A high-entropy crystalline / amorphous nano-metal multilayer film and its preparation method

Abstract

This invention discloses a high-entropy crystalline / amorphous nanoscale metal multilayer film and its preparation method, belonging to the field of nanoscale metal multilayer film coating materials. The nanoscale metal multilayer film comprises alternating layers of TaWMoCrZr and CrMoY; the thickness of the TaWMoCrZr layer is 5-100 nm, and the thickness of the CrMoY layer is 1.25-25 nm; the TaWMoCrZr layer is nanocrystalline, and the CrMoY layer is amorphous. This nanoscale metal multilayer film is prepared using magnetron sputtering, with the layer thickness controlled by adjusting the sputtering time. The resulting TaWMoCrZr / CrMoY coating has a nanoscale multilayer structure with clear and flat layer interfaces, uniform composition, dense structure, and excellent mechanical properties. Furthermore, through mixing enthalpy design, it achieves self-regulating component segregation, exhibiting good thermal stability and expanding the application range of multilayer film coatings.

Description

Technical Field

[0001] This invention relates to the field of nanoscale metal multilayer film coating materials, specifically to a high-entropy crystalline / amorphous nanoscale metal multilayer film and its preparation method. Background Technology

[0002] Compared with traditional metallic materials, nanoscale metal multilayer films exhibit superior comprehensive performance, possessing a higher combination of strength and plasticity, better resistance to radiation damage, and stronger resistance to fatigue failure. Therefore, they have the potential to become one of the choices for materials used in extreme environments, such as nuclear fuel cladding materials. Currently, various preparation methods are available for depositing nanoscale metal multilayer film coatings. Among them, magnetron sputtering is a relatively mature coating preparation technology due to its low-temperature operation, controllable deposition rate, excellent film quality, precise process, and good repeatability.

[0003] However, the cladding material for lead-bismuth fast reactors in Generation IV nuclear reactors not only needs sufficient strength and toughness to resist the synergistic effects of complex stresses (such as slow tensile stress, creep, and fatigue), but also needs to possess corrosion resistance against lead-bismuth corrosion. Currently, several preferred high-quality alternative materials are iron / Mainland steel (F / M steel) and austenitic steel. F / M steel suffers from fatal defects such as radiation embrittlement and low strength at high temperatures; the Ni element in austenitic steel easily dissolves into the liquid lead-bismuth metal, resulting in poor lead-bismuth compatibility. Therefore, to ensure the stable and normal operation of nuclear fuel cladding materials, designing a nano-metal multilayer film coating with excellent mechanical properties, thermal stability, and corrosion resistance has significant application value and importance. The TaWMoCrZr high-entropy crystalline monolayer film possesses excellent thermal stability, and the elements Ta, W, Mo, Cr, Zr, and Y are insoluble in lead and bismuth. Meanwhile, the CrMoY monolayer film has a uniform amorphous structure without easily corroded structural defects such as grain boundaries. Therefore, the question is how to combine TaWMoCrZr and CrMoY as crystalline and amorphous layers to form a composite material that combines the performance advantages of both films, thereby improving the protective performance of the lead-bismuth fast reactor cladding material. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a high-entropy crystalline / amorphous nano-metal multilayer film, its preparation method, and the preparation method thereof. The nano-metal multilayer film coating has a clear and flat layer interface, uniform microstructure, and excellent high-temperature structural stability and mechanical properties.

[0005] This invention is achieved through the following technical solution:

[0006] A high-entropy crystalline / amorphous nano-metal multilayer film comprising alternating layers of TaWMoCrZr and CrMoY;

[0007] The thickness of the TaWMoCrZr layer is 5-100 nm, and the thickness of the CrMoY layer is 1.25-25 nm;

[0008] The TaWMoCrZr layer is in a nanocrystalline morphology, while the CrMoY layer is in an amorphous morphology.

[0009] Preferably, the nanoindentation hardness of the nanometal multilayer film is 9.5–10.5 GPa, and the Young's modulus is 161–174 GPa.

[0010] Preferably, in the TaWMoCrZr layer, the atomic percentage ratio of the four elements Ta, W, Mo, and Cr is 1:1:1:1, and the atomic percentage of Zr is 16.8 at.%.

