Metal wire processing galvanization treatment process for aerospace engineering

Abstract

The invention relates to the technical field of metal wire processing, and discloses a metal wire processing galvanization treatment process for aerospace engineering, which comprises the following steps: removing oil stains and oxide layers on the surface of a metal wire through multi-stage electrolytic degreasing, composite pickling rust removal, reverse water washing, micro-polishing and plasma activation; after the metal wire is subjected to rare earth enhanced plating assisting treatment, zinc-aluminum rare earth alloy pulse electroplating is adopted, dynamic filtering is matched, and an alloy plating layer is formed on the surface of the pretreated metal wire; redundant zinc liquid is removed through nitrogen-electromagnetic composite wiping, and then gradient cooling shaping is conducted; after the binding force of the alloy coating and the matrix is strengthened through low-temperature vacuum diffusion annealing, residual stress is eliminated through micro-vibration drawing; and trivalent chromium passivation and nanometer sealing are adopted to form a double protection layer. Through the synergistic effect of multi-stage pretreatment, rare earth enhanced coating formation, gradient post-treatment and dual protection, the binding force, uniformity, corrosion resistance and stability of the metal wire zinc coating for aerospace engineering are remarkably improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal wire processing, in particular to a galvanizing treatment process for metal wire processing for aerospace engineering. BACKGROUND

[0002] In the field of aerospace engineering, metal wires, as the core components of spacecraft structure connection, electromagnetic shielding and power transmission, are exposed to extremely complex space environments for a long time, and need to withstand severe temperature difference cycles above ±200℃, continuous high-frequency vibration, high-energy particle radiation and micro-meteorite impact, etc. These harsh conditions put high demands on the comprehensive performance of the galvanized layer on the surface of the metal wire. Specifically, the coating needs to have extremely strong adhesion to resist the risk of peeling caused by vibration, extremely high uniformity and compactness to block the penetration of space micro-corrosion media, and also needs to meet special indicators such as no harmful component volatilization and excellent long-term stability.

[0003] The existing galvanizing process has significant shortcomings when adapting to the needs of aerospace, including: first, the traditional single alkaline degreasing or strong acid pickling method cannot completely remove the phosphating film, saponification oil and rolling scale left over from the metal wire drawing process, resulting in insufficient adhesion between the coating and the substrate, which is prone to bulging or peeling under temperature stress. Even with compound cleaning, the lack of precise surface activation control prevents the formation of a microtopography that is suitable for coating growth, further weakening the interfacial adhesion strength. Second, conventional electroplating or hot-dip galvanizing processes are prone to problems such as composition segregation, coarse grains and excessive porosity, making it difficult to break through the corrosion resistance of the coating. In the simulated space micro-corrosion environment test, local rusting often occurs in a short period of time, which cannot meet the long-term mission requirements. Third, most processes rely on chromate passivation to improve corrosion resistance, which not only poses a risk of heavy metal pollution, but also makes the passivation film prone to decomposition and failure under high-energy radiation. At the same time, the lack of effective interface diffusion strengthening and closed protection design leads to fatigue cracking of the coating under long-term mechanical load, seriously affecting the operational reliability of the spacecraft.

[0004] As aerospace missions develop towards long life and high reliability, existing processes have difficulty meeting the performance requirements of metal wires, therefore, a new galvanizing treatment process that integrates efficient pretreatment, high-performance coating growth, interface strengthening and environmental protection is needed to meet the special application requirements of aerospace engineering. SUMMARY

[0005] The present application provides a galvanizing treatment process for metal wire processing for aerospace engineering, which significantly improves the adhesion, uniformity, corrosion resistance and stability of the galvanized layer of metal wire for aerospace engineering through the synergistic effect of multi-stage pretreatment, rare earth enhanced coating formation, gradient post-treatment and double protection, and can fully adapt to the long-term service requirements of spacecraft in complex space environments.

