CN111441025A

CN111441025A - Corrosion-resistant high-entropy alloy film, preparation method and application thereof in seawater environment

Info

Publication number: CN111441025A
Application number: CN202010403292.9A
Authority: CN
Inventors: 蒲吉斌; 毛春龙; 王文哲; 陈善俊; 王立平; 毛金根; 卢光明
Original assignee: Jiangsu Jinshengyuan Special Valve Co ltd; Ningbo Institute of Material Technology and Engineering of CAS
Current assignee: Jiangsu Jinshengyuan Special Valve Co ltd; Ningbo Institute of Material Technology and Engineering of CAS
Priority date: 2020-05-13
Filing date: 2020-05-13
Publication date: 2020-07-24
Anticipated expiration: 2040-05-13
Also published as: CN111441025B

Abstract

The invention discloses a corrosion-resistant high-entropy alloy film, a preparation method and application thereof in a seawater environment^–3And annealing the VAlTiCrCu high-entropy alloy film in a Pa protective atmosphere at 700-1100 ℃ for 1-3 h, and cooling to room temperature to obtain the corrosion-resistant high-entropy alloy film. The invention adopts different temperatures to carry out annealing treatment on the VAlTiCrCu high-entropy alloy film, so that a new FCC phase is separated from the single-phase BCC structure of the VAlTiCrCu high-entropy alloy film, and the tissue structure is changedObviously, the hardness is improved by 20-30%, the elastic modulus is improved by 20-30%, the self-corrosion current density is further reduced, and the coating can be used for matrix protection in a seawater environment.

Description

Corrosion-resistant high-entropy alloy film, preparation method and application thereof in seawater environment

Technical Field

The invention relates to the technical field of alloy films and preparation thereof, in particular to a corrosion-resistant high-entropy alloy film, a preparation method and application thereof in a seawater environment.

Background

The traditional alloy system taking one or two elements and compounds as main elements tends to be mature and saturated through long-term research of people, and the performance of the traditional metal material cannot meet the requirements of people in production and life. Under the background, a novel alloy film material, namely a high-entropy alloy film, is widely concerned and researched in recent years due to the excellent comprehensive performance of the alloy film material. The high-entropy alloy film is an alloy film consisting of five or more element components, and the content of each element is between 5% and 35%, so that the design breaks through the design concept of the traditional alloy, and the high-entropy alloy film often has multiple ideal properties, such as excellent wear resistance, corrosion resistance, thermal stability and fracture-resistant tensile capacity.

At present, the research aiming at the field of high-entropy alloy is mainly based on as-cast alloy, but the research on the high-entropy alloy film is less, and the research on the mechanical property and the corrosion resistance of the high-entropy alloy film is less by improving the mechanical property and the corrosion resistance of the high-entropy alloy film through a heat treatment process. At present, high-entropy alloy targets or the combination of single elements and low-component alloy targets are selected more in the preparation process of the high-entropy alloy film. However, the element content of the high-entropy alloy target is difficult to regulate and control, the manufacturing process is complex and the cost is high; and the independent target material adopting a single element is difficult to obtain a high-entropy coating with uniform components.

Disclosure of Invention

The invention mainly aims to provide a corrosion-resistant high-entropy alloy film which has the advantages of obvious change of a tissue structure, improved hardness, improved elastic modulus and reduced self-corrosion current density, a preparation method and application in a seawater environment, thereby overcoming the defects in the prior art.

In order to achieve the purpose, the invention adopts the following technical scheme:

a preparation method of a corrosion-resistant high-entropy alloy film comprises the following steps:

(1) the magnetron sputtering splicing composite target is used as a cathode target material;

(2) carrying out mechanical grinding and polishing treatment and cleaning on the surface of the matrix, and putting the matrix into a magnetron sputtering cavity, wherein the matrix is parallel to the surface of a cathode target material in the center of the cavity;

(3) filling protective gas into the magnetron sputtering cavity as working gas, performing magnetron sputtering on the spliced composite target in the step (1) by adopting a magnetron sputtering technology, and depositing on the surface of the substrate treated in the step (2) to obtain a VAlTiCrCu high-entropy alloy film;

(4) putting a VAlTiCrCu high-entropy alloy film sample obtained by magnetron sputtering in a quartz tube in a muffle furnace, and controlling the vacuum degree to be lower than 1.0 × 10^–3Pa in a protective atmosphere;

(5) annealing the VAlTiCrCu high-entropy alloy film sample by using a muffle furnace, wherein the annealing temperature is 700-1100 ℃, the annealing time is 1-3 h, and the heating rate is 5-10 ℃/min;

(6) and then cooling to room temperature along with the furnace to obtain the corrosion-resistant high-entropy alloy film.

