Nuclear wear-resistant high-entropy alloy coating as well as preparation method and application thereof

Abstract

The invention discloses a nuclear wear-resistant high-entropy alloy coating as well as a preparation method and application thereof, and belongs to the technical field of high-entropy alloy coatings, Fe35-45Ni35-45Cr5-15Al3-7Ti3-7 high-entropy alloy coatings are prepared by a plasma spraying method, the existing Co-based or Co-containing high-entropy alloy coating is easy to transmutation, the transmutation rate is high, and the transmutation rate is high. A stable FCC solid solution structure is formed through a high-entropy effect; the corrosion resistance is improved by the element Cr, a compact Al2O3 / TiO2 oxidation film can be formed by the elements Al and Ti at high temperature, the oxidation resistance and the corrosion resistance are remarkably enhanced, and the corrosion-resistant aluminum alloy is particularly suitable for the protection requirements of a light water reactor and a fourth-generation nuclear reactor.

Description

Technical Field

[0001] This invention belongs to the field of high-entropy alloy coating technology, and particularly relates to a wear-resistant high-entropy alloy coating for nuclear applications, its preparation method, and its application. Background Technology

[0002] In the nuclear energy field, key structural components of nuclear reactors (such as fuel cladding and in-core components) operate for extended periods in extremely harsh environments, including high temperatures, high pressures, strong neutron radiation, high-temperature water / steam corrosion, and liquid metal corrosion. These severe conditions easily lead to radiation swelling, embrittlement, creep, stress corrosion cracking, and severe surface corrosion and wear, thereby threatening the safe operation and service life of the reactor. In recent years, high-entropy alloys, due to their unique "high-entropy effect," "lattice distortion effect," "hysteresis diffusion effect," and "cocktail effect," have exhibited many superior properties compared to traditional alloys, such as high strength, high hardness, good high-temperature stability, excellent corrosion resistance and wear resistance, and potentially excellent radiation resistance. This makes high-entropy alloy coatings a promising new material system for solving the surface protection challenges of key nuclear components.

[0003] Many high-performance high-temperature alloy coatings contain cobalt (Co). Under reactor neutron irradiation, stable Co-59 translocates into highly radioactive Co-60. Co-60 is one of the main sources of radiation exposure for workers after a nuclear power plant shutdown, significantly increasing maintenance difficulty, downtime, and radioactive waste disposal costs. Developing cobalt-free advanced coating materials is an important direction for the development of nuclear surface technology.

[0004] Therefore, a method for preparing a wear-resistant high-entropy alloy coating for nuclear applications is needed. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes a wear-resistant high-entropy alloy coating for nuclear applications, its preparation method, and its application.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] This invention provides a method for preparing a wear-resistant high-entropy alloy coating for nuclear applications, comprising the following steps:

[0008] Accurately weigh each component according to the following atomic percentages: Fe 35-45%, Ni 35-45%, Cr 5-15%, Al 3-7%, and Ti 3-7%, and mix them uniformly to obtain high-entropy alloy powder; preferably, accurately weigh each component according to the following atomic percentages: Fe 40-45%, Ni 40-45%, Cr 10-15%, Al 5-7%, and Ti 5-7%, and mix them uniformly to obtain high-entropy alloy powder; more preferably, accurately weigh each component according to the following atomic percentages: Fe 40%, Ni 40%, Cr 10%, Al 5%, and Ti 5%, and mix them uniformly to obtain high-entropy alloy powder, denoted as Fe 40 Ni 40 Cr 10 Al5Ti5;

[0009] The high-entropy alloy powder is sprayed onto the substrate using plasma spraying, and the resulting coating is then heat-treated to obtain the nuclear wear-resistant high-entropy alloy coating.

[0010] This invention utilizes atmospheric plasma spraying to prepare a nuclear-grade coating on a substrate surface. By adjusting the spraying parameters, the microstructure of the coating is optimized to the greatest extent, resulting in optimal coating performance. This method is low-cost and offers advantages such as relatively controllable heat input, high deposition efficiency, and minimal restrictions on substrate shape, making it an ideal choice for preparing engineered coatings. The coating produced by this invention exhibits excellent interlayer bonding, a dense structure, uniform powder melting, and superior wear resistance. The resulting FeNiCrAlTi nuclear-grade wear-resistant, Co-free, high-entropy alloy coating possesses excellent corrosion resistance, radiation resistance, and wear resistance.