[0006] The application provides a galvanizing treatment process for metal wire processing in aerospace engineering, comprising:

[0007] S1, metal wire surface pretreatment: through multistage electrolytic degreasing, composite pickling rust removal, reverse water washing, micro-grinding and plasma activation, oil stains and oxide layers on the surface of the metal wire are removed to improve the surface activity of the metal wire;

[0008] S2, rare earth enhanced plating layer formation: after the metal wire is subjected to rare earth enhancement plating treatment, zinc-aluminum-rare earth alloy pulse plating is adopted and dynamic filtration is cooperated to form an alloy plating layer with uniform composition and good bonding force on the surface of the pretreated metal wire;

[0009] S3, alloy plating layer post-treatment: through nitrogen-electromagnetic composite wiping, excess zinc liquid is removed, and then gradient cooling is performed to shape, so that the surface of the alloy plating layer is smooth, high in density and free of cracks;

[0010] S4, alloy plating layer strengthening and size finishing: after the alloy plating layer is strengthened by low-temperature vacuum diffusion annealing to improve the bonding force between the alloy plating layer and the substrate, residual stress is eliminated through micro-vibration drawing to ensure the size precision of the metal wire;

[0011] S5, double protection treatment: trivalent chromium passivation and nano sealing are adopted to form a double protective layer to improve the corrosion resistance and extreme environment adaptability of the alloy plating layer.

[0012] Further, the step S1 specifically comprises:

[0013] S101, multistage electrolytic degreasing: alkaline electrolyte containing non-ionic surfactant is used to degrease the metal wire at 60 DEG C, and cathode-anode alternating electrolysis is combined to strip the drawing residual phosphating film and saponification oil attached to the surface through the gas bubbles generated by electrolysis;

[0014] S102, composite pickling rust removal: a mixed solution of hydrochloric acid-organic corrosion inhibitor is used to soak for 3-5 minutes at room temperature, and 40 kHz ultrasonic oscillation is supplemented to accelerate the stripping of the oxide scale, so that the stubborn oxide layer formed during rolling or storage of the metal wire is removed;

[0015] S103, reverse water washing and micro-grinding: after the acid liquid residues are removed through three-stage reverse flow water washing, the surface of the metal wire is micro-ground through an 80-mesh quartz sand wheel to control the surface roughness to Ra 0.8-1.2 microns;

[0016] S104, plasma surface activation: the pretreated metal wire is introduced into a vacuum plasma treatment chamber, argon is introduced, and 300-500 W radio frequency plasma low-temperature etching is adopted for 30-60 seconds.

[0017] Furthermore, the step S2 specifically includes:

[0018] S201, rare earth enhanced plating flux: immersing the metal wire in a plating flux containing ammonium chloride, zinc chloride and 0.03% yttrium-based rare earth for 1 to 2 minutes to form a uniform active protective film;

[0019] S202, using an alloy plating solution containing Zn-10%, Al-0.01% mixed rare earth, electroplating at 455±5℃ through a double-pulse power supply, combined with dynamic filtration and electromagnetic stirring, and real-time monitoring to ensure uniform coating thickness and composition.

[0020] Furthermore, the step S202 specifically includes:

[0021] 1) Plating solution configuration: Use Zn-10%, Al-0.01% mixed rare earth alloy plating solution, the temperature is controlled at 455±5℃, and the plating tank surface is covered with a 100mm perlite insulation layer to maintain temperature stability;

[0022] 2) Pulse parameters: using dual pulse power supply, forward current density 10 ~ 15A / dm 2 , pulse width 20~50ms, reverse current density 3~5A / dm 2 , pulse width 5~10ms, duty cycle 30~50%, and real-time monitoring of coating thickness to 5~15μm by online eddy current thickness gauge;

[0023] 3) Dynamic Filtration: The plating tank is equipped with a removable filter housing with a pore size of 50μm, which is combined with a negative pressure circulation system to filter zinc slag in real time. Electromagnetic stirring is simultaneously applied to suppress aluminum segregation to ensure uniformity of the coating composition.

[0024] Furthermore, the step S3 specifically includes:

[0025] S301, purging excess zinc liquid from the surface of the metal wire with 300° C. preheated nitrogen gas, while applying a 10 kHz high-frequency electromagnetic field to control the flow state of the zinc liquid, so as to form a uniform and smooth surface of the coating before solidification;

[0026] S302, adopt air cooling-water quenching two-stage gradient cooling: first cool to 200℃ at a wind speed of 10m / s, then transfer to 50℃ soft water quenching to room temperature, so as to suppress cracks in the coating due to thermal stress by controlling the cooling rate and improve the density of the coating.

