A wear-resistant anticorrosive high-entropy alloy coating for deep water and deep buried water conservancy metal structure and a preparation method and application thereof

Abstract

The present application relates to the technical field of high-performance metal coating and underwater engineering protection, and particularly relates to a wear-resistant and corrosion-resistant high-entropy alloy coating for deep-water and deep-buried hydraulic metal structures and a preparation method and application thereof. The wear-resistant and corrosion-resistant high-entropy alloy coating for deep-water and deep-buried hydraulic metal structures is prepared by depositing core-shell structure high-entropy alloy powder on the surface of a substrate through a blue laser cladding process; wherein the core-shell structure high-entropy alloy powder comprises an inner core and an outer shell; the inner core is FeCoNiCrMn high-entropy alloy powder; and the outer shell is an Al-Ti-O shell layer. The wear-resistant and corrosion-resistant high-entropy alloy coating has excellent microhardness, wear resistance and corrosion resistance, is suitable for use in a water depth of 200 m or less, and has a wide application prospect in the field of protection of deep-water and deep-buried hydraulic metal structures.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of high-performance metal coating and underwater engineering protection, and particularly relates to a wear-resistant and corrosion-resistant high-entropy alloy coating for deep-water and deep-buried hydraulic metal structures and a preparation method and application thereof. BACKGROUND

[0002] Deep-water and deep-buried hydraulic metal structures such as submarine tunnel lining, deep-water gate, sea-crossing bridge foundation, etc. are prone to the following key problems in protective coating due to long-term service in extreme environments such as high pressure (≥5 MPa), high corrosion (Cl - concentration ≥3.5%), and strong abrasion (sand-containing water flow velocity ≥3 m / s). Firstly, abrasion-corrosion coupling damage: sand particle impact leads to mechanical wear, while seawater corrosion accelerates material failure, and traditional single-function protective coating (such as epoxy resin corrosion-resistant coating or tungsten carbide wear-resistant coating) is difficult to resist combined damage. Secondly, high-pressure interfacial peeling risk: due to the difference in thermal expansion coefficient between the coating and the substrate (such as Q345 steel), interfacial peeling occurs under deep-sea temperature fluctuation and high-pressure load due to low bonding strength, thereby causing local corrosion perforation. Thirdly, long-term maintenance difficulty: the existing coating lacks in-situ repair capability, and the cost of artificial maintenance in deep water environment is high, and traditional detection methods (such as ultrasonic flaw detection) cannot monitor coating micro-cracks and early corrosion in real time. In addition, the combined effects of long-term immersion, wet-dry alternation, high-speed water flow scouring, and sand abrasion also accelerate the combined effects of electrochemical corrosion and mechanical wear.

[0003] Therefore, the existing protection technology for deep-water and deep-buried hydraulic metal structures has three major bottlenecks: traditional coating is prone to peeling failure under high-pressure penetration; conventional stainless steel has insufficient hardness and poor cavitation erosion resistance; there is a lack of in-situ monitoring means for deep-buried structures, and maintenance relies on artificial underwater detection, which is costly and risky, and it is difficult to repair the structure damage after detection.

[0004] Currently, high-entropy alloys (HEA) are considered as an ideal candidate for deep-sea protective coating due to their high hardness, corrosion resistance, and thermal stability resulting from the synergistic effect of multiple main elements. However, the application of high-entropy alloys in deep-water and deep-buried hydraulic metal structures still has many bottlenecks. Firstly, there is a component conflict between high hardness requirement (such as Co, Cr enrichment) and corrosion resistance optimization (such as Cr passivation film continuity), leading to performance imbalance. Secondly, the preparation process has poor adaptability, and plasma and surfacing cladding easily cause substrate thermal deformation, limiting the application of complex components. In addition, the cold spraying process is highly sensitive to powder particle size, and coarse particles will lead to a decrease in coating density and deterioration of mechanical properties.

[0005] Therefore, developing a high-entropy alloy coating and its matching preparation process to solve the problems of wear and corrosion resistance imbalance, interface failure and maintenance lag in the coating of hydraulic metal structures under deep-sea high pressure environment is of great significance for promoting the leap of hydraulic metal structure protection or repair technology towards high performance, intelligence and long-term effectiveness. Summary of the Invention

[0006] To address the aforementioned problems, the present invention aims to provide a wear-resistant and corrosion-resistant high-entropy alloy coating for deep-water, deeply buried hydraulic metal structures, its preparation method, and its application. The wear-resistant and corrosion-resistant high-entropy alloy coating prepared by this invention, through multi-dimensional synergistic improvement of composition, structure, and process, comprehensively enhances the coating's microhardness, wear resistance, and corrosion resistance. It solves problems such as the imbalance between wear and corrosion resistance, interface failure, and susceptibility to wear and corrosion under high-pressure deep-sea environments, making it suitable for the protection of deep-water, deeply buried hydraulic metal structures (such as submarine tunnel linings and deep-water gates).

