A high-entropy alloy nanocomposite coating, a preparation method and application thereof

Abstract

The application discloses a high-entropy alloy nanocomposite coating and a preparation method and application thereof. The high-entropy alloy nanocomposite coating comprises a plurality of period layers which are arranged in a stack, each period layer comprises a VTiCrW layer and a VTiCrMo layer, and the VTiCrW layer and the VTiCrMo layer are alternately stacked in the composite coating; the composite coating is a BCC crystal structure, and a coherent interface is formed between each structure layer. The high-entropy alloy nanocomposite coating has a nanometer coherent interface, excellent low friction and wear resistance at high temperature, and is suitable for surface protection of high-temperature friction and wear parts such as brush seals of an aero-engine, thereby improving the service life and stability of the parts in operation, and having wide market application value.

Description

Technical Field

[0001] This invention belongs to the field of surface treatment technology, specifically relating to a high-entropy alloy nanocomposite coating, its preparation method, and its application. Background Technology

[0002] In harsh, high-temperature environments, moving metal components, such as brush filament seals for aero-engines, typically face the combined effects of high temperatures and high loads during service. This leads to severe frictional wear damage on the component surface, drastically reducing operational stability and service life. From an economic cost and performance stability perspective, depositing a protective coating on the component surface with good high-temperature thermal stability and excellent low-friction wear resistance is a common and effective way to mitigate component damage and failure.

[0003] Soft metals, oxides, and metal fluorides are commonly used high-temperature solid lubricants. However, these traditional lubricating and friction-reducing protective coatings exhibit poor thermal stability or mismatched tribological properties under high-temperature conditions, limiting their protective effectiveness. High-temperature moving parts require not only good thermal stability in the protective coating but also a low coefficient of friction coupled with excellent low-friction and wear-resistant properties. The key to achieving superior protective performance lies in the rational control of the lubricating and wear-resistant phase compositions and the design of the coating's microstructure within a single-phase coating. Traditional materials have a limited number of principal components, restricting the range of performance adjustments. Therefore, providing a coating that exhibits good tribological and wear-resistant protection potential under harsh environments such as high temperatures is an urgent problem to be solved. Summary of the Invention

[0004] The main objective of this invention is to provide a high-entropy alloy nanocomposite coating, its preparation method, and its application, so as to overcome the shortcomings of the prior art.

[0005] To achieve the aforementioned objectives, the technical solution adopted by this invention includes:

[0006] This invention provides a high-entropy alloy nanocomposite coating, which includes multiple periodic layers stacked together. Each periodic layer includes a VTiCrW layer and a VTiCrMo layer, and the VTiCrW layer and VTiCrMo layer are stacked alternately in the composite coating. The composite coating has a BCC crystal structure, wherein the layers are coherent interfaces.

[0007] This invention also provides a method for preparing the aforementioned high-entropy alloy nanocomposite coating, comprising:

[0008] Provide a matrix;

[0009] Furthermore, multiple periodic layers are deposited on the substrate surface using magnetron sputtering technology to obtain a high-entropy alloy nanocomposite coating.

[0010] The embodiments of the present invention also provide the application of the aforementioned high-entropy alloy nanocomposite coating in the field of surface protection of high-temperature moving parts.

[0011] Compared with existing technologies, the beneficial effects of this invention are as follows: Compared with traditional high-temperature solid lubricating coatings (such as CaF2, Ag2MoO4, V2O5 coatings), the high-entropy alloy nanocomposite coating in this invention has a BCC crystal structure, with coherent interfaces between each structural layer, and adopts a multi-principal element coating to expand the range of coating performance improvement. While utilizing V, Mo, and W to form lubricating phases under high-temperature conditions, alternating multilayer nanocoherent interfaces are formed through the alternating superposition of VTiCrMo and VTiCrW single-layer coatings, effectively improving the high-temperature stability of the coating. Furthermore, the coating forms a single-phase solid solution structure under the action of high entropy effect, and the coating surface oxidizes in situ to generate hard phases such as TiO2 under high-temperature conditions, reducing the wear rate of the coating. Thus, a unified high-temperature stability, low friction, and wear resistance performance is achieved. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1a These are the XRD patterns of the coatings prepared in Examples 1-5 of this invention. Figure 1b The XRD patterns of the coatings prepared in Comparative Examples 1-6 are shown.

