High wear and corrosion resistant functional alloy coating for aerospace equipment and method of making same

Abstract

The application discloses an aviation equipment high-wear-resistance and corrosion-resistance functional alloy plating layer and a preparation method thereof. The preparation method comprises the following steps: a base material pretreatment stage of carrying out oil removal and acid activation treatment on a metal workpiece; a nano composite plating solution preparation stage of taking nickel sulfate and sodium tungstate as main salts, adding silicon carbide nanoparticles, graphene oxide and mixed surfactants to obtain a plating solution; an ultrasonic auxiliary bidirectional pulse electrodeposition stage of starting ultrasonic waves and inputting bidirectional pulse current containing a forward polarization codeposition stage and a reverse anode polarization stage to carry out electrodeposition; and a post-plating vacuum heat treatment stage of carrying out in-situ heat treatment on the workpiece. The application realizes an environment-friendly process without hexavalent chromium, suppresses nano phase agglomeration and eliminates hydrogen evolution microcracks, and prepares a nickel tungsten-based nano composite alloy plating layer with high bonding strength, corrosion resistance and wear resistance.

Description

Technical Field

[0001] This invention relates to the field of surface treatment and electroplating technology, and is classified under International Patent Classification C25D. Specifically, it refers to a high wear-resistant and corrosion-resistant functionalized alloy coating for aviation equipment and its preparation method, applied to key components of aviation equipment. In particular, it relates to an electrodeposition and co-deposition technology without hexavalent chromium. Background Technology

[0002] Key components of aerospace engines, precision medical devices, and high-end new energy vehicle parts must withstand long-term high temperatures, high pressures, strong corrosion, and high-frequency friction on their surface materials during service. Traditional surface protection treatments rely on hexavalent chromium electroplating. However, hexavalent chromium electroplating releases toxic and carcinogenic chromic acid fumes, which are subject to environmental regulations.

[0003] Existing environmentally friendly alternatives include trivalent chromium electroplating, single-electrochemical nickel-phosphorus alloy plating, or nickel-tungsten-based alloy electroplating. While single-electrochemical nickel-tungsten alloy plating exhibits good thermodynamic stability at high temperatures, it suffers from high internal stress and is prone to penetrating microcracks. These microcracks can become penetration channels for localized corrosion in corrosive media, leading to substrate failure. Meanwhile, to improve the wear resistance of single-metal alloy systems, conventional composite modification methods involve directly adding hard nanoparticles to the plating bath for composite electroplating. However, due to the high specific surface energy of nanofillers, they are prone to agglomeration in high-ionic-strength plating baths. Agglomerated nanoparticles deposited on the workpiece surface become stress concentration points, leading to reduced coating bonding strength, increased density defects, and increased porosity, failing to meet the requirements of aerospace equipment for low wear rates and high bonding strength. Summary of the Invention

[0004] This invention solves the technical problems of existing environmentally friendly single alloy coatings having microcracks, insufficient wear and corrosion resistance, and the tendency of nanofillers to agglomerate in the electroplating solution, resulting in coating density defects.

[0005] This invention provides a high wear-resistant and corrosion-resistant functionalized alloy coating for aerospace equipment and its preparation method, comprising the following steps: Step 1, after the metal workpiece is degreased by organic solvent and alkaline electrolytic degreasing, the metal workpiece is acidically activated using a mixed solution of sulfuric acid and hydrofluoric acid; Step 2, a base solution is prepared using nickel sulfate and sodium tungstate as the main salts and sodium citrate as the complexing agent, silicon carbide nanoparticles and graphene oxide nanosheets are added to the base solution, and a mixed surfactant composed of hexadecyltrimethylammonium bromide and sodium dodecyl sulfate is added to obtain a nanocomposite plating solution; Step 3, the metal workpiece after Step 1 is placed as the cathode in the nanocomposite plating solution for ultrasonic-assisted bidirectional pulse electrodeposition, the ultrasonic waves are continuously turned on and bidirectional pulse current waveforms are input to both ends of the electrodes, the bidirectional pulse current waveforms include a forward polarization co-deposition pulse stage and a reverse anodic polarization pulse stage; Step 4, the metal workpiece with the composite coating is placed in a vacuum heating furnace for heat treatment.

