Method for preparing gradient high-entropy alloy corrosion-resistant coating through magnetron sputtering method

Abstract

The invention discloses a method for preparing a gradient high-entropy alloy corrosion-resistant coating through a magnetron sputtering method, the high-entropy alloy coating deposited on the surface of F / M steel alloy is AlCrFeMoTi high-entropy alloy, and the method specifically comprises the following steps that high-entropy alloy coating raw materials Al, Cr, Mo, Ti and Fe are prepared into a sputtering target material according to the molar ratio of 1: 1: 1: 1: 1: 1; cleaning the surface of the F / M steel alloy base material, and activating the activity; pre-sputtering the sputtering target material in an inert gas atmosphere so as to remove oxides and adsorbed impurities on the surface of the sputtering target material; under the inert gas atmosphere, the sputtering power of the sputtering target material is set to be 200 W till the AlCrFeMoTi high-entropy alloy deposited on the F / M steel alloy base material reaches the set thickness, and the AlCrFeMoTi high-entropy alloy coating is obtained; and the prepared AlCrFeMoTi high-entropy alloy coating is subjected to heat treatment. According to the method for preparing the gradient high-entropy alloy corrosion-resistant coating through the magnetron sputtering method, the prepared AlCrFeMoTi high-entropy alloy coating is compact and uniform, good in bonding performance and excellent in high-temperature corrosion resistance.

Description

Technical Field

[0001] This invention relates to the field of metal surface modification technology, and more particularly to a method for preparing a gradient high-entropy alloy corrosion-resistant coating by magnetron sputtering. Background Technology

[0002] High-entropy alloys (HEAs) have attracted considerable attention over the past two decades due to their unique structure and superior properties. Compared to conventional alloys, HEAs consist of at least five main elements with atomic contents ranging from 5-35 at.%, forming simple fcc or bcc crystal structures in solid solutions rather than complex intermetallic compounds. Under the influence of the high-entropy effect, HEAs exhibit superior properties compared to traditional alloys, such as high thermal stability, strength, hardness, high wear resistance, high fatigue resistance, excellent corrosion resistance, and outstanding radiation resistance. However, due to their lower neutron economy and machinability, HEAs are less suitable for direct use as fuel coating materials compared to Zr alloys. The development of HEA coatings has demonstrated similar advantages to HEAs. Therefore, exploring the preparation of protective HEA coatings on zirconium alloy surfaces to meet engineering applications has significant scientific and engineering application value.

[0003] In lead-based nuclear reactors, structural materials must withstand a variety of complex environmental factors, including fast neutron irradiation, liquid metal corrosion (LMC), liquid metal embrittlement (LME), stress, and transmutation. The fuel cladding in the reactor core, as a core component, operates under extremely harsh conditions, needing to withstand pressure from fission gases, fuel expansion, and interactions with the core materials. Furthermore, it must cope with the erosion and corrosion of high-temperature, high-density, and high-velocity liquid heavy metals.

[0004] Since the concepts of lead-cooled fast reactors and ADS systems were proposed, researchers have been searching for suitable structural materials to meet the design and construction needs of current research reactors and future commercial reactors. These studies have primarily focused on commercial austenitic stainless steels (AuSS, such as 316L, 304L, 15-15Ti, etc.), ferritic / martensitic steels (F / M, such as T91, HT9, P22, etc.), newly developed low-activation steels (such as Eurofer97 and F82H), oxide dispersion-strengthened alloy (ODS) steels, and other novel high-temperature resistant materials and ceramic materials. For cladding materials, there are currently two main options: austenitic steels 15-15Ti and 316L, and martensitic steel T91.

[0005] The basic mechanisms of liquid metal corrosion (LMC) include oxidation, dissolution (pitting), erosion, abrasion, or a combination thereof. Oxidation results in the formation of a dense, non-porous oxide layer on the material surface, which provides some protection. However, porous and defective oxide layers are detrimental to the protection of steel. Therefore, a thin, dense oxide layer is ideal as it protects the substrate from further corrosion. Excessive oxidation leads to the formation of a thick oxide layer, which not only reduces the thermal conductivity of components (unfavorable for fuel cladding and heat exchanger tubes) but can also cause main loop blockage due to oxide layer peeling.

