Heat-corrosion-resistant protective coating for marine environment as well as preparation method and application of heat-corrosion-resistant protective coating

Abstract

The invention discloses a thermal-corrosion-resistant protective coating for a marine environment and a preparation method and application thereof, the thermal-corrosion-resistant protective coating is a NiAlYX coating and located on the surface of a high-temperature-resistant alloy matrix, the NiAlYX coating contains 25-50% of Al, 0.05-5% of Y, 0.05-5% of X and the balance Ni according to atomic percent, and X is at least one of Hf, Si, Sc, Dy and Pt. A specific NiAlYX coating is arranged on a high-temperature-resistant alloy matrix, specific active elements selected in the coating can have high binding energy with corrosive ions, Cl <-> and S < 2-> ions are corroded through pinning, further internal permeation of the coating in the service process is prevented, and therefore the overall marine corrosion resistance of the coating is improved, the service life of the coating is prolonged, and the service life of the coating is prolonged. The method can be applied to key components of aero-engines or gas turbines.

Description

Technical Field

[0001] The present invention relates to the technical field of high-temperature protective coatings, and in particular to a heat-resistant corrosion-resistant protective coating for marine environments, a preparation method thereof, and applications thereof. Background Art

[0002] The rapid development of aviation industry technology and the deepening implementation of China's deep-sea exploration strategy are placing higher demands on aircraft engine performance. Research has shown that the service life of aircraft engines and gas turbines in marine environments is significantly shortened compared to other environments, potentially leading to serious safety accidents. Therefore, marine environmental protection for aircraft engine and gas turbine hot-end components has become a critical technical issue that urgently needs to be addressed.

[0003] To this end, it is urgent to carry out research and development of heat-resistant corrosion protective coatings for marine atmospheric environments to effectively protect the base alloy from thermal corrosion damage and significantly extend the service life of key components.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] The purpose of the present invention is to provide a heat-resistant corrosion protective coating for marine environment and its preparation method and application, so as to improve the above technical problems.

[0006] The present invention is achieved in that: In a first aspect, the present invention provides a heat-resistant corrosion protective coating for a marine environment. The heat-resistant corrosion protective coating is a NiAlYX coating and is located on the surface of a high-temperature resistant alloy substrate. Calculated by atomic percentage, the NiAlYX coating contains 25-50% Al, 0.05-5% Y, 0.05-5% X, and the remainder is Ni. X is at least one of Hf, Si, Sc, Dy, and Pt.

[0007] In an optional embodiment, the high-temperature resistant alloy substrate is a nickel-based high-temperature alloy. Preferably, the high-temperature resistant alloy substrate is a nickel-based single-crystal high-temperature alloy. More preferably, the high-temperature resistant alloy substrate is a second-generation nickel-based single-crystal high-temperature alloy N5.

[0008] In an optional embodiment, the thickness of the NiAlYX coating is 10µm to 100µm, preferably 40µm to 90µm.

[0009] In an optional embodiment, the NiAlYX coating contains 35-45% Al, 0.05-0.015% Y, and 0.05% X, where X is Hf.

[0010] In an optional embodiment, the NiAlYX coating is deposited by arc ion plating.

[0011] In a second aspect, the present invention provides a method for preparing a heat-resistant corrosion protective coating for a marine environment as described in any one of the aforementioned embodiments, comprising: depositing the NiAlYHf coating on the surface of a high-temperature resistant alloy substrate obtained by surface pretreatment.

[0012] In an optional embodiment, the deposition method is arc ion plating, which includes the following steps: depositing the NiAlYHf coating by arc ion plating, and then performing vacuum heat treatment.

[0013] In an optional embodiment, the arc ion plating conditions are as follows: the temperature of the high-temperature resistant alloy substrate is 250~450°C, protective gas argon is passed, the gas pressure is maintained at 0.5~3.5Pa, the target current is 50~120A, the electromagnetic parameters are: voltage 2.4~50V, frequency 1.0~33.3Hz, permanent magnet parameters 5000~15000Gs, substrate bias -50~-250V, duty cycle 50~90%; and / or the vacuum degree is ≥1.0×10 -3 Pa, heat treatment temperature 800℃~1100℃, heat treatment time 2h~8h.

[0014] In an optional embodiment, the surface pretreatment includes sequentially performing sandpaper polishing, surface cleaning and sand blasting.

[0015] Preferably, the sandpaper polishing conditions are: polishing with 800 mesh, 1200 mesh, and 2000 mesh sandpaper in sequence.

[0016] Preferably, the conditions for the sand blasting treatment are: the abrasive type is aluminum oxide particles, the abrasive particle size is 100~300 mesh, the jet distance is 5~15 cm, the jet angle is 35~135°, the jet time is 10~60 s, the compressed air pressure is 0.5~2 MPa, and a rough surface with a roughness of ≤10 µm is obtained.

[0017] Preferably, the surface cleaning is performed by ultrasonic cleaning at 45-65°C, alcohol cleaning for 10-20 min, acetone cleaning for 10-20 min, deionized water cleaning for 10-20 min, and then drying in a drying oven at 100-200°C.

