Dual nano composite high-entropy film and preparation method thereof

Abstract

The invention discloses a dual nano composite high-entropy film and a preparation method thereof. The dual nano composite high-entropy thin film is formed by co-depositing a high-entropy alloy and an amorphous alloy on the surface of a base material; in the dual nano composite high-entropy film, the content of the high-entropy alloy is 70-95% by mole, and the content of the amorphous alloy is 5-30% by mole; the dual nano-composite high-entropy thin film has a dual nano-composite structure and grain boundary segregation; the dual nano composite structure is a composite structure of a nano crystal and an amorphous-nano crystal; the nanocrystal contains a nano twin crystal; and the amorphous-nanocrystalline contains a nanometer amorphous material. The strength and uniform deformation capacity of the dual nano composite high-entropy film can be remarkably improved through the synergistic effect of the unique dual nano composite structure and grain boundary segregation in the dual nano composite high-entropy film, the strength and uniform deformation capacity of the dual nano composite high-entropy film are higher than those of a film independently prepared from any raw material, and the respective advantages of a high-entropy alloy and an amorphous alloy are fully played.

Description

Technical Field

[0001] The present invention relates to the technical field of high entropy films, and in particular to a double nanocomposite high entropy film and a preparation method thereof. Background Art

[0002] With the rapid development of fields such as biomedicine, flexible electronics, aerospace, and deep-sea and deep-earth applications, new requirements are constantly being placed on the toughness and uniform deformation capabilities of protective and functional films. High-entropy alloys, due to their unique design concept, possess four typical characteristics: high entropy effect, hysteresis diffusion effect, lattice distortion effect, and "cocktail" effect, resulting in excellent overall performance. For example, CoCrNi-based medium / high-entropy alloys and films exhibit high fracture toughness, high ductility, good wide temperature stability, and excellent corrosion and radiation resistance. However, due to insufficient strength and the structural characteristics of columnar nanocrystals in the films, shear localization is prone to occur during deformation, leading to deformation instability, which in turn affects their mechanical and tribological properties.

[0003] Amorphous alloys possess long-range structural disorder, lacking crystal defects such as dislocations and grain boundaries. They typically possess high strength but are also brittle, subjecting them to localized shear and catastrophic failure under high pressure. However, when amorphous alloys are reduced to nanometer or subnanometer scales, they exhibit excellent plastic rheological properties and can significantly regulate defects such as dislocations within the crystal. However, this limits their application size and scope.

[0004] Therefore, the existing technology still needs to be improved and developed. Summary of the Invention

[0005] In view of the above-mentioned deficiencies in the prior art, the object of the present invention is to provide a double nanocomposite high entropy film and a preparation method thereof, aiming to solve the problem that the existing high entropy films cannot achieve uniform deformation under high strength.

[0006] The technical solutions of the present invention are as follows:

[0007] In a first aspect of the present invention, a double nanocomposite high entropy film is provided, wherein the double nanocomposite high entropy film is formed by co-depositing a high entropy alloy and an amorphous alloy on a substrate surface;

[0008] In terms of molar percentage, in the double nanocomposite high entropy film, the content of the high entropy alloy is 70-95%, and the content of the amorphous alloy is 5-30%;

[0009] The double nanocomposite high entropy film has a double nanocomposite structure and grain boundary segregation;

[0010] The double nanocomposite structure is a composite structure of nanocrystals and amorphous-nanocrystals; the nanocrystals contain nanotwins; and the amorphous-nanocrystals contain nanoamorphous.

[0011] According to a preferred technical solution, the high entropy alloy is selected from one of CoCrNi, CoCrFeMnNi, CoCrFeNi, CoCrMnNi, CoCrVNi, and VCoNi.

[0012] According to a preferred technical solution, the amorphous alloy is selected from one of CuZr, CuZrAl, CuZrNi, CuZrCo, CuZrCr, and CuZrFe.

[0013] A second aspect of the present invention provides a method for preparing the double nanocomposite high entropy film as described in the first aspect, comprising:

[0014] In a magnetron sputtering apparatus, a substrate is provided, a high entropy alloy target and an amorphous alloy target are used as target materials, and an inert gas is used as a working gas. After the substrate reaches the sputtering temperature, dual-target co-sputtering is performed to co-deposit a double nano-composite high entropy film on the surface of the substrate.

[0015] According to a preferred technical solution, the working gas pressure in the cavity of the magnetron sputtering apparatus is 0.2-1.0 Pa.

[0016] According to a preferred technical solution, the sputtering temperature is 0 to 300°C.

