Preparation method of offshore wind power protection material of blue laser cladding additive nickel-copper-based eutectic high-entropy alloy

Abstract

The present application relates to the technical field of metal material surface protection, and in particular, relates to a preparation method of a blue laser cladding additive nickel-copper-based eutectic high-entropy alloy offshore wind power protection material. As one of the core pillar industries of global energy transformation, offshore wind power is long-term served in the extreme marine environment of high temperature, high humidity and high salt mist. The corrosion protection problem of key structural components (such as tower foundation, flange connecting surface, main shaft bearing, gear box shell, etc.) directly determines the operation safety and service life of the wind turbine generator. The present application combines innovative alloy composition design with advanced blue laser cladding technology to prepare a eutectic high-entropy alloy protection layer with excellent mechanical properties and corrosion resistance, providing a new technical solution for long-term protection of offshore wind power equipment. It belongs to the key technical innovation in the cross field of high-end equipment manufacturing and surface engineering.

Description

Technical Field

[0001] This invention relates to the field of surface protection technology for metallic materials, and more specifically, to a method for preparing a blue laser cladding additive nickel-copper-based eutectic high-entropy alloy offshore wind power protection material. Background Technology

[0002] Currently, the surface protection technologies commonly used in offshore wind power equipment mainly include the following categories:

[0003] Thermal spraying technologies, such as arc spraying of aluminum-zinc alloys and high-velocity flame spraying (HVOF) tungsten carbide coatings, offer advantages such as high efficiency and low cost. However, the coating and substrate are mechanically bonded, resulting in relatively low bonding strength (typically 30-60 MPa). Furthermore, the coating exhibits high porosity (5%-15%), making it susceptible to chloride ion penetration and undercoating corrosion. Consequently, its service life is generally 5-8 years.

[0004] Arc welding: This technology uses an electric arc to heat and melt welding wire to form a weld overlay on the surface of a substrate. Commonly used materials include stainless steel and nickel-based alloys. The advantage of this technology is its large coating thickness (up to 5-10 mm). However, it also requires a large heat input (usually exceeding 10 kJ / mm), leading to severe thermal deformation of the substrate. This results in coarse grains and welding stress in the weld zone, increasing susceptibility to cracking. Furthermore, the weld overlay exhibits poor compositional uniformity and unstable corrosion resistance.

[0005] Infrared laser cladding technology: This technology uses a 1064nm fiber laser as a heat source to clad alloy powder onto the substrate surface, forming a metallurgical bond coating. Compared to thermal spraying and arc welding, its heat input is controllable (heat-affected zone less than 0.5mm), its bonding strength is higher (80-150MPa), and its coating density is better. However, this technology has significant drawbacks when cladding alloys containing highly reflective metals: metals such as copper, gold, and silver have a reflectivity of over 80% to infrared lasers, resulting in extremely low laser energy utilization (less than 20%). Nickel-copper based alloys, due to their excellent resistance to seawater corrosion (copper can form on the surface...), offer a solution. Passivation films have become an ideal material for marine protection, but when the copper content exceeds 20%, severe energy reflection will occur during the infrared laser cladding process, resulting in large temperature fluctuations in the molten pool and easy generation of defects such as pores, incomplete fusion, and component segregation, which restricts its application in the high-end protection field of offshore wind power.

[0006] Existing patented technologies have already reported on research into laser cladding of nickel-copper based alloys:

[0007] Chinese patent CN101586238B discloses a method for laser cladding alloys on the surface of a steel pressure head. The patent application uses infrared laser cladding of high-temperature and wear-resistant alloy powder, but its alloy system does not contain copper and is mainly designed for high-temperature wear conditions. It does not have the salt spray corrosion resistance required for marine environments.

[0008] Patent application CN102899664A discloses a laser cladding nickel-based alloy powder. The copper content of this patent application is 8-11%, far lower than the 20-30% of this invention, and it does not employ a eutectic high-entropy alloy design. Therefore, the coating hardness and corrosion resistance cannot meet the long-term protection requirements for offshore wind power. Furthermore, this patent still uses traditional infrared laser cladding technology, failing to address the energy reflection problem caused by the high copper content.