[0018] In a third aspect, the present invention provides the use of a heat-resistant corrosion protective coating for a marine environment as described in any one of the aforementioned embodiments on the surface of a hot end component of an aircraft engine or a gas turbine.

[0019] The present invention has the following beneficial effects: by providing a specific NiAlYX coating on a high temperature resistant alloy substrate, the specific active elements selected in the coating can have a strong binding energy with the corrosive ions, and the Cl - , S 2-ions, preventing further internal penetration during service, thereby improving the overall marine corrosion resistance of the coating and extending its service life. It can be applied to key components of aircraft engines or gas turbines. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 This is a surface morphology of the heat-resistant corrosion protective coating for marine environments of Example 1; Figure 2 This is a surface morphology of the heat-resistant corrosion protective coating for marine environments of Example 3; Figure 3 This is a surface morphology of the heat-resistant corrosion protective coating for marine environments of Example 4; Figure 4 This is a cross-sectional morphology of the heat-resistant corrosion protective coating for marine environments of Example 5; Figure 5 This is a cross-sectional morphology of the heat-resistant corrosion protective coating for marine environments of Example 6; Figure 6 This is a cross-sectional morphology of the heat-resistant corrosion protective coating for marine environments of Example 7; Figure 7 This is a cross-sectional morphology of the heat-resistant corrosion protective coating for marine environments of Example 8; Figure 8 This is a cross-sectional morphology of the heat-resistant corrosion protective coating for marine environments of Example 9; Figure 9 Surface and cross-sectional morphology of the heat-resistant corrosion protective coating for marine environments of Example 10; Figure 10 This is a surface morphology of the heat-resistant corrosion protective coating for marine environments of Comparative Example 1; Figure 11 Comparison of the surface and cross-sectional morphologies of the heat-resistant corrosion protective coating for marine environments of Example 2 and Comparative Example 2; Figure 12 This is a cross-sectional morphology of the heat-resistant corrosion protective coating for marine environment of Comparative Example 3. DETAILED DESCRIPTION

[0022] To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer are used. Where the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be purchased commercially.

[0023] The following is a detailed description of a heat-resistant corrosion-resistant protective coating for marine environments provided by the present invention, its preparation method, and its application.

[0024] The inventors found through research that when aircraft engines or gas turbines are in service in a marine atmosphere, the incomplete combustion of aviation oil produces pollutants such as SO2, and the marine atmosphere contains a large amount of water vapor, Na + 、Cl - Plasma causes large amounts of NaCl and Na2SO4 particles to deposit on the blade surface. When an aircraft engine or gas turbine is operating, the deposited NaCl and Na2SO4 salts melt at high temperatures, accelerating the corrosion of the coating. Based on this, the following solution is proposed.

[0025] Some embodiments of the present invention provide a heat-resistant corrosion protective coating for a marine environment, wherein the heat-resistant corrosion protective coating is a NiAlYX coating and is located on the surface of a high-temperature resistant alloy substrate. Calculated by atomic percentage, the NiAlYX coating contains 25-50% Al, 0.05-5% Y, 0.05-5% X, and the remainder is Ni, and the X is at least one of Hf, Si, Sc, Dy, and Pt.

[0026] The Y (yttrium) element selected in the heat-resistant corrosion protective coating can effectively pin corrosive ions such as S and Cl, preventing the internal penetration of corrosive ions, and effectively improving the thermal corrosion performance of the coating in the marine environment, thereby extending the overall service life of the coating. Further, by selecting the X element, not only can the adhesion performance of the coating be significantly improved, making the coating have better high-temperature oxidation resistance, but it can also cooperate with the Y element to enhance the thermal corrosion performance and improve the overall performance of the coating.

[0027] It should be noted that in the embodiments of the present invention, the substrate is required to have high-temperature resistance, and no other restrictive requirements are imposed. In some preferred embodiments, the high-temperature resistant alloy substrate can be selected as a nickel-based high-temperature alloy. For example, the high-temperature resistant alloy substrate is a nickel-based single-crystal high-temperature alloy. Furthermore, the nickel-based single-crystal high-temperature alloy can be selected as a second-generation nickel-based single-crystal high-temperature alloy N5. The second-generation nickel-based single-crystal high-temperature alloy N5 is a high-temperature alloy material with excellent performance. It is mainly used to manufacture hot-end components such as turbine blades, guide vanes, and turbine disks of aircraft engines. These components are subjected to high temperatures, high pressures, and high speeds during engine operation, and have extremely high material performance requirements. The excellent performance of the second-generation nickel-based single-crystal high-temperature alloy N5 can meet the working requirements of these components and improve the performance and efficiency of the engine.