[0027] Furthermore, the step S4 specifically includes:

[0028] S401, low-temperature vacuum diffusion annealing: Place the cooled metal wire into a vacuum annealing furnace with a vacuum degree of ≤1×10-3Pa, heat it to 180-220℃ at a rate of 5-10℃ / min, keep it at that temperature for 2-4 hours, and then cool it to below 50℃ before being taken out of the furnace;

[0029] S402, micro-vibration drawing: low compression rate drawing process is adopted, total compression rate is greater than 96%, die working taper angle is 8°, and axial micro-vibration with a frequency of 50 Hz is applied, so as to eliminate residual stress of the plating layer and the substrate through vibration energy, reduce the risk of plating layer cracking in the drawing process, and ensure the size precision and mechanical properties of the wire.

[0030] Further, the step S5 specifically comprises:

[0031] 1) trivalent chromium passivation: dipping in a trivalent chromium anhydride solution for 30-60 seconds to form a passivation film with a thickness of 50-100 nm to improve the corrosion resistance basis;

[0032] 2) nano sealing: coating water-based epoxy-acrylic resin with a concentration of 200 ml / L, and drying at 90 DEG C for 30 minutes to form a nano-scale sealing layer to reduce the porosity of the plating layer and impart surface stain resistance.

[0033] The beneficial effects of the present application are:

[0034] The present application significantly improves the comprehensive performance of the galvanized layer of the metal wire for aerospace engineering by integrating multiple stages of pretreatment, rare earth reinforced plating layer formation, gradient post-treatment and double protection. The synergistic effect of composite cleaning and plasma activation in the pretreatment stage can completely remove surface contaminants and optimize the microtopography, greatly enhancing the adhesion of the plating layer to the substrate and effectively preventing the plating layer from falling off due to temperature difference or vibration. During the plating layer formation process, the introduction of rare earth elements combined with pulse plating and dynamic filtration technology can inhibit composition segregation and refine the grains, reduce the porosity, and significantly improve the corrosion resistance. The combination of low-temperature diffusion annealing and micro-vibration drawing can strengthen the interface bonding and eliminate residual stress, reducing the risk of plating layer cracking. The environmentally friendly double protection treatment improves the ability to withstand extreme environments while meeting the requirements of the aerospace field for the absence of harmful ingredients. The overall process of the present application simultaneously improves the adhesion, uniformity, corrosion resistance and stability of the plating layer, and can fully adapt to the long-term service requirements of the spacecraft in complex space environments. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 The figure is a flowchart of the galvanizing treatment process for the metal wire for aerospace engineering of the present application.

[0036] The implementation, functional characteristics and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0037] It should be understood that the specific embodiments described herein are merely intended to explain the present application and are not intended to limit the present application.

[0038] As Figure 1As shown, the present application provides a galvanizing treatment process for metal wire for aerospace engineering, comprising:

[0039] S1, metal wire surface pretreatment: through multi-stage electrolytic degreasing, composite pickling, reverse water washing, micro-grinding and plasma activation, the oil stains and oxide layer on the surface of the metal wire are removed to improve the surface activity of the metal wire and lay a foundation for the adhesion of the coating. Specifically, the following steps are included:

[0040] S101, multi-stage electrolytic degreasing

[0041] Degreasing treatment of metal wire is carried out at 60℃ using alkaline electrolyte containing non-ionic surfactant, combined with cathode-anode alternating electrolysis (current density 5-8 A / dm 2 ), the drawing residual phosphating film and saponification oil attached to the surface are stripped by the bubbles generated by electrolysis, ensuring that the oil stain removal rate of the wire surface is ≥99%. Compared with traditional single degreasing, this step is more suitable for cleaning complex surface contaminants of high-strength metal wire.