[0006] Specifically, in step one, the solution components used for alkaline electrolytic degreasing include sodium hydroxide, sodium carbonate, and trisodium phosphate; in the mixed solution of sulfuric acid and hydrofluoric acid used for acidic activation treatment, the volume ratio of sulfuric acid to hydrofluoric acid is configured as a first preset ratio, and the ambient temperature for acidic activation treatment is configured as room temperature.

[0007] Specifically, the mass concentration of the solution components used for alkaline electrolytic degreasing is configured as follows: sodium hydroxide 30 g / L to 50 g / L, sodium carbonate 20 g / L to 40 g / L, and trisodium phosphate 20 g / L to 40 g / L; the polarization method for alkaline electrolytic degreasing is configured as follows: using the metal workpiece as the cathode for a first preset time, and then using the metal workpiece as the anode for a second preset time; the first preset ratio is configured as 2:1, and the operation time for acid activation treatment is configured as 30 seconds to 60 seconds; between alkaline electrolytic degreasing and acid activation treatment, and after acid activation treatment, the metal workpiece is rinsed with deionized water.

[0008] Specifically, in step two, the mass concentration of nickel sulfate in the nanocomposite plating solution is configured to be 35 g / L to 50 g / L, the mass concentration of sodium tungstate is configured to be 50 g / L to 70 g / L, and the mass concentration of sodium citrate is configured to be 70 g / L to 90 g / L; the pH value of the nanocomposite plating solution is adjusted to between 6.5 and 7.0 by using sodium hydroxide or sulfuric acid.

[0009] Specifically, the average particle size of silicon carbide nanoparticles is configured to be 50 nm to 100 nm, and their addition concentration in the nanocomposite plating solution is configured to be 5 g / L to 12 g / L; the thickness of graphene oxide nanosheets is configured to be 1 nm to 3 nm, the sheet diameter is configured to be 1 μm to 3 μm, and their addition concentration in the nanocomposite plating solution is configured to be 0.5 g / L to 1.5 g / L; in the mixed surfactant, the addition concentration of hexadecyltrimethylammonium bromide is configured to be 0.2 g / L to 0.5 g / L, and the addition concentration of sodium dodecyl sulfate is configured to be 0.1 g / L to 0.3 g / L; when preparing the nanocomposite plating solution, the silicon carbide nanoparticles and graphene oxide nanosheets are pre-dispersed in deionized water containing the mixed surfactant, and pre-dispersed for a first preset time period by ultrasonic dispersion equipment.

[0010] Specifically, in step three, the amplitude of the forward current density in the forward polarization co-deposition pulse stage is greater than the amplitude of the reverse current density in the reverse anodic polarization pulse stage; the pulse conduction time in the forward polarization co-deposition pulse stage is greater than the pulse conduction time in the reverse anodic polarization pulse stage; and the operating frequency of the ultrasonic wave is configured to a first preset frequency value.

[0011] Specifically, the forward current density during the forward polarization co-deposition pulse phase is configured as 5 A / dm². 2 Up to 12A / dm 2 The forward pulse duty cycle is configured to be 60% to 70%; the reverse current density during the reverse anodic polarization pulse phase is configured to be 1.5 A / dm². 2 Up to 3A / dm 2 The reverse pulse duty cycle is configured to be 20% to 30%; the first preset frequency value is configured to be 40kHz; and the ultrasonic power density is configured to be 0.5W / cm². 2 Up to 0.8W / cm 2 The ultrasonic transmitting probe is positioned parallel between the cathode and the power supply board, which serves as the anode; the electrodeposition time of the metal workpiece in the nanocomposite plating solution is configured to be 45 to 90 minutes.

[0012] Specifically, in step four, the specific operating temperature of the heat treatment is configured to be between 350°C and 400°C; the vacuum degree of the vacuum heating furnace is configured to be below the first preset vacuum pressure value; the constant temperature holding time of the heat treatment is configured to be between 2 hours and 4 hours; after the heat treatment is completed, the metal workpiece is cooled to room temperature with the vacuum heating furnace.