[0028] Specifically, in some embodiments, the NiAlYX coating has a thickness of 10µm to 100µm, such as 10µm, 15µm, 20µm, 25µm, 30µm, 35µm, 40µm, 45µm, 50µm, 55µm, 60µm, 65µm, 70µm, 75µm, 80µm, 85µm, 90µm, 95µm, or 100µm, or any thickness between any two of the above, preferably 40µm to 90µm. When used in hot-end components of aviation equipment, if the thickness is too thin, it will be susceptible to corrosion by high-temperature fuel gas, pollutants, marine atmosphere, etc., and will not provide effective protection. If the thickness is too thick, the bonding performance will be affected to a certain extent, and the probability of thermal shock failure will increase.

[0029] Furthermore, in some embodiments, the NiAlYX coating contains 35-45% Al, 0.05-0.15% Y, and 0.05% X, where X is Hf. By further optimizing the composition of the NiAlYX layer, the NiAlYX layer can be made into a protective coating with good resistance to thermal corrosion in marine environments.

[0030] In some embodiments, the NiAlYX coating is deposited by arc ion plating. Arc ion plating can enhance the bonding strength and density of the NiAlYX coating by virtue of its high ionization rate, thereby achieving the wear resistance, high temperature resistance, and high precision of the NiAlYX coating.

[0031] Some embodiments of the present invention provide a method for preparing a heat-resistant corrosion protective coating for a marine environment as described in the aforementioned embodiment, comprising: depositing a NiAlYHf coating on the surface of a high-temperature resistant alloy substrate obtained by surface pretreatment.

[0032] Specifically, in some embodiments, the deposition method is arc ion plating, which includes the following steps: depositing the NiAlYHf coating by arc ion plating, and then performing vacuum heat treatment.

[0033] Furthermore, the arc ion plating conditions are as follows: the temperature of the high-temperature resistant alloy substrate is 250~450℃, the protective gas argon is passed, the gas pressure is maintained at 0.5~3.5Pa, the target current is 50~120A, the electromagnetic parameters are: voltage 2.4~50V, frequency 1.0~33.3Hz, permanent magnet parameters 5000~15000 Gs, substrate bias -50~-250V, and duty cycle 50~90%.

[0034] The coating is prepared by arc ion plating under conditions of electromagnetic and permanent magnetic composite magnetic fields. By adjusting the electromagnetic field and permanent magnetic field, it is possible to prepare high-quality NiAlYX coatings containing a large amount of high magnetic permeability material (Ni), achieving low-cost preparation of the coating, which has certain guiding significance in the industrial application of arc ion plating.

[0035] The vacuum degree of vacuum heat treatment is 9×10 -3 Pa, heat treatment temperature 800℃~1100℃, such as 800℃, 850℃, 900℃, 950℃, 1000℃, 1050℃ or 1100℃, etc., heat treatment time 2h~8h, such as 2h, 3h, 4h, 5h, 6h, 7h or 8h, etc. Generally speaking, the higher the heat treatment temperature, the shorter the heat treatment time. After vacuum heat treatment, element interdiffusion occurs between the coating and the substrate, further improving the bonding strength of the coating, thereby improving the heat corrosion resistance of the coating and extending its service life.

[0036] In some embodiments, the surface pretreatment includes sandpaper polishing, surface cleaning, and sand blasting. Pre-treating the substrate surface can improve the bonding performance and uniformity of the NiAlYX coating, thereby achieving better high temperature and corrosion resistance.

[0037] Specifically, in some embodiments, the sandpaper polishing conditions are: polishing with 800 mesh, 1200 mesh, and 2000 mesh sandpaper in sequence.

[0038] In some embodiments, the surface is cleaned by ultrasonic cleaning at 45-65°C, alcohol cleaning for 10-20 min, acetone cleaning for 10-20 min, deionized water cleaning for 10-20 min, and then dried in a drying oven at 100-200°C.

[0039] In some embodiments, the conditions for the sand blasting treatment are: the abrasive type is aluminum oxide particles, the abrasive particle size is 100-300 mesh, the jet distance is 5-15 cm, the jet angle is 35-135°, the jet time is 10-60 s, the compressed air pressure is 0.5-2 MPa, and a rough surface with a roughness of ≤10 µm is obtained.

[0040] It should be noted that the substrate surface requires further cleaning prior to arc ion plating, using high-pressure ion cleaning and metal ion cleaning. By applying a high bias voltage to the substrate surface, high-energy argon ions and metal ions clean the surface adsorbed atoms, improving the adhesion of the prepared coating. Without surface cleaning, a distinct interface layer will form between the substrate and the coating, primarily composed of aluminum oxide, which will seriously affect the coating's bonding strength, leading to easy peeling of the coating and seriously affecting the coating's heat-resistant corrosion performance and lifespan.

[0041] Specifically, before arc ion plating, the vacuum degree was drawn to greater than 1.0×10 -3 Pa, argon pressure 0.5~3.5Pa, substrate bias -600~-1000 V, cleaning time 20~35 min.

[0042] Furthermore, some embodiments of the present invention also provide the use of the heat-resistant corrosion protective coating for marine environment as described in any of the aforementioned embodiments on the surface of the hot end component of an aircraft engine or a gas turbine.

[0043] The features and performance of the present invention are further described in detail below with reference to the embodiments.