[0009] Furthermore, eutectic high-entropy alloys, as an emerging alloy system in recent years, possess the characteristics of uniform composition, stable microstructure, and excellent comprehensive performance. The eutectic structure is formed by the synergistic growth of two or more crystalline phases in a fixed proportion, retaining the high hardness and wear resistance of high-entropy alloys while also possessing the advantages of low segregation and high toughness of the eutectic structure. However, how to achieve eutecticization of nickel-copper based high-entropy alloys through compositional design, and how to prepare high-quality eutectic coatings using advanced cladding technology, are key technical challenges that urgently need to be solved in this field. Summary of the Invention

[0010] This invention addresses the shortcomings of existing technologies by providing a method for preparing a blue laser cladding additive nickel-copper-based eutectic high-entropy alloy offshore wind power protection material. This method innovatively introduces vanadium aluminum carbide (AlVC) and yttrium tributylene oxide (YTO). By precisely controlling the composition ratio of two trace alloy powders and using blue laser cladding technology, a stable nickel-copper-based eutectic high-entropy alloy protective layer was successfully prepared. This solved the problems of low energy utilization and numerous coating defects in infrared laser cladding of high copper alloys. At the same time, it significantly improved the hardness, corrosion resistance, and bonding strength of the protective material, meeting the long-term protection requirements of offshore wind power equipment for more than 15 years.

[0011] This invention provides a method for preparing a blue laser cladding additive nickel-copper-based eutectic high-entropy alloy offshore wind power protection material, the specific operation steps of which are as follows:

[0012] S1 Metal Powder Pretreatment: 25-35 parts by weight of Ni powder, 20-30 parts by weight of Cu powder, 15-20 parts by weight of Cr powder, 8-12 parts by weight of Mo powder, 5-8 parts by weight of Al powder, 3-6 parts by weight of Ti powder, 0.05-0.2 parts by weight of vanadium aluminum carbide powder (CAS: 12179-42-9), and 0.01-0.3 parts by weight of tri-n-butyl yttrium oxide powder are placed in a double planetary mixer and stirred at a speed of 200-300 r / min for 1-2 h. Then, the mixed powder is placed in a vacuum drying oven and dried at a temperature of 80-120℃ for 2-4 h to remove adsorbed moisture from the powder and obtain a uniformly dried mixed powder.

[0013] S2 Substrate Pretreatment: Select a substrate for offshore wind power (Q345 steel or 316L stainless steel). First, use 120#, 240#, 400#, 800#, and 1200# sandpaper to alternately dry and wet sand the substrate surface to remove the oxide scale and rough layer. Then, place the sanded substrate in an ultrasonic cleaning tank, add industrial alcohol as a cleaning agent, and ultrasonically degrease at a frequency of 40-60kHz for 30-60 minutes. Next, soak the substrate in a 5-10% dilute hydrochloric acid solution at room temperature for 10-20 minutes to remove rust until the substrate surface shows a uniform metallic luster. Finally, rinse the substrate surface with anhydrous ethanol 3-5 times and dry it with compressed air (pressure 0.4-0.6MPa) to obtain a clean pretreated substrate.

[0014] S3 Blue Laser Cladding Additive Manufacturing: Using a semiconductor blue laser cladding system, the pre-treated mixed powder from S1 is fed into the cladding area via a coaxial powder feeder (powder feeding method is coaxial). The powder feeder diameter is 2-4 mm, and the powder feeding gas is argon (99.99% purity). Blue laser cladding is performed on the substrate surface. The cladding process parameters are: laser wavelength 450-480 nm, laser power 2000-3000 W, scanning speed 3-5 mm / s, spot diameter 0.8-1.2 mm, powder feed rate 20-40 g / min, protective gas is argon (99.99% purity), protective gas flow rate 15-25 L / min, substrate preheating temperature during cladding is 100-200℃, and the cladding layer thickness is controlled at 1.5-2.5 mm, resulting in a nickel-copper based eutectic high-entropy alloy protective layer.

[0015] S4 Post-processing: After cladding, allow the protective layer to cool naturally to room temperature (cooling rate 5-10℃ / min). Use a diamond grinding wheel (80#-120# grit) for rough grinding to remove surface oxide scale and spatter. Then use a diamond grinding head (200#-500# grit) for fine grinding to achieve a surface roughness Ra≤1.6μm. Finally, use a wool wheel with diamond polishing paste (1-3μm grit) for polishing until the protective layer surface has a mirror-like luster, thus obtaining the final offshore wind power protection material (a material with a nickel-copper-based eutectic high-entropy alloy protective layer).