[0007] To achieve the above objectives, the first aspect of the present invention adopts the following technical solution:

[0008] A wear-resistant and corrosion-resistant high-entropy alloy coating for deep-water and deeply buried hydraulic metal structures is disclosed. The wear-resistant and corrosion-resistant high-entropy alloy coating is prepared by depositing core-shell high-entropy alloy powder onto the surface of a substrate using a blue laser cladding process. The core-shell high-entropy alloy powder comprises an inner core and an outer shell. The inner core is FeCoNiCrMn high-entropy alloy powder, and the outer shell is an Al-Ti-O shell layer.

[0009] Preferably, the FeCoNiCrMn high-entropy alloy powder is obtained by ball milling a mixture of Fe powder, Co powder, Ni powder, Cr powder, and Mn powder in an atomic ratio of (0.95~1.05):(1~1.1):(0.85~1):(1~1.1):(0.5~0.65). This invention utilizes high-entropy alloy powder with a specific atomic ratio, which is beneficial for improving the toughness, wear resistance, and corrosion resistance of the coating.

[0010] More preferably, the particle size of the Fe powder, Co powder, Ni powder, Cr powder, and Mn powder is 45~75μm; the particle size of the FeCoNiCrMn high-entropy alloy powder obtained by ball milling is 35~55μm.

[0011] Preferably, the ball milling process is performed at a rotation speed of 200-400 rpm, the ball-to-material ratio is (5-15):1, and the ball milling time is 30-60 h.

[0012] Preferably, the thickness of the Al-Ti-O shell is 50~100 nm; in the Al-Ti-O shell, the atomic ratio of Al, Ti, and O is (2~3):1:(3.5~5.5). In this process, the shell composition design can effectively reduce the oxidation and wear losses of the high-entropy alloy powder, thereby ensuring the hardness and wear resistance of the coating prepared by the high-entropy alloy.

[0013] More preferably, the Al-Ti-O shell is deposited on the surface of FeCoNiCrMn high-entropy alloy powder via a co-precipitation process; the conditions of the co-precipitation process are: immersing the FeCoNiCrMn high-entropy alloy powder in Al... 3+ / Ti 4+ In a mixed salt solution, the pH of the system is adjusted to 8-9, followed by mechanical stirring. The stirred mixture is then aged at 50-70℃ for 4-6 hours, and the resulting solid product is separated. This solid product is dried at 80-120℃ for 1-3 hours, and then calcined at 300-700℃ for 1-4 hours, thus achieving in-situ construction of the Al-Ti-O shell on the surface of FeCoNiCrMn high-entropy alloy powder. In this step, mechanical stirring induces heterogeneous nucleation and deposition of Al and Ti hydroxides on the surface of the high-entropy alloy powder, followed by aging treatment to promote further growth and densification of the shell. After aging, the product is washed, dried, and calcined to obtain Al-Ti-O coated high-entropy alloy powder with a stable core-shell structure.

[0014] More preferably, the Al 3+ / Ti 4+ In the mixed salt solution, the molar ratio of Al to Ti is (2-3):1. The Al... 3+ / Ti 4+ The total molar concentration of the mixed salt solution is 0.045~0.055 mol / L. The FeCoNiCrMn high-entropy alloy powder and Al... 3+ / Ti 4+ The ratio of the mixed salt solution used is (20~30)g : (800~1200)mL. The mechanical stirring speed is 300~500rpm, and the time is 30~60min.

[0015] This invention employs a blue laser cladding process, which can increase the absorption rate of high-entropy alloy metal powder to over 85%. Preferably, the conditions for the blue laser cladding process are: power of 3000~5000W, scanning speed of 5~15mm / s, powder feed rate of 6~10g / min, spot diameter of 2~3mm, overlap rate of 30~50%, and blue laser wavelength of 430~470nm; the blue laser cladding process is carried out under inert gas protection. This invention, by employing the blue laser cladding process, can form a dense coating on the substrate surface, with a porosity <0.5%, interfacial bonding strength >120MPa, and elemental segregation index ≤3%.