[0044] Example 1 This embodiment provides a method for preparing a heat-resistant corrosion protective coating for a marine environment, comprising the following steps: (1) The second-generation single crystal nickel-based alloy N5 was used as the substrate, and its surface was polished with 800 mesh, 1200 mesh, and 2000 mesh SiC sandpaper; it was ultrasonically cleaned with alcohol, acetone, and deionized water at 60°C for 10 min, and sandblasted for 5 min with a sandblasting distance of 5.0 cm.

[0045] (2) Prepare NiAlYHf target material for use. In terms of atomic percentage, the composition of NiAlYHf target material is: 35% Al, 0.05% Hf, 0.05% Y, and Ni balance.

[0046] (3) Reduce the vacuum to 5.0×10 -3 Pa, argon pressure 1.0 Pa, substrate bias -600 V, time 30 min, high bias ion cleaning.

[0047] (4) The conditions for depositing the NiAlYHf coating are as follows: pressure 1.0 Pa, argon flow rate 200 sccm, target current 70 A, electromagnetic voltage 4.8 V, frequency 1.0 Hz, permanent magnet 10000 Gs, substrate bias -70 V, duty cycle 70%, and time 240 min.

[0048] (5) Place the plated sample in a vacuum heat treatment furnace and vacuum the sample to 5.0×10-3 Pa and started heating to 900 °C at a heating rate of 10 °C / min and kept at this temperature for 5 h.

[0049] Scanning electron microscopy was used to observe the cross section of the NiAlYHf coating sample, and it was found that the coating had good adhesion to the substrate interface, with no pores or cracks at the interface. The coating thickness was about 40µm. After hot corrosion testing, the surface showed loose oxide morphology after hot corrosion at 900℃ for 20h under mixed salt conditions of 25% NaCl + 75% Na2SO4. The coating can also provide hot corrosion protection for the substrate, such as Figure 1 shown.

[0050] Example 2 This embodiment provides a method for preparing a heat-resistant corrosion protective coating for a marine environment, comprising the following steps: (1) The second-generation single crystal nickel-based alloy N5 was used as the substrate, and its surface was polished with 800 mesh, 1200 mesh, and 2000 mesh SiC sandpaper; it was ultrasonically cleaned with alcohol, acetone, and deionized water at 60°C for 10 min, and sandblasted for 5 min with a sandblasting distance of 10.0 cm.

[0051] (2) Prepare NiAlYHf target material for use. In terms of atomic percentage, the composition of NiAlYHf target material is: 45% Al, 0.05% Hf, 0.15% Y, and Ni balance.

[0052] (3) Reduce the vacuum to 9.0×10 -3 Pa, argon pressure 2.0 Pa, substrate bias -1000 V, time 25 min, high bias ion cleaning.

[0053] (4) The conditions for depositing the NiAlYHf coating are as follows: pressure 2.0 Pa, argon flow rate 200 sccm, target current 80 A, electromagnetic voltage 4.8 V, frequency 1.0 Hz, permanent magnet 15000 Gs, substrate bias -80 V, duty cycle 80%, and time 300 min.

[0054] (5) Place the plated sample in a vacuum heat treatment furnace and vacuum the sample to 9.0×10 -3 Pa and started heating to 1000 °C at a heating rate of 10 °C / min and kept at this temperature for 3 h.

[0055] Scanning electron microscopy (SEM) was used to observe the cross section of the NiAlYHf coating sample, revealing that the coating had a good interface with the substrate, with no pores or cracks at the interface, and the coating thickness was approximately 50 µm.

[0056] Example 3 This embodiment provides a method for preparing a heat-resistant corrosion protective coating for a marine environment, comprising the following steps: (1) The second-generation single crystal nickel-based alloy N5 was used as the substrate, and its surface was polished with 800 mesh, 1200 mesh, and 2000 mesh SiC sandpaper; it was ultrasonically cleaned at 60 ℃ for 10 min and sandblasted for 5 min with alcohol, acetone, and deionized water, respectively, with a sandblasting distance of 10.0 cm.

[0057] (2) Prepare NiAlYHf target material for use. In terms of atomic percentage, the composition of NiAlYHf target material is: 40% Al, 0.5% Hf, 0.1% Y, and Ni balance.

[0058] (3) Reduce the vacuum to 5.0×10 -4 Pa, argon pressure 1.5 Pa, substrate bias -700 V, time 20 min, high bias ion cleaning.

[0059] (4) The conditions for depositing the NiAlYHf coating are as follows: pressure 1.5 Pa, argon flow rate 200 sccm, target current 100 A, electromagnetic voltage 4.8 V, frequency 1.0 Hz, permanent magnet 5000 Gs, substrate bias -100 V, duty cycle 90%, and time 600 min.

[0060] (5) Place the plated sample in a vacuum heat treatment furnace and vacuum the sample to 5.0×10 -4 Pa and started heating to 800 °C at a heating rate of 10 °C / min and kept at this temperature for 3 h.