[0013] The present invention also provides a high wear-resistant and corrosion-resistant functionalized alloy coating for aerospace equipment, which is prepared by the above-mentioned preparation method; the alloy coating includes a nickel-tungsten alloy matrix, silicon carbide nanoparticles dispersed in the nickel-tungsten alloy matrix, and graphene nanosheets generated by in-situ reduction of graphene oxide.

[0014] Specifically, silicon carbide nanoparticles and graphene nanosheets are embedded at the grain boundaries of the nickel-tungsten alloy matrix; the graphene nanosheets form an interlayer slip film in the alloy coating structure and together with the silicon carbide nanoparticles constitute a reinforcing framework.

[0015] In addition, the aforementioned alloy coating can be applied to the surface of aerospace equipment substrates to form aerospace equipment components with anti-friction and salt spray resistance properties.

[0016] This invention modifies the surface charge of biphase nanofillers by combining compound cationic and anionic surfactants, and uses a controlled hydrogen removal process of ultrasonic-assisted cavitation dispersion and bidirectional pulsed electrodeposition to suppress nanomaterial aggregation and eliminate hydrogen evolution microcrack defects during electrodeposition. The resulting composite coating possesses a synergistic effect of rigid framework support and flexible self-lubrication, improving surface bonding strength while reducing wear rate and extending corrosion resistance time. This method abandons the hexavalent chromium system and has advantages such as strong process controllability and suitability for industrial application. Attached Figure Description

[0017] Figure 1 This is a flowchart of the preparation method provided in the embodiments of the present invention.

[0018] Figure 2 This is a logical structure block diagram of the ultrasound-assisted bidirectional pulsed electrodeposition device provided in an embodiment of the present invention.

[0019] Figure 3 This is a planar schematic diagram of the bidirectional pulse current waveform provided in an embodiment of the present invention.

[0020] Figure 4 This is a schematic diagram of the microscopic cross-sectional structure of the high wear-resistant and corrosion-resistant functionalized alloy coating provided in the embodiments of the present invention.

[0021] Figure 5 This is a partial cross-sectional structural diagram of an aviation equipment component provided in an embodiment of the present invention.

[0022] Explanation of reference numerals in the attached figures

[0023] In the diagram: 201-Cathode, 202-Anode plate, 203-Ultrasonic wave generator probe, 204-External bidirectional pulse power supply, 205-Electroplating tank, 206-Temperature control heating component, 207-Circulating filtration system, 401-Nickel-tungsten alloy matrix, 402-Silicon carbide nanoparticles, 403-Graphene nanosheets, 501-Aerospace equipment substrate, 502-High wear-resistant and corrosion-resistant functionalized alloy coating for aerospace equipment, V T1 - Positive polarization co-deposition pulse stage, V T2 - Reverse anodic polarization pulse phase. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0025] like Figure 1 As shown, this invention provides a high-wear-resistant and corrosion-resistant functionalized alloy coating for aerospace equipment and its preparation method. This method primarily targets the deposition of a protective layer on the surface of aerospace-grade alloy steel or titanium alloys, replacing the highly polluting hexavalent chromium electroplating process. The preparation method specifically includes the following steps.