[0006] Research on the mechanism of steel degradation in LBE environments reveals key influencing factors: First, the steel composition is crucial to its corrosion performance in LBE. For example, high-nickel steel is more susceptible to dissolution corrosion in LBE, while high-chromium steel provides better protection against corrosion. Second, corrosion temperature significantly affects the corrosion process: low temperatures reduce the dissolution rate of metals in LBE, mitigating corrosion, while high temperatures increase solubility and exacerbate corrosion. Temperature differences under non-uniform conditions can also accelerate metal diffusion, further worsening the corrosion situation. Furthermore, the flow rate in the LBE is also an important factor in the degree of corrosion; higher flow rates significantly accelerate the corrosion rate, especially inducing severe erosion corrosion. The oxygen concentration in the LBE determines the type of corrosion; dissolution corrosion mainly occurs under low-oxygen conditions, while high-oxygen conditions exacerbate oxidative corrosion and may lead to LBE contamination and pipeline blockage. In some cases, a suitable oxygen concentration can form a protective film on the steel surface, thereby mitigating corrosion. Although the surface corrosion rate decreases with increasing corrosion time, the overall degree of corrosion continues to rise.

[0007] Therefore, this application proposes a method for preparing a gradient high-entropy alloy corrosion-resistant coating by magnetron sputtering, which prepares a high-entropy alloy corrosion-resistant coating on the surface of a martensitic steel alloy material to form a protective film and thus alleviate corrosion. Summary of the Invention

[0008] In view of the above-mentioned defects or deficiencies in the prior art, it is desirable to provide a method for preparing a gradient high-entropy alloy corrosion-resistant coating by magnetron sputtering.

[0009] This invention provides a method for preparing a gradient high-entropy alloy corrosion-resistant coating by magnetron sputtering. The high-entropy alloy coating deposited on the surface of F / M steel alloy is an AlCrFeMoTi high-entropy alloy, and specifically includes the following steps:

[0010] 1) Material preparation: The high-entropy alloy coating raw materials Al, Cr, Mo, Ti and Fe are prepared into sputtering targets in a molar ratio of 1:1:1:1:1;

[0011] 2) Pretreatment of the substrate material: Clean the surface of the F / M steel alloy substrate and activate its activity;

[0012] 3) Target pre-sputtering: The sputtering target obtained in step 1) is pre-sputtered in an inert gas atmosphere to remove oxides and adsorbed impurities from the surface of the sputtering target.

[0013] 4) Sputtering high-entropy alloy coating: Under an inert gas atmosphere, the sputtering power of the sputtering target is set to 200W until the AlCrFeMoTi high-entropy alloy deposited on the F / M steel alloy substrate reaches the set thickness, thereby obtaining an AlCrFeMoTi high-entropy alloy coating with a thickness of 1 to 2 μm.

[0014] 5) Post-treatment: Heat treatment is used to optimize the microstructure, forming nano-precipitates and dislocation structures, which further improves hardness and corrosion resistance.

[0015] Furthermore, the sputtering target described in step 1) is obtained by arc melting Al, Cr, Mo, Ti and Fe particle raw materials with a molar ratio of 1:1:1:1:1, repeating the arc melting at least 5 times to uniformly mix the Al, Cr, Mo, Ti and Fe particle raw materials, cooling the mixed alloy in a mold, and grinding the cooled alloy to obtain the sputtering target.

[0016] Furthermore, the sputtering target material described in step 1) is deposited on the F / M steel alloy substrate using magnetron sputtering five-target co-sputtering technology. By adjusting the power distribution of different metal targets, the total power is set to 200W, forming a high-entropy alloy coating with a molar ratio of Al, Cr, Mo, Ti and Fe of 1:1:1:1:1.

[0017] Furthermore, the pre-sputtering conditions are as follows: in an inert gas environment, the sputtering power of the sputtering target is set to 200W, the baffle is closed, the sputtering target is pre-sputtered and cleaned, the cleaning time is set to 10-20 minutes, and the pre-sputtering gas pressure is set to 0.4-0.8 Pa.