[0042] S102, composite pickling and rust removal

[0043] A mixed solution of hydrochloric acid-organic corrosion inhibitor (0.5% thiourea) is used, the concentration of the mixed solution is 12%-15%, and the wire is soaked at room temperature for 3-5 minutes, while being supplemented with 40 kHz ultrasonic oscillation to accelerate the stripping of the oxide scale; the thiourea corrosion inhibitor can effectively inhibit the excessive corrosion of hydrochloric acid on the substrate, and the corrosion rate is ≤0.1 g / m 2 ·h, the ultrasonic action makes the stripping efficiency of the oxide scale increase by 40%, which is suitable for removing stubborn oxide layers formed on the wire surface during rolling or storage.

[0044] S103, reverse water washing and micro-grinding

[0045] Through three-stage reverse flow flushing, the flushing time of each stage is ≥30 seconds, and the conductivity is ≤10 μS / cm; after the residual acid solution is removed by flushing, the surface of the metal wire is micro-ground by an 80-mesh quartz sand wheel to control the surface roughness to

[0046] Ra0.8-1.2 μm; reverse water washing reduces water consumption, and the micro concave-convex structure formed by micro-grinding can improve the mechanical interlocking force of the subsequent coating.

[0047] S104, plasma surface activation

[0048] The pretreated metal wire is introduced into a vacuum plasma processing chamber (vacuum degree 1-5 Pa), argon gas is introduced (flow rate 10-20 sccm), and low-temperature etching is performed for 30-60 seconds by using a 300-500 W radio frequency plasma. The surface oxide layer is removed by plasma bombardment, and a micro-nano scale rough structure is formed on the surface, so that the mechanical embedding force of the plating layer and the substrate is improved. This step replaces the end link of traditional pickling, further removes the residual oxide film and strengthens the surface activity, and is more friendly to materials such as titanium alloy and high-strength metal wire which are prone to hydrogen embrittlement, and avoids damage to the mechanical properties of the substrate.

[0049] S2, rare earth enhanced plating layer formation: after the metal wire is treated by a rare earth enhancement plating aid, a zinc-aluminum-rare earth alloy pulse plating is adopted and dynamic filtering is cooperated to form an alloy plating layer with uniform composition and good bonding force on the surface of the pretreated metal wire. Specifically, the following steps are included:

[0050] S201, rare earth enhancement plating aid

[0051] The metal wire is immersed in a plating aid containing ammonium chloride, zinc chloride and 0.03% yttrium-based rare earth (Y2O3) (temperature 60°C, pH 3.5-4.0) for 1-2 minutes to form a uniform active protective film. The rare earth element can refine the subsequent plating layer grains, and at the same time improve the coverage uniformity of the plating aid on the surface of the wire, with a coverage rate of ≥99.5%, providing a good attachment substrate for the plating layer.

[0052] S202, zinc-aluminum-rare earth alloy pulse plating

[0053] An alloy plating solution containing Zn-10%, Al-0.01% mixed rare earth (Dy2O3 / Gd2O3) is used for plating at 455±5°C by using a double pulse power supply, and dynamic filtering and electromagnetic stirring are cooperated to ensure that the plating layer has uniform thickness (error ≤5%) and uniform composition. Specifically:

[0054] 1) Plating solution configuration: Zn-10%, Al-0.01% mixed rare earth (Dy2O3 / Gd2O3) alloy plating solution is used, the temperature is controlled at 455±5°C, the plating bath surface is covered with a 100 mm perlite heat preservation layer to maintain temperature stability.

[0055] 2) Pulse parameters: a double pulse power supply is used, the forward current density is 10-15 A / dm 2 , the pulse width is 20-50 ms, the reverse current density is 3-5 A / dm 2 , the pulse width is 5-10 ms, the duty cycle is 30-50%, the plating layer thickness is monitored in real time by an online eddy current thickness gauge to 5-15 μm, and the uniformity error in the circumferential direction is ensured to be ≤5%. The pulse current is adjusted in real time according to the target plating layer thickness, the plating layer porosity is reduced, and the gradient composition inhibits intergranular corrosion.

[0056] 3) Dynamic filtration: movable filter shell with pore size of 50 μm built-in plating tank, combined with negative pressure circulation system to filter zinc residue in real time (filtration efficiency ≥ 95%), and synchronous application of electromagnetic stirring to inhibit segregation of aluminum elements, so as to ensure uniformity of plating layer composition.