[0061] Scanning electron microscopy was used to observe the cross section of the NiAlYHf coating sample, and it was found that the coating had good adhesion to the substrate interface, with no pores or cracks at the interface. The coating thickness was about 85µm. After hot corrosion testing, a large amount of loose oxide morphology and cracks were found on the surface after 40h of hot corrosion at 900℃ under mixed salt conditions of 25% NaCl + 75% Na2SO4. At the same time, the morphology after peeling was visible. The remaining coating can also provide hot corrosion protection for the substrate. Figure 2 shown.

[0062] Example 4 This embodiment provides a method for preparing a heat-resistant corrosion protective coating for a marine environment, comprising the following steps: (1) The second-generation single crystal nickel-based alloy N5 was used as the substrate, and its surface was polished with 800 mesh, 1200 mesh, and 2000 mesh SiC sandpaper; ultrasonic cleaning was performed at 60°C for 5 min, and sand blowing was performed for 5 min with alcohol, acetone, and deionized water, respectively, with a sand blowing distance of 5.0 cm.

[0063] (2) Prepare NiAlYHf target material for use. In terms of atomic percentage, the composition of NiAlYHf target material is: 45% Al, 0.5% Hf, 0.1% Y, and Ni balance.

[0064] (3) Reduce the vacuum to 5.0×10 -4 Pa, argon pressure 2.0 Pa, substrate bias -1000 V, time 35 min, high bias ion cleaning.

[0065] (4) The conditions for depositing the NiAlYHf coating are as follows: pressure 2.0 Pa, argon flow rate 200 sccm, target current 100 A, electromagnetic voltage 4.8 V, frequency 1.0 Hz, permanent magnet 5000 Gs, substrate bias -100 V, duty cycle 90%, and time 540 min.

[0066] (5) Place the plated sample in a vacuum heat treatment furnace and vacuum the sample to 5.0×10 -4 Pa and started heating to 800 °C at a heating rate of 10 °C / min and kept at this temperature for 6 h.

[0067] Scanning electron microscopy was used to observe the cross section of the NiAlYHf coating sample, and it was found that the coating had good adhesion to the substrate interface, with no pores or cracks at the interface. The coating thickness was about 80 µm. After hot corrosion testing, a large amount of loose oxide morphology was found on the surface after hot corrosion at 900°C for 40 hours under mixed salt conditions of 25% NaCl + 75% Na2SO4. The surface showed the morphology after peeling, and new oxides were formed at the peeling site. The remaining coating can also provide hot corrosion protection for the substrate, such as Figure 3 shown.

[0068] Example 5 This embodiment provides a method for preparing a heat-resistant corrosion protective coating for a marine environment, comprising the following steps: (1) The second-generation single crystal nickel-based alloy N5 was used as the substrate, and its surface was polished with 800 mesh, 1200 mesh, and 2000 mesh SiC sandpaper; it was ultrasonically cleaned with alcohol, acetone, and deionized water at 60°C for 10 minutes, and sandblasted for 10 minutes, with a sandblasting distance of 10.0 cm.

[0069] (2) Prepare NiAlYHfSi target material for use. In terms of atomic percentage, the composition of NiAlYHfSi target material is: 40% Al, 0.5% Hf, 0.10% Y, 0.1% Si, and Ni as the balance.

[0070] (3) Reduce the vacuum to 9.0×10 -3 Pa, argon pressure 1.5 Pa, substrate bias -700 V, time 20 min, high bias ion cleaning.

[0071] (4) The conditions for depositing the NiAlYHfSi coating are as follows: pressure 1.5 Pa, argon flow rate 200 sccm, target current 100 A, electromagnetic voltage 4.8 V, frequency 1.0 Hz, permanent magnet 5000 Gs, substrate bias -100 V, duty cycle 90%, and time 600 min.

[0072] (5) Place the plated sample in a vacuum heat treatment furnace and vacuum the sample to 9.0×10 -3 Pa and started heating to 800 °C at a heating rate of 10 °C / min and kept at this temperature for 3 h.

[0073] Scanning electron microscopy (SEM) of the NiAlYHfSi coating revealed a good interface between the coating and the substrate, with no pores or cracks present. The coating thickness was approximately 85µm. Thermal corrosion testing revealed a relatively dense oxide layer on the coating surface after 20 hours of hot corrosion at 900°C in a mixed salt atmosphere of 25% NaCl and 75% Na2SO4. The oxide layer exhibited a small amount of flaking and cracking, but the remaining coating provided some protection for the substrate. The cross-sectional view is shown in Figure 2. Figure 4 shown.

[0074] Example 6 This embodiment provides a method for preparing a heat-resistant corrosion protective coating for a marine environment, comprising the following steps: (1) The second-generation single crystal nickel-based alloy N5 was used as the substrate, and its surface was polished with 800 mesh, 1200 mesh, and 2000 mesh SiC sandpaper; it was ultrasonically cleaned for 5 min at 60 °C with alcohol, acetone, and deionized water, and sandblasted for 5 min at a sandblasting distance of 5.0 cm.

[0075] (2) Prepare NiAlYHfSi target material for use. In terms of atomic percentage, the composition of NiAlYHfSi target material is: 25% Al, 0.05% Hf, 0.10% Y, 0.1% Si, and Ni as the balance.

