Radiation-resistant high-entropy alloy magnetron sputtering coating and preparation method thereof

Abstract

The invention discloses a radiation-resistant high-entropy alloy magnetron sputtering coating and a preparation method thereof, and belongs to the technical field of radiation-resistant coating materials. On the basis of the multi-element synergistic effect and lamination interface design of the high-entropy alloy, FeCrNi and FeNiCrMn are used as target materials, and the coating with the nanometer lamination structure is prepared by accurately regulating and controlling the target current, the gas flow, the deposition time and other process parameters of magnetron sputtering; meanwhile, accurate control over the single-layer film thickness and the interface density is achieved by adjusting the coupling relation between the sputtering power and the deposition rate, and it is ensured that all unit layers are flat and compact, and interface combination is complete. And a multi-heterogeneous interface is formed through the design of a laminated interface, so that a defect capture network is formed, the hardness of a single-layer coating is improved, the hardening rate after irradiation can be lower than that of a traditional single-layer coating, and the problems of crystallization and brittleness failure induced by irradiation are effectively relieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of radiation-resistant coating materials, and particularly relates to a radiation-resistant high-entropy alloy magnetron sputtering coating and a preparation method thereof. Background Art

[0002] Nuclear power is a clean energy source with many advantages such as sustainability, environmental friendliness, and economy. Vigorously developing nuclear power can improve China's energy structure, ensure energy security, and build a new energy system. Against the backdrop of the rapid development of nuclear power in China, ensuring nuclear safety has become particularly important. As the first safety barrier for nuclear safety, the nuclear fuel cladding shoulders the heavy responsibility of protecting the fuel pellets from the erosion of the coolant and preventing the leakage of nuclear fuel. The method of preparing a coating on the surface of a zirconium alloy cladding has a short R & D cycle and good economy, and does not require a large-scale improvement of the existing reactor structure, which is a very advantageous method.

[0003] Currently, a relatively large number of types of protective coatings have been developed, but there are still some problems. For example, the Cr coating has a failure problem caused by Zr-Cr diffusion during use, and the ceramic coating has limitations in preparation and application. Therefore, in the face of complex working conditions, it is still necessary to develop a new type of protective coating with stronger comprehensive performance. With the development of nuclear reactors, especially future commercial nuclear reactors, which have a high flux of neutrons of 14.1 MeV and may face irradiation damage exceeding 100 dpa. Therefore, in the face of increasingly stringent requirements for reactor materials, it is necessary to find new zirconium alloy coating materials for nuclear use, and high-entropy alloy coatings provide a new idea. Compared with traditional metals, high-entropy alloys have more excellent mechanical, irradiation, and corrosion resistance properties. In addition, the long-range disordered structure of amorphous alloys endows them with excellent radiation resistance characteristics, which can effectively absorb irradiation-induced damage and avoid the generation of crystal defects, and also has many excellent properties, such as high strength, high elastic limit, and good wear and corrosion resistance. However, this long-range disordered structure makes amorphous alloys brittle by themselves, which hinders their practical applications.

[0004] The existing patent CN115710688A discloses an anti-irradiation thin film material and a preparation method thereof. This patent uses a silicon wafer as a substrate, forms a tungsten-based film by electron beam evaporation coating, then deposits a tungsten layer by magnetron sputtering coating for the second time, and then undergoes sintering at 400-500 °C and oxygen annealing treatment at 200-600 °C to form a polycrystalline tungsten film with a thickness of 30-500 nm and low surface roughness. Then, this patent needs to combine two coating systems of electron beam evaporation and magnetron sputtering, and at the same time superimpose high-temperature sintering and oxygen annealing treatment. The steps are complex and the parameters need to be strictly controlled. Continuously passing oxygen during the annealing process may introduce oxidation impurities and affect the purity of the thin film.