[0017] In a preferred technical solution, when performing dual-target co-sputtering, the power of the high-entropy alloy target is 20 to 120 W, the power of the amorphous alloy target is 20 to 120 W, the rotation speed of the substrate is 30 to 80 rpm, the high-entropy alloy target and the amorphous alloy target are relatively distributed on both sides of the substrate, and the dual-target co-sputtering time is 3 to 8 hours. In a preferred technical solution, the target material is prepared by powder metallurgy or vacuum melting and has a purity greater than 99.9%.

[0018] A preferred technical solution further includes pre-sputtering the target material before performing dual-target co-sputtering.

[0019] According to a preferred technical solution, the pre-sputtering time is 5 to 10 minutes.

[0020] Beneficial Effects: The present invention provides a dual-nanocomposite high-entropy film comprising a nanocrystalline and amorphous-nanocrystalline dual-nanocomposite structure formed by co-depositing a high-entropy alloy and an amorphous alloy on the surface of a substrate. This unique dual-nanocomposite structure, in synergy with grain boundary segregation, significantly improves the strength and uniform deformation capability of the dual-nanocomposite high-entropy film, surpassing those obtained from films prepared from either raw material alone. This leverages the respective advantages of the high-entropy alloy and the amorphous alloy. Furthermore, the dual-nanocomposite high-entropy film, obtained by magnetron sputtering, can achieve large-area, uniform coating, exhibiting stable performance and wide application. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the dual nanocomposite structure.

[0022] Figure 2 This is a schematic diagram of the preparation process of double nanocomposite high entropy films.

[0023] Figure 3 (CoCrNi) of Example 1 91 X-ray diffraction spectra of (CuZr)9 double nanocomposite high entropy film, CoCrNi nanocrystalline film of comparative example 1, and CuZr amorphous film of comparative example 2.

[0024] Figure 4 (CoCrNi) of Example 1 91 High-resolution transmission electron microscopy image of (CuZr)9 double nanocomposite high entropy film.

[0025] Figure 5 (CoCrNi) of Example 1 91 Comparison of the mechanical properties of (CuZr)9 dual nanocomposite high entropy film, CoCrNi nanocrystalline film of comparative example 1, and CuZr amorphous film of comparative example 2. DETAILED DESCRIPTION

[0026] The present invention provides a double nanocomposite high entropy film and a preparation method thereof. To make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail below.

[0027] An embodiment of the present invention provides a double nanocomposite high entropy film, wherein the double nanocomposite high entropy film is formed by co-depositing a high entropy alloy and an amorphous alloy on a substrate surface;

[0028] In terms of molar percentage, in the double nanocomposite high entropy film, the content of the high entropy alloy is 70-95%, and the content of the amorphous alloy is 5-30%;

[0029] The double nanocomposite high entropy film has a double nanocomposite structure and grain boundary segregation;

[0030] The double nanocomposite structure is a composite structure of nanocrystals and amorphous-nanocrystals; the nanocrystals contain nanotwins; and the amorphous-nanocrystals contain nanoamorphous.

[0031] The present invention co-deposits high entropy alloy and amorphous alloy on the surface of the substrate, and by controlling the ratio of high entropy alloy and amorphous alloy, a double nanocomposite high entropy film is formed with a unique double nanocomposite structure. Figure 1 shown.

[0032] The present invention uses a high entropy alloy as the main part to form nanocrystals containing high-density nanotwins. Nanotwins can improve the strength and plasticity of the material; an amorphous alloy is used as an additional part, and is partially composited with the high entropy alloy to form nanocrystals containing nanoamorphous. The nanocrystals containing nanoamorphous are recorded as amorphous-nanocrystals. The plastic rheology of the nanoamorphous and the absorption or obstruction of dislocations can improve the strength and deformation capacity of the high entropy alloy, and grain boundary segregation can enhance this effect. If the amount of amorphous alloy added is too high, the brittleness will increase due to the expansion of shear bands along the amorphous region during deformation; if the amount added is too low, it will not be able to effectively hinder crystal defects such as dislocations, thereby failing to achieve the effect of simultaneously improving strength and plasticity. Therefore, it is necessary to limit the content of amorphous alloy in the double nanocomposite high entropy film so that the amorphous phase accounts for 5 to 30%. After the high-entropy alloy and amorphous alloy are reasonably combined, their respective advantages can be fully utilized. Within the support framework constructed by grain boundary segregation, the synergistic deformation of nanocrystals containing nanotwins and amorphous-nanocrystals can be achieved to achieve uniform deformation under high strength and avoid strain localization.