Further, in the step (1), the magnetron sputtering splicing composite target comprises at least one target period which is periodically arranged in the vertical direction, and each target period comprises V with equal atomic ratio which is sequentially stacked from top to bottom in the vertical direction₅₀Al₅₀Composite target material, equal atomic ratio Ti₅₀Cr₅₀A composite target material and a Cu target material; v of the same atomic ratio₅₀Al₅₀Composite target material, equal atomic ratio Ti₅₀Cr₅₀The purity content of the composite target and the Cu target is 99.9 percent.

Further, the magnetron sputtering splicing composite target comprises 5-20 target periods; in each target period, the V₅₀Al₅₀The thickness of the composite target material is 5 mm-45 mm, and the Ti₅₀Cr₅₀The thickness of the composite target material is 5 mm-45 mm, and the thickness of the Cu target material is 5 mm-45 mm.

Further, in the step (2), the material of the substrate is a stainless steel metal material, preferably 304 stainless steel or 316 stainless steel; after the surface of the matrix is mechanically polished, petroleum ether, acetone and alcohol are adopted for ultrasonic cleaning for 20 min.

Further, in the step (3), the magnetron sputtering technology adopts the process conditions that the sputtering power is 1000W-3000W, the substrate bias is-20V-60V, the substrate temperature is 30-400 ℃, and the pressure in the reaction cavity is 3 × 10^-2～7×10^-2mbar, the flow rate of the protective gas is 100-200 sccm, and the deposition time is 4-8 h; and the protective gas is an inert gas, particularly preferably argon, but is not limited thereto.

Further, in the step (3), before the magnetron sputtering, the reaction cavity is vacuumized to a vacuum degree lower than 1.0 × 10^–3Pa, bombarding the composite target by utilizing Ar ions for 30min, removing impurities and oxides on the surface of the target, and introducing Ar protective atmosphere in the sputtering process to prevent the oxides from being generated in the sputtering process; and the surface of the substrate is subjected to ion etching and cleaning for 15min by utilizing a glow discharge principle so as to remove an oxide layer and pollutants on the surface of the substrate.

Further, in the step (3), the prepared VAlTiCrCu high-entropy alloy thin film is of a single-phase body-centered cubic structure, the molecular formula of the VAlTiCrCu high-entropy alloy thin film is VAlTiCrCu, and the VAlTiCrCu high-entropy alloy thin film contains the following elements calculated according to atomic percentage: 10-20% of V, 10-20% of Al, 10-20% of Ti, 10-30% of Cr and 10-30% of Cu. The VAlTiCrCu high-entropy alloy film is obtained by depositing on the surface of a substrate by utilizing a magnetron sputtering technology, and has a single-phase body-centered cubic structure consisting of vanadium, aluminum, titanium, chromium and copper elements. In addition, the VAlTiCrCu film is deposited on the surface of the substrate by utilizing a magnetron sputtering technology, on one hand, the dimensional difference among the atoms of each element is large, so that the lattice distortion is easily caused, and on the other hand, the composition elements contain a large amount of V, Ti and Cr elements with a body-centered cubic structure, so that the VAlTiCrCu film obtained by the method has a single-phase body-centered cubic structure.

Furthermore, the hardness of the VAlTiCrCu high-entropy alloy thin film is more than 10Gpa, the elastic modulus is more than 220Gpa, and the self-corrosion current density is lower than 3.62 × 10^-8A/cm²(ii) a The thickness of the VAlTiCrCu high-entropy alloy film is 2000 nm-4000 nm.

