High-entropy alloy with amorphous-nanocrystalline columnar interval multi-level structure and preparation method thereof

Abstract

This invention discloses a high-entropy alloy with an amorphous-nanocrystalline columnar interspersed multi-level structure and its preparation method, belonging to the field of high-entropy alloy preparation technology. The high-entropy alloy is a Ni-Mo-Al-Cr-Co high-entropy alloy, prepared by magnetron sputtering. The microstructure of the high-entropy alloy is controlled by the deposition temperature to be either an amorphous structure or an amorphous-nanocrystalline biphase multi-level structure. The amorphous-nanocrystalline biphase multi-level structure exhibits a columnar interspersed morphology with alternating amorphous and nanocrystalline phases along the film growth direction. Furthermore, nanocrystalline strips are interspersed within the amorphous layers, and thin amorphous layers are also interspersed within the nanocrystalline strip columns, thus forming a multi-level interlaced layered heterostructure. This special layered heterostructure possesses an excellent heterogeneous strengthening mechanism. Therefore, this invention discusses the influence of the preparation process on the alloy structure and the influence of the constituent elements on the mechanical properties and surface characteristics of the alloy.

Description

Technical Field

[0001] This invention relates to the field of high-entropy alloy preparation technology, and in particular to a high-entropy alloy with an amorphous-nanocrystalline columnar spaced multi-level structure and its preparation method. Background Technology

[0002] High-entropy alloys are a novel type of multi-principal-element alloy, possessing advantages such as high-entropy stabilization effect, complex phase selectivity, and synergistic solid solution strengthening. These advantages result in excellent high-temperature strength, oxidation resistance, wear resistance, and corrosion resistance, making them promising candidates for applications in aerospace, new energy, and biomedicine. Despite their inherent strength advantages, a fundamental contradiction exists between strength and plasticity in material design and fabrication. Therefore, achieving a synergistic improvement in strength and plasticity at the thin-film scale is a critical technical challenge that urgently needs to be addressed in this field.

[0003] Amorphous-nanocrystalline (A / C) dual-phase structures achieve a synergistic effect of strengthening and toughening through the high hardness of the amorphous phase and the plastic load-bearing capacity of the nanocrystalline phase, thus improving ductility and crack resistance while ensuring high hardness and wear resistance. At the thin film scale, this structure can manifest as an amorphous phase encapsulating nanocrystals or an alternating columnar structure, which is beneficial for inhibiting crack propagation, improving fatigue life, and enhancing microstructural stability at high temperatures. Therefore, developing a controllable method for preparing amorphous-nanocrystalline dual-phase structures has significant engineering value for improving the comprehensive mechanical properties and service reliability of high-entropy alloy thin films.

[0004] Currently, methods such as high-energy beam irradiation, rapid solidification, thermal spraying, and laser cladding have been employed to obtain amorphous-nanocrystalline dual-phase structures. However, these methods face challenges in practical applications, including difficulties in precise structural control, compositional segregation, strong dependence on heat treatment, and significant industrialization difficulties. These problems stem from the spatial-temporal non-uniformity of energy input and cooling rate, selective evaporation and diffusion of molten elements, and excessive grain growth under thermal activation, making it difficult to simultaneously achieve the desired phase ratio, nanoscale size, and interface distribution at the thin film scale. Summary of the Invention

[0005] The purpose of this invention is to provide a high-entropy alloy with an amorphous-nanocrystalline columnar spacer structure, but at a smaller scale, nanocrystalline strips are interspersed in the amorphous layer, and thin amorphous layers are also interspersed inside the nanocrystalline strip columns, forming a multi-level interlaced layered heterostructure, and a method for its preparation thereof. This invention solves the above-mentioned problems by optimizing the deposition process parameters to promote the formation of the amorphous-nanocrystalline dual-phase columnar structure, thereby improving the microstructure consistency and mechanical properties of the film without relying on complex post-processing, and has good repeatability and industrialization prospects.

[0006] To achieve the above objectives, this invention discloses a method for preparing a high-entropy alloy with an amorphous-nanocrystalline columnar spaced multi-level structure, wherein the high-entropy alloy is a Ni-Mo-Al-Cr-Co high-entropy alloy with the chemical formula Ni a Mo b Al c Cr d Co e Among them, 22.97≤a≤25.51, 16.35≤b≤17.41, 14.08≤c≤18.04, 16.19≤d≤23.53, and 21.63≤e≤23.17; The high-entropy alloy is prepared by magnetron sputtering, and the microstructure of the high-entropy alloy is controlled by the deposition temperature to be an amorphous structure or an amorphous-nanocrystalline dual-phase multilevel structure.