[0016] More preferably, the inert gas is argon with a purity > 99.99%.

[0017] Preferably, the matrix is ​​one or more of Q345 steel matrix, Q235 steel matrix, Q355 steel matrix, and 16Mn steel matrix.

[0018] The second aspect of the present invention is as follows:

[0019] A method for preparing a wear-resistant and corrosion-resistant high-entropy alloy coating for deep-water, deeply buried hydraulic metal structures, as described above, includes the following steps:

[0020] (1) Fe powder, Co powder, Ni powder, Cr powder and Mn powder are mixed in an atomic ratio of (0.95~1.05)∶(1~1.1)∶(0.85~1)∶(1~1.1)∶(0.5~0.65) and then ball-milled to obtain FeCoNiCrMn high-entropy alloy powder;

[0021] (2) Using the FeCoNiCrMn high-entropy alloy powder as the core, an Al-Ti-O shell layer is deposited on the outer surface of the core through a co-precipitation process to obtain a high-entropy alloy powder with a core-shell structure;

[0022] (3) The high-entropy alloy powder with core-shell structure is deposited on the substrate surface by blue laser cladding process to obtain the wear-resistant and corrosion-resistant high-entropy alloy coating.

[0023] The third aspect of this invention adopts the following technical solution:

[0024] The application of a wear-resistant and corrosion-resistant high-entropy alloy coating as described above as a protective coating for deep-water and deeply buried hydraulic metal structures, wherein the deep-water and deeply buried hydraulic metal structures are one or more of the following: submarine tunnel lining, deep-water gate, and cross-sea bridge foundation.

[0025] Compared with the prior art, the beneficial effects of the present invention include at least the following:

[0026] The wear-resistant and corrosion-resistant high-entropy alloy coating for deep-water, buried hydraulic metal structures provided by this invention employs a FeCoNiCrMn high-entropy alloy system combined with an Al-Ti-O shell structure. This allows for the formation of a dense passivation film on the substrate surface. Simultaneously, the Co / Ti bonding enhances the hardness and toughness of the substrate, thereby synergistically improving the coating's hardness, wear resistance, and corrosion resistance, solving the problem of the inverse relationship between microhardness and corrosion resistance. Furthermore, by controlling the blue laser cladding parameters, this invention can form a dense coating with a compositional gradient transition from the surface to the substrate, avoiding interfacial delamination caused by deep-water temperature fluctuations.

[0027] Therefore, the wear-resistant and corrosion-resistant high-entropy alloy coating provided by this invention possesses excellent microhardness, wear resistance, and corrosion resistance, exhibits extreme environmental tolerance, and is suitable for water depths of 200m and below (Cl). - With a sand content of ≥3.5% and a flow velocity of ≥3m / s, it has broad application prospects in the protection of deep-water and deeply buried hydraulic metal structures and in the preparation of high-performance metal coatings. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the high-entropy alloy powder with a core-shell structure in this invention;

[0029] Figure 2 This is a schematic diagram of the laser cladding process in this invention. Detailed Implementation

[0030] The technical solutions and effects of the present invention will be clearly and completely described below with reference to specific embodiments and experimental examples. However, those skilled in the art should understand that the embodiments are only used to illustrate the technical solutions of the present invention and should not be regarded as limiting the scope of protection of the present invention. Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods; unless otherwise specified, the raw materials used are commercially available and commonly used in the art.

[0031] In the following embodiments, the initial particle size of the Fe powder, Co powder, Ni powder, Cr powder, and Mn powder used is 45-75 μm. The WC cemented carbide balls are obtained by mixing two different sizes of alloy balls (Φ6mm / Φ10mm, 4:1).

[0032] Example 1

[0033] This embodiment provides a wear-resistant and corrosion-resistant high-entropy alloy coating for deep-water and deeply buried hydraulic metal structures, which is prepared by a method including the following steps:

[0034] (1) Fe powder, Co powder, Ni powder, Cr powder, and Mn powder were mixed in an atomic ratio of 0.95:1.05:1:1:0.65 and then ball-milled to obtain FeCoNiCrMn high-entropy alloy powder. The ball milling speed was 300 rpm, the ball-to-material ratio was 10:1, and the ball milling time was 48 h. WC cemented carbide balls were used for ball milling. The particle size of the FeCoNiCrMn high-entropy alloy powder obtained after ball milling was 45±5 μm.