The invention also provides the corrosion-resistant high-entropy alloy film prepared by the preparation method, the corrosion-resistant high-entropy alloy film is of a structure with a body-centered cubic structure and a face-centered cubic structure, the hardness of the corrosion-resistant high-entropy alloy film is 10.03-13.24 GPa, the elastic modulus is 202.43-278.36 Gpa, and the self-corrosion current density is 5.26 × 10^-9～2.87×10^-7A/cm²。

The invention also provides application of the corrosion-resistant high-entropy alloy film in the field of matrix surface protection in a seawater environment.

Compared with the prior art, the invention has the following beneficial effects:

1) according to the invention, different temperatures are adopted to carry out annealing treatment on the VAlTiCrCu high-entropy alloy film, so that a new FCC phase is separated out from a single-phase BCC structure of the VAlTiCrCu high-entropy alloy film, the change of the organization structure is obvious, and on the basis of the existing high performance of the VAlTiCrCu high-entropy alloy film, the hardness is improved by 20-30%, the elastic modulus is improved by 20-30%, the self-corrosion current density is further reduced, and the self-corrosion current density is reduced by 1 order of magnitude at most;

2) the invention uses V as the target material₅₀Al₅₀-Ti₅₀Cr₅₀The forms of Cu are sequentially stacked and periodically arranged, the atomic ratio of each element in the new target material form is closer to 1:1:1:1:1 while ensuring low manufacturing cost and easy regulation and control of element types, the highest mixed entropy in a system is favorably obtained,thereby inhibiting the formation of intermetallic compounds, strengthening the solid solution of each element and obtaining the VAlTiCrCu high-entropy alloy film with more uniform structure components and better performance;

3) the VAlTiCrCu high-entropy alloy film is composed of corrosion-resistant components V, Al, Ti, Cr and Cu, and adopts a magnetron sputtering technology, and the composition elements of the VAlTiCrCu high-entropy alloy film contain a large amount of V, Ti and Cr elements with body-centered cubic structures to form a single-phase body-centered cubic structure, so that the VAlTiCrCu high-entropy alloy film has high hardness and excellent corrosion resistance, the hardness is higher than 10Gpa, the elastic modulus is higher than 220Gpa, and the self-corrosion current density is as low as 3.62 × 10^-8A/cm²Therefore, the material is a wear-resistant and corrosion-resistant material, can well protect a matrix in a severe environment with high wear and high corrosion, and can be used for matrix protection in seawater environment and the like.

Drawings

FIG. 1 is a schematic cross-sectional structure diagram of a VAlTiCrCu spliced composite target in embodiments 1 to 3 of the present invention.

FIG. 2 is an XRD diffraction pattern of the VAlTiCrCu high-entropy alloy film prepared in the embodiments 1-3 of the invention and the corrosion-resistant VAlTiCrCu high-entropy alloy film after annealing treatment.

FIG. 3 is a dynamic polarization curve diagram obtained by electrochemical testing of the VAlTiCrCu high-entropy alloy thin film prepared in embodiments 1-3 of the present invention and the annealed corrosion-resistant VAlTiCrCu high-entropy alloy thin film.

Detailed Description

The technical solutions of the present invention will be described in further detail below with reference to several preferred embodiments and accompanying drawings, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. It is to be noted that the following examples are intended to facilitate the understanding of the present invention, and do not set forth any limitation thereto. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention. The test methods in the following examples, which are not specified under specific conditions, are generally carried out under conventional conditions.

The invention mainly aims at the high-entropy alloy film, and adopts heat treatment to improve the mechanical property and the corrosion resistance of the high-entropy alloy film, thereby having very important significance.

Example 1

In this embodiment, the substrate is 304 stainless steel, and the surface of the substrate is a single-phase body-centered cubic VAlTiCrCu high-entropy alloy thin film.

The preparation method of the VAlTiCrCu high-entropy alloy film comprises the following steps:

the method adopts a magnetron sputtering technology to prepare the VAlTiCrCu high-entropy alloy film on the surface of a substrate, and specifically comprises the following steps:

(1) as shown in FIG. 1, V with equal atomic ratio and raw material purity of 99.9% or more was selected₅₀Al₅₀Target material, Ti of equal atomic ratio₅₀Cr₅₀Target material and Cu target material, in the vertical direction according to V₅₀Al₅₀-Ti₅₀Cr₅₀Sequentially stacking and arranging target materials with the thicknesses of 20mm, 20mm and 10mm from top to bottom in the sequence of Cu, wherein the target materials are in one target period; then, 12 target cycles were included in the vertical direction to form a tiled composite target.