[0005] Therefore, there is an urgent need for a high-entropy alloy coating with a simple process that can effectively alleviate the problems of irradiation-induced crystallization and brittle failure to solve the above problems. Summary of the Invention

[0006] To solve the above technical problems, the present invention proposes a radiation-resistant high-entropy alloy magnetron sputtering coating and a preparation method thereof.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] The present invention provides a preparation method of a radiation-resistant high-entropy alloy magnetron sputtering coating, comprising the following steps: using magnetron sputtering, sequentially and alternately depositing target materials FeCrNi and FeNiCrMn on a substrate to obtain the radiation-resistant high-entropy alloy magnetron sputtering coating;

[0009] The sputtering power of the magnetron sputtering is 40 - 60 W, the gas flow rate is 20 - 40 sccm, the target current is 100 - 140 mA, and the deposition time for each magnetron sputtering is 100 - 370 s;

[0010] The deposition rate when sputtering FeCrNi is 6.18333 nm / min, and the deposition rate when sputtering FeNiCrMn is 22.65 nm / min.

[0011] Technical principle: Based on the multi-element synergistic effect and laminated interface design of high-entropy alloys, using FeCrNi and FeNiCrMn as target materials, by precisely controlling process parameters such as the target current, gas flow rate, and deposition time of magnetron sputtering, a coating with a nano-laminated structure is prepared. At the same time, by adjusting the coupling relationship between the sputtering power and the deposition rate, precise control of the single-layer film thickness and interface density is achieved, ensuring that each unit layer is flat and dense and the interface bonding is complete. And the design of the laminated interface forms multiple heterogeneous interfaces, thereby forming a defect capture network. While increasing the hardness of the single-layer coating, the hardening rate after irradiation can be made lower than that of traditional single-layer coatings, effectively alleviating the problems of irradiation-induced crystallization and brittle failure.

[0012] Further, the distance between the target material and the substrate of the magnetron sputtering is 10 - 15 cm.

[0013] Further, the working gas pressure of the magnetron sputtering is 0.2 - 0.4 Pa.

[0014] Further, the average atomic percentage contents of Fe, Ni, and Cr in FeCrNi are 32.7 at.%, 32.6 at.%, and 34.7 at.% respectively.

[0015] Further, the average atomic percentage contents of Fe, Ni, Cr, and Mn in the FeNiCrMn are 26.5 at.%, 27.9 at.%, 24.2 at.%, and 21.4 at.%, respectively.

[0016] Further, the magnetron sputtering is carried out in an argon atmosphere, and the vacuum degree is 10 -4 ~10 -3 Pa.

[0017] Further, the residence time after each magnetron sputtering is 30 - 60 s.

[0018] Further, the substrate is a silicon wafer.

[0019] The present invention provides a radiation-resistant high-entropy alloy magnetron sputtering coating prepared by the preparation method described in the above technical solution, and the radiation-resistant high-entropy alloy magnetron sputtering coating is a FeNiCrMn / FeNiCr nano-laminated coating.

[0020] Further, the total thickness of the radiation-resistant high-entropy alloy magnetron sputtering coating is 2 - 2.2 μm, and the single-layer thickness is 30 - 50 nm.

[0021] Compared with the prior art, the present invention has the following advantages and technical effects:

[0022] By introducing the FeNiCrMn / FeNiCr heterointerface and regulating the single-layer thickness, the present invention can make the hardening rate after irradiation lower than that of the traditional single-layer coating while improving the hardness of the single-layer coating, effectively alleviating the problems of irradiation-induced crystallization and brittle failure.