[0026] Step S101, Substrate Pretreatment Stage. After the metal workpiece undergoes organic solvent degreasing and alkaline electrolytic degreasing sequentially, it is then acidically activated using a mixed solution of sulfuric acid and hydrofluoric acid. The substrate is typically 40Cr alloy steel, and the contact surfaces are polished to a roughness Ra of less than 0.2 micrometers before use. Specifically, the mass concentration of the solution components used for alkaline electrolytic degreasing is configured as follows: sodium hydroxide 30 g / L to 50 g / L, sodium carbonate 20 g / L to 40 g / L, and trisodium phosphate 20 g / L to 40 g / L. The polarization method for this alkaline electrolytic degreasing is configured to use the metal workpiece as the cathode for a first preset polarization time, followed by the metal workpiece as the anode for a second preset polarization time. By alternately changing the electrode polarity, the mechanical tearing action of the gas bubbles generated from the electrolysis of water is used to peel off the oil stains from the substrate surface. After alkaline electrolytic degreasing, acidic activation treatment is performed. The activation solution is a mixed aqueous solution of sulfuric acid and hydrofluoric acid. To ensure the exposure of surface metal atoms and avoid excessive corrosion, the volume ratio of sulfuric acid to hydrofluoric acid is configured as a first preset ratio of 2:1. The ambient temperature for the acid activation treatment is set to room temperature, and the operation time is set to 30 to 60 seconds. Furthermore, between the alkaline electrolytic degreasing and the acid activation treatment, and after the acid activation treatment, the metal workpiece is repeatedly rinsed with deionized water until the water film on the workpiece surface is continuous and the eluent is neutral.

[0027] Step S102, Nanocomposite plating solution preparation stage. A base solution is prepared using nickel sulfate and sodium tungstate as the main salts and sodium citrate as the complexing agent. In this embodiment, the mass concentration of nickel sulfate in the nanocomposite plating solution is configured to be 35 g / L to 50 g / L, the mass concentration of sodium tungstate is configured to be 50 g / L to 70 g / L, and the mass concentration of sodium citrate is configured to be 70 g / L to 90 g / L. The strong complexing ability of sodium citrate is utilized to achieve the induced co-deposition of nickel ions and tungstate ions. Simultaneously, to stabilize the solution system, boric acid at a concentration of 30 g / L to 40 g / L is added as a buffer. Subsequently, silicon carbide nanoparticles and graphene oxide nanosheets are added to the base solution as reinforcing phases, and a mixed surfactant composed of hexadecyltrimethylammonium bromide and sodium dodecyl sulfate is added to obtain a stable nanocomposite plating solution. Specifically, the average particle size of silicon carbide nanoparticles is configured to be 50 nm to 100 nm, and their addition concentration in the nanocomposite plating solution is configured to be 5 g / L to 12 g / L; the thickness of graphene oxide nanosheets is configured to be 1 nm to 3 nm, and the sheet diameter is configured to be 1 μm to 3 μm, and their addition concentration in the plating solution is configured to be 0.5 g / L to 1.5 g / L. To prevent the high specific surface energy nanoparticles from agglomerating and clustering in the high ion concentration electroplating solution, the addition concentration of hexadecyltrimethylammonium bromide in the mixed surfactant is configured to be 0.2 g / L to 0.5 g / L, and the addition concentration of sodium dodecyl sulfate is configured to be 0.1 g / L to 0.3 g / L. In the specific preparation operation, the silicon carbide nanoparticles and graphene oxide nanosheets are pre-dispersed in deionized water containing the mixed surfactant, and pre-dispersed for a first preset time period using an ultrasonic dispersion device. After the pre-dispersion is completed, they are slowly pumped into the base solution. Finally, the pH of the nanocomposite plating solution is precisely adjusted to between 6.5 and 7.0 by adding appropriate amounts of sodium hydroxide or dilute sulfuric acid. The anionic and cationic mixed surfactant system used in this step utilizes the electrostatic steric hindrance effect to stabilize the suspension, ensuring that the nanocomposite material remains homogeneously dispersed in the liquid phase.

[0028] Step S103, Ultrasonic-assisted bidirectional pulsed electrodeposition stage. The pre-treated metal workpiece is used as the cathode and placed in a nanocomposite plating solution for electrodeposition. Figure 2As shown, the electrodeposition operation in this embodiment relies on a specific hardware base. The device mainly includes an electroplating tank 205, which contains a nanocomposite plating solution. Metal workpieces are mounted on cathode holders and immersed in the liquid as cathodes 201; correspondingly, the anode plate 202 is made of pure nickel. The system is also equipped with an external bidirectional pulse power supply 204 with an independent control program, whose two poles are electrically connected to the cathode 201 and the anode plate 202, respectively. Ultrasonic wave generators 203 are arrayed at the bottom or sidewall of the electroplating tank 205. Preferably, the ultrasonic wave generators 203 are arranged parallel between the cathode 201 and the anode plate 202 to ensure uniform transmission of sound energy. The tank exterior is equipped with a temperature-controlled heating assembly 206 and a circulating filtration system 207 for maintaining electrolyte flow.