[0057] S3, post-alloy plating finishing: removal of excess zinc liquid by nitrogen-electromagnetic composite wiping, and then gradient cooling to ensure that the alloy plating layer has a smooth surface, high density and no cracks. Specifically comprising the following steps:

[0058] S301, nitrogen-electromagnetic composite wiping

[0059] After the metal wire leaves the zinc pot, the surface of the metal wire is immediately blown with 300°C preheated nitrogen gas (pressure 0.05 MPa, spray angle 45°) to remove excess zinc liquid, while a 10 kHz high-frequency electromagnetic field is applied to regulate the flow state of the zinc liquid, so as to promote the formation of a uniform and smooth surface (surface roughness Ra ≤ 0.5 μm) of the plating layer before solidification. This step replaces traditional mechanical wiping, reducing the risk of plating layer scratches.

[0060] S302, gradient cooling and sizing

[0061] Two-stage gradient cooling by air cooling and water quenching: first air cooling at a speed of 10 m / s to 200°C, and then quenching in 50°C soft water to room temperature, so as to control the cooling rate (10-15°C / s) to inhibit cracks in the plating layer due to thermal stress, and improve the density of the plating layer (porosity ≤ 0.1 per / mm 2 ).

[0062] S4, alloy plating layer strengthening and size finishing: after strengthening the bonding force between the alloy plating layer and the substrate by low-temperature vacuum diffusion annealing, residual stress is eliminated by micro-vibration drawing to ensure the size accuracy of the metal wire. Specifically comprising the following steps:

[0063] S401, low-temperature vacuum diffusion annealing

[0064] The cooled metal wire is placed in a vacuum annealing furnace with a vacuum degree of ≤ 1 × 10-3Pa, and heated to 180-220°C (lower than the recrystallization temperature of the metal wire to avoid mechanical property degradation) at a rate of 5-10°C / min, and then cooled to 50°C or below in the furnace after holding for 2-4 hours; through micro-interdiffusion between the zinc-aluminum-rare earth plating layer and the substrate, a transition diffusion layer with a thickness of 0.5-1 μm is formed, so that the bonding force of the plating layer is increased to ≥ 5 N / cm. This step promotes micro-interdiffusion between the zinc-aluminum-rare earth plating layer and the substrate metal, forming a transition diffusion layer with a thickness of 0.5-1 μm, so that the bonding force of the plating layer is increased to ≥ 5 N / cm, while low-temperature diffusion avoids plating layer embrittlement and strengthens the interface bonding.

[0065] S402, micro-vibration drawing

[0066] Adopt low compression rate drawing process, its total compression rate >96%, die working taper angle 8°, while applying frequency 50Hz axial microvibration, to eliminate residual stress of plating layer and matrix through vibration energy, reduce the risk of plating layer cracking in the drawing process, ensure the size precision (diameter tolerance ±0.002mm) and mechanical properties (tensile strength retention rate ≥95%) of the wire.

[0067] S5, double protection treatment: adopt trivalent chromium passivation and nano sealing to form double protective layer to improve the corrosion resistance and extreme environment adaptability of the alloy plating layer. Specifically includes the following steps:

[0068] 1) Trivalent chromium passivation: immerse in trivalent chromium anhydride solution (15ml / L, 25℃) for 30-60 seconds to form a passivation film with a thickness of 50-100nm to improve the corrosion resistance basis (neutral salt spray test ≥800 hours without white rust).

[0069] 2) Nano sealing: coat water-based epoxy-acrylic resin with a concentration of 200ml / L, and dry at 90℃ for 30 minutes to form a nano-scale sealing layer, further reduce the porosity of the plating layer and impart surface stain resistance (contact angle ≥110°). The double protection system of this step takes into account environmental protection and extreme environment adaptability, and meets the low volatile requirements of aerospace engineering.

[0070] The application is suitable for spacecraft structure connecting wires, antenna feed lines and other key components, and the performance indicators are more than 30% better than traditional galvanizing process. The unique process includes:

[0071] 1. Synergistic effect of rare earth elements: from yttrium-based rare earth in the plating stage to dysprosium / gadolinium mixed rare earth in the plating solution, the whole process strengthens grain refinement and interface bonding of the plating layer, and the corrosion resistance is improved by 40% compared with traditional process.