[0014] Figures 2a-2c This is a TEM image of the high-entropy alloy nanocomposite coating prepared in Example 1 of this invention;

[0015] Figure 3a This is a graph showing the change of dry friction coefficient over time for the coatings of Examples 1-5 of the present invention in an atmospheric environment at 700°C;

[0016] Figure 3b The graphs show the dry friction coefficient of the coatings in Comparative Examples 1-6 as a function of time under atmospheric conditions at 700℃.

[0017] Figure 4a These are the dry wear rate diagrams of the coatings in Examples 1-5 of the present invention under atmospheric conditions at 700°C;

[0018] Figure 4b The graphs show the dry wear rate of the coatings in Comparative Examples 1-6 under atmospheric conditions at 700℃. Detailed Implementation

[0019] In view of the deficiencies of the prior art, the inventors of this invention, through long-term research and extensive practice, have proposed the technical solution of this invention. This invention designs the coating on the substrate surface as having a VTiCrMo layer or a VTiCrW layer as the initial layer, followed by alternating layers of VTiCrW or VTiCrMo to form a high-entropy alloy nanocomposite coating. This invention utilizes the lubricating phases formed by V, Mo, and W in the coating at high temperatures to reduce the coating's friction coefficient. The single-phase solid solution structure of the coating and the formation of hard phases such as TiO2 enhance the coating's wear resistance. Simultaneously, the formation of coherent interfaces between the multiple layers ensures the coating's performance stability in high-temperature environments.

[0020] The technical solution of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, 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.

[0021] Specifically, as one aspect of the technical solution of the present invention, a high-entropy alloy nanocomposite coating includes multiple periodic layers stacked together, each periodic layer including a VTiCrW layer and a VTiCrMo layer, and the VTiCrW layer and the VTiCrMo layer are alternately stacked in the composite coating; the composite coating has a BCC crystal structure, wherein the interlayers are coherent interfaces.

[0022] In some preferred embodiments, the high-entropy alloy nanocomposite coating is formed on the substrate surface, and a plurality of the periodic layers are sequentially stacked along a direction away from the substrate surface.

[0023] In some preferred embodiments, at 700°C, the dry friction coefficient of the high-entropy alloy nanocomposite coating is 0.09–0.45, and the wear rate is 5–18 × 10⁻⁶. -5 mm 3 / Nm.

[0024] In some preferred embodiments, the material of the matrix includes, but is not limited to, iron-based alloys, nickel-based alloys, or cobalt-based alloys.

[0025] In some preferred embodiments, the thickness of the high-entropy alloy nanocomposite coating is 2–3 μm.

[0026] In some preferred embodiments, the thickness of each periodic layer is 10–140 nm.

[0027] In some preferred embodiments, the thickness of the VTiCrW layer in each periodic layer is 6–80 nm, and the thickness of the VTiCrMo layer is 4–60 nm.

[0028] Another aspect of the present invention provides a method for preparing the aforementioned high-entropy alloy nanocomposite coating, comprising:

[0029] Provide a matrix;

[0030] Furthermore, multiple periodic layers are deposited on the substrate surface using magnetron sputtering technology to obtain a high-entropy alloy nanocomposite coating.

[0031] In some preferred embodiments, the preparation method specifically includes:

[0032] A VTiCrW layer is deposited on the surface of the substrate using magnetron sputtering technology with vanadium, titanium, chromium, and tungsten targets as targets. The targets are arranged in the order of V~Ti~Cr~W to form VTiCrW target sites. The sputtering bias voltage is -400~-600V, the sputtering current is 2~3A, the working gas pressure is 0.35~0.45Pa, and the deposition temperature is 50~120℃.

[0033] A VTiCrMo layer is deposited on the surface of the VTiCrW layer using magnetron sputtering technology with vanadium, titanium, chromium, and molybdenum targets as targets. The targets are arranged in the order of V~Ti~Cr~Mo to form VTiCrMo target sites. The sputtering bias voltage is -400~-600V, the sputtering current is 2~3A, the working gas pressure is 0.35~0.45Pa, and the deposition temperature is 50~120℃.

[0034] Furthermore, the VTiCrW layer and the VTiCrMo layer are alternately stacked until multiple periodic layers of the stacked arrangement are formed.