[0007] Preferably, the high-entropy alloy thin film with an amorphous structure is prepared when the deposition temperature is room temperature.

[0008] Preferably, when the deposition temperature is 200℃ and 400℃, the high-entropy alloy film with an amorphous-nanocrystalline dual-phase multilevel structure is prepared. The amorphous-nanocrystalline dual-phase multilevel structure exhibits a columnar interspersed morphology in which the amorphous phase and the nanocrystalline phase are alternately arranged along the film growth direction. At a smaller scale, nanocrystalline strips are interspersed in the amorphous layer, and thin amorphous layers are also interspersed inside the nanocrystalline strip columns to form a multilevel interlaced layered heterostructure. The ratio of the amorphous phase to the nanocrystalline phase is (1.03-1.42):1.

[0009] Preferably, it includes the following steps: Step 1: Pre-treat the single-crystal silicon substrate to make its surface roughness less than 0.8nm, and then ultrasonically clean it in acetone and ethanol in sequence before drying. Step 2: Place the pretreated substrate into the magnetron sputtering coating chamber and evacuate until the back vacuum level is below 4.0 × 10⁻⁶. -4 Pa was deposited by DC magnetron sputtering using a NiMoAlCrCo alloy target; Step 3: After deposition, post-processing is performed in a vacuum environment and the furnace is cooled to room temperature to obtain Ni-Mo-Al-Cr-Co high-entropy alloy thin film.

[0010] Preferably, in step one, the single-crystal silicon substrate is a single-crystal silicon substrate with a (100) crystal plane; in step two, the NiMoAlCrCo alloy target contains Ni, Mo, Al, Cr and Co elements in equal atomic ratios.

[0011] Preferably, in step two, DC sputtering is used, with a DC power supply of 180W, Ar gas as the working gas with a flow rate of 20-30 sccm, and a deposition gas pressure of 0.4-0.6 Pa; the substrate rotation speed is 15 r / min, and the deposition time is 5400 s.

[0012] Preferably, the post-treatment in step three involves holding the material at the deposition temperature for 2 hours, during which the vacuum level of the cavity is maintained at 6 × 10⁻⁶. -4 Pa level.

[0013] The present invention also provides a high-entropy alloy prepared by the above preparation method, wherein the high-entropy alloy is a Ni-Mo-Al-Cr-Co high-entropy alloy with an amorphous-nanocrystalline columnar spaced multi-level structure or a single amorphous structure.

[0014] Preferably, when the Ni-Mo-Al-Cr-Co high-entropy alloy has a single amorphous structure, the nanoindentation hardness is 12.73 GPa.

[0015] Preferably, when the Ni-Mo-Al-Cr-Co high-entropy alloy has an amorphous-nanocrystalline columnar interspersed multi-level structure, the nanoindentation hardness is 15.06-15.44 GPa.

[0016] Therefore, the present invention has the following beneficial effects: 1. This invention provides a method for preparing a Ni-Mo-Al-Cr-Co high-entropy alloy. The method uses a NiMoAlCrCo alloy target and performs single-target sputtering on a substrate using magnetron sputtering technology. By controlling the deposition temperature, the microstructure of the alloy is effectively controlled, successfully preparing a Ni-Mo-Al-Cr-Co high-entropy alloy with uniform elemental distribution, an amorphous or amorphous-nanocrystalline columnar multi-level structure, and excellent comprehensive properties. After sputtering deposition, the alloy undergoes vacuum annealing. Because this alloy contains five components, it has a high mixing entropy and a low Gibbs free energy. At the high annealing temperature, atomic disorder increases, and diffusion ability is enhanced. This process significantly promotes the improvement of short-range order in the amorphous structure, thereby greatly enhancing the coating's resistance to shear stress and causing its hardness and modulus to show an upward trend, ultimately obtaining a high-entropy alloy material with significantly improved mechanical properties.