[0016] Reaction mechanism

[0017] The reaction mechanism for preparing the nickel-copper-based eutectic high-entropy alloy protective layer of this invention mainly includes the following aspects:

[0018] 1. Interaction mechanism between blue laser and highly reflective metals

[0019] Blue lasers have a wavelength of 450-480 nm, falling within the visible light band. Compared to infrared lasers (1064 nm), they have higher photon energy (2.5-2.7 eV). Copper's reflectivity to blue lasers is approximately 45-55%, significantly lower than the 80-85% reflectivity to infrared lasers, allowing for an increase in energy utilization to 40-50%. The shorter wavelength of blue lasers results in a smaller focused spot (0.8-1.2 mm), achieving a higher energy density. With a flow rate of W / mm², it can rapidly melt alloy powders with high copper content, forming a stable molten pool. The molten pool exists for approximately 10-20 ms. Under high-speed scanning (3-5 mm / s), the molten metal flows violently within the pool, promoting compositional homogenization and reducing the generation of porosity and incomplete fusion defects.

[0020] 2. Formation mechanism of eutectic high-entropy alloys

[0021] This invention constructs an alloy system with a high entropy effect by precisely controlling the composition ratio of Ni, Cu, Cr, Mo, Al, and Ti (the total atomic percentage is close to 100%). The high entropy effect causes the alloy to tend to form simple BCC or FCC solid solution phases, but by introducing Al and Ti elements (whose atomic radii differ significantly from Ni and Cu), a lattice distortion effect is generated. Simultaneously, the rapid solidification characteristics of blue laser cladding (cooling rate approximately...) are utilized. The temperature (℃ / s) inhibits the growth of coarse grains. When the alloy composition reaches the eutectic point, both FCC phase (mainly Ni and Cu) and BCC phase (mainly Cr, Mo, Al, and Ti) precipitate simultaneously in the molten pool, forming a lamellar eutectic structure. The interlamellar spacing of the eutectic structure is approximately 0.5-2 μm, and the interface bonding is tight, ensuring both high hardness and good toughness of the coating.

[0022] 3. Mechanism of action of vanadium aluminum carbide

[0023] Vanadium aluminum carbide (AlVC), used as a trace refining agent, decomposes into Al, V, and C elements during the cladding process. Al can form compounds with Ni and Ti. Intermetallic compounds such as TiAl enhance the high-temperature stability of the coating; V has a strong grain-refining effect, and the V(C,N) particles formed in the molten pool can act as heterogeneous nucleation sites, refining the interlamellar spacing of the eutectic structure from 2-3 μm to 0.5-1 μm, significantly improving the hardness and wear resistance of the coating; C can form with Cr and Mo... , The carbides are dispersed in the eutectic structure, further improving the wear resistance of the coating. The grain refinement effect is best when the AlVC addition is 0.05-0.2 parts; if the addition is less than 0.05 parts, the grain refinement is not obvious; if it exceeds 0.2 parts, coarse carbide agglomerates will be formed, resulting in a decrease in coating toughness.

[0024] 4. Mechanism of action of yttrium tri-n-butyl oxide

[0025] Tri-n-butyl yttrium oxide ( During the high-temperature cladding process, thermal decomposition occurs, generating... and butanol ( Butanol evaporates rapidly. It is uniformly dispersed in the molten pool in the form of nanoparticles (particle size 5-20nm). It possesses a high melting point (2410℃) and chemical stability. Its main functions include: ① improving the fluidity of the molten pool, reducing the surface tension of the molten pool, and reducing spatter and porosity during the cladding process; ② adsorbing impurity elements such as O and S in the molten pool, forming... Composite inclusions purify grain boundaries and improve the corrosion resistance of the coating; ③ Inhibit excessive growth of the BCC phase in the eutectic structure, promote the uniform distribution of the FCC and BCC phases, and improve the overall mechanical properties of the coating. When When the addition amount is 0.01-0.3 parts, The dispersion effect is optimal; if the amount added is less than 0.01 parts, the purification and refining effect is insufficient; if it exceeds 0.3 parts, it will lead to... Particle agglomeration leads to stress concentration and reduces the bonding strength of the coating.