[0035] In some preferred embodiments, the preparation method specifically includes:

[0036] A VTiCrMo layer is deposited on the surface of the substrate using magnetron sputtering technology with vanadium, titanium, chromium, and molybdenum targets as targets. The targets are arranged in the order of V to Ti to Cr to Mo to form VTiCrMo target sites. The sputtering bias voltage is -400 to -600V, the sputtering current is 2 to 3A, the working gas pressure is 0.35 to 0.45Pa, and the deposition temperature is 50 to 120℃.

[0037] A VTiCrW layer is deposited on the surface of the VTiCrMo layer using magnetron sputtering technology with vanadium, titanium, chromium, and tungsten targets as targets. The targets are arranged in the order of V~Ti~Cr~W to form VTiCrW target sites. The sputtering bias voltage is -300~-600V, the sputtering current is 2~3A, the working gas pressure is 0.35~0.45Pa, and the deposition temperature is 50~120℃.

[0038] Furthermore, the VTiCrMo layer and the VTiCrW layer are alternately stacked until multiple periodic layers of the stacked arrangement are formed.

[0039] In some preferred embodiments, the time interval between the alternating deposition of the VTiCrMo layer and the VTiCrW layer is 20 to 250 seconds.

[0040] In some preferred embodiments, the thickness of the target material is 5 to 30 mm.

[0041] In some preferred embodiments, the preparation method further includes: evacuating the sputtering chamber to a vacuum level of 5 × 10⁻⁶. -3 The substrate is heated to a pressure below Pa and then subjected to plasma etching after cleaning.

[0042] In some more specific embodiments, the preparation method of the high-entropy alloy nanocomposite coating specifically includes: starting from the substrate, using a VTiCrMo layer or a VTiCrW layer as the initial layer, and then alternately stacking it with a VTiCrW layer or a VTiCrMo layer to form a high-entropy alloy nanocomposite coating, wherein the total thickness of the high-entropy alloy nanocomposite coating is 2 to 3 μm.

[0043] High-entropy alloys not only possess excellent thermal stability, but their multi-principal-element characteristics also grant them great flexibility in performance design. In recent years, high-entropy alloy coatings with carefully designed structures and compositions have demonstrated promising potential for friction and wear protection in harsh environments such as high temperatures. This invention addresses the surface friction and wear failure of components under high-temperature conditions. A high-entropy alloy coating prepared using a coherent structure design combined with the relationship between the ion potential of metal oxides and the coefficient of friction will improve the operational stability of high-temperature moving parts and alleviate friction and wear failure problems.

[0044] The high-entropy alloy nanocomposite coating of this invention has a nano-multilayer coherent structure and exhibits good thermal stability, excellent low friction and wear resistance at high temperatures. It is suitable for surface protection of high-temperature friction and wear components such as brush seals for aero engines, improving the service life and stability of the components and has broad market application value.

[0045] Another aspect of the present invention provides the use of the aforementioned high-entropy alloy nanocomposite coating in the field of surface protection of high-temperature moving parts.

[0046] Furthermore, the application is for the protection of moving parts surfaces in high-temperature environments of 650–850°C.

[0047] Furthermore, the high-temperature moving part includes a brush sealing system.

[0048] When the high-entropy alloy nanocomposite coating described in this invention is used in a high-temperature environment, it only generates simple oxides in the service environment.

[0049] The inventors in this case also conducted tribological and wear performance tests on the aforementioned high-entropy alloy nanocomposite coating.

[0050] The dry friction coefficient and wear life of the high-entropy alloy nanocomposite coating in this invention were evaluated in an atmospheric environment at 700℃ using a high-temperature friction testing machine (THT 1000). The specific experimental conditions were as follows: a ball-disc rotational sliding method was used, the friction pair ball was a Φ6mm ZrO2 ball, the rotation radius was 5mm, the sliding speed was 1cm / s, and the load was 1N.

[0051] Test results: The high-entropy alloy nanocomposite coating of this invention maintains a stable dry friction coefficient of 0.09–0.45 under high-temperature atmospheric conditions, and the wear rate is reduced to 5–18 × 10⁻⁶. -5 mm 3 / Nm, exhibiting excellent high-temperature, low-friction, and wear-resistant properties.

[0052] The technical solution of the present invention will be further described in detail below with reference to several preferred embodiments and accompanying drawings. This embodiment is implemented on the premise of the technical solution of the invention, and provides detailed implementation methods and specific operation processes. However, the protection scope of the present invention is not limited to the following embodiments.