[0033] Among them, nanocrystals are crystalline structures; amorphous-nanocrystalline is an amorphous-crystalline composite structure. Nanocrystals refer to nanoscale crystals; amorphous-nanocrystalline refers to a composite material of nanoscale crystals and amorphous materials. Twins are a type of crystal defect, and nanotwins refer to twin planes with a nanoscale spacing; nanoamorphous refers to nanoscale amorphous materials. Nanoscale refers to materials within 100nm.

[0034] In some embodiments, the high entropy alloy is selected from one of CoCrNi, CoCrFeMnNi, CoCrFeNi, CoCrMnNi, CoCrVNi, and VCoNi, but is not limited thereto. Any high entropy alloy that can easily form high-density twins may be used.

[0035] In some embodiments, the amorphous alloy is selected from one of CuZr, CuZrAl, CuZrNi, CuZrCo, CuZrCr, and CuZrFe, but is not limited thereto. Any amorphous alloy having high amorphous forming ability and capable of promoting element segregation may be used.

[0036] An embodiment of the present invention provides a method for preparing the above-mentioned double nanocomposite high entropy film, comprising:

[0037] In a magnetron sputtering instrument, a substrate is provided, a high entropy alloy target and an amorphous alloy target are used as target materials, and an inert gas is used as the working gas. After the substrate reaches the sputtering temperature, dual-target co-sputtering is performed to co-deposit on the surface of the substrate to obtain a double nano-composite high entropy film.

[0038] The present invention adopts magnetron co-sputtering preparation technology, and controls the content ratio of high entropy alloy and amorphous alloy by controlling the power of high entropy alloy target. The schematic diagram of the preparation process of double nanocomposite high entropy film is shown in the figure. Figure 2 shown.

[0039] In some embodiments, the background vacuum in the magnetron sputtering chamber is less than 5×10 -4 Pa, for example, can be 1×10 -4 Pa, 2×10 -4 Pa, 3×10 -4 Pa, 4×10 -4 Pa, and specific point values ​​between the above point values, but not limited thereto, can be adjusted according to actual needs.

[0040] In some embodiments, the working gas pressure in the magnetron sputtering chamber is 0.2~1.0Pa, for example, it can be 0.2Pa, 0.3Pa, 0.4Pa, 0.5Pa, 0.6Pa, 0.7Pa, 0.8Pa, 0.9Pa or 1.0Pa, as well as specific point values ​​between the above point values, but is not limited to these and can be adjusted according to actual needs.

[0041] In some embodiments, the sputtering temperature is 0 to 300°C, for example, it can be 25°C, 50°C, 75°C, 100°C, 125°C, 150°C, 175°C, 200°C, 225°C, 250°C, 275°C or 300°C, as well as specific point values ​​between the above point values, but is not limited thereto and can be adjusted according to actual needs.

[0042] In some embodiments, when dual-target co-sputtering is performed, the power of the high-entropy alloy target is 20 to 120 W, the power of the amorphous alloy target is 20 to 120 W, the rotation speed of the substrate is 30 to 80 r / min, the high-entropy alloy target and the amorphous alloy target are relatively distributed on both sides of the substrate, and the time of the dual-target co-sputtering is 3 to 8 hours, but is not limited thereto and can be adjusted according to actual needs.

[0043] Specifically, the power of the high entropy alloy target is 20 to 120 W, for example, it can be 20 W, 30 W, 40 W, 50 W, 60 W, 70 W, 80 W, 90 W, 100 W, 110 W or 120 W, as well as specific values ​​between the above points, but is not limited thereto and can be adjusted according to actual needs.

[0044] The power of the amorphous alloy target is 20 to 120 W, for example, it can be 20 W, 30 W, 40 W, 50 W, 60 W, 70 W, 80 W, 90 W, 100 W, 110 W or 120 W, as well as specific values ​​between the above points, but is not limited thereto and can be adjusted according to actual needs.

[0045] The rotation speed of the substrate is 30 to 80 r / min, for example, 30 r / min, 40 r / min, 50 r / min, 60 r / min, 70 r / min or 80 r / min, and specific values ​​between the above points, but not limited thereto, and can be adjusted according to actual needs.

[0046] The time for the dual-target co-sputtering is 3 to 8 hours, for example, it can be 3 hours, 4 hours, 5 hours, 6 hours, 7 hours or 8 hours, as well as specific point values ​​between the above point values, but not limited to these; the time for the dual-target co-sputtering affects the thickness of the double nano-composite high-entropy film, the longer the time, the thicker it is, and it can be determined according to demand.