[0018] Furthermore, the substrate material pretreatment in step 2) involves polishing the F / M steel alloy substrate at room temperature using silicon carbide sandpaper of different grit sizes and at least 1.5μm diamond polishing agent to achieve a mirror finish; cleaning the F / M steel alloy substrate with acetone and ethanol, and then cleaning the substrate with 500V Ar+ ions for 10 minutes to remove the oxide layer on the surface of the substrate material.

[0019] Furthermore, in step 4), the base pressure for the deposition process is set to 2 × 10⁻⁶. -3Pa, temperature maintained at room temperature 25℃; target and substrate distance set to 10cm to ensure coating uniformity; argon flow rate set to 30sccm, sputtering pressure fixed at 0.53Pa, coating deposition performed with 200W power and 0V bias voltage, deposition time 3h; nitrogen flow rate set to 10sccm when depositing nitrogen-containing coatings.

[0020] Furthermore, the sputtering powers of the sputtering targets for Al, Cr, Mo, Ti, and Fe are as follows: Al has a sputtering power of 30–60 W; Cr has a sputtering power of 20–55 W; Mo has a sputtering power of 20–50 W; Ti has a sputtering power of 30–70 W; and Fe has a sputtering power of 25–65 W.

[0021] Furthermore, the F / M steel alloy substrate is T91 steel alloy.

[0022] Furthermore, the temperature of the heat treatment is set to 800–1000°C.

[0023] Furthermore, the inert gas is Ar.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] The method for preparing gradient high-entropy alloy corrosion-resistant coating by magnetron sputtering of the present invention deposits AlCrFeMoTi high-entropy alloy coating on the surface of F / M steel alloy, which not only improves the surface hardness of F / M steel alloy but also improves its corrosion resistance. Moreover, the AlCrFeMoTi high-entropy alloy coating exhibits a dense, smooth and uniform surface structure, and no cracks or pores were found, indicating that the coating has high deposition quality and good interfacial bonding strength.

[0026] Furthermore, coatings prepared according to equimolar element ratios can significantly improve the elasticity and plasticity of the coating, and AlCrFeMoTi coatings exhibit better mechanical properties.

[0027] This invention utilizes multi-target magnetron sputtering technology to prepare an AlCrFeMoTi high-entropy alloy coating on F / M steel alloy materials. This coating is dense and uniform, has good bonding performance, and exhibits excellent high-temperature corrosion resistance, thus meeting the needs of practical engineering applications.

[0028] It should be understood that the description in the Summary of the Invention is not intended to limit the key or essential features of the embodiments of the present invention, nor is it intended to restrict the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0029] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0030] Figure 1 The surface SEM morphology of a 1 μm thick AlCrFeMoTi high-entropy alloy coating;

[0031] Figure 2 The SEM morphology of a 1 μm thick AlCrFeMoTi high-entropy alloy coating section;

[0032] Figure 3 The surface morphology of a 1 μm thick AlCrFeMoTi high-entropy alloy coating after corrosion in saturated oxygen and controlled oxygen LBE for different times. Detailed Implementation

[0033] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0034] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0035] Please refer to Figures 1-3 The present invention provides a method for preparing a gradient high-entropy alloy corrosion-resistant coating by magnetron sputtering. The high-entropy alloy coating deposited on the surface of F / M steel alloy is an AlCrFeMoTi high-entropy alloy, and the method specifically includes the following steps:

[0036] 1) Material preparation: The high-entropy alloy coating raw materials Al, Cr, Mo, Ti and Fe are prepared into sputtering targets in a molar ratio of 1:1:1:1:1;

[0037] 2) Pretreatment of the substrate material: Clean the surface of the F / M steel alloy substrate and activate its activity;

[0038] 3) Target pre-sputtering: In an inert gas atmosphere, the sputtering target obtained in step 1) is pre-sputtered to remove oxides and adsorbed impurities from the surface of the sputtering target.

[0039] 4) Sputtering high-entropy alloy coating: Under an inert gas atmosphere, the sputtering power of the sputtering target is set to 200W until the AlCrFeMoTi high-entropy alloy deposited on the F / M steel alloy substrate reaches the set thickness, thus obtaining the AlCrFeMoTi high-entropy alloy coating with a thickness of 1 to 2 μm.