[0017] 2. The Ni-Mo-Al-Cr-Co high-entropy alloy prepared by this invention comprises Mo and Co, which are relatively refractory metals with high melting points and excellent high-temperature resistance, thus contributing to maintaining the alloy's structural stability and strength under high-temperature service conditions. Ni and Al help improve the alloy's plasticity and ductility, enhancing the deformation compatibility of the film under external loads. Cr helps improve the alloy's hardness and wear resistance, and can also improve the density of the surface oxide film to enhance oxidation resistance. The Ni-Mo-Al-Cr-Co high-entropy alloy can be deposited as a thin film or coating on the surface of other high-temperature resistant materials or substrates using magnetron sputtering technology. By optimizing process parameters during and after deposition, the high-temperature stability, wear resistance, and oxidation resistance of the substrate surface can be improved, thereby expanding its application potential in surface protection and high-temperature components.

[0018] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0019] Figure 1 The images show the XRD results of the Ni-Mo-Al-Cr-Co high-entropy alloys at different deposition temperatures in Examples 1-3 of this invention. Figure 2 These are characterization images of the Ni-Mo-Al-Cr-Co high-entropy alloy amorphous material in Example 1 of the present invention, where (a) is the TEM microstructure and (b) is a diffraction spot image. Figure 3 This is an EDS scan elemental distribution diagram of the microstructure of the Ni-Mo-Al-Cr-Co high-entropy alloy amorphous material in Example 1 of the present invention; Figure 4 These are characterization images of the Ni-Mo-Al-Cr-Co high-entropy alloy amorphous-nanocrystalline material in Example 2 of the present invention, where (a) is the TEM microstructure and (b) is a diffraction spot image. Figure 5 This is an EDS elemental distribution diagram of the microstructure of the Ni-Mo-Al-Cr-Co high-entropy alloy amorphous-nanocrystalline material in Example 2 of the present invention; Figure 6 These are characterization images of the Ni-Mo-Al-Cr-Co high-entropy alloy amorphous-nanocrystalline material in Example 3 of the present invention, where (a) is the TEM microstructure and (b) is a diffraction spot image. Figure 7 This is an EDS scan elemental distribution diagram of the microstructure of the Ni-Mo-Al-Cr-Co high-entropy alloy amorphous-nanocrystalline material in Example 3 of the present invention; Figure 8Load-displacement curves of Ni-Mo-Al-Cr-Co high-entropy alloys at different deposition temperatures in Examples 1-3 of this invention; Figure 9 The results show the nanoindentation hardness and modulus of the Ni-Mo-Al-Cr-Co high-entropy alloys at different deposition temperatures in Examples 1-3 of this invention.

[0020] Figure 10 This is a schematic diagram of the layered heterostructure of the Ni-Mo-Al-Cr-Co high-entropy alloy under loading in embodiments 2-3 of the present invention, which is a multi-level interlaced amorphous-nanocrystalline structure. Detailed Implementation

[0021] This invention provides a Ni-Mo-Al-Cr-Co high-entropy alloy with the following atomic ratios: Ni: 22.97%, Mo: 16.35%, Al: 18.02%, Cr: 21.03%, and Co: 21.63%. Or Ni: 23.17%, Mo: 16.40%, Al: 14.08%, Cr: 23.53%, Co: 23.17%; Or Ni: 25.51%, Mo: 17.41%, Al: 18.04%, Cr: 16.19%, Co: 22.86%.

[0022] Ni-Mo-Al-Cr-Co high-entropy alloys exhibit an amorphous structure when deposited at room temperature, and an amorphous-nanocrystalline dual-phase multilevel structure when deposited at 200℃ and 400℃. The nanoindentation hardness of Ni-Mo-Al-Cr-Co high-entropy alloys ranges from 12.73 to 15.44 GPa.

[0023] This invention also provides a method for preparing Ni-Mo-Al-Cr-Co high-entropy alloys, comprising the following steps: Step 1: Remove stains and oxide layer from the substrate surface. Specifically, the monocrystalline silicon substrate is polished to a surface roughness of less than 0.8 nm. Then, the polished substrate is ultrasonically cleaned in pure acetone and ethanol for 10 minutes in sequence, followed by rapid drying. Ultrasonic cleaning removes stains and dust from the substrate surface, making the substrate surface clean and free of stains and dust, which helps to improve the bonding force between the alloy and the substrate.