(2) Mechanically polishing the surface of the matrix, sequentially ultrasonically cleaning with petroleum ether, acetone and alcohol for 20min, and blow-drying with nitrogen; and then, putting the substrate into a magnetron sputtering cavity, wherein the substrate is parallel to the surface of the target material in the center of the cavity. Before deposition, vacuumizing to a vacuum degree lower than 10^-3And Pa, bombarding the composite target for 30min by utilizing Ar ions, and carrying out ion etching on the matrix sample for 15 min.

(3) Filling 99.99 wt.% high-purity argon with the flow rate of 150sccm into the reaction cavity, carrying out magnetron sputtering on the spliced composite target in the step (1), depositing for 6h on the surface of the substrate treated in the step (2) to obtain the VAlTiCrCu high-entropy alloy film, wherein in the sputtering process, the temperature of the substrate is set to be 300 ℃, the sputtering power is 2000W, the bias voltage of the substrate is set to be-50V, and the pressure in the reaction cavity is 6 × 10^-2mbar, and obtaining the VAlTiCrCu high-entropy alloy film.

The VAlTiCrCu high-entropy alloy film obtained by magnetron sputtering is subjected to hardness, elastic modulus and corrosion resistance improvement, and the method specifically comprises the following steps:

(1) placing the prepared VAlTiCrCu high-entropy alloy film sample in a quartz tube in a muffle furnace, and pumping to a vacuum degree of 10^-3Pa below;

(2) annealing the sample by adopting a muffle furnace, wherein the heating rate is 10 ℃/min, the annealing temperature is controlled to be 700 ℃, the annealing time is 3h, and sufficient high-purity argon is introduced for protection;

(3) and heating the VAlTiCrCu high-entropy alloy film sample from room temperature to a specified temperature, carrying out heat preservation treatment, and then cooling to room temperature along with a furnace to obtain the corrosion-resistant high-entropy alloy film.

The following tests were performed on the valticrccu high-entropy alloy thin film (as a control) prepared in the above example and the corrosion-resistant high-entropy alloy thin film samples:

1. the components and the structure of the VAlTiCrCu high-entropy alloy thin film sample are analyzed by X-ray diffraction, and the analysis is shown in FIG. 3.

2. The surface of the VAlTiCrCu high-entropy alloy thin film sample was pressed into six points each having a depth of 200nm by a Nanoindenter (MTS Corporation, G200), hardness and elastic modulus were measured, and average values were calculated from the measurement results, and specific values thereof are shown in Table 2.

3. Carrying out electrochemical test on the VAlTiCrCu high-entropy alloy film samples before and after annealing at 700 ℃ to obtain a dynamic polarization curve, as shown in FIG. 3; specific values of the self-etching potential and the self-etching current density are shown in Table 3.

Example 2

In this embodiment, the substrate material is 304 stainless steel, and the surface of the substrate is a VAlTiCrCu high-entropy alloy thin film.

(3) Filling 99.99 wt.% high-purity argon with the flow rate of 150sccm into the reaction cavity, carrying out magnetron sputtering on the spliced composite target in the step (1), depositing for 6 hours on the surface of the substrate treated in the step (2) to obtain the VAlTiCrCu high-entropy alloy film, wherein in the sputtering process, the temperature of the substrate is set to be 300 ℃, the sputtering power is 2000W, the bias voltage of the substrate is set to be-50V, and the pressure in the reaction cavity is 4 × 10^-2mbar, and obtaining the VAlTiCrCu high-entropy alloy film.

(2) annealing the sample by adopting a muffle furnace, wherein the heating rate is 10 ℃/min, the annealing temperature is controlled to be 900 ℃, the annealing time is 2h, and sufficient high-purity argon is introduced for protection;

(3) and heating the VAlTiCrCu high-entropy alloy film sample from room temperature to a specified temperature, then carrying out heat preservation treatment, and then cooling to room temperature along with a furnace to obtain the corrosion-resistant high-entropy alloy film, wherein the BCC and the FCC exist when the two types are the same.