[0029] During the electrodeposition process, the temperature-controlled heating component 206 sets the operating temperature between 55°C and 65°C. The ultrasonic wave generator 203 is continuously activated, with its operating frequency configured at 40kHz and the ultrasonic power density configured at 0.5W / cm². 2 Up to 0.8W / cm 2 At the same time, a bidirectional pulse current waveform is input to both ends of the electrodes through an external bidirectional pulse power supply 204. For example... Figure 3 As shown, the bidirectional pulsed current waveform includes a positively polarized co-deposition pulse phase (V... T1 ) and reverse anodic polarization pulse phase (V T2 From the waveform structure, the positive current density amplitude (I) during the positive polarization co-deposition pulse phase is... f The magnitude of the reverse current density during the reverse anodic polarization pulse phase is greater than that of the reverse current density (I). r ); and the pulse conduction time (t) during the positive polarization co-deposition pulse phase. on,f The pulse conduction time (t) is greater than that of the reverse anodic polarization pulse phase. on,r The specific parameter configuration is as follows: forward current density is configured to 5A / dm². 2 Up to 12A / dm 2 The positive pulse on-time is 20ms and the off-time is 10ms. The mathematical calculation process for the positive pulse duty cycle is shown in the following formula:

[0030]

[0031] Among them, D f t represents the duty cycle of the positive pulse. on,f t represents the on-time of the positive pulse. off,f This indicates the forward pulse turn-off time. In this embodiment, the forward pulse duty cycle is configured to be 60% to 70%. On the other hand, the reverse current density is configured to be 1.5 A / dm². 2 Up to 3A / dm2 The reverse pulse on-time is 2ms and the off-time is 5ms, corresponding to a reverse pulse duty cycle configured to be 20% to 30%. The total electrodeposition time of the metal workpiece in this composite plating solution is configured to be 45 minutes to 90 minutes depending on the required thickness.

[0032] Based on the aforementioned multiphysics configuration, this invention establishes a deeply coupled hydrogen control and toughening / anti-agglomeration mechanism. During the forward pulse phase, the cathode potential in the solution rapidly polarizes. Silicon carbide and graphene oxide particles, coated with hexadecyltrimethylammonium bromide and carrying a positive charge, arrive at the substrate surface simultaneously with complexed nickel-tungsten ions under a strong electric field, achieving physical encapsulation-based co-deposition. Accompanying the metal reduction, a hydrogen evolution side reaction occurs, and the attached hydrogen bubbles hinder the continuous growth of the crystal lattice, inducing porosity and through-cracks. By introducing a brief reverse anodic polarization pulse phase, the system dissolves the sharp dendrites formed during forward growth, weakening the adhesion of hydrogen bubbles to the metal surface. Continuously applied ultrasound induces a strong cavitation effect in the liquid phase. The high-speed microjets generated by the instantaneous rupture of microbubbles clear away residual hydrogen bubbles loosened by the reverse pulse, achieving forced physical desorption of the gas. This multi-field synergistic mechanism eliminates pinhole defects in the coating.

[0033] Step S104, Post-plating Vacuum Heat Treatment Stage. After electrodeposition, the workpiece is removed, cleaned, and dried. Subsequently, the metal workpiece with the deposited composite coating is placed in a vacuum furnace for heat treatment. In this step, the vacuum level of the vacuum furnace is configured to a first preset vacuum pressure value (…). The specific operating temperature for heat treatment is configured to be 350℃ to 400℃; the constant temperature holding time for heat treatment is configured to be 2 hours to 4 hours. After heat treatment, the cooling rate is controlled to allow the metal workpiece to slowly and naturally cool to room temperature in the vacuum heating furnace. Through this in-situ vacuum thermal reduction process, the graphene oxide embedded in the coating can be thermally reduced in situ to graphene with excellent lubrication properties, while releasing the lattice distortion and residual internal stress accumulated during the electrocrystallization process, thereby improving the adhesion between the coating and the substrate.