[0024] Step 2: In a vacuum environment, magnetron sputtering is performed on the substrate using a NiMoAlCrCo alloy target. After deposition, the substrate is cooled to room temperature in the furnace to obtain a Ni-Mo-Al-Cr-Co high-entropy alloy on a single-crystal silicon substrate, as detailed below: S1. After ultrasonic cleaning, the monocrystalline silicon substrate is fixed onto the substrate disk and automatically conveyed into the magnetron sputtering coating chamber. A vacuum is then drawn until the back vacuum level reaches 4.0 × 10⁻⁶.-4 Below Pa.

[0025] S2. Single-target sputtering was performed using a NiMoAlCrCo alloy target. The deposition pressure was 0.5 Pa, the deposition temperature was room temperature, 200℃, and 400℃, the substrate rotation speed was 15 r / min, and the deposition time was 5400 s.

[0026] In the NiMoAlCrCo alloy target, Ni, Mo, Al, Cr and Co are in equal atomic ratios. The NiMoAlCrCo alloy target is sputtered by DC power supply with a DC power supply of 180W. The gas used is Ar gas with an Ar gas delivery rate of 20 sccm.

[0027] S3. After deposition, the film deposited at room temperature is cooled to room temperature in the high vacuum coating chamber; the films deposited at 200℃ and 400℃ are kept at the high vacuum coating chamber for 2 hours.

[0028] Due to the prolonged bombardment of the substrate by sputtered atoms during the deposition process, the Ni-Mo-Al-Cr-Co high-entropy alloy experiences a certain temperature rise. After deposition and heat preservation, the alloy is cooled to room temperature in a high-vacuum coating chamber before being removed. This reduces the internal stress of the Ni-Mo-Al-Cr-Co high-entropy alloy layer and prevents surface oxidation by air. During the heat preservation process, the Ar gas pressure is 6 × 10⁻⁶. -4 Pa.

[0029] This invention employs DC sputtering to deposit a Ni-Mo-Al-Cr-Co high-entropy alloy on the surface of an ultrasonically cleaned single-crystal silicon wafer, and generates Ar gas through Ar ionization. + Ions, accelerated by the cathode potential, bombard the cathode target (NiMoAlCrCo), sputtering target atoms and secondary electrons. The target atoms deposit onto the anode substrate in the opposite direction. The secondary electrons move in a circular trajectory perpendicular to the electric and magnetic fields in the orthogonal electromagnetic field, enhancing collisions with Ar molecules and increasing the probability of Ar ionization. The key advantages of this technology are high ionization rate, fast deposition rate, low operating temperature, and controllable element content, minimizing target element agglomeration and backsputtering phenomena that could lead to microstructure inhomogeneity. Finally, the material is naturally cooled to room temperature in a high-vacuum coating chamber to avoid rapid exposure to air oxidation, allowing the deposited atoms to fully diffuse and form the final Ni-Mo-Al-Cr-Co high-entropy alloy. This Ni-Mo-Al-Cr-Co high-entropy alloy is an amorphous or amorphous-nanocrystalline dual-phase material. The amorphous material exhibits uniform element distribution, while the amorphous-nanocrystalline dual-phase material shows elemental segregation. Nanoindentation testing revealed that the hardness of the amorphous thin film was 12.73 GPa, and the hardness of the amorphous-nanocrystalline thin film was the highest at 15.44 GPa, which is much higher than that of similar alloys, effectively improving the comprehensive mechanical properties of the alloy material.

[0030] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0031] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0032] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. These other embodiments are also covered within the scope of protection of this invention.

[0033] Unless otherwise specified, the reagents, instruments, and equipment used in this invention are all commonly used by those skilled in the art, and the testing standards all use national or international standards commonly used in the field, without further explanation.

[0034] Example 1 This embodiment provides a method for preparing a Ni-Mo-Al-Cr-Co high-entropy alloy, including the following steps; Step 1: The single-crystal silicon substrate was ultrasonically cleaned for 10 minutes each in analytical grade acetone and ethanol, and then dried quickly with warm air.

[0035] Step 2: Fix the single-crystal silicon substrate onto the base plate, and automatically transport it into the magnetron sputtering vacuum coating chamber. Evacuate the chamber until the back vacuum level reaches 4.0 × 10⁻⁶. -4 Below Pa.