[0035] (2) Using the FeCoNiCrMn high-entropy alloy powder prepared above as the core, an Al-Ti-O shell layer was constructed in situ on its surface by co-precipitation method to obtain a high-entropy alloy powder with a core-shell structure. The thickness of the Al-Ti-O shell layer is 52±2nm; the atomic ratio of Al, Ti and O in the Al-Ti-O shell layer is 2.2∶1∶3.8.

[0036] The specific process steps of the co-precipitation method are as follows: immerse 20g of FeCoNiCrMn high-entropy alloy powder in 1000mL of Al... 3+ / Ti 4+ In a mixed salt solution, the pH of the system was adjusted to 8.0, and then mechanically stirred at 350 rpm for 40 min. The stirred mixture was then aged at 55℃ for 5 h. After aging, a solid product was obtained. The solid product was washed with deionized water, dried at 80℃ for 1 h, and then calcined in an inert gas at 300℃ for 2 h to obtain a core-shell structured high-entropy alloy powder.

[0037] Among them, Al 3+ / Ti 4+ The concentration of the mixed salt solution is 0.048 mol / L. Al 3+ / Ti 4+ In the mixed salt solution, the molar ratio of Al to Ti is 2.2:1. Specifically, Al... 3+ / Ti 4+ The mixed salt solution was prepared as follows: Al(NO3)3·9H2O was dissolved in deionized water and stirred at room temperature (25±5℃) to obtain a 0.033 mol / L aluminum nitrate solution. Separately, TiOSO4 was dissolved in deionized water, and 5-10 drops of nitric acid were added. The mixture was stirred and mixed at 50℃ to obtain a 0.015 mol / L titanium oxysulfate solution. The titanium oxysulfate solution was then slowly added to the aluminum nitrate solution and mixed, with the total volume adjusted with deionized water to ensure the Al concentration in the solution was within acceptable limits. 3+ / Ti 4+ The total concentration was 0.048 mol / L, which yielded Al. 3+ / Ti 4+ A mixed salt solution is used for the subsequent coprecipitation coating process.

[0038] A schematic diagram of the core-shell structured high-entropy alloy powder obtained in this step is shown below. Figure 1 As shown, its core is FeCoNiCrMn high-entropy alloy powder, and its outer shell is Al-Ti-O.

[0039] (3) Using Q345 steel substrate as the substrate to be clad, and the high-entropy alloy powder with core-shell structure obtained above as the cladding material, a wear-resistant and corrosion-resistant high-entropy alloy coating is prepared on the surface of the steel substrate using blue laser cladding technology.

[0040] A schematic diagram of the laser cladding process is shown below. Figure 2 As shown, the specific process is as follows: Blue laser cladding is used as the deep-water coating adaptability preparation process. Coaxial powder feeding is used, and elemental segregation is suppressed by utilizing a water-cooled substrate. The cooling rate of the water-cooled substrate is 10. 6 K / s. Blue laser cladding was performed on the surface of a Q345 steel substrate in a pressure chamber (2MPa) simulating a water depth of 200m. The blue laser cladding power was 3000W, the scanning speed was 5mm / s, the powder feed rate was 8g / min, the spot diameter was 2.5mm, the overlap rate was 40%, and the wavelength of the blue laser was 450nm. Inert gas protection (Ar purity > 99.99%) was used during the blue laser cladding process. After the blue laser cladding was completed, cooling was performed, thereby generating a dense coating in situ on the surface of the Q345 steel substrate, which is the wear-resistant and corrosion-resistant high-entropy alloy coating of this embodiment.

[0041] Tests showed that the wear-resistant and corrosion-resistant high-entropy alloy coating prepared in this embodiment had a porosity of 0.45%, a thickness of 325 μm, an interfacial bonding strength of 160 MPa, and an elemental segregation index of 2.2%.

[0042] Example 2

[0043] This embodiment provides a wear-resistant and corrosion-resistant high-entropy alloy coating for deep-water and deeply buried hydraulic metal structures, which is prepared by a method including the following steps:

[0044] (1) Fe powder, Co powder, Ni powder, Cr powder, and Mn powder were mixed in an atomic ratio of 1:1:1:1:0.55 and then ball-milled to obtain FeCoNiCrMn high-entropy alloy powder. The ball milling speed was 300 rpm, the ball-to-material ratio was 10:1, and the ball milling time was 48 h. WC cemented carbide balls were used for ball milling. The particle size of the FeCoNiCrMn high-entropy alloy powder obtained after ball milling was 45 ± 5 μm.