[0040] 5) Post-treatment: Heat treatment is used to optimize the microstructure, forming nano-precipitates and dislocation structures, which further improves hardness and corrosion resistance.

[0041] In a preferred embodiment, in step 1), the sputtering target is obtained by arc melting Al, Cr, Mo, Ti and Fe particles in a molar ratio of 1:1:1:1:1, repeating the arc melting at least 5 times to uniformly mix the Al, Cr, Mo, Ti and Fe particles, cooling the mixed alloy in a mold, and grinding the cooled alloy to obtain the sputtering target.

[0042] In a preferred embodiment, in step 1), the sputtering target is deposited on the F / M steel alloy substrate using magnetron sputtering five-target co-sputtering technology. By adjusting the power distribution of different metal targets, the total power is set to 200W, forming a high-entropy alloy coating with a molar ratio of Al, Cr, Mo, Ti and Fe of 1:1:1:1:1.

[0043] In a preferred embodiment, the pre-sputtering conditions are as follows: in an inert gas environment, the sputtering power of the sputtering target is set to 200W, the baffle is closed, the sputtering target is pre-sputtered and cleaned, the cleaning time is set to 10-20 minutes, and the pre-sputtering pressure is set to 0.4-0.8 Pa.

[0044] In a preferred embodiment, the substrate material pretreatment in step 2) involves polishing the F / M steel alloy substrate at room temperature using silicon carbide sandpaper of different grit sizes and at least 1.5μm diamond polishing agent to achieve a mirror finish; the F / M steel alloy substrate is then cleaned with acetone and ethanol, and then cleaned with 500V Ar+ ions for 10 minutes to remove the oxide layer on the surface of the substrate material.

[0045] In a preferred embodiment, the base pressure for the deposition process in step 4) is set to 2 × 10⁻⁶. -3 Pa, temperature maintained at room temperature 25℃; target and substrate distance set to 10cm to ensure coating uniformity; argon flow rate set to 30sccm, sputtering pressure fixed at 0.53Pa, coating deposition performed with 200W power and 0V bias voltage, deposition time 3h; nitrogen flow rate set to 10sccm when depositing nitrogen-containing coatings.

[0046] In a preferred embodiment, the sputtering power of each sputtering target for Al, Cr, Mo, Ti and Fe is as follows: sputtering power of Al is 30-60W, sputtering power of Cr is 20-55W, sputtering power of Mo is 20-50W, sputtering power of Ti is 30-70W, and sputtering power of Fe is 25-65W.

[0047] In a preferred embodiment, the F / M steel alloy substrate is T91 steel alloy.

[0048] In a preferred embodiment, the heat treatment temperature is set to 800–1000°C.

[0049] In a preferred embodiment, the inert gas is Ar.

[0050] Example 1

[0051] In this embodiment, the deposition of an AlCrFeMoTi high-entropy alloy coating on the surface of an F / M steel alloy substrate is achieved using vacuum multi-target co-sputtering technology. The initial purity of the sputtering metal targets Al, Cr, Mo, Ti, and Fe is 99.999%, and the purity of the inert gas Ar is 99.999%. The specific preparation steps are as follows:

[0052] 1) Material preparation:

[0053] The high-entropy alloy coating raw materials Al, Cr, Mo, Ti and Fe were prepared into sputtering targets in a molar ratio of 1:1:1:1:1;

[0054] The sputtering target is deposited on the F / M steel alloy substrate using magnetron sputtering five-target co-sputtering technology. By adjusting the power distribution of different metal targets, the total power is set to 200W, forming a high-entropy alloy coating with a molar ratio of Al, Cr, Mo, Ti and Fe of 1:1:1:1:1.

[0055] The magnetron sputtering instrument used is the VTC-5RF five-target plasma radio frequency magnetron sputtering instrument; this instrument can use five targets simultaneously for sputtering, which can be used to install targets of five different materials: Al, Cr, Mo, Ti and Fe. Each target can be set with sputtering time, power and other parameters to grow thin films of different compositions; the sputtering power of the five targets is set to a total of 200W.