1. the components and the structure of the VAlTiCrCu high-entropy alloy thin film sample are analyzed by X-ray diffraction, and the analysis is shown in FIG. 2.

3. Carrying out electrochemical test on the VAlTiCrCu high-entropy alloy film samples before annealing and after annealing at 900 ℃ to obtain a dynamic polarization curve, as shown in FIG. 3; specific values of the self-etching potential and the self-etching current density are shown in Table 3.

Example 3

a magnetron sputtering technology is adopted to prepare the VAlTiCrCu high-entropy alloy film on the surface of a substrate, and the method mainly comprises the following steps:

(3) 99.99 wt.% of high-purity argon with the flow rate of 150sccm is filled into the reaction cavity, the spliced composite target in the step (1) is subjected to magnetron sputtering, and the treatment is carried out in the step (2)Depositing the surface of the substrate for 6h to obtain the VAlTiCrCu high-entropy alloy film, wherein in the sputtering process, the temperature of the substrate is set to be 300 ℃, the sputtering power is 2000W, the bias voltage of the substrate is-50V, and the pressure in a reaction cavity is 5 × 10^-2mbar, and obtaining the VAlTiCrCu high-entropy alloy film.

(2) annealing the sample by adopting a muffle furnace, wherein the heating rate is 10 ℃/min, the annealing temperature is controlled to be 1100 ℃, the annealing time is 1h, and sufficient high-purity argon is introduced for protection;

3. Carrying out electrochemical test on the VAlTiCrCu high-entropy alloy film samples before annealing and after annealing at different temperatures to obtain a dynamic polarization curve, as shown in FIG. 3; specific values of the self-etching potential and the self-etching current density are shown in table 3 below.

The components and the structure of the corrosion-resistant VAlTiCrCu high-entropy alloy thin film samples prepared in the embodiments 1 to 3 are analyzed by X-ray diffraction, and FIG. 2 is an XRD diffraction pattern of the VAlTiCrCu high-entropy alloy thin film (used as a contrast) and the corrosion-resistant VAlTiCrCu high-entropy alloy thin film after annealing treatment. The structure of the single-phase BCC structure is obtained before annealing treatment and after annealing treatment at 700 ℃, and after annealing treatment at 900 ℃ and 1100 ℃, a new FCC structure is separated out on the basis of the original BCC structure, and the structure is the existing structure of the BCC and the FCC when the two structures are the same.

The content of the element components of the VAlTiCrCu high-entropy alloy thin film samples (as a control) prepared in examples 1 to 3 are shown in Table 1:

table 1: component content of VAlTiCrCu high-entropy alloy film

Element(s)	V	Al	Ti	Cr	Cu
						Content (at.%)	12.93	17.26	14.43	26.33	29.05

As can be seen from Table 1, the atomic percentages of the elements in the VAlTiCrCu high-entropy alloy film sample meet the requirement that the atomic percentages of the elements in the high-entropy alloy are 5-35%.

The surfaces of the three film samples annealed in examples 1 to 3 were pressed into six points each having a depth of 200nm by a nanoindentation apparatus, and the hardness and the elastic modulus were measured, and the results are shown in table 2 below.

Table 2: hardness and elastic modulus of VAlTiCrCu high-entropy alloy film before and after annealing

Annealing temperature	Untreated	700℃	900℃	1100℃
					Modulus of elasticity/Gpa	228.24	202.43	275.25	278.36
hardness/Gpa	10.36	10.03	13.24	12.68

As can be seen from Table 2, before and after annealing, the VAlTiCrCu high-entropy alloy film has higher hardness and elastic modulus, and it is worth mentioning that the hardness and elastic modulus of the corrosion-resistant VAlTiCrCu high-entropy alloy film sample are improved by 20-30% after annealing at 900 ℃ and annealing at 1100 ℃.

The VAlTiCrCu corrosion-resistant high-entropy alloy thin film samples before and after annealing in the examples 1 to 3 are subjected to electrochemical tests, and specific values of the self-corrosion potential and the self-corrosion current density are shown in the following table 3.

Table 3: self-corrosion potential and self-corrosion current density before and after annealing of VAlTiCrCu high-entropy alloy film

As can be seen from Table 3, the corrosion resistance of the VAlTiCrCu corrosion-resistant high-entropy alloy film is improved to different degrees after annealing treatment. Wherein, after annealing treatment at 1100 ℃, the self-corrosion current density is even reduced by one order of magnitude, and the corrosion resistance is greatly improved after annealing treatment.