[0011] Preferably, the atomic percentage ratio of Cr, Mo, and Y in the CrMoY layer is 1:1:1.

[0012] A method for preparing a high-entropy crystalline / amorphous nano-metal multilayer film includes the following steps:

[0013] Step 1: Clean and dry the substrate surface;

[0014] Step 2: Vacuum etching is performed on the substrate cleaned in Step 1.

[0015] Step 3: Using a combination of TaWMoCr alloy target and Zr target, and a CrMoY alloy target, TaWMoCrZr crystal layer and CrMoY layer are alternately deposited on the substrate by magnetron sputtering to obtain a nano-metal multilayer film.

[0016] During magnetron sputtering, the DC power of the TaWMoCr alloy target is 200W, the RF power of the Zr target is 100W, the DC power of the CrMoY alloy target is 200W, and the total deposition time is 7496–9664 seconds.

[0017] Step 4: Cool the nano-metal multilayer film to room temperature in the furnace to obtain a high-entropy crystalline / amorphous nano-metal multilayer film.

[0018] Preferably, the method for alternating magnetron sputtering deposition of TaWMoCrZr crystal layers and CrMoY layers in step 3 is as follows:

[0019] First, a TaWMoCrZr crystal layer was sputtered onto the substrate using a combination of TaWMoCr alloy target and Zr target.

[0020] Then, an amorphous CrMoY layer was deposited by sputtering using a CrMoY alloy target.

[0021] Repeat the above process, using a combined target and a CrMoY alloy target to alternately deposit TaWMoCrZr crystalline layers and CrMoY amorphous layers until the preset conditions are met, to obtain a nano-metal multilayer film.

[0022] Preferably, the deposition gas pressure of the magnetron sputtering is set to 0.3 Pa and the substrate rotation speed is 15 r / min.

[0023] Preferably, both the TaWMoCr alloy target and the CrMoY alloy target are atomic targets.

[0024] Preferably, the cooling time in step 4 is 2-3 hours.

[0025] Application of a high-entropy crystalline / amorphous nano-metal multilayer film, wherein the nano-metal multilayer film is used in the cladding of a lead-bismuth fast reactor in a nuclear reactor.

[0026] Compared with the prior art, the present invention has the following beneficial technical effects:

[0027] This invention proposes a high-entropy crystalline / amorphous nano-metal multilayer coating, unique in that it features alternating layers of TaWMoCrZr nanocrystalline layers and CrMoY amorphous layers. This design cleverly utilizes the fact that elements such as Ta, W, Mo, Cr, Zr, and Y are insoluble in lead-bismuth alloys, along with the excellent thermal stability exhibited by the high-entropy crystalline monolayer of TaWMoCrZr and the uniform amorphous structure formed by the CrMoY monolayer. Furthermore, the TaWMoCrZr layer exists in a nanocrystalline morphology, while the CrMoY layer exhibits an amorphous morphology; their alternating superposition forms a multilayer film structure with a clear and flat interface, uniform composition, and dense microstructure. This crystalline / amorphous nano-multilayer film not only possesses excellent mechanical properties but also effectively captures irradiation defects due to the heterogeneous characteristics of the crystalline / amorphous interface, enhancing the overall stability of the coating. More importantly, this invention, by rationally selecting high-melting-point metal elements insoluble in lead-bismuth alloys as high-entropy components, designs a refractory high-entropy alloy composition, resulting in excellent thermal stability of this high-entropy crystalline / amorphous nano-multilayer film coating. This design approach not only enhances the coating's corrosion resistance but also enables it to exhibit superior overall performance in the extreme environments of nuclear energy fields such as lead-bismuth fast reactors. Compared to protective coatings prepared using existing technologies, the high-entropy nano-metal multilayer film of this invention, through careful selection of alloying elements and optimized preparation methods, successfully achieves a comprehensive improvement in mechanical properties, thermal stability, and corrosion resistance. This innovative design not only expands the application range of multilayer film coatings but also provides strong material support for the engineering needs of nuclear energy fields such as lead-bismuth fast reactors, demonstrating its enormous potential as a material for service in extreme environments. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 A TEM cross-sectional image of the TaWMoCrZr / CrMoY high-entropy crystalline / amorphous nanomultilayer film prepared in Example 1 of this invention.