[0023] By introducing the interface, the present invention improves the plasticity of the amorphous alloy. While maintaining the radiation resistance advantage of the amorphous phase, the high-entropy amorphous / high-entropy amorphous nano-layer breaks through the limitation of the plastic deformation ability of the material, and synergistically exerts the high-entropy effect and the amorphous characteristics, opening up a new path for the development of advanced coatings resistant to radiation damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0025] Figure 1 It is a cross-sectional scanning electron microscope image of the radiation-resistant FeNiCrMn / FeNiCr magnetron sputtering coating prepared in Example 1, where a is 500 nm and b is 100 nm;

[0026] Figure 2 It is a cross-sectional scanning electron microscope image of the single-layer magnetron sputtering coatings prepared in Comparative Example 1 (a) and Comparative Example 2 (b);

[0027] Figure 3 Bar chart of the hardness change of the coatings prepared in Example 1 and Comparative Examples 1-2 before and after irradiation;

[0028] Figure 4 TEM image of the irradiated FeNiCrMn / FeNiCr nanolayered coating prepared in Example 1;

[0029] Figure 5 Cross-sectional TEM image of the FeNiCrMn / FeNiCr nanolayered coating prepared in Example 1. Detailed implementation manners

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0031] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific implementation manners.

[0032] The embodiments of the present invention provide a method for preparing a radiation-resistant high-entropy alloy magnetron sputtering coating, including the following steps: using magnetron sputtering, sequentially depositing the target materials FeCrNi and FeNiCrMn on the substrate alternately to obtain the radiation-resistant high-entropy alloy magnetron sputtering coating.

[0033] In a preferred embodiment, the sputtering power of the magnetron sputtering is 40-60 W, the gas flow rate is 20-40 sccm, the target current is 100-140 mA, and the deposition time for each magnetron sputtering is 100-370 s; more preferably: the sputtering power is 40-60 W, the gas flow rate is 20-40 sccm, the target current is 110-130 mA, and the deposition time for each magnetron sputtering is 100-280 s; the deposition rate when sputtering FeCrNi is 6.18333 nm / min, and the deposition rate when sputtering FeNiCrMn is 22.65 nm / min. The present invention precisely regulates process parameters such as the target current, gas flow rate, and deposition time of magnetron sputtering to prepare a coating with a nanolayered structure, and at the same time realizes precise control of the single-layer film thickness and interface density by adjusting the coupling relationship between the sputtering power and the deposition rate, ensuring that each unit layer is flat and dense and the interface bonding is complete.

[0034] In a preferred embodiment, the distance between the target material and the substrate of the magnetron sputtering is 10-15 cm.

[0035] In a preferred embodiment, the working pressure of the magnetron sputtering is 0.2 to 0.4 Pa.

[0036] In a preferred embodiment, the average atomic percentages of Fe, Ni, and Cr in the FeCrNi are 32.7 at.%, 32.6 at.%, and 34.7 at.%, respectively. FeCrNi has excellent strength and toughness and radiation resistance. Using FeCrNi as a target to prepare a coating together with FeNiCrMn is beneficial to obtaining a nano-laminated coating with excellent radiation resistance.

[0037] In a preferred embodiment, the average atomic percentages of Fe, Ni, Cr, and Mn in the FeNiCrMn are 26.5 at.%, 27.9 at.%, 24.2 at.%, and 21.4 at.%, respectively. Based on the multi-element synergistic effect of high-entropy alloys, the present invention selects FeNiCrMn as a target, avoiding the long-lived radioactive isotopes generated by cobalt elements contained in existing alloys such as FeCoNiCr, FeCoNiCrMn, CoCrFeMnNi, etc. after irradiation, which will significantly affect neutron economy and increase maintenance risks. Combining with FeCrNi, a nano-laminated coating with excellent radiation resistance is finally obtained.

[0038] In a preferred embodiment, the diameters of the targets FeCrNi and FeNiCrMn are both 50 mm, and the thicknesses are both 4 mm.

[0039] In a preferred embodiment, the magnetron sputtering is carried out in an argon atmosphere, and the vacuum degree is 10 -4 ~10 -3 Pa.

[0040] In a preferred embodiment, the residence time after each magnetron sputtering is 30 to 60 s.

[0041] In a preferred embodiment, the substrate is a silicon wafer.