[0076] (3) Reduce the vacuum to 1.0×10 -4 Pa, argon pressure 2.0 Pa, substrate bias -1000 V, time 35 min, high bias ion cleaning.

[0077] (4) The conditions for depositing the NiAlYHfSi coating are as follows: pressure 2.0 Pa, argon flow rate 200 sccm, target current 100 A, electromagnetic voltage 4.8 V, frequency 1.0 Hz, permanent magnet 5000 Gs, substrate bias -100 V, duty cycle 90%, and time 540 min.

[0078] (5) Place the plated sample in a vacuum heat treatment furnace and vacuum the sample to 1.0×10 -4Pa and started heating to 900 °C at a heating rate of 10 °C / min and kept at this temperature for 6 h.

[0079] Scanning electron microscopy (SEM) was used to observe the cross section of the NiAlYHfSi coating sample, revealing that the coating had a good interface with the substrate, with no pores or cracks at the interface. The coating thickness was approximately 80µm. Thermal corrosion testing revealed that after 20 hours of thermal corrosion at 900°C using a mixed salt solution of 25% NaCl and 75% Na2SO4, the coating surface oxide layer was relatively dense, with a small amount of flaking, providing good protection for the substrate. Figure 5 shown.

[0080] Example 7 This embodiment provides a method for preparing a heat-resistant corrosion protective coating for a marine environment, comprising the following steps: (1) The second-generation single crystal nickel-based alloy N5 was used as the substrate, and its surface was polished with 800 mesh, 1200 mesh, and 2000 mesh SiC sandpaper; it was ultrasonically cleaned with alcohol, acetone, and deionized water at 60°C for 10 minutes, and sandblasted for 10 minutes, with a sandblasting distance of 10.0 cm.

[0081] (2) Prepare NiAlYHfSiScPt target material for use. In terms of atomic percentage, the composition of NiAlYHfSiScPt target material is: 45% Al, 0.05% Hf, 0.15% Y, 0.05% Sc, 0.05% Si, 0.05% Pt, and Ni as the balance.

[0082] (3) Reduce the vacuum to 5.0×10 -3 Pa, argon pressure 3.0 Pa, substrate bias -800 V, time 35 min, high bias ion cleaning.

[0083] (4) The conditions for depositing the NiAlYHfSiScPt coating are as follows: pressure 3.0 Pa, argon flow rate 200 sccm, target current 100 A, electromagnetic voltage 4.8 V, frequency 1.0 Hz, permanent magnet 5000 Gs, substrate bias -100 V, duty cycle 90%, and time 480 min.

[0084] (5) Place the plated sample in a vacuum heat treatment furnace and vacuum the sample to 5.0×10 -3 Pa and started heating to 900 °C at a heating rate of 10 °C / min and kept at this temperature for 6 h.

[0085] Scanning electron microscopy of the NiAlYHfSiScPt coating sample revealed a good interface between the coating and the substrate, with no pores or cracks at the interface. The coating thickness was approximately 70µm. A thermal corrosion test revealed that after 100 hours of thermal corrosion at 900°C in a mixed salt solution of 25% NaCl + 75% Na2SO4, the coating surface oxide layer was relatively loose, cracked, and flaked. Corrosion had already reached the substrate, rendering it unable to provide protection. Figure 6 shown.

[0086] Example 8 This embodiment provides a method for preparing a heat-resistant corrosion protective coating for a marine environment, comprising the following steps: (1) The second-generation single crystal nickel-based alloy N5 was used as the substrate, and its surface was polished with 800 mesh, 1200 mesh, and 2000 mesh SiC sandpaper; it was ultrasonically cleaned with alcohol, acetone, and deionized water at 60°C for 10 minutes, and sandblasted for 10 minutes, with a sandblasting distance of 10.0 cm.

[0087] (2) Prepare NiAlYHfPtDy target material for use. In terms of atomic percentage, the composition of NiAlYHfPtDy target material is: 25% Al, 0.05% Hf, 0.05% Y, 0.05% Pt, 0.05% Dy, and Ni as the balance.

[0088] (3) Reduce the vacuum to 5.0×10 -3 Pa, argon pressure 1.5 Pa, substrate bias -800 V, time 30 min, high bias ion cleaning.

[0089] (4) The conditions for depositing the NiAlYHfPtDy coating are as follows: pressure 1.5 Pa, argon flow rate 200 sccm, target current 100 A, electromagnetic voltage 4.8 V, frequency 1.0 Hz, permanent magnet 5000 Gs, substrate bias -100 V, duty cycle 90%, and time 240 min.

[0090] (5) Place the plated sample in a vacuum heat treatment furnace and vacuum the sample to 5.0×10 -3 Pa and started heating to 900 °C at a heating rate of 10 °C / min and kept at this temperature for 4 h.