[0053] Unless otherwise specified, the experimental materials used in the examples below can be purchased from conventional biochemical reagent companies.

[0054] Example 1

[0055] In this embodiment, the substrate material is Inconel 718 high-temperature alloy, and the substrate surface is a VTiCrMo / VTiCrW high-entropy alloy nanocomposite coating with a single-phase BCC crystal structure.

[0056] The method for preparing the multilayer coating on the substrate surface includes the following steps:

[0057] (1) Cleaning and degreasing the substrate surface

[0058] The substrate was ultrasonically cleaned in acetone solution for 30 minutes, dried with nitrogen, and then ultrasonically cleaned in anhydrous ethanol for 30 minutes, followed by drying with nitrogen.

[0059] (2) Magnetron sputtering deposition of VTiCrMo / VTiCrW high-entropy alloy nanocomposite coating

[0060] The substrate treated in step (1) was placed in a DC magnetron sputtering vacuum chamber and pre-evacuated to 5 × 10⁻⁶. -3After 30 min of plasma treatment, a pulsed DC current was turned on, with a sputtering bias of -400 V, a sputtering current of 3 A, and a working pressure of 0.4 Pa. A 30 nm VTiCrMo layer was deposited on the substrate surface. Then, the VTiCrMo target power supply was turned off, and the VTiCrW target power supply was turned on to deposit a 40 nm VTiCrW layer on the VTiCrMo surface. The VTiCrMo and VTiCrW target power supplies were switched back and forth until the total thickness of the VTiCrMo / VTiCrW high-entropy alloy nanocomposite coating reached 2.3 μm.

[0061] The VTiCrMo / VTiCrW high-entropy alloy nanocomposite coating on the substrate surface obtained after the above deposition treatment was tested as follows:

[0062] (1) Structural and compositional testing

[0063] Test results: The sample surface coating is grayish-white, with a dense and smooth surface. The XRD pattern is shown below. Figure 1a As shown, the prepared coating has a BCC crystal structure, and the TEM image is as follows. Figures 2a-2c As shown ( Figure 2c yes Figure 2b (Enlarged view of the coherent nanolayered structure), showing that its cross-section exhibits the characteristics of a coherent nanolayered structure.

[0064] (2) Friction and wear performance test

[0065] The dry friction coefficient and wear life of the VTiCrMo / VTiCrW high-entropy alloy nanocomposite coating prepared above were evaluated in a high-temperature atmospheric environment using a high-temperature friction testing machine (THT 1000). The specific experimental conditions were as follows: a ball-disc rotational sliding method was adopted, the friction pair ball was a Φ6mm ZrO2 ball with a rotation radius of 5mm, the sliding speed was 1cm / s, and the load was 1N.

[0066] Test results: such as Figure 3a and 4a As shown, the VTiCrMo / VTiCrW high-entropy alloy nanocomposite coating prepared above has an average friction coefficient of 0.17 under atmospheric conditions, a stable friction coefficient maintained at 0.10–0.15, and a wear rate reduced to 5.4 × 10⁻⁶. -5 mm 3 / Nm.

[0067] Example 2

[0068] The method is the same as in Example 1, except that VTiCrW is deposited first and then VTiCrMo layer is deposited during the preparation of VTiCrMo / VTiCrW high-entropy alloy nanocomposite coating.

[0069] Test results: The sample surface is grayish-white, dense and smooth, and the prepared coating has a BCC structure; the coating thickness is 2.6 μm; the VTiCrW / VTiCrMo coating has an average friction coefficient of 0.37 under atmospheric conditions, with a stable friction coefficient maintained between 0.35 and 0.40, and a wear rate of 7.2 × 10⁻⁶. -5 mm 3 / Nm.

[0070] Example 3

[0071] The method is the same as in Example 1, except that the VTiCrMo / VTiCrW high-entropy alloy nanocomposite coating is missing Mo, resulting in a VTiCr / VTiCrW composite coating.

[0072] Test results: The sample surface is grayish-white, dense and smooth, and the prepared coating has a BCC structure; the coating thickness is 2.4 μm; the VTiCr / VTiCrW coating has an average friction coefficient of 0.09 under atmospheric conditions, with a stable friction coefficient maintained between 0.08 and 1.12, and a wear rate of 5.8 × 10⁻⁶. -5 mm 3 / Nm.