[0045] (2) Using the FeCoNiCrMn high-entropy alloy powder obtained above as the core, an Al-Ti-O shell layer is constructed in situ on its surface by co-precipitation method to obtain a core-shell structured high-entropy alloy composite powder. The average thickness of the Al-Ti-O shell layer is 85±2nm; the atomic ratio of Al, Ti and O in the Al-Ti-O shell layer is 2.5∶1∶5.

[0046] The specific process steps of the co-precipitation method are as follows: immerse 30g of FeCoNiCrMn high-entropy alloy powder in 1000mL of Al... 3+ / Ti 4+ In a mixed salt solution, the pH of the system was adjusted to 8.0, and then mechanically stirred at 300 rpm for 40 min. The stirred mixture was then aged at 55℃ for 5 h. After aging, a solid product was obtained. The solid product was washed with deionized water, dried at 80℃ for 1 h, and then calcined in an inert gas at 500℃ for 2 h to obtain a core-shell structured high-entropy alloy powder.

[0047] Among them, Al 3+ / Ti 4+ The concentration of the mixed salt solution is 0.05 mol / L. Al 3+ / Ti 4+ In the mixed salt solution, the molar ratio of Al to Ti is 2.5:1. Al 3+ / Ti 4+ The preparation method of the mixed salt solution was the same as in Example 1, except that the ratio of Al and Ti in the solution was changed to ensure that the Al obtained was... 3+ / Ti 4+ The concentration of the mixed salt solution is 0.05 mol / L, Al 3+ / Ti 4+ The molar ratio of Al to Ti in the mixed salt solution is 2.5:1.

[0048] (3) Using Q345 steel as the substrate to be clad, and the core-shell structured high-entropy alloy powder obtained above as the cladding material, a wear-resistant and corrosion-resistant high-entropy alloy coating is prepared on the surface of the steel substrate using blue laser cladding technology. The specific process is as follows: Blue laser cladding is used as the deep-water coating adaptability preparation process, coaxial powder feeding is used, and water-cooled substrate is used to suppress element segregation. The cooling rate of the water-cooled substrate is 10. 6K / s. Blue laser cladding was performed on the surface of a Q345 steel substrate in a pressure chamber (2MPa) simulating a water depth of 200m. The blue laser cladding power was 4000W, the scanning speed was 10mm / s, the powder feed rate was 8g / min, the spot diameter was 2.5mm, the overlap rate was 40%, and the wavelength of the blue laser was 450nm. Inert gas protection (Ar purity > 99.99%) was used during the blue laser cladding process. After the blue laser cladding was completed, cooling was performed to generate a dense coating in situ on the surface of the Q345 steel substrate, which is the wear-resistant and corrosion-resistant high-entropy alloy coating of this embodiment.

[0049] Tests showed that the wear-resistant and corrosion-resistant high-entropy alloy coating prepared in this embodiment had a porosity of 0.48%, a thickness of 426 μm, an interfacial bonding strength of 180 MPa, and an elemental segregation index of 2.1%.

[0050] Example 3

[0051] This embodiment provides a wear-resistant and corrosion-resistant high-entropy alloy coating for deep-water and deeply buried hydraulic metal structures, which is prepared by a method including the following steps:

[0052] (1) Fe powder, Co powder, Ni powder, Cr powder, and Mn powder were mixed in an atomic ratio of 1:1.1:0.85:1.1:0.5 and then ball-milled to obtain FeCoNiCrMn high-entropy alloy powder. The ball milling speed was 300 rpm, the ball-to-material ratio was 10:1, and the ball milling time was 48 h. WC cemented carbide balls were used for ball milling. The particle size of the FeCoNiCrMn high-entropy alloy powder obtained after ball milling was 45±5 μm.

[0053] (2) Using the FeCoNiCrMn high-entropy alloy powder obtained above as the core, an Al-Ti-O shell layer is constructed on its surface by co-precipitation method to obtain a core-shell structured high-entropy alloy composite powder. The average thickness of the Al-Ti-O shell layer is 75±2 nm; the atomic ratio of Al, Ti and O in the Al-Ti-O shell layer is 3:1:5.5.