[0034] To further verify the technical effects of the preparation method provided in this application, this embodiment also provides a set of comparative verification experiments. The test substrate is uniformly 40Cr alloy steel.

[0035] Example 1: A nickel-tungsten-silicon carbide-graphene composite coating prepared entirely using the method of this invention. The specific formulation and its preferred parameters are: nickel sulfate 38 g / L, sodium tungstate 60 g / L, sodium citrate 75 g / L; silicon carbide 10 g / L, graphene oxide 1 g / L; the mixed surfactants include cetyltrimethylammonium bromide 0.2 g / L and sodium dodecyl sulfate 0.15 g / L; pH 6.8. The ultrasonic frequency is 40 kHz, and the power density is 0.8 W / cm³. 2 Forward current density: 8 A / dm 2 Reverse current density 2A / dm 2 Heat treatment temperature 400℃.

[0036] Comparative Example 1: Traditional DC electroplating hard chrome layer.

[0037] Comparative Example 2: Traditional DC electroplating of nickel-tungsten single alloy.

[0038] Comparative Example 3: The formulation was exactly the same as in Example 1, but the ultrasound and bidirectional pulse power supply were not turned on.

[0039] Each group of samples was tested according to International Organization for Standardization (ISO) standards for microhardness, dry friction wear rate, bond strength, and salt spray rust initiation time. The specific test data are summarized in the table below.

[0040]

[0041] The experimental data show that although the traditional hard chrome layer in Comparative Example 1 has the highest microhardness, it is brittle and prone to microparticle detachment and abrasive wear during friction tests, resulting in a high overall wear rate. In Comparative Example 3, due to the lack of a physical ultrasonic dispersion field and a reverse electrolytic hydrogen removal mechanism, the biphase nanomaterials were directly mixed into the DC electroplating solution, causing the high specific surface energy nanoparticles to physically aggregate within the coating, forming loose defects and pinholes. These defects reduced the bonding strength of Comparative Example 3 to 95 MPa and the salt spray corrosion protection time to 32 hours. In contrast, Example 1, by employing multidimensional physical field depth control, achieved a uniform and densely dispersed distribution of the reinforcing phase, and eliminated residual stress and microcracks in the early stages of crystallization. The wear rate limit of the resulting coating was reduced to... mm 3 / Nm, neutral salt spray shows red rust after more than 120 hours, and the bonding strength reaches 165MPa.

[0042] Based on the above process, another embodiment of the present invention provides a high wear-resistant and corrosion-resistant functionalized alloy coating for aerospace equipment. For example... Figure 4As shown, the highly wear-resistant and corrosion-resistant functionalized alloy coating is prepared by the method described in the foregoing embodiments. In terms of physical microstructure, the alloy coating comprises a nickel-tungsten alloy matrix 401, silicon carbide nanoparticles 402 dispersed in the nickel-tungsten alloy matrix 401, and graphene nanosheets 403 generated by in-situ reduction of graphene oxide.

[0043] Specifically, observing their microscopic arrangement, silicon carbide nanoparticles 402 and graphene nanosheets 403 are embedded at the grain boundaries of the nickel-tungsten alloy matrix 401. Due to the highly extended two-dimensional layered structure of the graphene nanosheets 403, they are uniformly embedded in the alloy coating structure, forming a continuous interlayer slip film during macroscopic mechanical contact. Simultaneously, the extremely hard silicon carbide nanoparticles 402 interweave and nest with this flexible slip film, jointly forming a reinforcing framework within the alloy coating. Through this composite dual-phase reinforcing structure, when the corrosive medium attempts to penetrate the substrate, the two-dimensional graphene layers force the corrosive liquid to continuously change its penetration path, forming a microscopic labyrinth effect within the coating cross-section, thereby extending the corrosion path. During the contact friction process, the rigid silicon carbide particles bear the main positive load and cut the grinding surface, while the graphene undergoes stable interlayer shear slip triggered by frictional heat, generating a transfer lubricating film in situ on the contact friction surface. This achieves a high degree of synergy between rigid skeleton support and flexible self-lubrication, and suppresses the dry wear rate of the coating.