[0030] Figure 2 This is a high-resolution photograph of the TaWMoCrZr / CrMoY high-entropy crystalline / amorphous nanolayered film prepared in Example 1 of the present invention.

[0031] Figure a shows a high-resolution photograph of the TaWMoCrZr crystal layer in the TaWMoCrZr / CrMoY high-entropy crystalline / amorphous nanomultilayer film.

[0032] Figure b shows a high-resolution image of the CrMoY amorphous layer in the TaWMoCrZr / CrMoY high-entropy crystalline / amorphous nanomultilayer film.

[0033] Figure 3 EDS elemental surface scan image of the TaWMoCrZr / CrMoY high-entropy crystalline / amorphous nanomultilayer film prepared in Example 1 of this invention.

[0034] Figure 4 The results show the nanoindentation hardness of the high-entropy crystalline / amorphous nanomultilayer films of TaWMoCrZr / CrMoY with different modulation periods according to the present invention. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0036] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0037] The challenge lies in combining TaWMoCrZr and CrMoY materials to form a composite material that provides effective protection in extreme environments. This composite material must possess a uniform and dense microstructure and superior performance, which largely depends on the selection of its preparation techniques and process parameters. Therefore, precisely selecting magnetron sputtering process parameters and modulation parameters to control the microstructure of the coating and prepare novel high-entropy nanolayered films with excellent mechanical properties, thermal stability, and corrosion resistance is a key issue in composite material preparation.

[0038] Based on the above problems, this application provides a high-entropy crystalline / amorphous nano-metal multilayer film, comprising alternating stacked TaWMoCrZr layers and CrMoY layers;

[0039] The thickness of the TaWMoCrZr layer is 5-100 nm, the thickness of the CrMoY layer is 1.25-25 nm, and the thickness of the nano-metal multilayer film is 1 μm.

[0040] The TaWMoCrZr layer is in the form of nanocrystals, with the atomic percentage ratio of Ta, W, Mo, and Cr being 1:1:1:1, and the atomic percentage of Zr being 16.8 at.%.

[0041] The CrMoY layer is amorphous, and the atomic percentage ratio of Cr, Mo, and Y is 1:1:1.

[0042] The nanoindentation hardness of the TaWMoCrZr / CrMoY high-entropy crystalline / amorphous nanomultilayer film coating is 9.5–10.5 GPa, and the Young's modulus is 161–174 GPa.

[0043] This application discloses a high-entropy crystalline / amorphous nano-metal multilayer film. The TaWMoCrZr high-entropy crystalline layer exhibits excellent thermal stability, and the elements Ta, W, Mo, Cr, Zr, and Y are insoluble in lead and bismuth. Meanwhile, the CrMoY monolayer film has a uniform amorphous structure without easily corroded structural defects such as grain boundaries. The TaWMoCrZr high-entropy crystalline layer and the CrMoY monolayer film are coupled together using magnetron sputtering technology to form a multilayer film structure. The multilayer film has a clear and flat interface, uniform composition, and dense structure, and possesses excellent mechanical properties, thermal stability, and corrosion resistance.

[0044] Correspondingly, based on the aforementioned high-entropy crystalline / amorphous nanometal multilayer film, this application also provides a method for preparing the high-entropy crystalline / amorphous nanometal multilayer film, comprising the following steps:

[0045] Step 1: Ultrasonic cleaning and drying of the silicon substrate surface is performed to improve the adhesion between the coating and the substrate.

[0046] Specifically, the silicon substrate is polished on one side, then ultrasonically cleaned in acetone and ethanol for 15 minutes each, and then quickly dried to make the silicon substrate surface clean and free of stains and dust, with a roughness of less than 0.8 nm, which is beneficial to improving the adhesion between the coating and the substrate.

[0047] Step 2: Vacuum etch the substrate after cleaning in Step 1.