[0047] In some embodiments, the target material is prepared by powder metallurgy or vacuum melting, and has a purity greater than 99.9%.

[0048] In some embodiments, before performing dual-target co-sputtering, the target material is pre-sputtered to remove oxide layers or impurities on the target material surface.

[0049] In some embodiments, the pre-sputtering time is 5 to 10 minutes, for example, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes or 10 minutes, as well as specific points between the above points, but is not limited thereto and can be adjusted according to actual needs.

[0050] In some embodiments, after the substrate reaches the sputtering temperature, the substrate is kept at the temperature for at least 10 minutes to achieve temperature uniformity. After the sputtering is completed, the substrate is naturally cooled to below 50° C. and then taken out.

[0051] The present invention will be further described below with reference to specific examples.

[0052] Example 1

[0053] This embodiment provides a double nanocomposite high entropy film, the preparation method of which is as follows:

[0054] Preparation of target material: CoCrNi and CuZr alloy with an atomic ratio of 99.9% or higher is used as the target material.

[0055] Preparation of substrate: Single-side polished single-crystal silicon wafers were ultrasonically cleaned in acetone and deionized water for 15 minutes and dried. They were then fixed on a bracket with high-temperature tape and placed into the chamber of the magnetron sputtering instrument. The vacuum process was started.

[0056] Uniform temperature of substrate: When the vacuum degree of the chamber is lower than 5×10 -4 When the temperature reaches 300°C, the substrate heating button can be turned on and the temperature can be set to 300°C. After reaching 300°C, keep the temperature for 10 minutes to make the substrate temperature uniform.

[0057] Pre-sputtering: Set the argon flow rate to 20 sccm, adjust the gas pressure in the chamber to 0.3 Pa, set the DC power supply power to 100 W, and perform pre-sputtering for 10 minutes with the baffle closed to remove impurities and oxide layers on the target surface.

[0058] Coating: Set the substrate speed to 30 r / min, the CoCrNi alloy target power to 100 W, the CuZr alloy target power to 20 W, the argon flow rate to 20 sccm, and the working gas pressure to 0.3 Pa. After the power stabilizes, open the baffle and start coating. The deposition time is 5 h.

[0059] Cooling and sampling: After the coating is completed, let the film cool down naturally to below 50℃ in the vacuum chamber, open the chamber and take it out to obtain (CoCrNi) 91 (CuZr)9 double nanocomposite high entropy film.

[0060] Comparative Example 1

[0061] This comparative example provides a CoCrNi nanocrystalline thin film, and its preparation method is basically the same as that of Example 1, except that an equiatomic CoCrNi alloy with a purity of ≥99.9% is used as a target material and the power is set to 100W to obtain the CoCrNi nanocrystalline thin film.

[0062] Comparative Example 2

[0063] This comparative example provides a CuZr amorphous thin film, and its preparation method is basically the same as that of Example 1, except that an equiatomic ratio CuZr alloy with a purity of ≥99.9% is used as a target material and the power is set to 100W to obtain a CuZr amorphous thin film.

[0064] Performance Testing

[0065] The X-ray diffraction spectra of the three films prepared in Example 1 and Comparative Examples 1-2 were obtained by grazing incidence X-ray diffractometer at an incident angle of 1.5°, a step size of 0.02°, a voltage of 45 kV, and a current of 200 mA. The results are as follows: Figure 3 shown. Figure 3 Among them, the CoCrNi nanocrystalline film shows a sharp diffraction peak, indicating that it is a crystalline structure, and the CuZr amorphous film shows a bun-shaped diffraction peak, indicating that it is an amorphous structure. 91 The (CuZr)9 double nanocomposite high entropy film exhibits a broadened diffraction peak, indicating the existence of an amorphous-crystalline composite structure.

[0066] Through transmission electron microscopy analysis, we obtained (CoCrNi) 91 The microstructure of (CuZr)9 double nanocomposite high entropy film is shown in the following figure. Figure 4 shown. Figure 4 In the figure, (a) is a high-resolution transmission electron microscopy image. The upper left of (a) shows a nanocrystalline region with a high density of twins, and the lower right of (a) shows an amorphous-nanocrystalline composite region embedded with nanoamorphous crystals. The fast Fourier transform (FFT) of region b in (a) shows that it is a crystalline structure, as shown in (b); the FFT of region c in (a) shows that it is an amorphous structure, as shown in (c). These results are consistent with those shown in the X-ray diffraction spectrum.