[0044] Based on the above embodiments, the aforementioned high wear-resistant and corrosion-resistant functionalized alloy coating for aerospace equipment can be applied to the surface of the aerospace equipment substrate 501 to form an aerospace equipment component with strong friction resistance and salt spray resistance. For example... Figure 5 As shown, the component mainly comprises an aerospace equipment substrate 501, and the outer surface of the aerospace equipment substrate 501 is physically coated with the aforementioned high wear-resistant and corrosion-resistant functionalized alloy coating 502 for aerospace equipment. The aerospace equipment substrate 501 can be a rotor component of an aero-engine or an actuator cylinder of a precision landing gear. By covering the surface of such load-bearing components with a high-density composite alloy coating, the components can be given resistance to fretting wear and resistance to high-salt spray corrosion from the ocean, extending the service life of the aerospace equipment under operational conditions and reducing maintenance costs.

[0045] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a high wear-resistant and corrosion-resistant functionalized alloy coating for aerospace equipment, characterized in that, Includes the following steps: Step 1: After the metal workpiece is degreased sequentially by organic solvent and alkaline electrolytic degreasing, it is acidically activated using a mixed solution of sulfuric acid and hydrofluoric acid. Step 2: A base solution is prepared using nickel sulfate and sodium tungstate as the main salts and sodium citrate as the complexing agent. Silicon carbide nanoparticles and graphene oxide nanosheets are added to the base solution, along with a mixed surfactant composed of hexadecyltrimethylammonium bromide and sodium dodecyl sulfate, to obtain a nanocomposite plating solution. Step 3: The metal workpiece from Step 1 is placed as the cathode in the nanocomposite plating solution for ultrasonic-assisted bidirectional pulsed electrodeposition. Ultrasonic waves are continuously activated, and bidirectional pulsed current waveforms are input to both electrodes. These bidirectional pulsed current waveforms include a forward polarization co-deposition pulse stage and a reverse anodic polarization pulse stage. Step 4: The metal workpiece with the deposited composite coating is placed in a vacuum furnace for heat treatment.

2. The method for preparing a high wear-resistant and corrosion-resistant functionalized alloy coating for aerospace equipment as described in claim 1, characterized in that, In step one, the solution components used for alkaline electrolytic degreasing include sodium hydroxide, sodium carbonate, and trisodium phosphate; in the mixed solution of sulfuric acid and hydrofluoric acid used for acidic activation treatment, the volume ratio of sulfuric acid to hydrofluoric acid is configured as a first preset ratio, and the ambient temperature for acidic activation treatment is configured as room temperature.

3. The method for preparing a high wear-resistant and corrosion-resistant functionalized alloy coating for aerospace equipment as described in claim 2, characterized in that, The mass concentration of the solution components used for alkaline electrolytic degreasing is configured as follows: sodium hydroxide 30 g / L to 50 g / L, sodium carbonate 20 g / L to 40 g / L, and trisodium phosphate 20 g / L to 40 g / L; the polarization mode of alkaline electrolytic degreasing is configured as follows: the metal workpiece is used as the cathode for a first preset time, and then the metal workpiece is used as the anode for a second preset time; the first preset ratio is configured as 2:1, and the operation time of the acid activation treatment is configured as 30 seconds to 60 seconds; between the alkaline electrolytic degreasing and the acid activation treatment, and after the acid activation treatment, the metal workpiece is rinsed with deionized water.

4. The method for preparing a high wear-resistant and corrosion-resistant functionalized alloy coating for aerospace equipment as described in claim 1, characterized in that, In step two, the mass concentration of nickel sulfate in the nanocomposite plating solution is configured to be 35 g / L to 50 g / L, the mass concentration of sodium tungstate is configured to be 50 g / L to 70 g / L, and the mass concentration of sodium citrate is configured to be 70 g / L to 90 g / L; the pH value of the nanocomposite plating solution is adjusted to between 6.5 and 7.0 by using sodium hydroxide or sulfuric acid.