[0042] In a preferred embodiment, the substrate further includes a pretreatment step before magnetron sputtering; the pretreatment is: cleaning the silicon wafer with ethanol 3 to 4 times, then rinsing with deionized water for 10 to 15 min until a uniform water film can be formed on the silicon wafer, indicating that organic substances have been effectively removed; ultrasonically cleaning the cleaned silicon wafer with deionized water and absolute ethanol for 30 min in sequence, and then drying it with nitrogen blowing.

[0043] The present invention provides a radiation-resistant high-entropy alloy magnetron sputtering coating prepared by the preparation method described in the above technical solution, and the radiation-resistant high-entropy alloy magnetron sputtering coating is a FeNiCrMn / FeNiCr nano-laminated coating.

[0044] In a preferred embodiment, the total thickness of the radiation-resistant high-entropy alloy magnetron sputtering coating is 2-2.2 μm, and the single-layer thickness is 30-50 nm.

[0045] Unless otherwise specified, the raw materials in the embodiments of the present invention are all obtained through commercial channels.

[0046] Example 1

[0047] A method for preparing a radiation-resistant FeNiCrMn / FeNiCr magnetron sputtering coating with a single-layer thickness of 30 nm, the specific steps are as follows:

[0048] (1) Use high-purity argon to evacuate the vacuum chamber to make the vacuum degree of the vacuum chamber reach 10 -4 ~10 -3 Pa to remove pollutants that may have an adverse effect on the coating quality.

[0049] (2) The substrate is a silicon wafer with an orientation of (100). The silicon wafer is cleaned with ethanol 3 times, and then rinsed with deionized water for 10-15 min until a uniform water film can be formed on the silicon wafer; the cleaned silicon wafer is ultrasonically cleaned with deionized water and absolute ethanol for 30 min in sequence, and then blown dry with nitrogen.

[0050] (3) Set the sputtering power of the FeNiCr target to 60 W, the target current to 130 mA, and the deposition rate to 6.18333 nm / min; the sputtering power of the FeNiCrMn target to 60 W, the target current to 110 mA, and the deposition rate to 22.65 nm / min; the gas flow rate is 40 sccm for both, the distance between the target and the silicon wafer is 10 cm for both, and the working gas pressure is 0.3 Pa for both. The entire magnetron sputtering process is carried out under argon protection; the diameters of the FeCrNi and FeNiCrMn targets are both 50 mm, and the thicknesses are both 4 mm; during the magnetron sputtering process, observe whether the glow discharge of the sputtering target is normal and stable at regular intervals to prevent the target from short-circuiting, causing equipment damage and affecting the deposition quality of the thin film. Glow discharge is carried out at a gas pressure of 3.0 Pa. After the glow discharge is completed, the gas pressure is adjusted to the working gas pressure.

[0051] (4) Start sputtering. First, use the FeNiCr target to sputter for 100 s to deposit a thin film, and then stop for 30 s; replace the target with the FeNiCrMn target, and after sputtering for 280 s, stop for 30 s.

[0052] (5) Repeat step (4) to achieve the alternating deposition of the FeCrNi and FeNiCrMn targets on the silicon wafer, and obtain a radiation-resistant FeNiCrMn / FeNiCr magnetron sputtering coating with a single-layer thickness of 30 nm, which is the FeNiCrMn / FeNiCr nano-laminated coating. The total thickness of the coating is 2.2 μm.

[0053] Example 2

[0054] A preparation method of a FeNiCrMn / FeNiCr magnetron sputtering coating with a single-layer film thickness of 40 nm and radiation resistance. The difference from Example 1 is that step (4) is as follows: Start sputtering. First, use a FeNiCr target to sputter for 130 s to deposit a thin film, and then pause for 30 s. Replace the target with a FeNiCrMn target, sputter for 370 s, and then pause for 30 s. Finally, a FeNiCrMn / FeNiCr magnetron sputtering coating with a single-layer film thickness of 40 nm and radiation resistance is obtained, which is the FeNiCrMn / FeNiCr nano-laminated coating, and the total thickness of the coating is 2.1 μm.