[0036] Step 3: A Ni-Mo-Al-Cr-Co high-entropy alloy was deposited on a single-crystal silicon substrate using magnetron sputtering with a DC single target. The NiMoAlCrCo alloy target contained Ni, Mo, Al, Cr, and Co in equiatomic ratios. The DC power supply was 180W, the deposition gas pressure was 0.5Pa, the deposition temperature was room temperature, the Ar gas delivery rate was 20 sccm, the substrate rotation speed was 15 r / min, and the deposition time was 5400 s.

[0037] Step 4: The single-crystal silicon substrate with Ni-Mo-Al-Cr-Co high-entropy alloy deposited in Step 3 is naturally cooled to room temperature in a high-vacuum coating chamber for 2-3 hours to obtain a high-entropy alloy with the following composition: Ni-22.97%, Mo-16.35%, Al-18.02%, Cr-21.03%, Co-21.63%, and a thickness of 3.02 μm.

[0038] The XRD pattern of the high-entropy alloy with Ni-22.97%, Mo-16.35%, Al-18.02%, Cr-21.03%, and Co-21.63% prepared in this embodiment is shown in the figure. Figure 1 As shown, the Ni-Mo-Al-Cr-Co high-entropy alloy prepared at room temperature exhibits only a broadened diffuse scattering peak in the 20-35° range, indicating that it is an amorphous structure.

[0039] Its microstructure and elemental distribution are as follows: Figure 2 as well as Figure 3 As shown, the results indicate that the alloy structure is amorphous, and the elements Ni, Mo, Al, Cr, and Co are uniformly distributed. Its mechanical property test results are as follows: Figure 8 as well as Figure 9 As shown, using the displacement control method, the sample was held for 1 second after the indentation depth reached approximately 200 nm and then unloaded. Under the same loading force, the sample prepared at room temperature had a greater indentation depth. The curve was generally positioned to the right, and the slope of the loading segment curve was lower, indicating that the material had lower compressive strength, lower contact stiffness, and a relatively loose structure. The hardness was measured to be 12.98±0.13 GPa and the elastic modulus was 183.06±1.73 GPa by fitting the loading segment curve.

[0040] Example 2 This embodiment provides a method for preparing a Ni-Mo-Al-Cr-Co high-entropy alloy, including the following steps; Step 1: The single-crystal silicon substrate was ultrasonically cleaned for 10 minutes each in analytical grade acetone and ethanol, and then dried quickly with warm air.

[0041] Step 2: Fix the single-crystal silicon substrate onto the base plate, and automatically transport it into the magnetron sputtering vacuum coating chamber. Evacuate the chamber until the back vacuum level reaches 4.0 × 10⁻⁶. -4 Below Pa.

[0042] Step 3: Deposit Ni-Mo-Al-Cr-Co high-entropy alloy on a single-crystal silicon substrate using magnetron sputtering DC single-target sputtering.

[0043] In the NiMoAlCrCo alloy target, Ni, Mo, Al, Cr and Co are in equal atomic ratios. The DC power supply is 180W, the deposition gas pressure is 0.5Pa, the deposition temperature is 200℃, the Ar gas delivery rate is 20sccm, the substrate rotation speed is 15r / min, and the deposition time is 5400s.

[0044] Step 4: Continue to heat the single-crystal silicon substrate obtained in Step 3 in a high-vacuum coating chamber for 2 hours, with a heat preservation pressure of 6 × 10⁻⁶. -4 Pa.

[0045] Step 5: Take out the heat-insulated sample from Step 4 to obtain a high-entropy alloy with the following composition: Ni-23.17%, Mo-16.40%, Al-14.08%, Cr-23.53%, Co-23.17%, and a thickness of 2.65 μm.

[0046] The XRD pattern of the high-entropy alloy with Ni-23.17%, Mo-16.40%, Al-14.08%, Cr-23.53%, and Co-23.17% prepared in this embodiment is shown in the figure. Figure 1 As shown, the results indicate that a diffraction peak appears near 44° (the 69° diffraction peak is the substrate Si), exhibiting a strong {111} texture, indicating the presence of a crystalline structure. Furthermore, local magnification of the diffraction pattern in the range of 15° to 25° reveals the presence of amorphous peaks, thus the material is an amorphous-crystalline two-phase composite structure.