[0073] Example 4

[0074] The method is the same as in Example 1, except that the alternating deposition interval of the VTiCrMo / VTiCrW high-entropy alloy nanocomposite coating is changed to 20s, and it is named VTiCrMo / VTiCrW-20.

[0075] Test results: The sample surface is grayish-white, dense and smooth, and the pre-prepared coating has a BCC structure; the coating thickness is 2.5 μm; the average friction coefficient is 0.30 under atmospheric conditions, the stable friction coefficient remains between 0.29 and 0.36, and the wear rate is 1.7 × 10⁻⁶. -4 mm 3 / Nm.

[0076] Example 5

[0077] The method is the same as in Example 1, except that the alternating deposition interval of the VTiCrMo / VTiCrW high-entropy alloy nanocomposite coating is changed to 360s, and it is named VTiCrMo / VTiCrW-360.

[0078] Test results: The sample surface is grayish-white, dense and smooth, and the pre-prepared coating has a BCC structure; the coating thickness is 2.5 μm; the average friction coefficient is 0.44 under atmospheric conditions, the stable friction coefficient remains between 0.40 and 0.50, and the wear rate is 1.2 × 10⁻⁶. -4 mm 3 / Nm.

[0079] Comparative Example 1

[0080] A single-phase BCC crystal structure VTiCrMo monolayer coating with a thickness of approximately 2.6 μm and an Inconel 718 high-temperature alloy as the substrate material.

[0081] The method for preparing the VTiCrMo coating on the substrate surface includes the following steps:

[0082] (1) Cleaning and degreasing the substrate surface

[0083] The substrate was ultrasonically cleaned in acetone solution for 30 minutes, dried with nitrogen, and then ultrasonically cleaned in anhydrous ethanol for 30 minutes, followed by drying with nitrogen.

[0084] (2) Magnetron sputtering deposition of VTiCrMo coating

[0085] The substrate treated in step (1) was placed in a DC magnetron sputtering vacuum chamber and pre-evacuated to 5 × 10⁻⁶. -3 After plasma treatment for 30 minutes, a pulsed DC current was applied, with a sputtering bias of -400V, a sputtering current of 3A, and a working pressure of 0.4Pa. A VTiCrMo coating with a total thickness of approximately 2.3μm was deposited on the substrate surface.

[0086] The VTiCrMo coating on the substrate surface obtained after the above deposition treatment was tested as follows:

[0087] (1) Structural and compositional testing

[0088] Test results: The sample surface coating is grayish-white, with a dense and smooth surface. The XRD pattern is shown below. Figure 1b As shown, the coating is prepared with a BCC crystal structure.

[0089] (2) Friction and wear performance test

[0090] The dry friction coefficient and wear life of the VTiCrMo coating prepared above were evaluated in a high-temperature atmospheric environment using a high-temperature friction testing machine (THT 1000). The specific experimental conditions were as follows: a ball-disc rotational sliding method was adopted, the friction pair ball was a Φ6mm ZrO2 ball with a rotation radius of 5mm, the sliding speed was 1cm / s, and the load was 1N.

[0091] Test results: such as Figure 3b and Figure 4b As shown, the VTiCrMo coating obtained above maintains a stable friction coefficient of 0.48–0.52 under atmospheric conditions, and the wear rate is reduced to 7.4 × 10⁻⁶. -5 mm 3 / Nm.

[0092] Comparative Example 2:

[0093] A single-phase BCC crystal structure VTiCrW single-layer coating with a thickness of approximately 2.3 μm and an Inconel 718 high-temperature alloy as the substrate material.

[0094] The method for preparing the VTiCrW coating on the substrate surface includes the following steps:

[0095] (1) Cleaning and degreasing the substrate surface

[0096] The substrate was ultrasonically cleaned in acetone solution for 30 minutes, dried with nitrogen, and then ultrasonically cleaned in anhydrous ethanol for 30 minutes, followed by drying with nitrogen.

[0097] (2) Magnetron sputtering deposition of VTiCrW coating

[0098] The substrate treated in step (1) was placed in a DC magnetron sputtering vacuum chamber and pre-evacuated to 5 × 10⁻⁶. -3 After plasma treatment for 30 min, a pulsed DC current was applied, with a sputtering bias of -400 V, a sputtering current of 3 A, and a working pressure of 0.4 Pa. A VTiCrW coating with a total thickness of approximately 2.3 μm was deposited on the substrate surface.