[0048] Specifically, the ultrasonically cleaned silicon substrate is fixed on a base plate and sent into a vacuum coating chamber, then the back vacuum is evacuated to 4.0 × 10⁻⁶. -4 Below Pa. In a high vacuum environment, using Ar... + Ion etching is performed at a power of 200W and a gas flow rate of 60sccm for 5 minutes to remove impurities from the substrate surface, which helps to improve the adhesion between the coating and the substrate.

[0049] Step 3: Using a combination of TaWMoCr alloy target and Zr target, and a CrMoY alloy target, TaWMoCrZr crystal layer and CrMoY layer are alternately deposited on the substrate by magnetron sputtering.

[0050] Specifically, when the vacuum level is below 4.0 × 10⁻⁴ Pa, a TaWMoCrZr crystalline layer is first deposited on the substrate by sputtering using a combination of TaWMoCr alloy target and Zr target. Then, an amorphous CrMoY layer is deposited by sputtering using a CrMoY alloy target. The above process is repeated, with TaWMoCrZr crystalline layer and CrMoY amorphous layer deposited alternately using the combination target and CrMoY alloy target until the preset conditions are met, thus obtaining a nano-metal multilayer film.

[0051] During the magnetron sputtering process, the DC power of the TaWMoCr alloy target was 200W, the RF power of the Zr target was 100W, the DC power of the CrMoY alloy target was 200W, the deposition gas pressure was set to 0.3Pa, the substrate rotation speed was 15r / min, the total deposition time was 7496~9664 seconds, and the thickness of the nano-metal multilayer film was 1μm.

[0052] The purity of the TaWMoCr alloy target is 99.9 wt.% (Ta:W:Mo:Cr = 1:1:1:1 at.%), the purity of the Zr target is 99.9 wt.%, and the purity of the CrMoY alloy target is 99.9 wt.% (Cr:Mo:Y = 1:1:1 at.%).

[0053] Step 4: After deposition, the nano-metal multilayer film is cooled to room temperature in a high-vacuum coating chamber, and then removed to obtain a high-entropy crystalline / amorphous nano-metal multilayer film.

[0054] The furnace cooling process aims to avoid debonding and cracking caused by the difference in thermal expansion coefficients between the substrate and the coating material, while also preventing oxidation reactions of the coating due to contact with air at high temperatures.

[0055] The principle of this method for preparing high-entropy crystalline / amorphous nanolayered film coatings is as follows: A suitable amount of argon gas is filled into a vacuum chamber, and a high voltage is applied between the cathode target and the anode. Under the influence of the electric field, electrons are accelerated and collide with argon gas molecules, causing them to ionize and generate Ar⁺ and electrons. These Ar⁺ particles are accelerated under the influence of the electric field and bombard the target surface, giving the target atoms or molecules sufficient kinetic energy to detach from the target surface, forming sputtered particles. Figure 1 As shown, the prepared TaWMoCrZr / CrMoY high-entropy crystalline / amorphous nanomultilayer film coating has the morphology of a crystalline / amorphous multilayer film, in which the TaWMoCrZr layer is in the form of nanocrystalline morphology and the CrMoY layer is in the form of amorphous morphology. The layer interfaces are clear and straight, the composition is uniform, and the structure is dense.

[0056] Example 1

[0057] A method for preparing a high-entropy crystalline / amorphous nano-metal multilayer film includes the following steps:

[0058] Step 1: The polished Si(111) substrate was ultrasonically cleaned in acetone and anhydrous ethanol for 15 min and then dried to remove impurities from the surface of the silicon substrate.

[0059] Step 2: Fix the silicon substrate onto the base plate, and automatically transport it into the magnetron sputtering vacuum coating chamber until the back vacuum level reaches 4.0 × 10⁻⁶. -4 Etching begins below Pa, with an etching power of 200W, an etching gas pressure of 1.0Pa, and a time of 5 minutes.

[0060] Step 3: Begin magnetron sputtering deposition of TaWMoCrZr / CrMoY high-entropy crystalline / amorphous nanolayer film coating.

[0061] First, argon gas was introduced for 30 seconds, followed by pre-sputtering for 10 seconds. A TaWMoCrZr crystal layer was prepared by co-sputtering using a TaWMoCr alloy target and a Zr target. The DC power of the TaWMoCr alloy target was 200W, and the RF power of the Zr target was 100W.