[0011] Furthermore, the substrate is a stainless steel substrate.

[0012] Furthermore, the particle size of the high-entropy alloy powder is 15–53 μm.

[0013] Furthermore, during the plasma spraying process: the distance between the plasma spray gun and the substrate is 120mm, the spraying voltage is 40-50V, the spraying current is 450-550A, the powder feeding rate is 30-40g / min, the argon flow rate is 30-40Slpm, and the hydrogen flow rate is 4-6Slpm.

[0014] Furthermore, the heat treatment temperature is 500–600°C, and the time is 3–5 hours.

[0015] Furthermore, before plasma spraying, the process includes pretreatment of the substrate: first, the substrate is cleaned with acetone to remove oil stains from the substrate surface, then it is roughened by sandblasting until the surface roughness is uniform, and finally it is dried and preheated at 95°C for 2 hours.

[0016] Furthermore, the thickness of the wear-resistant high-entropy alloy coating for nuclear applications is >250μm.

[0017] Furthermore, 250 μm < the thickness of the wear-resistant high-entropy alloy coating for nuclear applications < 400 μm.

[0018] The present invention also provides a wear-resistant high-entropy alloy coating for nuclear applications prepared according to the above method.

[0019] The present invention also provides an application of the above-mentioned nuclear wear-resistant high-entropy alloy coating in nuclear equipment.

[0020] The wear-resistant high-entropy alloy coating of the present invention is particularly suitable for the protection requirements of light water reactors and fourth-generation nuclear reactors, such as nuclear equipment including fuel cladding or in-core components.

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

[0022] 1) This invention proposes a method for preparing high-entropy alloy coatings using plasma spraying. Conventional Co-based or Co-containing high-entropy alloy coatings are prone to transmutation. This invention forms a stable FCC solid solution structure through the high-entropy effect. Cr element improves corrosion resistance, and Al and Ti elements can form a dense Al2O3 / TiO2 oxide film at high temperatures, significantly enhancing oxidation resistance and corrosion resistance, which is especially suitable for the protection requirements of light water reactors and fourth-generation nuclear reactors.

[0023] 2) The method employed in this invention is simple in preparation, low in cost, and offers relatively controllable heat input with minimal restrictions on substrate shape, enabling industrial-scale production. The high-entropy alloy coating prepared by this invention is primarily composed of the FCC phase, exhibiting better phase stability and being less prone to harmful phase transformations under irradiation. Simultaneously, the inherent high ductility and strong work-hardening capability of the FCC structure ensure the coating's reliability under complex mechanical stress and fretting wear conditions. Subsequent heat treatment further enhances the coating's hardness and wear resistance.

[0024] 3) The preparation method used in this invention has little impact on the substrate, which can effectively ensure the original state of the substrate. The prepared coating has high density, high adhesion, and controllable coating thickness. It has good corrosion resistance and wear resistance, which can meet the needs of practical engineering applications. Attached Figure Description

[0025] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0026] Figure 1 Fe in Example 1 40 Ni40 Cr 10 SEM images of Al5Ti5 powder, (a) showing the low-magnification powder morphology and (b) showing the high-magnification powder morphology.

[0027] Figure 2 Fe prepared in Example 1 40 Ni 40 Cr 10 SEM images of the surface and cross-section of the Al5Ti5 coating, (a) showing the surface morphology and (b) showing the cross-sectional morphology;

[0028] Figure 3 Fe prepared in Example 2 40 Ni 40 Cr 10 SEM images of the surface and cross-section of the Al5Ti5 coating, (a) showing the surface morphology and (b) showing the cross-sectional morphology;

[0029] Figure 4 The powdered Fe in Example 1 40 Ni 40 Cr 10 Al5Ti5 and sprayed Fe 40 Ni 40 Cr 10 X-ray diffraction pattern of Al5Ti5 coating;

[0030] Figure 5 The image shows the Vickers hardness diagrams of the wear-resistant high-entropy alloy coating for nuclear applications before and after heat treatment in Example 1.