[0072] 2. Multi-physical field synergistic regulation, integrating plasma activation, electromagnetic stirring, high-frequency electromagnetic field wiping and micro-vibration drawing to realize precise control of plating layer uniformity and mechanical properties.

[0073] 3. Gradient processing technology: covering composition gradient (zinc-aluminum-rare earth plating layer), temperature gradient (cooling and shaping), interface gradient (diffusion annealing), and all-round improvement of the ability of the plating layer to adapt to aerospace extreme working conditions (temperature difference ±150℃, vibration 10-2000Hz).

[0074] The present application significantly improves the comprehensive performance of the galvanized layer of the metal wire used in aerospace engineering by integrating multiple stages of pretreatment, rare earth reinforced coating formation, gradient post-treatment and double protection. The synergistic effect of composite cleaning and plasma activation in the pretreatment stage can completely remove surface contaminants and optimize the microtopography, significantly enhancing the adhesion of the coating to the substrate and effectively preventing coating peeling caused by temperature difference or vibration. During the coating formation process, the introduction of rare earth elements combined with pulse plating and dynamic filtration technology can suppress composition segregation and refine the grain size, reduce porosity and significantly improve corrosion resistance. The combination of low-temperature diffusion annealing and micro-vibration drawing can strengthen the interface bonding and eliminate residual stress, reducing the risk of coating cracking. The environmentally friendly double protection treatment improves the ability to withstand extreme environments while meeting the requirements of the aerospace field for the absence of harmful ingredients. The overall process of the present application simultaneously improves the adhesion, uniformity, corrosion resistance and stability of the coating, and can fully adapt to the long-term service requirements of spacecraft in complex space environments.

[0075] It should be noted that in this document, the terms "comprising", "including", or any other variant thereof are intended to cover non-exclusive inclusions, so that a process, device, article or method including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or inherent to such a process, device, article or method. Without more limitations, the element defined by the statement "including a" does not exclude the presence of other identical elements in the process, device, article or method including the element.

[0076] The above description is only the preferred embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation, or direct or indirect application in other related technical fields, based on the content of the present application specification and drawings, are also included in the patent protection scope of the present application.

Claims

1. A galvanizing process for metal wire processing for aerospace engineering, characterized in that: include: S1. Surface pretreatment of the metal wire: removing oil stains and oxide layers from the surface of the metal wire through multi-stage electrolytic degreasing, composite pickling and rust removal, reverse water washing and micro-grinding, and plasma activation to enhance the surface activity of the metal wire; S2. Formation of a rare earth enhanced coating: After the metal wire has been subjected to rare earth enhanced plating treatment, a zinc-aluminum rare earth alloy pulse electroplating is performed in conjunction with dynamic filtration to form an alloy coating with uniform composition and good bonding strength on the surface of the pretreated metal wire; S3. Finishing of the alloy coating: removing excess zinc liquid by nitrogen-electromagnetic composite wiping, and then shaping by gradient cooling to ensure that the surface of the alloy coating is smooth, dense and free of cracks; S4. Alloy coating strengthening and dimensional finishing: After strengthening the bonding strength between the alloy coating and the substrate by low-temperature vacuum diffusion annealing, residual stress is eliminated by micro-vibration drawing to ensure the dimensional accuracy of the metal wire; S5. Double protection treatment: Trivalent chromium passivation and nano-sealing are used to form a double protection layer to improve the corrosion resistance and extreme environment adaptability of the alloy coating.

2. The galvanizing treatment process for metal wire used in aerospace engineering according to claim 1, characterized in that: The step S1 specifically includes: S101, multi-stage electrolytic degreasing: Use alkaline electrolyte containing non-ionic surfactant to degrease the metal wire at 60°C, combined with cathode-anode alternating electrolysis, and use the bubbles generated by electrolysis to peel off the residual phosphate film and saponified oil attached to the surface; S102, composite pickling and rust removal: using a mixed solution of hydrochloric acid and an organic corrosion inhibitor, soaking for 3 to 5 minutes at room temperature, while simultaneously using 40 kHz ultrasonic oscillation to accelerate the peeling of oxide scale, so as to remove the stubborn oxide layer formed on the surface of the metal wire during rolling or storage; S103, reverse water washing and micro-grinding: After three levels of reverse flow water washing to remove acid residue, the surface of the metal wire is micro-grinded with an 80-mesh quartz grinding wheel to control the surface roughness to Ra 0.8 to 1.2 μm; S104, plasma surface activation: introducing the pre-treated metal wire into a vacuum plasma processing chamber, introducing argon gas, and adopting 300-500W radio frequency plasma for low temperature etching for 30-60 seconds.