[0047] Its microstructure and elemental distribution are as follows: Figure 4 and Figure 5 As shown, the alloy structure is an amorphous-nanocrystalline dual-phase hierarchical structure. This structure exhibits a columnar morphology where amorphous and nanocrystalline phases alternate along the film growth direction. At a smaller scale, nanocrystalline strips are interspersed within the amorphous layers, and thin amorphous layers are also interspersed within the nanocrystalline strip columns, thus forming a multi-level, interlaced layered heterostructure. The ratio of amorphous to crystalline phases is approximately 1.42:1. Its mechanical property test results are as follows... Figure 8 as well as Figure 9 As shown, the microstructure diagram during loading is as follows: Figure 10 As shown, using the displacement control method, the sample was held for 1 second after the indentation depth reached approximately 250 nm and then unloaded. During the indentation process, the loading curve was significantly steeper than that of the room temperature sample, indicating a significant increase in contact stiffness. The indentation depth was significantly reduced under the same load, indicating a significant increase in the film's hardness. The hardness was measured to be 15.44 ± 0.10 GPa and the elastic modulus was 189.75 ± 1.56 GPa by fitting the loading curve.

[0048] Example 3 This embodiment provides a method for preparing a Ni-Mo-Al-Cr-Co high-entropy alloy, including the following steps; Step 1: The single-crystal silicon substrate was ultrasonically cleaned for 10 minutes each in analytical grade acetone and ethanol, and then dried quickly with warm air.

[0049] Step 2: Fix the single-crystal silicon substrate onto the base plate, and automatically transport it into the magnetron sputtering vacuum coating chamber. Evacuate the chamber until the back vacuum level reaches 4.0 × 10⁻⁶. -4 Below Pa.

[0050] Step 3: Deposit Ni-Mo-Al-Cr-Co high-entropy alloy on a single-crystal silicon substrate using magnetron sputtering DC single-target sputtering.

[0051] In the NiMoAlCrCo alloy target, Ni, Mo, Al, Cr and Co are in equal atomic ratios. The DC power supply is 180W, the deposition gas pressure is 0.5Pa, the deposition temperature is 400℃, the Ar gas delivery rate is 20sccm, the substrate rotation speed is 15r / min, and the deposition time is 5400s.

[0052] Step 4: Continue to heat the single-crystal silicon substrate obtained in Step 3 in a high-vacuum coating chamber for 2 hours, with a heat preservation pressure of 6 × 10⁻⁶. -4 Pa.

[0053] Step 5: Take out the heat-insulated sample from Step 4 to obtain a high-entropy alloy with the following composition: Ni-25.51%, Mo-17.41%, Al-18.04%, Cr-16.19%, Co-22.86%, and a thickness of 2.65μm.

[0054] The XRD pattern of the high-entropy alloy prepared in this embodiment, containing Ni-25.51%, Mo-17.41%, Al-18.04%, Cr-16.19%, and Co-22.86%, is shown below. Figure 1 As shown, a diffraction peak appears near 44° (the 69° diffraction peak is the substrate Si), exhibiting a strong {111} texture, indicating the presence of a crystalline structure. Furthermore, local magnification of the diffraction pattern in the range of 15° to 25° reveals the presence of amorphous peaks, thus the material is an amorphous-crystalline two-phase composite structure.

[0055] Its microstructure and elemental distribution are as follows: Figure 6 and Figure 7 As shown, the alloy structure is an amorphous-nanocrystalline dual-phase hierarchical structure. This structure exhibits a columnar morphology where amorphous and nanocrystalline phases alternate along the film growth direction. At a smaller scale, nanocrystalline strips are interspersed within the amorphous layers, and thin amorphous layers are also interspersed within the nanocrystalline strip columns, thus forming a multi-level interlaced layered heterostructure. The ratio of amorphous to crystalline phases is approximately 1.03:1, and some elements (such as Ni and Cr) show obvious columnar segregation. The mechanical property test results are as follows: Figure 8 as well as Figure 9 As shown, the microstructure diagram during loading is as follows: Figure 10 As shown, the displacement control method was used to hold the load for 1 second when the indentation depth reached about 250 nm and then unloaded. During the indentation process, the indentation depth increased under the same load, indicating that the hardness of the film decreased slightly. The hardness was measured to be 15.01±0.17 GPa and the elastic modulus was 196.00±1.51 GPa by curve fitting of the loading segment.