[0091] Scanning electron microscopy was used to observe the cross section of the NiAlYHfPtDy coating sample, and it was found that the coating had a good interface with the substrate, with no pores or cracks at the interface. The coating thickness was about 35µm. After hot corrosion testing, the coating surface was relatively loose after 40 hours of hot corrosion at 900℃ under the conditions of mixed salt 25% NaCl + 75% Na2SO4, with a small amount of peeling of the oxide layer and internal corrosion in the cross section. The coating has a certain protective function, such as Figure 7 shown.

[0092] Example 9 The only difference between this embodiment and embodiment 8 is that the coating of this embodiment does not contain Dy element. In terms of atomic percentage, the NiAlHfYPt target contains Hf, Y, and Pt active elements. The preparation process is basically the same as that of embodiment 8.

[0093] The surface and cross-sectional morphology of the NiAlHfYPt coating sample were observed using a scanning electron microscope. Before corrosion, it was similar to the NiAlYHfPtDy in Example 8. After hot corrosion at 900°C mixed salt for 100 hours, the cross-sectional morphology was observed. The corrosion depth of the NiAlHfYPtDy layer in Example 8 was smaller than that in this comparative example. Figure 8 shown.

[0094] Example 10 This embodiment provides a method for preparing a heat-resistant corrosion protective coating for a marine environment, comprising the following steps: (1) The second-generation single crystal nickel-based alloy N5 was used as the substrate, and its surface was polished with 800 mesh, 1200 mesh, and 2000 mesh SiC sandpaper; it was ultrasonically cleaned with alcohol, acetone, and deionized water at 60°C for 10 min, and sandblasted for 5 min with a sandblasting distance of 5.0 cm.

[0095] (2) Prepare NiAlYHf target material for use. In terms of atomic percentage, the composition of NiAlYHf target material is: 35% Al, 0.05% Hf, 0.10% Y, and Ni balance.

[0096] (3) Reduce the vacuum to 5.0×10 -3 Pa, argon pressure 1.0 Pa, substrate bias -600 V, time 30 min, high bias ion cleaning.

[0097] (4) The conditions for depositing the NiAlYHf coating are as follows: pressure 1.0 Pa, argon flow rate 200 sccm, target current 70 A, electromagnetic voltage 4.8 V, frequency 1.0 Hz, permanent magnet 10000 Gs, substrate bias -70 V, duty cycle 70%, and time 240 min.

[0098] (5) Place the plated sample in a vacuum heat treatment furnace and vacuum the sample to 5.0×10 -3 Pa and started heating to 900 °C at a heating rate of 10 °C / min and kept at this temperature for 5 h.

[0099] Scanning electron microscopy was used to observe the cross section of the NiAlYHf coating sample, and it was found that the coating had a good interface with the substrate, no pores or cracks existed at the interface, and the coating thickness was about 40µm. After hot corrosion testing, the corrosion surface was relatively dense after 20h of hot corrosion at 900℃ under the mixed salt conditions of 25% NaCl + 75% Na2SO4, with a small amount of loose oxide on the surface, but new dense oxides grew under the loose oxides. From the cross-sectional morphology, it was observed that the coating can also provide hot corrosion protection for the substrate, such as Figure 9 shown.

[0100] Comparative Example 1 The preparation method provided in this comparative example differs from that in Example 1 in that the coating does not contain the Y element. In terms of atomic percentage, the NiAlHf target contains 35% Al and 0.05% Hf, with the remainder being Ni. The preparation process is essentially the same as in Example 1.

[0101] The surface and cross-sectional morphology of the NiAlHf coating sample were observed using a scanning electron microscope. The surface cross-section before corrosion was similar to that in Example 1. After the NiAlHf coating sample was corroded at 900 °C for 20 h, a large amount of loose oxide layer and many pores were observed on the coating surface, indicating severe internal corrosion and oxidation, and the corrosion layer fell off over a large area. Figure 10 shown.

[0102] By comparing Example 1 with Comparative Example 1, it can be seen that the NiAlHfY coating can effectively improve the continuity and adhesion of the oxide layer, and pin the corrosive elements to prevent the internal penetration of the corrosive elements.

[0103] Comparative Example 2 The preparation method provided in this comparative example differs from that in Example 2 in that the coating does not contain the Y element. In terms of atomic percentage, the NiAlHf target material contains 45% Al, 0.05% Hf, and the balance is Ni. The preparation process is essentially the same as in Example 2.

[0104] Scanning electron microscopy was used to observe the surface and cross-sectional morphology of the NiAlHf coating sample. Before corrosion, it was similar to the NiAlYHf in Example 2. After 100 hours of hot corrosion in a mixed salt at 900 ° C, the corrosion zone depth of the NiAlHf coating was nearly 140 μm, and a large number of holes and corrosion peeling areas appeared on the coating surface. After adding the Y element and hot corrosion in a mixed salt at 900 ° C for 100 hours, the corrosion zone depth of the coating was nearly 120 μm. From the surface morphology, it can be seen that the surface morphology of the NiAlHfY coating is denser and has a better barrier effect on corrosive ions. However, the surface of the NiAlHf coating has a large number of needle-shaped oxides and poorer density, which is conducive to the rapid entry of corrosive ions into the coating and accelerates the corrosion process. Figure 11 shown.

