8. The preparation method according to claim 1, characterized in that, The substrate includes steel or glass; and / or, the high-entropy alloy includes at least one of AlCoCrFeNi high-entropy alloy, FeCoNiCuMn high-entropy alloy, FeCoNiAlMn high-entropy alloy, CoCrFeMnNi high-entropy alloy, CoCrFeNiTi high-entropy alloy, AlCoCrCuFeNi high-entropy alloy, CoCrFeNiMo high-entropy alloy, CoCrFeNiCu high-entropy alloy, CoCrFeNiNb high-entropy alloy, FeCoNiCuZr high-entropy alloy and FeCrCoZrNi high-entropy alloy; and / or, the substrate is a clean substrate; and / or, after the substrate is soaked in ethanol and ultrasonically cleaned to remove surface dirt, sputtering film deposition is then carried out.

9. The preparation method according to claim 8, characterized in that, The atomic percentage composition of the AlCoCrFeNi high-entropy alloy is: Al 15.0-25.0 at.%, Co 15.0-25.0 at.%, Cr 15.0-25.0 at.%, Fe 15.0-25.0 at.%, Ni 15.0-25.0 at.%, and the total amount of inevitable impurities is not more than 0.5 at.%; and / or, the atomic percentage composition of the FeCoNiAlMn high-entropy alloy is: Fe 10.0-30.0 at.%, Co 10.0-30.0 at.%, Ni 10.0-30.0 at.%, Al 10.0-30.0 at.%, Mn 10.0-30.0 at.%, and the total amount of inevitable impurities is not more than 0.5 at.%; and / or, the atomic percentage composition of the FeCoNiCuMn high-entropy alloy is: Fe 15.0-25.0 at.%, Co 15.0-25.0 at.%, Ni 15.0-25.0 at.%, Cu 15.0-25.0 at.%, Mn 15.0-25.0 at.%, and the total amount of inevitable impurities is not more than 0.5 at.%; and / or, in the AlCoCrFeNi high-entropy alloy, the multi-layer film precursor is arranged in the order of Ni / Cr / Co / Al / Fe elemental films, and the substrate is connected to the Fe elemental film; And / or, in the FeCoNiAlMn high-entropy alloy, the multilayer film precursor is arranged in the order of Ni / Mn / Co / Al / Fe single-element films, and the substrate is connected to the Fe single-element film; And / or, in the FeCoNiCuMn high-entropy alloy, the multilayer film precursor is arranged in the order of Ni / Cu / Co / Mn / Fe single-element films, and the substrate is connected to the Fe single-element film.

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

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