Example 4

(1) selecting V with equal atomic ratio with raw material purity of more than or equal to 99.9%₅₀Al₅₀Target material, Ti of equal atomic ratio₅₀Cr₅₀Target material, Cu target material, in the vertical direction according to V₅₀Al₅₀-Ti₅₀Cr₅₀Sequentially stacking and arranging target materials with the thicknesses of 20mm, 20mm and 10mm from top to bottom in the sequence of Cu, wherein the target materials are in one target period; then, 20 target cycles were included in the vertical direction to form a tiled composite target.

(2) Mechanically polishing the surface of the matrix, sequentially ultrasonically cleaning with petroleum ether, acetone and alcohol for 20min, and blow-drying with nitrogen; and then, putting the substrate into a magnetron sputtering cavity, wherein the substrate is parallel to the surface of the target material in the center of the cavity. Before deposition, vacuumizing to a vacuum degree lower than 10^-3Pa, bombarding the composite target for 30min by using Ar ions, and pairingAnd carrying out ion etching on the matrix sample for 15 min.

(3) Filling 99.99 wt.% high-purity argon with the flow rate of 100sccm into the reaction cavity, carrying out magnetron sputtering on the spliced composite target in the step (1), depositing for 8 hours on the surface of the substrate treated in the step (2) to obtain the VAlTiCrCu high-entropy alloy film, wherein in the sputtering process, the temperature of the substrate is set to be 400 ℃, the sputtering power is set to be 1000W, the bias voltage of the substrate is set to be-60V, and the pressure in the reaction cavity is set to be 3 × 10^-2mbar, and obtaining the VAlTiCrCu high-entropy alloy film.

(2) annealing the sample by adopting a muffle furnace, wherein the heating rate is 5 ℃/min, the annealing temperature is controlled to be 900 ℃, the annealing time is 1h, and sufficient high-purity argon is introduced for protection;

Example 5

(1) selecting V with equal atomic ratio with raw material purity of more than or equal to 99.9%₅₀Al₅₀Target material, Ti of equal atomic ratio₅₀Cr₅₀Target material, Cu target material, in the vertical direction according to V₅₀Al₅₀-Ti₅₀Cr₅₀Sequentially stacking and arranging target materials with the thicknesses of 20mm, 20mm and 10mm from top to bottom in the sequence of Cu, wherein the target materials are in one target period; then, 5 target periods are included in the vertical direction to form a spliced composite target。

(3) Filling 99.99 wt.% high-purity argon with the flow rate of 200sccm into the reaction cavity, carrying out magnetron sputtering on the spliced composite target in the step (1), depositing for 4 hours on the surface of the substrate treated in the step (2) to obtain the VAlTiCrCu high-entropy alloy film, wherein in the sputtering process, the temperature of the substrate is set to be 30 ℃, the sputtering power is 3000W, the bias voltage of the substrate is set to be-20V, and the pressure in the reaction cavity is 7 × 10^-2mbar, and obtaining the VAlTiCrCu high-entropy alloy film.

(2) annealing the sample by adopting a muffle furnace, wherein the heating rate is 8 ℃/min, the annealing temperature is controlled to be 900 ℃, the annealing time is 3h, and sufficient high-purity argon is introduced for protection;

Comparative example 1

Referring to CN 110129731A, in the comparative example, the substrate material is stainless steel, and the surface of the substrate is a CoCrFeMnNi high-entropy alloy thin film.

The preparation method of the CoCrFeMnNi high-entropy alloy film comprises the following steps:

the method adopts a magnetron sputtering technology to prepare the CoCrFeMnNi high-entropy alloy film on the surface of a matrix, and mainly comprises the following steps:

(1) with a purity of 99.99 percent byHigh-purity Co after heat preservation and homogenization treatment for 48 hours at 1000 DEG C₂₀Cr₂₀Fe₂₀Mn₂₀Ni₂₀(at%) alloy as a target.