[0055] Figure 1 It is a cross-sectional scanning electron microscope image of the radiation-resistant FeNiCrMn / FeNiCr magnetron sputtering coating prepared in Example 1, where a is 500 nm and b is 100 nm. From Figure 1 part a in it, it can be seen that the total thickness of the radiation-resistant FeNiCrMn / FeNiCr magnetron sputtering coating prepared in Example 1 is 2.2 μm; from Figure 1 part b in it, it can be seen that the single-layer film thickness of the radiation-resistant FeNiCrMn / FeNiCr magnetron sputtering coating prepared in Example 1 is 30 nm.

[0056] Comparative Example 1

[0057] A preparation method of a single-layer FeNiCr magnetron sputtering coating is as follows:

[0058] Steps (1)-(2) are the same as those in Example 1;

[0059] (3) Set the sputtering power of the FeNiCr target to 60 W, the target current to 130 mA, the gas flow rate to 40 sccm, the distance between the target and the silicon wafer to 10 cm, and the working gas pressure to 0.3 Pa. The entire magnetron sputtering process is carried out under argon protection; during the magnetron sputtering process, observe whether the glow discharge of the sputtering target is normal and stable at regular intervals to prevent the target from short-circuiting, causing equipment damage and affecting the deposition quality of the thin film. Start glow discharge at a gas pressure of 3.0 Pa, and after the glow discharge is completed, adjust the gas pressure to the working gas pressure.

[0060] (4) Start sputtering, use a FeNiCr target to sputter for 120 min to obtain a single-layer FeNiCr magnetron sputtering coating with a thickness of 2.2 μm.

[0061] Comparative Example 2

[0062] A preparation method of a single-layer FeNiCrMn magnetron sputtering coating is as follows:

[0063] Steps (1)-(2) are the same as those in Example 1;

[0064] (3) Set the sputtering power of the FeNiCrMn target to 60 W, the target current to 130 mA, the gas flow rate to 40 sccm, the distance between the target and the silicon wafer to 10 cm, and the working gas pressure to 0.3 Pa. The entire magnetron sputtering process is carried out under argon protection; during the magnetron sputtering process, observe whether the glow discharge of the sputtering target is normal and stable at regular intervals to prevent the target from short-circuiting, causing equipment damage and affecting the deposition quality of the thin film. Glow discharge is initiated at a gas pressure of 3.0 Pa. After the glow discharge is completed, adjust the gas pressure to the working gas pressure.

[0065] (4) Start sputtering. Use the FeNiCrMn target to sputter for 120 min to obtain a single-layer FeNiCrMn magnetron sputtering coating with a thickness of 2.0 μm.

[0066] Figure 2 Are cross-sectional scanning electron microscope images of the single-layer magnetron sputtering coatings prepared in Comparative Example 1(a) and Comparative Example 2(b). From Figure 2 It can be seen that both the single-layer FeNiCr magnetron sputtering coating prepared in Comparative Example 1 and the single-layer FeNiCrMn magnetron sputtering coating prepared in Comparative Example 2 have relatively flat fracture surfaces.

[0067] Use the 2×1.7 MV tandem accelerator in the Accelerator Laboratory of Wuhan University. Set the irradiation energy to 3 MeV and select an irradiation dose of 1 dpa of Fe 3+ ions to conduct irradiation experiments on the coatings prepared in Example 1 and Comparative Examples 1-2, and use a nanoindentation instrument to measure the hardness and elastic modulus of the coatings before and after irradiation. At the same time, calculate the irradiation hardening rate according to the following formula, and the results are shown in Table 1.

[0068] Irradiation hardening rate = (hardness after irradiation - hardness before irradiation) / hardness before irradiation × 100%.