[0105] By comparing Example 2 with Comparative Example 2, the NiAlYHf coating can effectively slow down the corrosion degree of the coating, and the dense corrosion products can slow down the corrosion progress of the coating and extend its service life.

[0106] Comparative Example 3 The preparation method provided in this comparative example differs from that in Example 10 in that the coating does not contain the Hf element. In terms of atomic percentage, the NiAlHf target material contains 35% Al, 0.10% Y, and the balance Ni. The preparation process is essentially the same as that in Example 10.

[0107] After the hot corrosion test, the cross section was observed by scanning electron microscopy after hot corrosion at 900℃ for 20h under the conditions of mixed salt 25% NaCl + 75% Na2SO4. It can be seen that a small amount of internal corrosion products are generated inside the corrosion layer and the oxide layer has cracking. The coating can also provide hot corrosion protection for the substrate. Compared with Example 10, the internal corrosion is more obvious. Figure 12 shown.

[0108] In summary, the thermal corrosion coating material for marine environment and the preparation method thereof provided in the embodiments of the present invention deposit a NiAlYX coating on the surface of the substrate. The combination of the Y element and the X element can pin corrosive ions such as S and Cl, effectively prevent the internal diffusion of corrosive ions, and maintain the relative integrity of the oxide layer, thereby improving the thermal corrosion resistance of the coating in marine environment.

[0109] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A heat-resistant corrosion-resistant protective coating for marine environments, characterized in that: The heat-resistant corrosion protective coating is a NiAlYX coating and is located on the surface of a high-temperature resistant alloy substrate. Calculated by atomic percentage, the NiAlYX coating contains 25-50% Al, 0.05-5% Y, 0.05-5% X, and the remainder is Ni. The X is at least one of Hf, Si, Sc, Dy, and Pt.

2. The heat-resistant corrosion-resistant protective coating for marine environment according to claim 1, characterized in that: The high temperature resistant alloy substrate is a nickel-based high temperature alloy. Preferably, the high temperature resistant alloy substrate is a nickel-based single crystal high temperature alloy. More preferably, the high temperature resistant alloy substrate is a second-generation nickel-based single crystal high temperature alloy N5.

3. The heat-resistant corrosion-resistant protective coating for marine environment according to claim 1, characterized in that: The thickness of the NiAlYX coating is 10µm to 100µm, preferably 40µm to 90µm.

4. The heat-resistant corrosion-resistant protective coating for marine environments according to any one of claims 1 to 3, characterized in that: The NiAlYX coating contains 35-45% Al, 0.05-0.15% Y, and 0.05% X, where X is Hf.

5. The heat-resistant corrosion-resistant protective coating for marine environment according to any one of claims 1 to 3, characterized in that: The NiAlYX coating is deposited by arc ion plating.

6. A method for preparing a heat-resistant corrosion-resistant protective coating for a marine environment according to any one of claims 1 to 5, characterized in that: It includes: The NiAlYHf coating is deposited on the surface of the high-temperature resistant alloy substrate obtained through surface pretreatment.

7. The preparation method according to claim 6, characterized in that The deposition method is arc ion plating, which includes the following steps: depositing NiAlYHf coating by arc ion plating, and then performing vacuum heat treatment.

8. The preparation method according to claim 7, characterized in that Arc ion plating conditions are as follows: the temperature of the high-temperature resistant alloy substrate is 250~450℃, protective gas argon is passed, the gas pressure is maintained at 0.5~3.5Pa, the target current is 50~120A, the electromagnetic parameters are: voltage 2.4~50V, frequency 1.0~33.3Hz, permanent magnet parameters 5000~15000Gs, substrate bias voltage -50~-250V, and duty cycle 50~90%; And / or, the vacuum degree of the vacuum heat treatment is ≥1.0×10 -3 Pa, heat treatment temperature 800℃~1100℃, heat treatment time 2h~8h.

9. The preparation method according to any one of claims 6 to 8, characterized in that The surface pre-treatment includes sandpaper polishing, surface cleaning and sand blasting in sequence; Preferably, the sandpaper polishing conditions are: polishing with 800 mesh, 1200 mesh, and 2000 mesh sandpaper in sequence; Preferably, the surface cleaning is performed by ultrasonic cleaning at 45-65°C, alcohol cleaning for 10-20 minutes, acetone cleaning for 10-20 minutes, deionized water cleaning for 10-20 minutes, and then drying in a drying oven at 100-200°C. Preferably, the conditions for the sand blasting treatment are: the abrasive type is aluminum oxide particles, the abrasive particle size is 100-300 mesh, the spray distance is 5-15 cm, the spray angle is 35-135°, the spray time is 10-60 s, the compressed air pressure is 0.5-2 MPa, and a rough surface with a roughness of ≤10 μm is obtained; Preferably, before arc ion plating, the high temperature resistant alloy substrate is first subjected to high bias ion cleaning.

10. Use of the heat-resistant corrosion protective coating for marine environments according to any one of claims 1 to 5 on the surface of hot end components of aircraft engines or gas turbines.

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