(2) Polishing the surface of the substrate, sequentially performing ultrasonic cleaning with acetone, alcohol and deionized water for 15min to remove impurities and dirt on the surface, fixing the substrate on a circular baffle plate, sending into a sample chamber, vacuumizing to a vacuum degree of less than or equal to 5 × 10^-5Pa; and pre-sputtering the target for 30min by using Ar ions.

(3) The vacuum degree of the sampling chamber is less than or equal to 2.5 × 10^-6Pa, feeding the sample into the sputtering cavity to ensure that the vacuum degree in the reaction cavity is less than or equal to 2.5 × 10^-6And (3) after Pa, filling argon with the flow rate of 20sccm, and depositing on the surface of the substrate for 30min to obtain the CoCrFeMnNi high-entropy alloy film, wherein the sputtering power is set to be 150W in the sputtering process.

(4) Then, liquid nitrogen cryogenic treatment is carried out for 10 times, and the obtained CoCrFeMnNi high-entropy alloy thin film has the hardness of 9.1GPa and the elastic modulus of 152 GPa.

In the comparison example, most of the high-entropy alloy targets are integrally formed targets, the types and the components of the targets are not easy to control, and the high-entropy alloy targets are not only easy to control the types and the components, but also excellent in performance.

Comparative example 2

This comparative example is substantially identical to example 1 except that the annealing temperature was 400 ℃.

Through detection, the VAlTiCrCu high-entropy alloy film prepared in the comparative example has a single-phase BCC structure before and after annealing treatment. The content of the elements of the VAlTiCrCu high-entropy alloy film sample prepared in the comparative example is shown in Table 4:

table 4: comparative example 2 contains the elements of the VAlTiCrCu high-entropy alloy thin film

Element(s)	V	Al	Ti	Cr	Cu
						Content (at.%)	12.93	17.26	14.43	26.33	29.05

As can be seen from Table 4, the atomic percentages of the elements in the VAlTiCrCu high-entropy alloy film sample meet the requirement that the atomic percentages of the elements in the high-entropy alloy are 5-35%.

Six points with the depth of 200nm were pressed into the surface of the film sample annealed in this comparative example by a nanoindentation apparatus, and the hardness and the elastic modulus were measured, and the measurement results are shown in table 5 below.

Table 5: hardness and elastic modulus of VAlTiCrCu high-entropy alloy film before and after annealing

Annealing temperature	Untreated	400℃
			Modulus of elasticity/Gpa	228.24	180.09
hardness/Gpa	10.36	7.71

As can be seen from Table 5, the hardness and the elastic modulus of the VAlTiCrCu high-entropy alloy film sample are reduced by 20 to 30 percent after annealing at 400 ℃.

The VAlTiCrCu corrosion-resistant high-entropy alloy thin film samples before and after annealing in the comparative example are subjected to electrochemical tests, and specific values of the self-corrosion potential and the self-corrosion current density are shown in the following table 6.

Table 6: self-corrosion potential and self-corrosion current density before and after annealing of VAlTiCrCu high-entropy alloy film

As can be seen from Table 6, the corrosion resistance of the VAlTiCrCu high-entropy alloy film is slightly reduced after annealing treatment at 400 ℃.

The aspects, embodiments, features and examples of the present invention should be considered as illustrative in all respects and not intended to be limiting of the invention, the scope of which is defined only by the claims. Other embodiments, modifications, and uses will be apparent to those skilled in the art without departing from the spirit and scope of the claimed invention.

The use of headings and chapters in this disclosure is not meant to limit the disclosure; each section may apply to any aspect, embodiment, or feature of the disclosure.

Throughout this specification, where a composition is described as having, containing, or comprising specific components or where a process is described as having, containing, or comprising specific process steps, it is contemplated that the composition of the present teachings also consist essentially of, or consist of, the recited components, and the process of the present teachings also consist essentially of, or consist of, the recited process steps.

Unless specifically stated otherwise, use of the terms "comprising", "including", "having" or "having" is generally to be understood as open-ended and not limiting.

It should be understood that the order of steps or the order in which particular actions are performed is not critical, so long as the teachings of the invention remain operable. Further, two or more steps or actions may be performed simultaneously.

In addition, the inventors of the present invention have also made experiments with other materials, process operations, and process conditions described in the present specification with reference to the above examples, and have obtained preferable results.