[0031] Figure 6 Fe in the sprayed state in Example 1 40 Ni 40 Cr 10 Al5Ti5 coating and heat-treated Fe 40 Ni 40 Cr 10 Wear coefficient diagram of Al5Ti5 coating;

[0032] Figure 7 Fe in Example 1 40 Ni 40 Cr 10 Cross-sectional morphology of Al5Ti5 coating after 1500h corrosion resistance test in SnPb etchant. Detailed Implementation

[0033] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0034] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0035] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0036] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0037] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0038] An embodiment of the present invention provides a method for preparing a wear-resistant high-entropy alloy coating for nuclear applications, comprising the following steps:

[0039] Accurately weigh each component according to the following atomic percentages: Fe 35-45%, Ni 35-45%, Cr 5-15%, Al 3-7%, and Ti 3-7%, and mix them uniformly to obtain high-entropy alloy powder; preferably, accurately weigh each component according to the following atomic percentages: Fe 40-45%, Ni 40-45%, Cr 10-15%, Al 5-7%, and Ti 5-7%, and mix them uniformly to obtain high-entropy alloy powder; more preferably, accurately weigh each component according to the following atomic percentages: Fe 40%, Ni 40%, Cr 10%, Al 5%, and Ti 5%, and mix them uniformly to obtain high-entropy alloy powder, denoted as Fe 40 Ni 40 Cr 10 Al5Ti5;

[0040] High-entropy alloy powder was sprayed onto a substrate using plasma spraying, and the resulting coating was then heat-treated to obtain a wear-resistant high-entropy alloy coating for nuclear applications.

[0041] Conventional Co-based or Co-containing high-entropy alloy coatings are prone to transmutation. This invention forms a stable FCC solid solution structure through the high-entropy effect; Cr element enhances corrosion resistance, and Al and Ti elements can form a dense Al2O3 / TiO2 oxide film at high temperatures, significantly enhancing oxidation resistance and corrosion resistance, making it particularly suitable for the protection requirements of light water reactors and fourth-generation nuclear reactors.

[0042] In embodiments of the present invention, the substrate is a stainless steel substrate. For example, the stainless steel substrate is 304 stainless steel with dimensions of 10mm × 10mm × 2mm.

[0043] In the embodiments of the present invention, the particle size of the high-entropy alloy powder is 15–53 μm. The high-entropy alloy powder is vacuum dried before plasma spraying to ensure its flowability and degree of melting, preventing over-burning and the resulting numerous pores in the coating, which would affect the deposition efficiency and porosity of the coating.

[0044] In an embodiment of the present invention, during the plasma spraying process: the distance between the plasma spray gun and the substrate is 120 mm, the spraying voltage is 40–50 V, the spraying current is 450–550 A, the powder feeding rate is 30–40 g / min, the argon flow rate is 30–40 slpm, and the hydrogen flow rate is 4–6 slpm. This invention utilizes plasma spraying under an argon protective atmosphere and hydrogen heating conditions to spray pre-placed alloy powder (Fe... 40 Ni 40 Cr 10 Al5Ti5 high-entropy alloy coating powder is heated and melted on the surface of 304 stainless steel. The coating is then formed through high-temperature spraying and rapid cooling (the instantaneous heating temperature reaches several thousand degrees Celsius, followed by rapid cooling to room temperature). The nuclear wear-resistant high-entropy alloy coating prepared by this invention exhibits high deposition efficiency, low porosity, and good interlayer bonding. After heat treatment, it forms an FCC phase structure, an L12 phase (the L12 phase belongs to the superlattice of FCC and is formed after heat treatment), and a partially oxide phase structure.

[0045] In an embodiment of the present invention, the heat treatment temperature is 500-600°C and the time is 3-5 hours. If the time is lower than this, the second phase will precipitate with a small size, and if the time is higher than this, the second phase will grow larger and the quantity will decrease.