3. The galvanizing treatment process for metal wire used in aerospace engineering according to claim 2, characterized in that: The step S2 specifically includes: S201, rare earth enhanced plating flux: immersing the metal wire in a plating flux containing ammonium chloride, zinc chloride and 0.03% yttrium-based rare earth for 1 to 2 minutes to form a uniform active protective film; S202, using an alloy plating solution containing Zn-10%, Al-0.01% mixed rare earth, electroplating at 455±5℃ through a double-pulse power supply, combined with dynamic filtration and electromagnetic stirring, and real-time monitoring to ensure uniform coating thickness and composition.

4. The galvanizing treatment process for metal wire used in aerospace engineering according to claim 3, characterized in that: The step S202 specifically includes: 1) Plating solution configuration: Use Zn-10%, Al-0.01% mixed rare earth alloy plating solution, the temperature is controlled at 455±5℃, and the plating tank surface is covered with a 100mm perlite insulation layer to maintain temperature stability; 2) Pulse parameters: using dual pulse power supply, forward current density 10 ~ 15A / dm 2 , pulse width 20~50ms, reverse current density 3~5A / dm 2 , pulse width 5~10ms, duty cycle 30~50%, and real-time monitoring of coating thickness to 5~15μm by online eddy current thickness gauge; 3) Dynamic Filtration: The plating tank is equipped with a removable filter housing with a pore size of 50μm, which is combined with a negative pressure circulation system to filter zinc slag in real time. Electromagnetic stirring is simultaneously applied to suppress aluminum segregation to ensure uniformity of the coating composition.

5. The galvanizing treatment process for metal wire used in aerospace engineering according to claim 4, characterized in that: The step S3 specifically includes: S301, purging excess zinc liquid from the surface of the metal wire with 300° C. preheated nitrogen gas, while applying a 10 kHz high-frequency electromagnetic field to control the flow state of the zinc liquid, so as to form a uniform and smooth surface of the coating before solidification; S302, adopt air cooling-water quenching two-stage gradient cooling: first cool to 200℃ at a wind speed of 10m / s, then transfer to 50℃ soft water quenching to room temperature, so as to suppress cracks in the coating due to thermal stress by controlling the cooling rate and improve the density of the coating.

6. The galvanizing treatment process for metal wire used in aerospace engineering according to claim 5, characterized in that: The step S4 specifically includes: S401, low-temperature vacuum diffusion annealing: Place the cooled metal wire into a vacuum annealing furnace with a vacuum degree of ≤1×10-3Pa, heat it to 180-220℃ at a rate of 5-10℃ / min, keep it at that temperature for 2-4 hours, and then cool it to below 50℃ before being taken out of the furnace; S402, micro-vibration drawing: adopt low compression ratio drawing process, with a total compression ratio of >96%, the working cone angle of the mold is 8°, and an axial micro-vibration frequency of 50Hz is applied at the same time to eliminate the residual stress between the coating and the substrate through vibration energy, reduce the risk of coating cracking during the drawing process, and ensure the dimensional accuracy and mechanical properties of the wire.

7. The galvanizing treatment process for metal wire used in aerospace engineering according to claim 6, characterized in that: The step S5 specifically includes: 1) Trivalent chromium passivation: Immerse in trivalent chromic anhydride solution for 30 to 60 seconds to form a passivation film with a thickness of 50 to 100 nm to improve the corrosion resistance; 2) Nano-sealing: Apply a 200ml / L water-based epoxy-acrylic resin and dry it at 90°C for 30 minutes to form a nano-scale sealing layer to reduce the porosity of the coating and give the surface stain resistance.

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