While the invention has been described with reference to illustrative embodiments, it will be understood by those skilled in the art that various other changes, omissions and/or additions may be made and substantial equivalents may be substituted for elements thereof without departing from the spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. Moreover, unless specifically stated any use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another.

Claims

1. The preparation method of the corrosion-resistant high-entropy alloy film is characterized by comprising the following steps of:

2. The method for preparing a corrosion-resistant high-entropy alloy thin film according to claim 1, wherein, in the step (1), the magnetron sputtering splicing composite target comprises at least one target period arranged periodically in the vertical direction, and each target period comprises V with equal atomic ratio which are sequentially stacked from top to bottom in the vertical direction₅₀Al₅₀Composite target material, equal atomic ratio Ti₅₀Cr₅₀A composite target material and a Cu target material; v of the same atomic ratio₅₀Al₅₀Composite target material, equal atomic ratio Ti₅₀Cr₅₀The purity content of the composite target and the Cu target is 99.9 percent.

3. The method for preparing the corrosion-resistant high-entropy alloy thin film according to claim 2, wherein the magnetron sputtering splicing composite target comprises 5-20 target periods; in each target period, the V₅₀Al₅₀The thickness of the composite target material is 5 mm-45 mm, and the Ti₅₀Cr₅₀The thickness of the composite target material is 5 mm-45 mm, and the thickness of the Cu target material is 5 mm-45 mm.

4. The method for preparing the corrosion-resistant high-entropy alloy film according to claim 1, wherein in the step (2), the substrate is made of a stainless steel metal material, and after mechanical polishing treatment is performed on the surface of the substrate, petroleum ether, acetone and alcohol are used for ultrasonic cleaning for 20 min.

5. The method for preparing the corrosion-resistant high-entropy alloy film according to claim 1, wherein in the step (3), the magnetron sputtering technology adopts the process conditions that the sputtering power is 1000W-3000W, the substrate bias voltage is-20V-60V, the substrate temperature is 30-400 ℃, and the pressure in the reaction cavity is 3 × 10^-2～7×10^-2mbar, the flow rate of the protective gas is 100-200 sccm, and the deposition time is 4-8 h; and the protective gas is an inert gas.

6. The method for preparing a corrosion-resistant high-entropy alloy thin film according to claim 1, wherein in the step (3), before magnetron sputtering, the reaction chamber is vacuumized to a vacuum degree of less than 1.0 × 10^–3And Pa, bombarding the composite target for 30min by utilizing Ar ions, and carrying out ion etching cleaning on the surface of the substrate for 15min by utilizing a glow discharge principle.

7. The method for preparing the corrosion-resistant high-entropy alloy thin film according to claim 1, wherein in the step (3), the prepared VAlTiCrCu high-entropy alloy thin film is of a single-phase body-centered cubic structure, the molecular formula of the VAlTiCrCu high-entropy alloy thin film is VAlTiCrCu, and the VAlTiCrCu high-entropy alloy thin film contains the following elements in atomic percentage: 10-20% of V, 10-20% of Al, 10-20% of Ti, 10-30% of Cr and 10-30% of Cu.

8. The method for preparing the corrosion-resistant high-entropy alloy thin film according to claim 7, wherein the VAlTiCrCu high-entropy alloy thin film has hardness of more than 10Gpa, elastic modulus of more than 220Gpa and self-corrosion current density of less than 3.62 × 10^-8A/cm²(ii) a The thickness of the VAlTiCrCu high-entropy alloy film is 2000 nm-4000 nm.

9. According to the rightThe corrosion-resistant high-entropy alloy thin film prepared by the preparation method of any one of claims 1 to 8, wherein the corrosion-resistant high-entropy alloy thin film is of a structure in which a body-centered cubic structure and a face-centered cubic structure coexist, the hardness of the corrosion-resistant high-entropy alloy thin film is 10.03 to 13.24GPa, the elastic modulus of the corrosion-resistant high-entropy alloy thin film is 202.43 to 278.36Gpa, and the self-corrosion current density of the corrosion-resistant high-entropy alloy thin film is 5.26 × 10^-9～2.87×10^-7A/cm²。

10. The use of the corrosion-resistant high-entropy alloy thin film of claim 9 in the field of protection in a seawater environment.