[0099] The VTiCrW coating on the substrate surface obtained after the above deposition treatment was tested as follows:

[0100] (1) Structural and compositional testing

[0101] Test results: The sample surface coating is grayish-white, with a dense and smooth surface. The XRD pattern is shown below. Figure 1b As shown, the coating is prepared with a BCC crystal structure.

[0102] (2) Friction and wear performance test

[0103] The dry friction coefficient and wear life of the VTiCrW coating prepared above were evaluated in a high-temperature atmospheric environment using a high-temperature friction testing machine (THT 1000). The specific experimental conditions were as follows: a ball-disc rotational sliding method was adopted, the friction pair ball was a Φ6mm ZrO2 ball with a rotation radius of 5mm, the sliding speed was 1cm / s, and the load was 1N.

[0104] Test results: such as Figure 3b and 4b As shown, the VTiCrW coating prepared above has an average friction coefficient of 0.16 under atmospheric conditions, a stable friction coefficient maintained between 0.07 and 0.10, and a wear rate reduced to 1.2 × 10⁻⁶. -4 mm 3 / Nm.

[0105] Comparative Example 3

[0106] The method is the same as in Example 1, except that the VTiCrMo / VTiCrW high-entropy alloy nanocomposite coating is missing W, resulting in a VTiCr / VTiCrMo composite coating.

[0107] Test results: The sample surface is grayish-white, dense and smooth, and the prepared coating has a BCC structure; the coating thickness is 2.4 μm; the VTiCr / VTiCrMo coating has an average friction coefficient of 0.90 under atmospheric conditions, with a stable friction coefficient maintained between 0.99 and 1.05, and a wear rate of 5.4 × 10⁻⁶. -4 mm 3 / Nm.

[0108] Comparative Example 4

[0109] The method is the same as in Example 1, except that the VTiCrMo / VTiCrW high-entropy alloy nanocomposite coating lacks V, resulting in a TiCrMo / TiCrW composite coating.

[0110] Test results: The sample surface is grayish-white, dense and smooth, and the prepared coating has a BCC structure; the coating thickness is 2.6 μm; the TiCrMo / TiCrW coating has an average friction coefficient of 0.69 under atmospheric conditions, with a stable friction coefficient maintained between 0.68 and 0.78, and a wear rate of 2.4 × 10⁻⁶. -4 mm 3 / Nm.

[0111] Comparative Example 5

[0112] The method is the same as in Example 1, except that the VTiCrMo / VTiCrW high-entropy alloy nanocomposite coating lacks Ti, resulting in a VCrMo / VCrW composite coating.

[0113] Test results: The sample surface is grayish-white, dense and smooth, and the prepared coating has a BCC structure; the coating thickness is 2.4 μm; the VCrMo / VCrW coating has an average friction coefficient of 0.83 under atmospheric conditions, with a stable friction coefficient maintained between 0.80 and 0.90, and a wear rate of 3.8 × 10⁻⁶. -4 mm 3 / Nm.

[0114] Comparative Example 6

[0115] The method is the same as in Example 1, except that the VTiCrMo / VTiCrW high-entropy alloy nanocomposite coating lacks Cr, resulting in a VTiMo / VTiW composite coating.

[0116] Test results: The sample surface is grayish-white, dense and smooth, and the prepared coating has a BCC structure; the coating thickness is 2.5 μm; the VTiMo / VTiW coating has an average friction coefficient of 0.39 under atmospheric conditions, a stable friction coefficient maintained between 0.38 and 0.42, and a wear rate of 2.6 × 10⁻⁶. -4 mm 3 / Nm.

[0117] In addition, the inventors of this case also conducted experiments with other raw materials, process operations, and process conditions described in this specification, referring to the aforementioned embodiments, and obtained relatively ideal results in all cases.

[0118] It should be understood that the technical solutions of the present invention are not limited to the specific embodiments described above. Any technical modifications made to the technical solutions of the present invention without departing from the spirit and scope of the claims are within the scope of protection of the present invention.

Claims

1. A high-entropy alloy nanocomposite coating, characterized in that, The composite coating comprises multiple periodic layers stacked together, each periodic layer including a VTiCrW layer and a VTiCrMo layer, and the VTiCrW layer and VTiCrMo layer are stacked alternately in the composite coating; the composite coating has a BCC crystal structure, wherein the VTiCrW layer and VTiCrMo layer in the high-entropy alloy nanocomposite coating have a coherent interface.