[0026] Technical effect

[0027] Compared with the prior art, the present invention has the following significant advantages:

[0028] 1. Stable eutectic structure and excellent comprehensive performance: By optimizing the alloy composition and cladding process, the prepared protective layer forms a uniform FCC+BCC lamellar eutectic structure with a Vickers hardness of 610-650HV, which is 25%-55% higher than that of traditional infrared laser cladding nickel-copper alloy (420-530HV); after 720h neutral salt spray test, there are no corrosion spots on the surface and the corrosion rate is less than 0.001mm / a, which is far superior to thermal sprayed aluminum-zinc alloy (0.01-0.03mm / a); the bonding strength reaches 387-415MPa, which is 6-8 times that of thermal sprayed coating, meeting the stringent performance requirements of offshore wind power equipment for protective materials.

[0029] 2. Significant advantages of blue laser cladding: Using 450-480nm blue laser as the heat source solves the problem of high reflection of infrared laser by high copper alloys, and the laser energy utilization rate is increased to 40-50%, and the stability of the molten pool is significantly improved; the density of the cladding layer reaches more than 99.5%, with no obvious defects such as pores and cracks, and the coating thickness uniformity error is less than ±5%.

[0030] 3. Synergistic Effect of Trace Alloys: The synergistic effect of vanadium aluminum carbide and yttrium tri-n-butyl oxide achieves multiple effects such as grain refinement, grain boundary purification, and microstructure homogenization. Compared with the control group without trace alloys, the coating hardness increases by 15-20%, corrosion resistance increases by 30-40%, and bonding strength increases by 10-15%, demonstrating an excellent synergistic enhancement effect.

[0031] 4. Strong process adaptability and broad application prospects: The preparation process of this invention can be applied to offshore wind power substrates of different specifications (Q345 steel, 316L stainless steel, etc.). The cladding process can achieve automated continuous production with a production efficiency of 0.5-1m² / h. The coating thickness can be adjusted within the range of 1.5-3.0mm according to requirements. It can be used not only for surface protection of new units, but also for remanufacturing corroded parts of old units, with significant economic and social benefits. Attached Figure Description

[0032] Figure 1 This is an optical microscope image of the cross-section of the protective layer in Example 2. Detailed Implementation

[0033] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features and effects of the present invention, in conjunction with detailed embodiments and comparative examples, is provided.

[0034] I. Experimental Materials and Equipment

[0035] Metal powders: Ni powder (99.9% purity, particle size 50-150μm), Cu powder (99.9% purity, particle size 50-150μm), Cr powder (99.8% purity, particle size 50-150μm), Mo powder (99.8% purity, particle size 50-150μm), Al powder (99.7% purity, particle size 50-150μm), Ti powder (99.7% purity, particle size 50-150μm), vanadium aluminum carbide powder (CAS: 12179-42-9, 99.5% purity, particle size 10-30μm), tri-n-butyl yttrium oxide powder (99.5% purity, particle size 10-30μm).

[0036] Base material: Q345 steel base material (size 100mm×100mm×10mm, chemical composition: C≤0.20%, Si≤0.55%, Mn≤1.60%, P≤0.035%, S≤0.035%, Fe balance); 316L stainless steel base material (size 100mm×100mm×10mm, chemical composition: C≤0.03%, Si≤1.00%, Mn≤2.00%, P≤0.045%, S≤0.030%, Cr 16.00-18.00%, Ni10.00-14.00%, Mo 2.00-3.00%, Fe balance).

[0037] Equipment: Dual planetary mixer (model: XQM-2L), vacuum drying oven (model: DZF-6050), semiconductor blue laser cladding equipment (model: BL-3000, laser wavelength 450-480nm), ultrasonic cleaner (model: KQ-600VDB), Vickers hardness tester (model: HV-1000), salt spray test chamber (model: YWX / Q-750), universal tensile testing machine (model: WDW-300), scanning electron microscope (model: SEM-SU8010).

[0038] II. Performance Testing Methods

[0039] Hardness testing: Referring to GB / T4340.1-2024 "Metallic materials Vickers hardness test - Part 1: Test method", 10 different test points were selected on the surface of the protective layer using a Vickers hardness tester. The loading force was 500g and the loading time was 15s. The average value was taken as the final Vickers hardness value.