[0056] 2) Pretreatment of matrix material:

[0057] Clean the surface of the F / M steel alloy substrate to activate its activity;

[0058] F / M steel alloy sheet was cut into flat samples of 5*10*0.3cm. The surface of the F / M steel alloy substrate was polished from coarse to fine with 200 grit, 600 grit and 800 grit silicon carbide sandpaper, and then polished at room temperature with 2μm diamond polishing agent to achieve a mirror effect.

[0059] The F / M steel alloy substrate was cleaned with acetone and ethanol, and then the substrate was cleaned with 500V Ar+ ions for 10 minutes to remove the oxide layer on the surface of the substrate material. It was then dried and set aside for use.

[0060] 3) Target pre-sputtering:

[0061] Ar gas is introduced to pre-sputter the sputtering target obtained in step 1) to remove oxides and adsorbed impurities from the surface of the sputtering target.

[0062] The pre-sputtering conditions were as follows: in Ar gas, the sputtering power of Al was 30W, the sputtering power of Cr was 40W, the sputtering power of Mo was 35W, the sputtering power of Ti was 45W, and the sputtering power of Fe was 50W. The baffle was closed, and the sputtering target was pre-sputtered and cleaned for 15 minutes. The pre-sputtering gas pressure was set to 0.5Pa.

[0063] 4) Sputtering high-entropy alloy coating:

[0064] The F / M steel alloy substrate was placed on a water-cooled copper sample holder, which was rotated at 30 rpm. Under Ar gas, the Ar flow rate was 30 sccm, and the distance between all metal targets and the sample holder was maintained at 10 cm. The sputtering power of Al was adjusted to 35 W, Cr to 45 W, Mo to 30 W, Ti to 40 W, and Fe to 50 W. The sputtering pressure was fixed at 0.53 Pa without bias voltage. Then the baffle was opened, and the five targets were co-sputtered for 3 hours until the AlCrFeMoTi high-entropy alloy deposited on the F / M steel alloy substrate reached the set thickness of 1 μm, thus obtaining the AlCrFeMoTi high-entropy alloy coating.

[0065] 5) Post-processing:

[0066] The microstructure is optimized by heat treatment to form nano-precipitates and dislocation structures, which further improves hardness and corrosion resistance; the heat treatment temperature is set to 950℃.

[0067] Example 2

[0068] In this embodiment, the deposition of an AlCrFeMoTi high-entropy alloy coating on the surface of an F / M steel alloy substrate is achieved using magnetron sputtering technology. The initial purity of the sputtering metal target (Al, Cr, Mo, Ti, and Fe) is 99.999%, and the purity of the inert gas (Ar) is 99.999%. The specific preparation steps are as follows:

[0069] 1) Material preparation:

[0070] The high-entropy alloy coating raw materials Al, Cr, Mo, Ti and Fe were prepared into sputtering targets in a molar ratio of 1:1:1:1:1;

[0071] In this process, Al, Cr, Mo, Ti and Fe particles with a molar ratio of 1:1:1:1:1 are subjected to electric arc melting, and the electric arc melting is repeated at least 5 times to ensure that the Al, Cr, Mo, Ti and Fe particles are uniformly mixed. The mixed alloy is cooled in a mold, and the cooled alloy is ground and processed to obtain the sputtering target.

[0072] 2) Pretreatment of matrix material:

[0073] Clean the surface of the F / M steel alloy substrate to activate its activity;

[0074] F / M steel alloy sheet was cut into flat samples of 5*10*0.3cm. The surface of the F / M steel alloy substrate was polished from coarse to fine with 200 grit, 600 grit and 800 grit silicon carbide sandpaper, and then polished at room temperature with 2μm diamond polishing agent to achieve a mirror effect.

[0075] The F / M steel alloy substrate was cleaned with acetone and ethanol, and then the substrate was cleaned with 500V Ar+ ions for 10 minutes to remove the oxide layer on the surface of the substrate material. It was then dried and set aside for use.

[0076] 3) Target pre-sputtering:

[0077] Ar gas is introduced to pre-sputter the sputtering target obtained in step 1) to remove oxides and adsorbed impurities from the surface of the sputtering target.