[0062] Then, an amorphous CrMoY layer was prepared using a CrMoY alloy target with a DC power of 200W.

[0063] Secondly, co-sputtering of TaWMoCr and Zr targets was initiated, with alternating deposition with CrMoY targets. The substrate rotation speed was 15 r / min, the deposition gas pressure was set to 0.3 Pa, the argon flow rate was 60 sccm, the deposition temperature was room temperature, the thickness of the monolayer TaWMoCrZr crystal layer was set to 100 nm, the thickness of the monolayer CrMoY amorphous layer was set to 25 nm, the modulation period was 8, and the total film thickness was 1 μm.

[0064] Step 4: After the sample has cooled naturally to room temperature in the vacuum coating chamber for 2-3 hours, it is taken out to obtain a TaWMoCrZr / CrMoY high-entropy crystalline / amorphous nano-multilayer film coating with a thickness of about 1.00 μm.

[0065] The microstructure of the prepared TaWMoCrZr / CrMoY high-entropy crystalline / amorphous nanomultilayer film coating was characterized. The morphology of the TaWMoCrZr / CrMoY high-entropy crystalline / amorphous nanomultilayer film coating is crystalline / amorphous nanomultilayer film, in which the TaWMoCrZr layer is nanocrystalline and the CrMoY layer is amorphous. The multilayer film interface is clear and straight, the composition is uniform, and the structure is dense.

[0066] Example 2

[0067] A method for preparing a high-entropy crystalline / amorphous nano-metal multilayer film includes the following steps:

[0068] Step 1: The polished Si(111) substrate was ultrasonically cleaned in acetone and anhydrous ethanol for 15 min and then dried to remove impurities from the surface of the silicon substrate.

[0069] Step 2: Fix the silicon substrate onto the base plate, and automatically transport it into the magnetron sputtering vacuum coating chamber until the back vacuum level reaches 4.0 × 10⁻⁶. -4 Etching begins below Pa, with an etching power of 200W, an etching gas pressure of 1.0Pa, and a time of 5 minutes.

[0070] Step 3: Begin magnetron sputtering deposition of TaWMoCrZr / CrMoY high-entropy crystalline / amorphous nanolayer film coating.

[0071] First, argon gas was introduced for 30 seconds, followed by pre-sputtering for 10 seconds. A TaWMoCrZr crystal layer was prepared by co-sputtering using a TaWMoCr alloy target and a Zr target. The DC power of the TaWMoCr alloy target was 200W, and the RF power of the Zr target was 100W.

[0072] Then, an amorphous CrMoY layer was prepared using a CrMoY alloy target with a DC power of 200W.

[0073] Secondly, co-sputtering of TaWMoCr and Zr targets was initiated, with alternating deposition with CrMoY targets. The substrate rotation speed was 15 r / min, the deposition gas pressure was set to 0.3 Pa, the argon flow rate was 60 sccm, the deposition temperature was room temperature, the thickness of the monolayer TaWMoCrZr crystal layer was set to 50 nm, the thickness of the monolayer CrMoY amorphous layer was set to 12.5 nm, the number of periods was 16, and the total film thickness was 1 μm.

[0074] Step 4: After the sample has cooled naturally to room temperature in the vacuum coating chamber for 2-3 hours, it is taken out to obtain a TaWMoCrZr / CrMoY high-entropy crystalline / amorphous nano-multilayer film coating with a thickness of about 1.00 μm.

[0075] The microstructure of the prepared TaWMoCrZr / CrMoY high-entropy crystalline / amorphous nanomultilayer film coating was characterized. The morphology of the TaWMoCrZr / CrMoY high-entropy crystalline / amorphous nanomultilayer film coating is crystalline / amorphous nanomultilayer film, in which the TaWMoCrZr layer is nanocrystalline and the CrMoY layer is amorphous. The multilayer film interface is clear and straight, the composition is uniform, and the structure is dense.

[0076] Example 3

[0077] A method for preparing a high-entropy crystalline / amorphous nano-metal multilayer film includes the following steps:

[0078] Step 1: The polished Si(111) substrate was ultrasonically cleaned in acetone and anhydrous ethanol for 15 min and then dried to remove impurities from the surface of the silicon substrate.