[0069] Table 1

[0070]

[0071] Figure 3 Are bar charts of the hardness changes of the coatings prepared in Example 1 and Comparative Examples 1-2 before and after irradiation. Combining the data in Table 1 with Figure 3The result analysis shows that the introduction of the heterogeneous interface increases the hardness of the FeNiCrMn / FeNiCr coating by 19.85% compared to that of the FeNiCrMn coating. At the same time, the irradiation hardening rate is significantly reduced from 39.33% of single-layer FeNiCr and 35.95% of FeNiCrMn to 16.88%. This phenomenon indicates that the heterogeneous interface structure of the present invention successfully achieves a significant reduction in the irradiation hardening rate by effectively suppressing the irradiation-induced crystallization behavior, demonstrating its excellent anti-irradiation performance.

[0072] Figure 4 TEM image of the irradiated FeNiCrMn / FeNiCr nano-laminated coating prepared in Example 1. From Figure 4 it can be seen that no obvious irradiation cavities or swelling phenomena are observed in the interface region of the FeNiCrMn / FeNiCr nano-laminated coating, indicating its excellent anti-irradiation performance.

[0073] Figure 5 Cross-sectional TEM image of the FeNiCrMn / FeNiCr nano-laminated coating prepared in Example 1. From Figure 5 it can be seen that compared with the single-layer FeNiCr and FeNiCrMn coatings, the crystallization phenomenon of the FeNiCrMn / FeNiCr nano-laminated coating prepared in the present invention is suppressed within the range of 5 - 10 nm, showing a unique synergistic effect of irradiation defect capture and crystallization inhibition.

[0074] The above is only the preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A method for preparing a radiation-resistant high-entropy alloy magnetron sputtering coating, characterized in that: The following steps are involved: Using magnetron sputtering, the target materials FeCrNi and FeNiCrMn are alternately deposited on the substrate in sequence to obtain the radiation-resistant high-entropy alloy magnetron sputtering coating; The sputtering power of the magnetron sputtering is 40-60W, the gas flow rate is 20-40sccm, the target current is 100-140mA, and the deposition time of each magnetron sputtering is 100-370s; The deposition rate when sputtering FeCrNi is 6.18333 nm / min, and the deposition rate when sputtering FeNiCrMn is 22.65 nm / min.

2. The preparation method according to claim 1, characterized in that: The distance between the target material and the substrate of the magnetron sputtering is 10 to 15 cm.

3. The preparation method according to claim 1, characterized in that: The working gas pressure of the magnetron sputtering is 0.2-0.4Pa.

4. The preparation method according to claim 1, characterized in that: The average atomic percentages of Fe, Ni and Cr in the FeCrNi are 32.7 at.%, 32.6 at.% and 34.7 at.%, respectively.

5. The preparation method according to claim 1, characterized in that: The average atomic percentages of Fe, Ni, Cr and Mn in the FeNiCrMn are 26.5 at.%, 27.9 at.%, 24.2 at.% and 21.4 at.%, respectively.

6. The preparation method according to claim 1, characterized in that: The magnetron sputtering was carried out in an argon atmosphere with a vacuum degree of 10 -4 ~10 -3 Pa.

7. The preparation method according to claim 1, characterized in that: The dwell time after each magnetron sputtering is 30 to 60 seconds.

8. The preparation method according to claim 1, characterized in that: The substrate is a silicon wafer.

9. A radiation-resistant high-entropy alloy magnetron sputtering coating prepared according to the preparation method according to any one of claims 1 to 8, characterized in that: The radiation-resistant high-entropy alloy magnetron sputtering coating is a FeNiCrMn / FeNiCr nano-laminated coating.

10. The radiation-resistant high-entropy alloy magnetron sputtering coating according to claim 9, characterized in that: The total thickness of the radiation-resistant high-entropy alloy magnetron sputtering coating is 2 to 2.2 μm, and the thickness of a single layer is 30 to 50 nm.

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