[0046] In an embodiment of the present invention, before plasma spraying, a pretreatment process for the substrate is included: first, the substrate is cleaned with acetone to remove oil stains from the substrate surface, then it is roughened by sandblasting until the surface roughness is uniform to enhance the adhesion of the coating, and finally it is dried and preheated at 95°C for 2 hours.

[0047] In an embodiment of the present invention, the thickness of the wear-resistant high-entropy alloy coating for nuclear applications is >250 μm.

[0048] In an embodiment of the present invention, 250 μm < the thickness of the nuclear wear-resistant high-entropy alloy coating < 400 μm.

[0049] In a preferred embodiment of the present invention, the method for preparing a wear-resistant high-entropy alloy coating for nuclear applications is as follows:

[0050] 1) Clean the stainless steel substrate with acetone before spraying to remove oil and dirt, and roughen the surface by sandblasting to increase roughness and enhance the adhesion of the coating.

[0051] 2) Use clamps to fix the stainless steel substrate onto the spraying rack;

[0052] 3) Accurately weigh each component according to the following atomic percentages: Fe 40%, Ni 40%, Cr 10%, Al 5%, and Ti 5%, mix them evenly to obtain high-entropy alloy powder (Fe 40 Ni 40 Cr 10 Al5Ti5); The high-entropy alloy powder was placed in a drying oven and vacuum dried for 30 minutes, and then placed in a powder feeder;

[0053] 4) High-entropy alloy powder is sprayed onto a stainless steel substrate using plasma spraying. The spraying distance is adjusted, the vertical distance between the bottom of the spray gun and the substrate is controlled to be 120mm, and the movement trajectory of the spray gun is determined.

[0054] 5) High-entropy alloy coatings were prepared by plasma spraying, with a spraying voltage of 40-50V, a spraying current of 450-550A, a powder feeding rate of 30-40g / min, an argon flow rate of 30-40Slpm, and a hydrogen flow rate of 4-6Slpm.

[0055] 6) Allow the high-entropy alloy coating to cool to room temperature in an atmospheric environment;

[0056] 7) The prepared high-entropy alloy coating is subjected to heat treatment at a temperature of 550℃±50℃ for 3 to 5 hours to obtain a nuclear wear-resistant high-entropy alloy coating.

[0057] Embodiments of the present invention also provide a nuclear wear-resistant high-entropy alloy coating prepared according to the above method.

[0058] The wear-resistant high-entropy alloy coating for nuclear applications provided in this embodiment of the invention can be used in nuclear equipment, for example, nuclear equipment including fuel cladding or in-core components.

[0059] In an embodiment of the present invention, a liquid metal corrosion device equipped with an automatic oxygen concentration measurement and control system was used to conduct a static lead-bismuth (SnPb) corrosion experiment at 550°C. The SnPb corrosion solution was prepared as follows: a lead-bismuth eutectic alloy (lead content 44.53 wt.%, bismuth content 55.47 wt.%) was used, with a total impurity content not exceeding 0.1 wt.% (or ≤100 ppm, individual impurity element ≤10 ppm). The lead-bismuth eutectic alloy was added to a reaction vessel, and then the temperature was raised to 550°C. Once the target temperature (550°C) and dissolved oxygen concentration (oxygen content 5 × 10⁻⁶) were reached... -6 ~5×10 -5 After stabilizing for one hour, a SnPb etching solution was obtained (wt%).

[0060] Unless otherwise specified, the room temperature in this invention is 25±2℃.

[0061] All raw materials used in the embodiments of this invention were obtained through commercial purchase.

[0062] It should be noted that any aspects not described in detail in this invention are conventional practices in the field and are not the focus of this invention.

[0063] The technical solution of the present invention will be further illustrated by the following embodiments.

[0064] Example 1

[0065] A method for preparing a wear-resistant high-entropy alloy coating for nuclear applications, comprising the following steps:

[0066] Step 1: Select a 304 stainless steel workpiece (10mm×10mm×2mm), clean the surface oil stains with acetone using ultrasonic cleaning, then perform sandblasting roughening treatment until the surface roughness is uniform, then place it at 95℃ for drying and preheating for 2 hours, and use a fixture to place the preheated substrate (i.e., the 304 stainless steel workpiece) stably on the spraying rack.