[0079] Step 2: Fix the silicon substrate onto the base plate, and automatically transport it into the magnetron sputtering vacuum coating chamber until the back vacuum level reaches 4.0 × 10⁻⁶. -4 Etching begins below Pa, with an etching power of 200W, an etching gas pressure of 1.0Pa, and a time of 5 minutes.

[0080] Step 3: Begin magnetron sputtering deposition of TaWMoCrZr / CrMoY high-entropy crystalline / amorphous nanolayer film coating.

[0081] First, argon gas was introduced for 30 seconds, followed by pre-sputtering for 10 seconds. A TaWMoCrZr crystal layer was prepared by co-sputtering using a TaWMoCr alloy target and a Zr target. The DC power of the TaWMoCr alloy target was 200W, and the RF power of the Zr target was 100W.

[0082] Then, an amorphous CrMoY layer was prepared using a CrMoY alloy target with a DC power of 200W.

[0083] Secondly, co-sputtering of TaWMoCr and Zr targets was initiated, with alternating deposition with CrMoY targets. The substrate rotation speed was 15 r / min, the deposition gas pressure was set to 0.3 Pa, the argon flow rate was 60 sccm, the deposition temperature was room temperature, the thickness of the monolayer TaWMoCrZr crystal layer was set to 25 nm, the thickness of the monolayer CrMoY amorphous layer was set to 6.25 nm, the number of periods was 32, and the total film thickness was 1 μm.

[0084] Step 4: After the sample has cooled naturally to room temperature in the vacuum coating chamber for 2-3 hours, it is taken out to obtain a TaWMoCrZr / CrMoY high-entropy crystalline / amorphous nano-multilayer film coating with a thickness of about 1.00 μm.

[0085] The microstructure of the prepared TaWMoCrZr / CrMoY high-entropy crystalline / amorphous nanomultilayer film coating was characterized. The morphology of the TaWMoCrZr / CrMoY high-entropy crystalline / amorphous nanomultilayer film coating is crystalline / amorphous nanomultilayer film, in which the TaWMoCrZr layer is nanocrystalline and the CrMoY layer is amorphous. The multilayer film interface is clear and straight, the composition is uniform, and the structure is dense.

[0086] Example 4

[0087] A method for preparing a high-entropy crystalline / amorphous nano-metal multilayer film includes the following steps:

[0088] Step 1: The polished Si(111) substrate was ultrasonically cleaned in acetone and anhydrous ethanol for 15 min and then dried to remove impurities from the surface of the silicon substrate.

[0089] Step 2: Fix the silicon substrate onto the base plate, and automatically transport it into the magnetron sputtering vacuum coating chamber until the back vacuum level reaches 4.0 × 10⁻⁶. -4 Etching begins below Pa, with an etching power of 200W, an etching gas pressure of 1.0Pa, and a time of 5 minutes.

[0090] Step 3: Begin magnetron sputtering deposition of TaWMoCrZr / CrMoY high-entropy crystalline / amorphous nanolayer film coating.

[0091] First, argon gas was introduced for 30 seconds, followed by pre-sputtering for 10 seconds. A TaWMoCrZr crystal layer was prepared by co-sputtering using a TaWMoCr alloy target and a Zr target. The DC power of the TaWMoCr alloy target was 200W, and the RF power of the Zr target was 100W.

[0092] Then, an amorphous CrMoY layer was prepared using a CrMoY alloy target with a DC power of 200W.

[0093] Next, co-sputtering of TaWMoCr and Zr targets was initiated, and deposition was carried out alternately with CrMoY targets. The substrate rotation speed was 15 r / min, the deposition gas pressure was set to 0.3 Pa, the argon flow rate was 60 sccm, the deposition temperature was room temperature, the thickness of the monolayer TaWMoCrZr crystal layer was set to 10 nm, the thickness of the monolayer CrMoY amorphous layer was set to 2.5 nm, the number of periods was 80, and the total film thickness was 1 μm.