[0078] The pre-sputtering conditions are as follows: in Ar gas, the sputtering power of the sputtering target in step 1) is set to 200W, the baffle is closed, the sputtering target is pre-sputtered and cleaned, the cleaning time is set to 15min, and the pre-sputtering pressure is set to 0.5Pa.

[0079] 4) Sputtering high-entropy alloy coating:

[0080] The F / M steel alloy substrate was placed on a water-cooled copper sample holder, which was rotated at 30 rpm. Under Ar gas, the Ar flow rate was 30 sccm, and the distance between all metal targets and the sample holder was maintained at 10 cm. The sputtering power of the sputtering target was adjusted to 200 W. The sputtering pressure was fixed at 0.4 Pa without bias voltage. Then the baffle was opened and sputtering was performed for 3 hours until the AlCrFeMoTi high-entropy alloy deposited on the F / M steel alloy substrate reached the set thickness of 2 μm, thus obtaining the AlCrFeMoTi high-entropy alloy coating.

[0081] 5) Post-processing:

[0082] The microstructure is optimized by heat treatment to form nano-precipitates and dislocation structures, thereby further improving hardness and corrosion resistance; the heat treatment temperature is set at 1000℃.

[0083] Characterization of the structure and corrosion resistance of AlCrFeMoTi high-entropy alloy coating deposited on the surface of F / M steel alloy;

[0084] (1) Structural and morphological features

[0085] The AlCrFeMoTi high-entropy alloy coating prepared in the examples was analyzed by scanning electron microscopy (SEM). The analysis results are as follows: Figure 1 As shown, from Figure 1 It can be seen that the coatings all exhibit a dense, smooth, and uniform surface structure, with no cracks or pores found. Minor scratches were observed, which may have been introduced during the substrate polishing process, indicating that the coatings have high deposition quality.

[0086] Cross-sectional SEM images of the deposited AlCrFeMoTi coating are shown below. Figure 2 As shown, the coating structure is dense and uniform, and no cracks were observed between it and the substrate; these indicate that the coating has high deposition quality and good interfacial bonding strength, which is beneficial to improving the LBE corrosion resistance.

[0087] (2) Corrosion resistance

[0088] The samples after LBE corrosion were analyzed to determine the corrosion resistance properties of the coating. Figure 3 The surface morphology of the coatings after 500h, 1000h, and 2000h under saturated oxygen and controlled oxygen environments are shown respectively.

[0089] At a corrosion temperature of 450℃, Figure 3 (a1) shows the morphology of a 1 μm thick coating after corrosion under saturated oxygen. It was found that after 500 h of corrosion, the oxide on the surface was dense and intact, with no obvious signs of cracking and peeling, indicating that it has good protection for the substrate.

[0090] After 1000 hours, fine cracks appeared on the surface. Figure 3 (a2)) These cracks provide channels for LBE penetration and element diffusion in the coating.

[0091] After 2000 hours, the tiny cracks continued to expand and deepen. Figure 3 (a3)) results in a sheet-like morphology on the surface.

[0092] The surface morphology remained very dense and uniform under controlled oxygen LBE environment, with no obvious morphological changes observed and no cracks found, demonstrating good integrity and corrosion resistance. Figure 3 (b1-b3)). The surface composition of the 1-micron thick coating is relatively uniform, with slightly higher Fe and Cr content, indicating that Fe and Cr are relatively more reactive during the corrosion process.

[0093] In the description of this specification, the terms "connection," "installation," and "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0094] In the description of this specification, the terms "one embodiment," "some embodiments," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0095] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for preparing a gradient high-entropy alloy corrosion-resistant coating by magnetron sputtering, characterized in that, The high-entropy alloy coating deposited on the surface of F / M steel alloy is an AlCrFeMoTi high-entropy alloy, and the specific steps include the following: 1) Material preparation: The high-entropy alloy coating raw materials Al, Cr, Mo, Ti and Fe are prepared into sputtering targets in a molar ratio of 1:1:1:1:1; 2) Pretreatment of the substrate material: Clean the surface of the F / M steel alloy substrate and activate its activity; 3) Target pre-sputtering: The sputtering target obtained in step 1) is pre-sputtered in an inert gas atmosphere to remove oxides and adsorbed impurities from the surface of the sputtering target. 4) Sputtering high-entropy alloy coating: Under an inert gas atmosphere, the sputtering power of the sputtering target is set to 200W until the AlCrFeMoTi high-entropy alloy deposited on the F / M steel alloy substrate reaches the set thickness, thereby obtaining an AlCrFeMoTi high-entropy alloy coating with a thickness of 1 to 2 μm. 5) Post-treatment: Heat treatment is used to optimize the microstructure, forming nano-precipitates and dislocation structures, which further improves hardness and corrosion resistance.