[0054] The specific process steps of the co-precipitation treatment are as follows: 30g of FeCoNiCrMn high-entropy alloy powder is immersed in 1000mL of Al... 3+ / Ti 4+ In a mixed salt solution, the pH of the system was adjusted to 8.0, and then mechanically stirred at 500 rpm for 40 min. The stirred mixture was then aged at 55℃ for 5 h. After aging, a solid product was obtained. The solid product was washed with deionized water, dried at 80℃ for 1 h, and then calcined in an inert gas at 350℃ for 2 h to obtain a core-shell structured high-entropy alloy powder.

[0055] Among them, Al3+ / Ti 4+ The concentration of the mixed salt solution is 0.05 mol / L. Al 3+ / Ti 4+ In the mixed salt solution, the molar ratio of Al to Ti is 3:1. Al 3+ / Ti 4+ The preparation method of the mixed salt solution was the same as in Example 1, except that the ratio of Al and Ti in the solution was changed to ensure that the Al obtained was... 3+ / Ti 4+ The concentration of the mixed salt solution is 0.05 mol / L, Al 3+ / Ti 4+ The molar ratio of Al to Ti in the mixed salt solution is 3:1.

[0056] (3) Using Q345 steel as the substrate to be clad, and the core-shell structured high-entropy alloy powder obtained above as the cladding material, a wear-resistant and corrosion-resistant high-entropy alloy coating is prepared on the surface of the steel substrate using blue laser cladding technology. The specific process is as follows: Blue laser cladding is used as the deep-water coating adaptability preparation process, coaxial powder feeding is used, and water-cooled substrate is used to suppress element segregation. The cooling rate of the water-cooled substrate is 10. 6 K / s. Blue laser cladding was performed on the surface of a Q345 steel substrate in a pressure chamber (2MPa) simulating a water depth of 200m. The blue laser cladding power was 5000W, the scanning speed was 15mm / s, the powder feed rate was 8g / min, the spot diameter was 2.5mm, the overlap rate was 40%, and the wavelength of the blue laser was 450nm. Inert gas protection (Ar purity > 99.99%) was used during the blue laser cladding process. After the blue laser cladding was completed, cooling was performed, thereby generating a dense coating in situ on the surface of the Q345 steel substrate, which is the wear-resistant and corrosion-resistant high-entropy alloy coating of this embodiment.

[0057] Tests showed that the wear-resistant and corrosion-resistant high-entropy alloy coating prepared in this embodiment had a porosity of 0.35%, a thickness of 480 μm, an interfacial bonding strength of 170 MPa, and an elemental segregation index of 2.6%.

[0058] Comparative Example 1

[0059] This comparative example provides a wear-resistant and corrosion-resistant high-entropy alloy coating. Its preparation method is basically the same as that of Example 1. The only difference is that in step (1), Fe powder, Co powder, Ni powder and Cr powder are mixed in an atomic ratio of 0.95:1.05:1:1 and then ball-milled to obtain FeCoNiCr high-entropy alloy powder. The FeCoNiCr high-entropy alloy powder is used for subsequent preparation. The remaining process steps and parameters are the same as those in Example 1.

[0060] Comparative Example 2

[0061] This comparative example provides a wear-resistant and corrosion-resistant high-entropy alloy coating, the preparation method of which is basically the same as that of Example 1. The only difference is that in step (2), the preparation of the Al-Ti-O shell is omitted. In step (3), the FeCoNiCrMn high-entropy alloy powder obtained after ball milling is directly used as the cladding material for laser cladding, and the specific process parameters are the same as those in Example 1.

[0062] Comparative Example 3

[0063] This comparative example provides a wear-resistant and corrosion-resistant high-entropy alloy coating, the preparation method of which is basically the same as that of Example 1, except that in step (2), an Al2O3 shell is used to replace the Al-Ti-O shell in Example 1 to prepare a core-shell structured high-entropy alloy powder.

[0064] Specifically, steps (1) and (3) of this comparative example are the same as in Example 1, and step (2) is adjusted as follows: using the FeCoNiCrMn high-entropy alloy powder obtained above as the core, an Al2O3 shell layer is constructed on its surface by co-precipitation method to obtain a core-shell structured high-entropy alloy composite powder. Among them, the average thickness of the Al2O3 shell layer is 48±2nm; in the Al2O3 shell layer, the atomic ratio of Al to O is 2∶3.1.