[0040] Corrosion resistance testing: Following GB / T10125-2021 "Artificial Atmosphere Corrosion Test - Salt Spray Test", the neutral salt spray test (NSS) was used to evaluate corrosion resistance. The test temperature was 35℃, with continuous spraying of 5% NaCl solution (pH 6.5-7.2) at a spray pressure of 0.07-0.1 MPa and a salt spray deposition rate of 1-2 mL / (h·80cm²). The corrosion condition of the protective layer surface was observed at 240h, 480h, and 720h, and the number and area of ​​corrosion spots were recorded.

[0041] Bond strength testing: Referring to GB / T8642-2002 "Determination of Bond Strength of Thermal Spray Coatings", a tensile shear test was used to test the bond strength between the protective layer and the substrate. The sample size was 100mm×25mm×10mm (substrate size) + 2mm (coating thickness). The coated surfaces of two samples were bonded together with epoxy resin adhesive, cured at 80℃ for 2 hours, and then a tensile test was performed on a universal tensile testing machine at a tensile speed of 2mm / min. The maximum load at fracture was recorded. The bond strength σ = F / S (F is the maximum load, and S is the bonded area).

[0042] Microstructure analysis: Samples were cut from the protective layer using wire cutting. After grinding and polishing, the samples were etched with aqua regia (nitric acid: hydrochloric acid = 1:3) for 10-15 seconds. The microstructure morphology of the coating was observed using scanning electron microscopy (SEM) to analyze the morphology and size of the eutectic structure.

[0043] Example 1

[0044] S1 metal powder pretreatment: 25 parts Ni powder, 20 parts Cu powder, 15 parts Cr powder, 8 parts Mo powder, 5 parts Al powder, 3 parts Ti powder, 0.05 parts vanadium aluminum carbide powder (CAS: 12179-42-9), and 0.01 parts tri-n-butyl yttrium oxide powder were placed in a double planetary mixer and stirred at 200 r / min for 1 h. Then, the mixture was placed in a vacuum drying oven and dried at 80℃ for 2 h to obtain the mixed powder.

[0045] S2 Substrate Pretreatment: Select Q345 steel substrate, and alternately polish it with 120#, 240#, 400#, 800# and 1200# sandpaper in dry and wet mode. Then place it in an ultrasonic cleaning tank and use industrial alcohol to ultrasonically remove oil at a frequency of 40kHz for 30 minutes. Next, soak it in 5% dilute hydrochloric acid solution at room temperature to remove rust for 10 minutes. Finally, rinse it three times with anhydrous ethanol and blow it dry with compressed air.

[0046] S3 Blue Laser Cladding Additive Manufacturing: Utilizing a BL-3000 blue laser cladding system with coaxial powder feeding (2mm diameter powder feeding tube) and 99.99% argon gas. Process parameters: laser wavelength 450nm, laser power 2000W, scanning speed 3mm / s, spot diameter 0.8mm, powder feed rate 20g / min, protective gas 99.99% argon, flow rate 15L / min, substrate preheating temperature 100℃, cladding layer thickness 1.5mm.

[0047] S4 post-processing: Naturally cool to room temperature (cooling rate 5℃ / min), rough grinding with 80# diamond grinding wheel, fine grinding with 200# diamond grinding head, polishing with 1μm diamond polishing paste, surface roughness Ra=1.5μm.

[0048] Example 2

[0049] S1 metal powder pretreatment: 30 parts Ni powder, 25 parts Cu powder, 18 parts Cr powder, 10 parts Mo powder, 6.5 parts Al powder, 4.5 parts Ti powder, 0.1 parts vanadium aluminum carbide powder (CAS: 12179-42-9), and 0.1 parts tri-n-butyl yttrium oxide powder were placed in a double planetary mixer and stirred at 250 r / min for 1.5 h. Then, the mixture was placed in a vacuum drying oven and dried at 100℃ for 3 h to obtain a mixed powder.

[0050] S2 Substrate Pretreatment: Select 316L stainless steel substrate, and alternately polish it with 120#, 240#, 400#, 800# and 1200# sandpaper in dry and wet mode. Then place it in an ultrasonic cleaning tank and use industrial alcohol to ultrasonically remove oil at a frequency of 50kHz for 45 minutes. Next, soak it in 8% dilute hydrochloric acid solution at room temperature to remove rust for 15 minutes. Finally, rinse it 4 times with anhydrous ethanol and blow it dry with compressed air.