[0067] Step 2: Accurately weigh each component according to the following atomic percentages: Fe 40%, Ni 40%, Cr 10%, Al 5%, and Ti 5%, mix thoroughly to obtain high-entropy alloy powder (Fe 40 Ni 40 Cr 10 Al5Ti5); Fe 40 Ni 40 Cr 10After vacuum drying of Al5Ti5 high-entropy alloy powder (particle size 15-53μm) for 30 minutes, it is placed in the powder feeder. The distance between the plasma spray gun and the substrate is adjusted to 120mm, the spraying voltage is 47V, the spraying current is 550A, the powder feeding rate is 35g / min, the argon flow rate is 40Slpm, and the hydrogen flow rate is 6Slpm. Spraying begins after the flame is stabilized.

[0068] Step 3: Use a serpentine reciprocating program to make the robotic arm drive the spray gun to spray the substrate at a uniform speed to ensure the coating thickness;

[0069] Step 4: Allow the high-entropy alloy coating to cool to room temperature in an atmospheric environment (the resulting coating is denoted as the sprayed Fe state). 40 Ni 40 Cr 10 Al5Ti5 coating);

[0070] Step 5: Heat-treat the prepared high-entropy alloy coating at 550℃ for 4 hours, and then air-cool it to room temperature to obtain a nuclear wear-resistant high-entropy alloy coating.

[0071] Figure 1 For Fe 40 Ni 40 Cr 10 The SEM image of Al5Ti5 powder shows that the average particle size is 40μm, indicating good powder integrity and high sphericity, which is beneficial to powder flowability and ensures deposition rate during the spraying process.

[0072] Figure 2 The surface and cross-sectional SEM images of the nuclear wear-resistant high-entropy alloy coating prepared in this embodiment show that the coating has extremely low porosity and high deposition efficiency, uniform oxide distribution (black stripe parts), high bonding rate between the coating and the substrate, and a coating thickness greater than 300 μm.

[0073] Figure 4 The powdered Fe of this invention 40 Ni 40 Cr 10 Al5Ti5 and sprayed Fe 40 Ni 40 Cr 10 The X-ray diffraction pattern of the Al5Ti5 coating shows that the phase composition did not change before and after spraying, and both phases are composed of FCC, which has good wear resistance and potential for certain ductility.

[0074] Figure 5 The Vickers hardness diagrams of the nuclear wear-resistant high-entropy alloy coating prepared in this embodiment before and after heat treatment show that the average hardness of the coating in the sprayed state is about 250 HV, and the hardness after heat treatment is about 450 HV.

[0075] The prepared coating was subjected to a rotational friction and wear test. The grinding ball was a cemented carbide ball, the load was 10 N, the frequency was 180 RPM, and the rotation radius was 3 mm. Figure 6 The wear coefficient diagrams for the nuclear wear-resistant high-entropy alloy coating prepared in this embodiment before and after heat treatment show that the average wear coefficient of the coating in the sprayed state is about 0.57, and the average wear coefficient in the heat-treated state is about 0.27.

[0076] Figure 7 Fe prepared in this embodiment 40 Ni 40 Cr 10 The cross-sectional morphology of the Al5Ti5 coating after 1500 hours of corrosion resistance testing in SnPb etchant shows that the SnPb-affected layer thickness is only about 4 μm, and it is well bonded to the substrate without any coating peeling. This indicates that the Fe... 40 Ni 40 Cr 10 The Al5Ti5 coating exhibits good resistance to SnPb corrosion.

[0077] Comparative Example 1

[0078] Same as Example 1, except that the heat treatment temperature is 650°C.

[0079] The results showed that the Vickers hardness of the final coating prepared in this comparative example was around 400 HV, the average wear coefficient in the heat-treated state was 0.35, and the SnPb influence layer thickness was 5 ± 1 μm after 1500 h of corrosion resistance testing in SnPb etchant.