[0065] The specific process steps of the co-precipitation method are as follows: immerse 20g of FeCoNiCrMn high-entropy alloy powder in 1000mL of Al... 3+ In a salt solution, the pH of the system was adjusted to 8.0, followed by mechanical stirring at 350 rpm for 40 min. The stirred mixture was then aged at 55℃ for 5 h. After aging, a solid product was obtained. The solid product was washed with deionized water, dried at 80℃ for 1 h, and then calcined in an inert gas atmosphere at 300℃ for 2 h to obtain a core-shell structured high-entropy alloy powder. Among them, Al 3+ The concentration of the salt solution is 0.048 mol / L. Al 3+ The salt solution was prepared by dissolving Al(NO3)3·9H2O in deionized water and stirring at room temperature (25±5℃) to obtain a 0.048 mol / L aluminum nitrate solution, which was used for the subsequent coprecipitation coating process.

[0066] Comparative Example 4

[0067] This comparative example provides a high-entropy alloy composite coating, which is the coating material disclosed in patent application number 2024110221644, and consists of a high-entropy alloy matrix AlCoCrFeNiM a It consists of carbide-reinforced particles. M is a carbide reinforcing element, selected from one or more of Ti, Zr, V, Ta, Nb, W, and Mo, and the carbide-reinforced particles are selected from one of WC, NbC, and ZrC.

[0068] Comparative Example 5

[0069] This comparative example provides an AlCoCrFeNi high-entropy alloy coating, which is the coating material disclosed in patent application No. 2025106015704.

[0070] Experiment Example 1: Coating Performance Test

[0071] The high-entropy alloy coatings prepared in Examples 1-3 and Comparative Examples 1-3 were tested for hardness, wear performance and corrosion performance, and compared with the coating performance disclosed in Comparative Examples 4 and 5.

[0072] The coating hardness test method is as follows: each coating sample is prepared into a 1×1×1cm specimen using wire cutting, and polished with 400, 600, 800, 1000, 1500 and 2000 grit SiC metallographic sandpaper. Diamond polishing fluid is used to polish the specimen on a polishing machine until a mirror effect is achieved. Finally, Vickers hardness tester is used to test the hardness with a load of 300g and a loading time of 15s.

[0073] The test method for the wear performance of the coating is as follows: the wear performance of the prepared coating is tested using a tribological tester; silicon nitride ceramic balls with a diameter of 12.7 mm are selected as the wear pair, and the wear test is carried out using a reciprocating friction mode; the specific experimental parameters are set as follows: load 100 N, wear stroke 2 mm, vibration frequency 5 Hz, test duration 30 min.

[0074] The method for testing the corrosion performance of the coating is as follows: the coating sample, after polishing during hardness testing, is cold-mounted and sealed. A standard three-electrode system is used, with the working electrode being the surface of the coating to be tested, the auxiliary electrode being a platinum electrode, and the reference electrode being a saturated KCl / calomel electrode. The testing method is dynamic potential polarization curve, with a scanning range of -1 to 1V and a scanning rate of 0.01V / s.

[0075] The performance test results of the coating materials in Examples 1-3 and Comparative Examples 1-5 are shown in Table 1.

[0076] Table 1. Performance test results of various coating materials

[0077]

[0078] As can be seen from the experimental results in Table 1, the high-entropy alloy coatings provided in Examples 1-3 of this invention possess excellent microhardness, wear resistance, and corrosion resistance. However, Comparative Examples 1-3, by altering the composition or structure of the high-entropy alloy powder, resulted in varying degrees of deterioration in the hardness, wear resistance, and corrosion resistance of the coatings. Furthermore, Comparative Examples 4-5 represent existing high-entropy alloy coatings, whose hardness is significantly lower than that of the coating of this invention, and whose corrosion current density is an order of magnitude higher, indicating poor corrosion resistance.

[0079] In summary, the wear-resistant and corrosion-resistant high-entropy alloy coating provided by this invention possesses excellent microhardness, wear resistance, and corrosion resistance, making it suitable for water depths below 200m (Cl). - With a sand content of ≥3.5% and a flow velocity of ≥3m / s, it has broad application prospects in the protection of deep-water and deeply buried hydraulic metal structures.

[0080] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the protection scope of the present invention.