[0051] S3 Blue Laser Cladding Additive Manufacturing: Utilizing a BL-3000 blue laser cladding system with coaxial powder feeding (3mm diameter powder feeding tube) and 99.99% argon as the powder feeding gas. Process parameters: laser wavelength 465nm, laser power 2500W, scanning speed 4mm / s, spot diameter 1.0mm, powder feed rate 30g / min, protective gas 99.99% argon, flow rate 20L / min, substrate preheating temperature 150℃, cladding layer thickness 1.75mm.

[0052] S4 post-processing: Naturally cool to room temperature (cooling rate 8℃ / min), rough grinding with 100# diamond grinding wheel, fine grinding with 300# diamond grinding head, polishing with 2μm diamond polishing paste, surface roughness Ra=1.2μm.

[0053] Example 3

[0054] S1 metal powder pretreatment: 32 parts Ni powder, 28 parts Cu powder, 19 parts Cr powder, 11 parts Mo powder, 7 parts Al powder, 5 parts Ti powder, 0.15 parts vanadium aluminum carbide powder (CAS: 12179-42-9), and 0.2 parts tri-n-butyl yttrium oxide powder were placed in a double planetary mixer and stirred at 280 r / min for 1.8 h. Then, the mixture was placed in a vacuum drying oven and dried at 110 °C for 3.5 h to obtain the mixed powder.

[0055] S2 Substrate Pretreatment: Select Q345 steel substrate, and alternately polish it with 120#, 240#, 400#, 800# and 1200# sandpaper in dry and wet mode. Then place it in an ultrasonic cleaning tank and ultrasonically degrease it with industrial alcohol at a frequency of 55kHz for 50 minutes. Next, soak it in 9% dilute hydrochloric acid solution at room temperature for 18 minutes to remove rust. Finally, rinse it 5 times with anhydrous ethanol and blow it dry with compressed air.

[0056] S3 Blue Laser Cladding Additive Manufacturing: Utilizing a BL-3000 blue laser cladding system with coaxial powder feeding (3.5mm diameter powder feeding tube) and 99.99% argon as the powder feeding gas. Process parameters: laser wavelength 475nm, laser power 2800W, scanning speed 4.5mm / s, spot diameter 1.1mm, powder feed rate 35g / min, protective gas 99.99% argon, flow rate 22L / min, substrate preheating temperature 180℃, cladding layer thickness 2.0mm.

[0057] S4 post-processing: Natural cooling to room temperature (cooling rate 9℃ / min), rough grinding with a 120# diamond grinding wheel, fine grinding with a 500# diamond grinding head, polishing with 3μm diamond polishing paste, surface roughness Ra=1.0μm.

[0058] Example 4

[0059] S1 metal powder pretreatment: 35 parts Ni powder, 30 parts Cu powder, 20 parts Cr powder, 12 parts Mo powder, 8 parts Al powder, 6 parts Ti powder, 0.2 parts vanadium aluminum carbide powder (CAS: 12179-42-9), and 0.3 parts tri-n-butyl yttrium oxide powder were placed in a double planetary mixer and stirred at 300 r / min for 2 h. Then, the mixture was placed in a vacuum drying oven and dried at 120℃ for 4 h to obtain the mixed powder.

[0060] S2 Substrate Pretreatment: Select 316L stainless steel substrate, and alternately polish it with 120#, 240#, 400#, 800# and 1200# sandpaper in dry and wet mode. Then place it in an ultrasonic cleaning tank and ultrasonically degrease it with industrial alcohol at a frequency of 60kHz for 60 minutes. Next, soak it in 10% dilute hydrochloric acid solution at room temperature for 20 minutes to remove rust. Finally, rinse it 5 times with anhydrous ethanol and blow it dry with compressed air.

[0061] S3 Blue Laser Cladding Additive Manufacturing: Utilizing a BL-3000 blue laser cladding system with coaxial powder feeding (4mm diameter powder feeding tube) and 99.99% argon gas. Process parameters: laser wavelength 480nm, laser power 3000W, scanning speed 5mm / s, spot diameter 1.2mm, powder feed rate 40g / min, protective gas 99.99% argon, flow rate 25L / min, substrate preheating temperature 200℃, cladding layer thickness 2.5mm.