[0080] Example 2

[0081] Same as Example 1, except that the spraying parameters are as follows: the distance between the plasma spray gun and the substrate is set to 120mm, the spraying voltage is 45V, the spraying current is 450A, the powder feeding rate is 30g / min, the argon flow rate is 30Slpm, and the hydrogen flow rate is 4Slpm.

[0082] Figure 3 The surface and cross-sectional SEM images of the nuclear wear-resistant high-entropy alloy coating prepared in this embodiment show that the coating has extremely low porosity and high deposition efficiency, reduced oxide content, good adhesion between the coating and the substrate, and a thickness of about 274 μm.

[0083] The nuclear wear-resistant high-entropy alloy coating prepared in this embodiment has a Vickers hardness of 260 HV and an average wear coefficient of 0.66 in the heat-treated state. After a corrosion resistance test in SnPb etchant for 1500 h, the SnPb influence layer thickness is 15 μm.

[0084] Example 3

[0085] Same as Example 1, except that the spraying parameters are as follows: the distance between the plasma spray gun and the substrate is set to 120mm, the spraying voltage is 40V, the spraying current is 550A, the powder feeding rate is 40g / min, the argon flow rate is 40Slpm, and the hydrogen flow rate is 6Slpm.

[0086] The final coating obtained in this embodiment has good adhesion to the substrate, a thickness of 340 μm, a Vickers hardness of 382 HV, and an average wear coefficient of 0.39 in the heat-treated state. After 1500 h of corrosion resistance testing in SnPb etchant, the SnPb-affected layer thickness is 8 μm.

[0087] Example 4

[0088] Same as Example 1, except that the heat treatment temperature is 600°C and the heat treatment time is 3 hours.

[0089] The final coating obtained in this embodiment has good adhesion to the substrate, a thickness of 330 μm, a Vickers hardness of 405 HV, and an average wear coefficient of 0.42 in the heat-treated state. After 1500 h of corrosion resistance testing in SnPb etchant, the SnPb-affected layer thickness is 7 μm.

[0090] Example 5

[0091] Same as Example 1, except that the heat treatment temperature is 500°C and the heat treatment time is 5 hours.

[0092] The final coating obtained in this embodiment has good adhesion to the substrate, a thickness of 315 μm, a Vickers hardness of 411 HV, and an average wear coefficient of 0.47 in the heat-treated state. After 1500 h of corrosion resistance testing in SnPb etchant, the SnPb-affected layer thickness is 6 μm.

[0093] Example 6

[0094] Same as Example 1, except that the powder composition is Fe. 45 Ni 35 Cr 10 Al5Ti5.

[0095] The final coating obtained in this embodiment showed good adhesion to the substrate, a thickness of 300 μm, a Vickers hardness of 330 HV, and an average wear coefficient of 0.4 in the heat-treated state. After 1500 hours of corrosion resistance testing in SnPb etching solution, the SnPb influence layer thickness was 11 μm. The increase in influence layer thickness was due to the increased Fe content in the material, resulting in a thicker oxide layer.

[0096] Comparative Example 2

[0097] Same as Example 1, except that the heat treatment temperature is 450°C.

[0098] The final coating thickness obtained in this comparative example was 330 μm, with a Vickers hardness of 362 HV and an average wear coefficient of 0.49 in the heat-treated state. After 1500 h of corrosion resistance testing in SnPb etchant, the SnPb-affected layer thickness was 7 μm. Due to the excessively low heat treatment temperature, the L12 phase precipitation was incomplete, resulting in a decrease in material hardness and wear resistance.

[0099] Comparative Example 3

[0100] Same as Example 1, except that the plasma spraying parameters are: the distance between the plasma spray gun and the substrate is set to 120mm, the spraying voltage is 45V, the spraying current is 600A, the powder feeding rate is 44g / min, the argon flow rate is 35Slpm, and the hydrogen flow rate is 6Slpm.

[0101] The results showed that the Vickers hardness of the final coating prepared in this comparative example was around 370 HV, and the average wear coefficient in the heat-treated state was 0.4. After 1500 h of corrosion resistance testing in SnPb etchant, the thickness of the SnPb-affected layer was 8 ± 1 μm.