Claims

1. A wear-resistant and corrosion-resistant high-entropy alloy coating for deep-water and deeply buried hydraulic metal structures, characterized in that, The wear-resistant and corrosion-resistant high-entropy alloy coating is prepared by depositing core-shell high-entropy alloy powder onto the surface of a substrate using a blue laser cladding process; wherein, the core-shell high-entropy alloy powder includes an inner core and an outer shell; the inner core is FeCoNiCrMn high-entropy alloy powder; and the outer shell is an Al-Ti-O shell layer; The Al-Ti-O shell is deposited on the surface of FeCoNiCrMn high-entropy alloy powder via a co-precipitation process. The conditions for this co-precipitation process are: immersing the FeCoNiCrMn high-entropy alloy powder in Al... 3+ / Ti 4+ The mixture is placed in a mixed salt solution, and the pH of the system is adjusted to 8-9. Then, it is mechanically stirred, and the stirred mixture is aged at 50-70℃ for 4-6 hours. The solid product is then separated, dried at 80-120℃ for 1-3 hours, and then calcined at 300-700℃ for 1-4 hours. This achieves the in-situ construction of the Al-Ti-O shell on the surface of FeCoNiCrMn high-entropy alloy powder.

2. The wear-resistant and corrosion-resistant high-entropy alloy coating for deep-water and deeply buried hydraulic metal structures according to claim 1, characterized in that, The FeCoNiCrMn high-entropy alloy powder is obtained by ball milling Fe powder, Co powder, Ni powder, Cr powder and Mn powder in an atomic ratio of (0.95~1.05):(1~1.1):(0.85~1):(1~1.1):(0.5~0.65).

3. The wear-resistant and corrosion-resistant high-entropy alloy coating for deep-water and deeply buried hydraulic metal structures according to claim 2, characterized in that, The particle size of the Fe powder, Co powder, Ni powder, Cr powder, and Mn powder is 45~75μm; the particle size of the FeCoNiCrMn high-entropy alloy powder obtained by ball milling is 35~55μm.

4. The wear-resistant and corrosion-resistant high-entropy alloy coating for deep-water and deeply buried hydraulic metal structures according to claim 2, characterized in that, The ball milling process is performed at a rotation speed of 200-400 rpm, a ball-to-material ratio of (5-15):1, and a milling time of 30-60 h.

5. The wear-resistant and corrosion-resistant high-entropy alloy coating for deep-water and deeply buried hydraulic metal structures according to claim 1, characterized in that, The thickness of the Al-Ti-O shell is 50~100nm; in the Al-Ti-O shell, the atomic ratio of Al, Ti and O is (2~3):1:(3.5~5.5).

6. The wear-resistant and corrosion-resistant high-entropy alloy coating for deep-water and deeply buried hydraulic metal structures according to any one of claims 1 to 4, characterized in that, The conditions for the blue laser cladding process are as follows: power of 3000~5000W, scanning speed of 5~15mm / s, powder feeding rate of 6~10g / min, spot diameter of 2~3mm, overlap rate of 30~50%, and wavelength of blue laser of 430~470nm; the blue laser cladding process is carried out under inert gas protection.

7. The wear-resistant and corrosion-resistant high-entropy alloy coating for deep-water and deeply buried hydraulic metal structures according to any one of claims 1 to 4, characterized in that, The matrix is ​​one or more of Q345 steel matrix, Q235 steel matrix, Q355 steel matrix, and 16Mn steel matrix.

8. A method for preparing a wear-resistant and corrosion-resistant high-entropy alloy coating for deep-water, deeply buried hydraulic metal structures as described in any one of claims 1 to 7, characterized in that, Includes the following steps: (1) Fe powder, Co powder, Ni powder, Cr powder and Mn powder are mixed in an atomic ratio of (0.95~1.05)∶(1~1.1)∶(0.85~1)∶(1~1.1)∶(0.5~0.65) and then ball-milled to obtain FeCoNiCrMn high-entropy alloy powder; (2) Using the FeCoNiCrMn high-entropy alloy powder as the core, an Al-Ti-O shell layer is deposited on the outer surface of the core through a co-precipitation process to obtain a high-entropy alloy powder with a core-shell structure; (3) The high-entropy alloy powder with core-shell structure is deposited on the substrate surface by blue laser cladding process to obtain the wear-resistant and corrosion-resistant high-entropy alloy coating.

9. The application of a wear-resistant and corrosion-resistant high-entropy alloy coating as described in any one of claims 1 to 7 in the use of it as a protective coating for deep-water, deeply buried hydraulic metal structures, characterized in that... The deep-water, buried hydraulic metal structure refers to one or more of the following: submarine tunnel lining, deep-water gate, and cross-sea bridge foundation.

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