[0056] Therefore, this invention prepares a high-entropy alloy with amorphous and amorphous-nanocrystalline columnar interstices using magnetron sputtering technology. By controlling the preparation conditions, the structure of the high-entropy alloy is controlled. In the prepared NiMoAlCrCo pentagonal high-entropy alloy, Mo and Co impart high-temperature stability, Ni and Al improve plasticity, and Cr enhances hardness and oxidation resistance, significantly improving the mechanical properties and surface characteristics of the alloy.

[0057] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a high-entropy alloy with an amorphous-nanocrystalline columnar spaced multi-level structure, characterized in that, The high-entropy alloy is a Ni-Mo-Al-Cr-Co high-entropy alloy with the chemical formula Ni. a Mo b Al c Cr d Co e Among them, 22.97≤a≤25.51, 16.35≤b≤17.41, 14.08≤c≤18.04, 16.19≤d≤23.53, and 21.63≤e≤23.17; The high-entropy alloy was prepared by magnetron sputtering, and the microstructure of the high-entropy alloy was controlled by the deposition temperature to be an amorphous structure or an amorphous-nanocrystalline dual-phase multilevel structure. The preparation method specifically includes the following steps: Step 1: Pre-treat the single-crystal silicon substrate to make its surface roughness less than 0.8 nm, and then ultrasonically clean it in acetone and ethanol in sequence before drying. Step 2: Place the pretreated substrate into the magnetron sputtering coating chamber and evacuate until the back vacuum level is below 4.0 × 10⁻⁶. -4 Pa was deposited by DC magnetron sputtering using a NiMoAlCrCo alloy target; Step 3: After deposition, post-processing is performed in a vacuum environment and the furnace is cooled to room temperature to obtain Ni-Mo-Al-Cr-Co high-entropy alloy thin film; When the deposition temperature is 200℃ or 400℃, the high-entropy alloy film with an amorphous-nanocrystalline dual-phase multilevel structure is prepared. The amorphous-nanocrystalline dual-phase multilevel structure exhibits a columnar interspersed morphology in which amorphous phase and nanocrystalline phase are alternately arranged along the film growth direction. Among them, nanocrystalline strips are interspersed in the layers of amorphous phase with columnar interspersed amorphous phase, and thin amorphous layers are interspersed inside the strips of nanocrystalline phase with columnar interspersed amorphous phase, thereby forming a multilevel interlaced layered heterostructure. The ratio of amorphous phase to nanocrystalline phase is (1.03-1.42):

1. When the deposition temperature is room temperature, the high-entropy alloy thin film with an amorphous structure is prepared. In step three, the post-treatment involves holding the material at the deposition temperature for 2 hours, while maintaining the cavity vacuum at 6 × 10⁻⁶ during this period. -4 Pa level.

2. The method for preparing a high-entropy alloy with an amorphous-nanocrystalline columnar spaced multi-level structure according to claim 1, characterized in that, In step one, the single-crystal silicon substrate is a single-crystal silicon substrate with a (100) crystal plane; in step two, the NiMoAlCrCo alloy target contains Ni, Mo, Al, Cr and Co elements in equal atomic ratios.

3. The method for preparing a high-entropy alloy with an amorphous-nanocrystalline columnar spaced multi-level structure according to claim 2, characterized in that, In step two, DC sputtering was used, with a DC power supply of 180W, Ar gas as the working gas with a flow rate of 20-30 sccm, and a deposition gas pressure of 0.4-0.6 Pa; the substrate rotation speed was 15 r / min, and the deposition time was 5400 s.

4. A high-entropy alloy having an amorphous-nanocrystalline columnar spaced multi-level structure, characterized in that, The high-entropy alloy is prepared by the preparation method according to any one of claims 1-3, and the high-entropy alloy is a Ni-Mo-Al-Cr-Co high-entropy alloy with an amorphous-nanocrystalline columnar spaced multi-level structure or a single amorphous structure.

5. A high-entropy alloy with an amorphous-nanocrystalline columnar spaced multi-level structure according to claim 4, characterized in that, When the Ni-Mo-Al-Cr-Co high-entropy alloy has a single amorphous structure, the nanoindentation hardness is 12.73 GPa.

6. A high-entropy alloy with an amorphous-nanocrystalline columnar spaced multi-level structure according to claim 4, characterized in that, When the Ni-Mo-Al-Cr-Co high-entropy alloy has an amorphous-nanocrystalline columnar spacer structure, the nanoindentation hardness is 15.06-15.44 GPa.

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