[0102] Comparative Example 4

[0103] Same as Example 1, except that the plasma spraying parameters are: the distance between the plasma spray gun and the substrate is set to 120 mm, the spraying voltage is 55 V, the spraying current is 600 A, the powder feeding rate is 35 g / min, the argon flow rate is 40 S lpm, and the hydrogen flow rate is 4 S lpm.

[0104] The results showed that the Vickers hardness of the final coating prepared in this comparative example was around 400 HV, and the average wear coefficient in the heat-treated state was 0.5. After 1500 hours of corrosion resistance testing in SnPb etchant, the SnPb-affected layer thickness was 15 ± 1 μm. In this comparative example, the increased coating porosity and oxide content led to a decrease in the wear coefficient and an increase in the SnPb-affected layer thickness.

[0105] Comparative Example 5

[0106] Same as Example 1, except that the plasma spraying parameters are: the distance between the plasma spray gun and the substrate is set to 150 mm, the spraying voltage is 35 V, the spraying current is 400 A, the powder feeding rate is 40 g / min, the argon flow rate is 45 S lpm, and the hydrogen flow rate is 8 S lpm.

[0107] The results showed that the Vickers hardness of the final coating prepared in this comparative example was around 300 HV, and the average wear coefficient in the heat-treated state was 0.56. After 1500 hours of corrosion resistance testing in SnPb etchant, the SnPb-affected layer thickness was 18 ± 2 μm. In this comparative example, increasing the spray gun height led to a decrease in coating adhesion, and the SnPb etchant penetrated into the coating from the coating adhesion points, corroding the coating.

[0108] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preparing a wear-resistant high-entropy alloy coating for nuclear applications, characterized in that, Includes the following steps: Accurately weigh each component according to the following atomic percentages: Fe 35-45%, Ni 35-45%, Cr 5-15%, Al 3-7%, and Ti 3-7%, mix them evenly to obtain high-entropy alloy powder; The high-entropy alloy powder is sprayed onto the substrate using plasma spraying, and the resulting coating is then heat-treated to obtain the nuclear wear-resistant high-entropy alloy coating.

2. The method for preparing a wear-resistant high-entropy alloy coating for nuclear applications according to claim 1, characterized in that, The high-entropy alloy powder has a particle size of 15–53 μm.

3. The method for preparing a wear-resistant high-entropy alloy coating for nuclear applications according to claim 1, characterized in that, During plasma spraying: the distance between the plasma spray gun and the substrate is 120mm, the spraying voltage is 40-50V, the spraying current is 450-550A, the powder feeding rate is 30-40g / min, the argon flow rate is 30-40Slpm, and the hydrogen flow rate is 4-6Slpm.

4. The method for preparing a wear-resistant high-entropy alloy coating for nuclear applications according to claim 1, characterized in that, The heat treatment is performed at a temperature of 500–600°C for 3–5 hours.

5. The method for preparing a wear-resistant high-entropy alloy coating for nuclear applications according to claim 1, characterized in that, Before plasma spraying, the process includes pretreatment of the substrate: cleaning the substrate with acetone, roughening the surface by sandblasting until the surface roughness is uniform, and finally drying and preheating at 95°C for 2 hours.

6. The method for preparing a wear-resistant high-entropy alloy coating for nuclear applications according to claim 1, characterized in that, The thickness of the wear-resistant high-entropy alloy coating for nuclear applications is >250μm.

7. The method for preparing a wear-resistant high-entropy alloy coating for nuclear applications according to claim 6, characterized in that, 250μm < the thickness of the wear-resistant high-entropy alloy coating for nuclear applications < 400μm.

8. A wear-resistant high-entropy alloy coating for nuclear applications, characterized in that, It is prepared according to any one of claims 1 to 7.

9. The application of the nuclear wear-resistant high-entropy alloy coating as described in claim 8 in nuclear equipment.

10. The application according to claim 9, characterized in that, The nuclear equipment includes fuel cladding or reactor internals.

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