[0062] S4 post-processing: Naturally cool to room temperature (cooling rate 10℃ / min), rough grinding with 120# diamond grinding wheel, fine grinding with 500# diamond grinding head, polishing with 3μm diamond polishing paste, surface roughness Ra=0.8μm.

[0063] Comparative Example 1 (without added trace amounts of alloy powder)

[0064] Except for the absence of vanadium aluminum carbide and tri-n-butyl yttrium oxide powder in S1, the remaining steps are exactly the same as in Example 2.

[0065] Comparative Example 2 (using infrared laser cladding)

[0066] Except for the use of a 1064nm infrared laser cladding device (power 2500W) in S3, the other steps are exactly the same as in Example 2.

[0067] Comparative Example 3 (Vanadium Aluminum Carbide Addition Exceeds Standard)

[0068] Except for the addition of 0.3 parts of vanadium aluminum carbide powder in S1, the other steps are exactly the same as in Example 2.

[0069] Comparative Example 4 (insufficient addition of tri-n-butyl yttrium oxide)

[0070] Except for the addition of 0.005 parts of tri-n-butyl yttrium oxide powder in S1, the other steps are exactly the same as in Example 2.

[0071] Table 1: Hardness Test Results

[0072]

[0073] Analysis: The Vickers hardness of Examples 1-4 was significantly higher than that of the comparative examples, with Example 4 exhibiting the highest hardness (650 HV). Comparative Example 1, lacking trace alloying, had a 14.5% lower hardness compared to Example 2. Comparative Example 2, employing infrared laser cladding, had low energy utilization, resulting in coarse microstructure and a hardness of only 420 HV. Comparative Example 3, with excessive vanadium aluminum carbide addition, exhibited carbide agglomeration, limiting the hardness improvement. Comparative Example 4, with insufficient addition of tri-n-butyl yttrium oxide, showed poor purification and refinement effects, resulting in a lower hardness than Example 2.

[0074] Table 2: Corrosion Resistance Test Results

[0075]

[0076] Analysis: Examples 1-4 showed no corrosion pits and extremely low corrosion rates after 720 hours of salt spray testing, demonstrating excellent corrosion resistance. Comparative Example 1, lacking the purifying effect of trace alloys, developed pitting corrosion after 480 hours; Comparative Example 2, with its pore-defect infrared laser cladding coating, developed pitting corrosion after 240 hours and extensive rusting after 720 hours; Comparative Example 3, with excessive vanadium aluminum carbide leading to grain boundary stress concentration, showed minor pitting corrosion after 720 hours; Comparative Example 4, with insufficient yttrium tributyl oxide, had poor purifying effect and a large number of pitting corrosions.

[0077] Table 3: Results of combined strength tests

[0078]

[0079] The bonding strength of Examples 1-4 all exceeded 380 MPa, and the fracture location was in the adhesive layer, indicating that the bonding strength between the coating and the substrate was higher than that of the adhesive itself. Comparative Example 1, without the addition of trace alloys, had weak interfacial bonding and fractured at the coating-substrate interface; Comparative Example 2, with its infrared laser cladding coating having internal defects, fractured within the coating; Comparative Example 3, with excessive vanadium aluminum carbide leading to increased coating brittleness, fractured within the coating; Comparative Example 4, with insufficient yttrium tributyl oxide, had poor interfacial cleansing effect and fractured at the coating-substrate interface. Figure 1 In Example 2, the cross-sectional optical microscope image of the protective layer shows that the coating is dense without cracks or obvious pores. ImageJ software analysis shows that its density is 99.7%, the coating is tightly bonded to the substrate, and can form a metallurgical bond. The coating thickness is about 1.75 mm.