[0094] Step 4: After the sample has cooled naturally to room temperature in the vacuum coating chamber for 2-3 hours, it is taken out to obtain a TaWMoCrZr / CrMoY high-entropy crystalline / amorphous nano-multilayer film coating with a thickness of about 1.00 μm.

[0095] The microstructure of the prepared TaWMoCrZr / CrMoY high-entropy crystalline / amorphous nanomultilayer film coating was characterized. The morphology of the TaWMoCrZr / CrMoY high-entropy crystalline / amorphous nanomultilayer film coating is crystalline / amorphous nanomultilayer film. Among them, the TaWMoCrZr layer has a partial amorphous and partial nanocrystalline morphology due to its small layer thickness, while the CrMoY layer has an amorphous morphology. The multilayer film interface is relatively clear and straight, the composition is uniform, and the structure is dense.

[0096] Example 5

[0097] A method for preparing a high-entropy crystalline / amorphous nano-metal multilayer film includes the following steps:

[0098] Step 1: The polished Si(111) substrate was ultrasonically cleaned in acetone and anhydrous ethanol for 15 min and then dried to remove impurities from the surface of the silicon substrate.

[0099] Step 2: Fix the silicon substrate onto the base plate, and automatically transport it into the magnetron sputtering vacuum coating chamber until the back vacuum level reaches 4.0 × 10⁻⁶. -4 Etching begins below Pa, with an etching power of 200W, an etching gas pressure of 1.0Pa, and a time of 5 minutes.

[0100] Step 3: Begin magnetron sputtering deposition of TaWMoCrZr / CrMoY high-entropy crystalline / amorphous nanolayer film coating.

[0101] First, argon gas was introduced for 30 seconds, followed by pre-sputtering for 10 seconds. A TaWMoCrZr crystal layer was prepared by co-sputtering using a TaWMoCr alloy target and a Zr target. The DC power of the TaWMoCr alloy target was 200W, and the RF power of the Zr target was 100W.

[0102] Then, an amorphous CrMoY layer was prepared using a CrMoY alloy target with a DC power of 200W.

[0103] Secondly, TaWMoCr and Zr targets were co-sputtered simultaneously and deposited alternately with CrMoY targets. The substrate rotation speed was 15 r / min, the deposition gas pressure was set to 0.3 Pa, the argon flow rate was 60 sccm, the deposition temperature was room temperature, the thickness of the monolayer TaWMoCrZr crystal layer was set to 5 nm, the thickness of the monolayer CrMoY amorphous layer was set to 1.25 nm, the number of periods was 160, and the total film thickness was 1 μm.

[0104] Step 4: After the sample has cooled naturally to room temperature in the vacuum coating chamber for 2-3 hours, it is taken out to obtain a TaWMoCrZr / CrMoY high-entropy crystalline / amorphous nano-multilayer film coating with a thickness of about 1.00 μm.

[0105] The microstructure of the prepared TaWMoCrZr / CrMoY high-entropy crystalline / amorphous nanomultilayer film coating was characterized. The morphology of the TaWMoCrZr / CrMoY high-entropy crystalline / amorphous nanomultilayer film coating is crystalline / amorphous nanomultilayer film. The TaWMoCrZr layer has a partial amorphous and partial nanocrystalline morphology due to its small layer thickness, while the CrMoY layer is amorphous. The multilayer film interface is relatively clear and straight, and slightly curved compared to thicker multilayer films. The composition is uniform and the structure is dense.

[0106] Figure 1 A TEM cross-sectional image of the high-entropy crystalline / amorphous nanolayered film prepared in Example 1 is shown. Figure 2 High-resolution photograph of the high-entropy crystalline / amorphous nanolayered film prepared in Example 1. Figure 3 EDS elemental surface scan images of the high-entropy crystalline / amorphous nanomultilayer film prepared in Example 1 are shown. Figure 4 The nanoindentation hardness results of high-entropy crystalline / amorphous nanomultilayer film coatings with different layer thicknesses are presented.