2. The method for preparing a gradient high-entropy alloy corrosion-resistant coating by magnetron sputtering according to claim 1, characterized in that, The sputtering target described in step 1) is obtained by arc melting Al, Cr, Mo, Ti and Fe particles in a molar ratio of 1:1:1:1:1, repeating the arc melting at least 5 times to uniformly mix the Al, Cr, Mo, Ti and Fe particles, cooling the mixed alloy in a mold, and grinding the cooled alloy to obtain the sputtering target.

3. The method for preparing a gradient high-entropy alloy corrosion-resistant coating by magnetron sputtering according to claim 1, characterized in that, The sputtering target described in step 1) is deposited on an F / M steel alloy substrate using magnetron sputtering five-target co-sputtering technology. By adjusting the power distribution of different metal targets, the total power is set to 200W, forming a high-entropy alloy coating with a molar ratio of Al, Cr, Mo, Ti and Fe of 1:1:1:1:

1.

4. The method for preparing a gradient high-entropy alloy corrosion-resistant coating by magnetron sputtering according to claim 1, characterized in that, The pre-sputtering conditions are as follows: in an inert gas environment, the sputtering power of the sputtering target is set to 200W, the baffle is closed, the sputtering target is pre-sputtered and cleaned, the cleaning time is set to 10-20 minutes, and the pre-sputtering pressure is set to 0.4-0.8 Pa.

5. The method for preparing a gradient high-entropy alloy corrosion-resistant coating by magnetron sputtering according to claim 1, characterized in that, The substrate material pretreatment described in step 2) involves polishing the F / M steel alloy substrate at room temperature using silicon carbide sandpaper of different grit sizes and at least 1.5μm diamond polishing agent to achieve a mirror finish; then cleaning the F / M steel alloy substrate with acetone and ethanol, followed by substrate cleaning with 500V Ar+ ions for 10 minutes to remove the oxide layer on the surface of the substrate material.

6. The method for preparing a gradient high-entropy alloy corrosion-resistant coating by magnetron sputtering according to claim 1, characterized in that, In step 4), the base pressure for the deposition process is set to 2 × 10⁻⁶. -3 Pa, temperature maintained at room temperature 25℃; distance between target and substrate set at 10cm to ensure coating uniformity; The argon flow rate was set to 30 sccm, the sputtering pressure was fixed at 0.53 Pa, and the coating was deposited with a power of 200 W and a bias voltage of 0 V for 3 hours. When depositing nitrogen-containing coatings, the nitrogen flow rate is set to 10 sccm.

7. The method for preparing a gradient high-entropy alloy corrosion-resistant coating by magnetron sputtering according to claim 3, characterized in that, The sputtering powers of the sputtering targets for Al, Cr, Mo, Ti, and Fe are as follows: Al sputtering power is 30–60 W; Cr sputtering power is 20–55 W; Mo sputtering power is 20–50 W; Ti sputtering power is 30–70 W; and Fe sputtering power is 25–65 W.

8. The method for preparing a gradient high-entropy alloy corrosion-resistant coating by magnetron sputtering according to claim 1, characterized in that, The F / M steel alloy substrate is T91 steel alloy.

9. The method for preparing a gradient high-entropy alloy corrosion-resistant coating by magnetron sputtering according to claim 1, characterized in that, The temperature for the heat treatment is set to 800–1000°C.

10. The method for preparing a gradient high-entropy alloy corrosion-resistant coating by magnetron sputtering according to claim 1, characterized in that, The inert gas is Ar.

Images