[0080] This invention discloses a method for preparing a blue laser cladding additive nickel-copper-based eutectic high-entropy alloy marine wind power protective material. By adding 0.05-0.2 parts of vanadium aluminum carbide powder (CAS: 12179-42-9) and 0.01-0.3 parts of tri-n-butyl yttrium oxide powder, combined with 450-480nm blue laser cladding technology, the prepared protective layer exhibits a uniform and stable FCC+BCC lamellar eutectic structure, a Vickers hardness of 610-650HV, a bonding strength of 387-415MPa, and no corrosion pits after 720h neutral salt spray testing, with a corrosion rate below 0.001mm / a. This method not only solves the technical bottlenecks of high energy reflectivity and numerous coating defects in traditional infrared laser cladding of high-copper alloys, but also achieves multiple effects such as grain refinement, grain boundary purification, and microstructure homogenization through the synergistic effect of vanadium aluminum carbide and tri-n-butyl yttrium oxide, significantly improving the overall performance of the protective material. The protective material of this invention can meet the long-term protection requirements of offshore wind power equipment for more than 15 years, reduce the unit operation and maintenance costs, and at the same time, it has strong process adaptability and can be extended to the surface protection field of various marine engineering equipment.

[0081] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for preparing a blue laser cladding additive nickel-copper-based eutectic high-entropy alloy offshore wind power protection material, characterized in that, The operation steps are: S1 metal powder pretreatment: 25-35 parts by mass of Ni powder, 20-30 parts by mass of Cu powder, 15-20 parts by mass of Cr powder, 8-12 parts by mass of Mo powder, 5-8 parts by mass of Al powder, 3-6 parts by mass of Ti powder, 0.05-0.2 parts by mass of vanadium aluminum carbide powder, 0.01-0.3 parts by mass of tri-n-butoxy yttrium powder are mixed after stirring and then dried in a vacuum drying oven to obtain a mixed powder; S2 substrate pretreatment: the substrate for offshore wind power is polished, degreased and derusted until the metal luster on the surface of the substrate is exposed, then washed with anhydrous ethanol and dried; S3 blue laser cladding: the pretreated mixed powder is sent into the cladding area by using a blue laser cladding equipment, and a nickel-copper eutectic high-entropy alloy protective layer is formed on the surface of the substrate by blue laser cladding treatment; S4 post-treatment: the surface of the protective layer is polished after cladding to obtain an offshore wind power protection material.

2. The production method according to claim 1, characterized by, The vanadium aluminum carbide powder in S1 has a CAS number of 12179-42-9, and the addition amount is 0.08-0.15 parts by mass.

3. The production method according to claim 1, characterized by, The tri-n-butoxy yttrium powder in S1 has an addition amount of 0.05-0.2 parts by mass.

4. The preparation method according to claim 1, characterized in that, The particle size of the metal powder in S1 is 50-150 μm, the stirring and mixing are performed by using a double-planetary mixer, the stirring speed is 200-300 r / min, and the stirring time is 1-2 h.

5. The preparation method according to claim 1, characterized in that, The drying temperature of the vacuum drying oven in S1 is 90-110°C, and the drying time is 2.5-3.5 h.

6. The method of claim 1, wherein, The substrate for offshore wind power in S2 is Q345 steel or 316L stainless steel, the degreasing method in the substrate pretreatment is ultrasonic degreasing, the frequency of ultrasonic degreasing is 40-60 kHz, and the ultrasonic degreasing time is 30-60 min; the rust removal treatment adopts 5-10% dilute hydrochloric acid solution for immersion at room temperature for 10-20 min.

7. The preparation method according to claim 1, characterized in that, The process parameters of blue laser cladding in S3 are: laser wavelength is 460-470 nm, laser power is 2200-2800 W, scanning speed is 3.5-4.5 mm / s, spot diameter is 0.9-1.1 mm, and powder feeding amount is 25-35 g / min.

8. The method of claim 1, wherein, The protective gas for blue laser cladding in S3 is argon with a purity of 99.99%, the protective gas flow is 18-22 L / min, the powder feeding gas is argon with a purity of 99.99%, and the powder feeding tube diameter is 2-4 mm.

9. The method of claim 1, wherein, The substrate preheating temperature during blue laser cladding in S3 is 120-180°C, the thickness of the nickel-copper eutectic high-entropy alloy protective layer after cladding is 1.5-2.5 mm, and the density is ≥99.5%.

10. The method of claim 1, wherein, The post-treatment in S4 includes rough polishing, fine polishing and polishing, the rough polishing adopts 80#-120# diamond grinding wheel, the fine polishing adopts 200#-500# diamond grinding head, the polishing adopts 1-3 μm diamond polishing paste, and the surface roughness of the final protective layer is Ra≤1.6 μm.

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