[0107] This high-entropy crystalline / amorphous multilayer coating comprises alternating layers of TaWMoCrZr and CrMoY. Since Ta, W, Mo, Cr, Zr, and Y are all insoluble in lead-bismuth alloys, and the TaWMoCrZr high-entropy crystalline monolayer exhibits excellent thermal stability, while the CrMoY monolayer possesses a uniform amorphous structure, the designed TaWMoCrZr / CrMoY high-entropy crystalline / amorphous nanolayer coating effectively solves the problem of traditional nuclear reactor protective coatings being susceptible to lead-bismuth corrosion, demonstrating excellent mechanical properties and corrosion resistance. Furthermore, the crystalline / amorphous nanolayer coating, due to its heterogeneous interface, can effectively capture irradiation defects. Moreover, by selecting high-melting-point metal elements as high-entropy components, a refractory high-entropy alloy is designed, resulting in a high-entropy crystalline / amorphous nanolayer coating with excellent thermal stability. Therefore, this novel high-entropy crystalline / amorphous multilayer coating with superior comprehensive performance has the potential to become one of the choices for materials used in extreme environments.

[0108] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A high-entropy crystalline / amorphous nano-metal multilayer film, characterized in that, Includes alternating stacked TaWMoCrZr and CrMoY layers; The thickness of the TaWMoCrZr layer is 5-100 nm, and the thickness of the CrMoY layer is 1.25-25 nm; The TaWMoCrZr layer is in the form of nanocrystalline morphology, and the CrMoY layer is in the form of amorphous morphology. In the TaWMoCrZr layer, the atomic percentage ratio of the four elements Ta, W, Mo and Cr is 1:1:1:1, and the atomic percentage of Zr is 16.8 at.%. The method for preparing a high-entropy crystalline / amorphous nano-metal multilayer film includes the following steps: Step 1: Clean and dry the substrate surface; Step 2: Vacuum etch the substrate cleaned in Step 1; Step 3: Using a combination of TaWMoCr alloy target and Zr target, and a CrMoY alloy target, TaWMoCrZr crystal layer and CrMoY layer are alternately deposited on the substrate by magnetron sputtering to obtain a nano-metal multilayer film. During magnetron sputtering, the DC power of the TaWMoCr alloy target is 200W, the RF power of the Zr target is 100W, the DC power of the CrMoY alloy target is 200W, and the total deposition time is 7496–9664 seconds. The method for alternating magnetron sputtering deposition of TaWMoCrZr crystalline layers and CrMoY amorphous layers is as follows: First, a TaWMoCrZr crystal layer was sputtered onto the substrate using a combination of TaWMoCr alloy target and Zr target. Then, an amorphous CrMoY layer was deposited by sputtering using a CrMoY alloy target; Repeat the above process, using a combined target and a CrMoY alloy target to alternately deposit TaWMoCrZr crystalline layer and CrMoY amorphous layer until the preset modulation period and preset thickness are reached to obtain a nano-metal multilayer film. Step 4: Cool the nano-metal multilayer film to room temperature in the furnace to obtain a high-entropy crystalline / amorphous nano-metal multilayer film.

2. The high-entropy crystalline / amorphous nano-metal multilayer film according to claim 1, characterized in that, The nanoindentation hardness of the nanometal multilayer film is 9.5–10.5 GPa, and the Young's modulus is 161–174 GPa.

3. The high-entropy crystalline / amorphous nano-metal multilayer film according to claim 1, characterized in that, The atomic percentage ratio of Cr, Mo, and Y in the CrMoY layer is 1:1:

1.

4. A high-entropy crystalline / amorphous nano-metal multilayer film according to claim 1, characterized in that, The deposition gas pressure for magnetron sputtering is set to 0.3 Pa, and the substrate rotation speed is 15 r / min.

5. The high-entropy crystalline / amorphous nano-metal multilayer film according to claim 1, characterized in that, Both the TaWMoCr alloy target and the CrMoY alloy target are equiatomic targets.

6. The high-entropy crystalline / amorphous nano-metal multilayer film according to claim 1, characterized in that, The cooling time for step 4 is 2-3 hours.

7. An application of the high-entropy crystalline / amorphous nano-metal multilayer film according to any one of claims 1-6, characterized in that, The aforementioned nano-metal multilayer film is used in the cladding of a lead-bismuth fast reactor in a nuclear reactor.

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