5. The method for preparing a high wear-resistant and corrosion-resistant functionalized alloy coating for aerospace equipment as described in claim 4, characterized in that, The silicon carbide nanoparticles have an average particle size of 50 nm to 100 nm, and their concentration in the nanocomposite plating solution is configured to be 5 g / L to 12 g / L. The graphene oxide nanosheets have a thickness of 1 nm to 3 nm and a sheet diameter of 1 μm to 3 μm, and their concentration in the nanocomposite plating solution is configured to be 0.5 g / L to 1.5 g / L. In the mixed surfactant, the concentration of hexadecyltrimethylammonium bromide is configured to be 0.2 g / L to 0.5 g / L, and the concentration of sodium dodecyl sulfate is configured to be 0.1 g / L to 0.3 g / L. When preparing the nanocomposite plating solution, the silicon carbide nanoparticles and the graphene oxide nanosheets are pre-dispersed in deionized water containing the mixed surfactant, and pre-dispersed for a first preset time period using an ultrasonic dispersion device.

6. The method for preparing a high wear-resistant and corrosion-resistant functionalized alloy coating for aerospace equipment as described in claim 1, characterized in that, In step three, the amplitude of the forward current density in the forward polarization co-deposition pulse stage is greater than the amplitude of the reverse current density in the reverse anodic polarization pulse stage; the pulse conduction time in the forward polarization co-deposition pulse stage is greater than the pulse conduction time in the reverse anodic polarization pulse stage; and the operating frequency of the ultrasonic wave is configured to a first preset frequency value.

7. The method for preparing a high wear-resistant and corrosion-resistant functionalized alloy coating for aerospace equipment as described in claim 6, characterized in that, The forward current density during the forward polarization co-deposition pulse phase is configured to be 5 A / dm. 2 Up to 12A / dm 2 The forward pulse duty cycle is configured to be 60% to 70%; the reverse current density during the reverse anodic polarization pulse phase is configured to be 1.5 A / dm². 2 Up to 3A / dm 2 The reverse pulse duty cycle is configured to be 20% to 30%; the first preset frequency value is configured to be 40kHz; and the ultrasonic power density is configured to be 0.5W / cm². 2 Up to 0.8W / cm 2 The ultrasonic transmitting probe is arranged parallel between the cathode and the power supply board serving as the anode; the electrodeposition time of the metal workpiece in the nanocomposite plating solution is configured to be 45 minutes to 90 minutes.

8. The method for preparing a high wear-resistant and corrosion-resistant functionalized alloy coating for aerospace equipment as described in claim 1, characterized in that, In step four, the specific operating temperature of the heat treatment is configured to be between 350°C and 400°C; the vacuum degree of the vacuum heating furnace is configured to be below a first preset vacuum pressure value; the constant temperature holding time of the heat treatment is configured to be between 2 hours and 4 hours; after the heat treatment is completed, the metal workpiece is cooled to room temperature along with the vacuum heating furnace.

9. A high wear-resistant and corrosion-resistant functionalized alloy coating for aerospace equipment, characterized in that, The high wear-resistant and corrosion-resistant functionalized alloy coating for aerospace equipment is prepared by the method described in any one of claims 1 to 8; the alloy coating comprises a nickel-tungsten alloy matrix, silicon carbide nanoparticles dispersed in the nickel-tungsten alloy matrix, and graphene nanosheets generated by in-situ reduction of graphene oxide.

10. The high wear-resistant and corrosion-resistant functionalized alloy coating for aerospace equipment as described in claim 9, characterized in that, The silicon carbide nanoparticles and graphene nanosheets are embedded at the grain boundaries of the nickel-tungsten alloy matrix; the graphene nanosheets form an interlayer slip film in the alloy coating structure and together with the silicon carbide nanoparticles constitute a reinforcing framework.

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