[0067] The micro-pillar compression test was carried out by the in-situ micro-nanomechanical testing system. The results are as follows Figure 5 shown. Figure 5 In the figure, a is the stress-strain curve, b, c, and d are the stress-strain curves before and after compression (CoCrNi) 91 Micro-pillar morphology of (CuZr)9 double nanocomposite high entropy film, CoCrNi nanocrystalline film and CuZr amorphous film. The black arrows indicate shear bands, where shear localization (non-uniform deformation) occurs. 91 The (CuZr)9 double nanocomposite high entropy film not only has improved strength but also can achieve uniform deformation of more than 30% without the occurrence of shear bands.

[0068] In summary, the present invention provides a double nano-composite high entropy film and a preparation method thereof. The double nano-composite high entropy film is formed by co-depositing a high entropy alloy and an amorphous alloy on the surface of a substrate; in terms of molar percentage, the content of the high entropy alloy in the double nano-composite high entropy film is 70-95%, and the content of the amorphous alloy is 5-30%; the double nano-composite high entropy film has a double nano-composite structure and grain boundary segregation; the double nano-composite structure is a composite structure of nanocrystals and amorphous-nanocrystallines; the nanocrystals contain nano-twins; the amorphous-nanocrystallines contain nano-amorphous. The unique double nano-composite structure and grain boundary segregation in the double nano-composite high entropy film of the present invention can synergistically improve its strength and uniform deformation ability, making its strength and uniform deformation ability higher than that of a film prepared from any raw material alone, giving full play to the respective advantages of high entropy alloys and amorphous alloys.

[0069] It should be understood that the application of the present invention is not limited to the above examples. For those skilled in the art, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A double nanocomposite high entropy film, It is characterized in that The double nanocomposite high entropy film is formed by co-depositing a high entropy alloy and an amorphous alloy on the surface of a substrate; In terms of molar percentage, in the double nanocomposite high entropy film, the content of the high entropy alloy is 70-95%, and the content of the amorphous alloy is 5-30%; The double nanocomposite high entropy film has a double nanocomposite structure and grain boundary segregation; The double nanocomposite structure is a composite structure of nanocrystal and amorphous-nanocrystal; the nanocrystal contains nano twins; and the amorphous-nanocrystal contains nano amorphous.

2. The double nanocomposite high entropy film according to claim 1, It is characterized in that The high entropy alloy is selected from one of CoCrNi, CoCrFeMnNi, CoCrFeNi, CoCrMnNi, CoCrVNi and VCoNi.

3. The double nanocomposite high entropy film according to claim 1, It is characterized in that The amorphous alloy is selected from one of CuZr, CuZrAl, CuZrNi, CuZrCo, CuZrCr and CuZrFe.

4. A method for preparing a double nanocomposite high entropy film as claimed in any one of claims 1 to 3, It is characterized in that include: In a magnetron sputtering apparatus, a substrate is provided, a high entropy alloy target and an amorphous alloy target are used as target materials, and an inert gas is used as a working gas. After the substrate reaches the sputtering temperature, dual-target co-sputtering is performed to co-deposit on the surface of the substrate to obtain a double nano-composite high entropy film.

5. The method for preparing the double nanocomposite high entropy film according to claim 4, It is characterized in that The working gas pressure in the cavity of the magnetron sputtering instrument is 0.2-1.0 Pa.

6. The method for preparing the double nanocomposite high entropy film according to claim 4, It is characterized in that The sputtering temperature is 0-300°C.

7. The method for preparing the double nanocomposite high entropy film according to claim 4, It is characterized in that When performing dual-target co-sputtering, the power of the high entropy alloy target is 20 to 120 W, the power of the amorphous alloy target is 20 to 120 W, the rotation speed of the substrate is 30 to 80 r / min, the high entropy alloy target and the amorphous alloy target are relatively distributed on both sides of the substrate, and the dual-target co-sputtering time is 3 to 8 hours.

8. The method for preparing the double nanocomposite high entropy film according to claim 4, It is characterized in that The target material is prepared by powder metallurgy or vacuum melting, and has a purity greater than 99.9%.

9. The method for preparing the double nanocomposite high entropy film according to claim 4, It is characterized in that Before performing dual-target co-sputtering, the target material is pre-sputtered.

10. The method for preparing the double nanocomposite high entropy film according to claim 9, It is characterized in that The pre-sputtering time is 5 to 10 minutes.

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