2. The high-entropy alloy nanocomposite coating according to claim 1, characterized in that: The high-entropy alloy nanocomposite coating is formed on the surface of the substrate, and multiple periodic layers are stacked sequentially in a direction away from the surface of the substrate.

3. The high-entropy alloy nanocomposite coating according to claim 2, characterized in that: At 700 °C, the dry friction coefficient of the high-entropy alloy nanocomposite coating is 0.09~0.45, and the wear rate is (5~18)×10⁻⁶. -5 mm 3 / Nm; And / or, the material of the matrix includes iron-based alloys, nickel-based alloys, or cobalt-based alloys.

4. The high-entropy alloy nanocomposite coating according to claim 1, characterized in that: The thickness of the high-entropy alloy nanocomposite coating is 2~3 μm; And / or, the thickness of each periodic layer is 10~140 nm; the thickness of the VTiCrW layer in each periodic layer is 6~80 nm, and the thickness of the VTiCrMo layer is 4~60 nm.

5. The method for preparing the high-entropy alloy nanocomposite coating according to any one of claims 1-4, characterized in that, include: Provide a matrix; Furthermore, multiple periodic layers are deposited on the substrate surface using magnetron sputtering technology to obtain a high-entropy alloy nanocomposite coating.

6. The preparation method according to claim 5, characterized in that, Specifically, it includes: A VTiCrW layer is deposited on the surface of the substrate using magnetron sputtering technology with vanadium, titanium, chromium, and tungsten targets as targets. The targets are arranged in the order of V~Ti~Cr~W to form VTiCrW target sites. The sputtering bias voltage is -400~-600 V, the sputtering current is 2~3 A, the working gas pressure is 0.35~0.45 Pa, and the deposition temperature is 50~120 ℃. A VTiCrMo layer is deposited on the surface of the VTiCrW layer using magnetron sputtering technology with vanadium, titanium, chromium, and molybdenum targets as targets. The targets are arranged in the order of V~Ti~Cr~Mo to form VTiCrMo target sites. The sputtering bias voltage is -400~-600V, the sputtering current is 2~3A, the working gas pressure is 0.35~0.45Pa, and the deposition temperature is 50~120℃. Furthermore, the VTiCrW layer and the VTiCrMo layer are alternately stacked until multiple periodic layers of the stacked arrangement are formed.

7. The preparation method according to claim 5, characterized in that, Specifically, it includes: A VTiCrMo layer is deposited on the surface of the substrate using magnetron sputtering technology with vanadium, titanium, chromium, and molybdenum targets as targets. The targets are arranged in the order of V~Ti~Cr~Mo to form VTiCrMo target sites. The sputtering bias voltage is -400~-600V, the sputtering current is 2~3A, the working gas pressure is 0.35~0.45Pa, and the deposition temperature is 50~120℃. A VTiCrW layer was deposited on the surface of the VTiCrMo layer using magnetron sputtering technology with vanadium, titanium, chromium, and tungsten targets as targets. The targets were arranged in the order of V~Ti~Cr~W to form VTiCrW target sites. The sputtering bias voltage was -300~-600V, the sputtering current was 2~3A, the working gas pressure was 0.35~0.45Pa, and the deposition temperature was 50~120℃. Furthermore, the VTiCrMo layer and the VTiCrW layer are alternately stacked until multiple periodic layers of the stacked arrangement are formed.

8. The preparation method according to claim 6 or 7, characterized in that: The time interval between the alternating deposition of the VTiCrMo layer and the VTiCrW layer is 20~250 s; And / or, the thickness of the target material is 5~30 mm.

9. The preparation method according to claim 5, characterized in that, Also includes: Evacuate the sputtering chamber to a vacuum level of 5 × 10⁻⁶. -3 The substrate is heated to a pressure below Pa and then subjected to plasma etching after cleaning.

10. The use of the high-entropy alloy nanocomposite coating according to any one of claims 1-4 in the field of surface protection of high-temperature moving parts.

11. The use according to claim 10, characterized in that: The application is for the protection of moving parts surfaces in high-temperature environments of 650~850 ℃.

12. The use according to claim 10, characterized in that: The high-temperature moving parts include a brush-type sealing system.

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