Cold spraying repairing method for aluminum alloy paddle

Abstract

The invention relates to the technical field of blade repairing treatment, discloses a cold spraying repairing method for an aluminum alloy blade and aims to solve the problems that a base body is prone to being damaged and the performance of a repairing layer is poor in an existing repairing method. The method comprises the steps of mechanical polishing, cold spraying, mechanical coping and follow-up protection, specifically, surface inspection, pretreatment, spraying operation and multi-dimensional inspection are sequentially conducted on cold spraying, 501.1-mark pure aluminum-Al2O3 mixed powder is adopted, after positioning and precise parameter spraying are conducted through a special tool, coping is conducted till the molded surface requirement is met, and then micro-arc oxidation and paint spraying protection are conducted. The method is low in cold spraying temperature, free of damage to a base body, excellent in repairing layer performance, high in precision, high in corrosion resistance and abrasion resistance and stable and reliable in process, the operation and maintenance cost can be remarkably reduced, and the service life of the paddle is prolonged.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of paddle repair processing, in particular to a cold spraying repair method for an aluminum alloy paddle. BACKGROUND

[0002] The aluminum alloy paddle is a key part in the fields of ships, aerospace, etc., and needs to serve in a complex and severe working condition environment for a long time. The surface of the aluminum alloy paddle is prone to damage due to corrosion, wear and other factors, thereby affecting the overall operation performance of the equipment. Therefore, effectively repairing the damaged aluminum alloy paddle is an important link to ensure the stable operation of the related equipment.

[0003] In the prior art, there is a cold spraying repair method for the aluminum alloy paddle. However, the pretreatment process design of the method is not perfect. The cleaning operation is mostly performed once, and the removal effect of the oxide film is not controlled. As a result, oil stains or incomplete oxide film fragments may still remain on the surface of the substrate, which directly affects the bonding effect of the coating and the substrate. Meanwhile, the fixing clamp used in the spraying process is mostly of a general type, which is difficult to adapt to the curved surface structure of the paddle, cannot realize stable and accurate positioning, and only judges the coating quality through simple visual observation after spraying. The method lacks systematic detection of the coating thickness and comparative verification of the core performance, and also fails to accurately verify the profile size after repair. Finally, the repaired coating is prone to problems such as poor bonding, peeling or fragmentation, and the profile precision of the paddle is difficult to meet the actual use requirements. SUMMARY

[0004] In view of the above problems existing in the prior art aluminum alloy paddle repair method, the application provides a cold spraying repair method, which optimizes the repair process route, accurately matches the material system and process parameters, and realizes the following purposes:

[0005] Overcome the coating bonding defects caused by incomplete pretreatment and insufficient positioning accuracy in the prior art cold spraying repair method, and improve the bonding reliability of the repaired layer and the aluminum alloy substrate.

[0006] Through the standardized multi-dimensional inspection after spraying and the accurate mechanical grinding process, the profile precision and surface quality of the repaired paddle are ensured to meet the use standard.

[0007] With the complete subsequent protection treatment, the corrosion and wear resistance of the paddle is enhanced, and the service life thereof is prolonged.

[0008] To achieve the above purposes, the application provides the following technical scheme:

[0009] The aluminum alloy paddle cold spraying repair method of the application takes the 2A11 die-forged aluminum alloy paddle as the repair object, and realizes performance recovery through a coherent process. The specific technical scheme is as follows:

[0010] The repair method comprises the following steps:

[0011] S1, mechanical polishing: using a manual grinding wheel or abrasive belt to polish the corroded part of the paddle, completely removing the surface corrosion layer, damaged paint layer and micro-arc oxidation layer until the fresh 2A11 aluminum alloy substrate is exposed, the substrate surface after polishing has no sharp edges and unpolished areas, providing a foundation for subsequent coating bonding;

[0012] S2, cold spraying: as the core repair process, surface inspection, pretreatment, spraying operation and post-spraying inspection are performed in turn, specifically including:

[0013] S2.1 surface inspection: ① visually observing the to-be-sprayed part and the surrounding area to confirm that there is no visible damage such as scratches and scratches; ② measuring the size deviation of the to-be-sprayed part using tools with precision meeting the measurement requirements (such as micrometer, vernier caliper), determining the minimum thickness of the repair layer to ensure complete coverage of the damaged area;

[0014] S2.2 pretreatment: ① surface cleaning: clean the to-be-sprayed part and the surrounding area with alcohol or acetone, and repeat the operation after blowing dry with compressed air until there is no oil stain and impurity residue on the surface to avoid the influence of oil stain on the coating bonding; ② oxide film removal: uniformly polish the to-be-sprayed part with sandpaper until the oxide film is completely removed and the surface is uniformly rough, and blow off the surface polishing dust with compressed air to further improve the physical bonding force between the coating and the substrate;

[0015] S2.3 spraying operation: ① clamping and fixing: fix the paddle on the cold spraying station through a special tool to ensure stable positioning of the paddle root and tip, and match the paddle profile with the spraying direction to avoid displacement during spraying; ② powder preparation: select pure aluminum with a grade of 501.1 and Al2O3 mixed powder as the spraying raw material, screen out agglomerated particles through a screen, and then put them into a drying oven to prevent the powder from being affected by moisture; ③ gun adjustment: check the gun for water and gas leakage by introducing compressed gas, and confirm that the powder feeding volume, gas flow and other modules of the spraying system are working properly; ④ secondary cleaning: clean the to-be-sprayed part with alcohol / acetone again and blow dry to further purify the surface; ⑤ powder spraying: set the cold spraying process parameters according to the repair layer thickness and the paddle curved surface shape, and uniformly spray the powder to the to-be-sprayed part until the coating is higher than the surrounding substrate surface, leaving a margin for subsequent polishing; ⑥ disassembly and cleaning: carefully remove the paddle after spraying, and simultaneously clean the surface protection tool and excess sprayed powder;

[0016] S2.4 Post-coating inspection: ① Thickness inspection: Use a thickness gauge to select multiple evenly distributed test points on the area to be coated to confirm that the thickness of the repair layer meets the preset requirements; ② Appearance inspection: Visually inspect the coating surface for continuity and uniformity, without defects such as peeling, cracking, blistering, or nodules, and ensure that there is no coating residue in non-coated areas; ③ Performance sampling inspection: On 2A11 aluminum alloy test pieces prepared in the same batch as the blades, a comparison coating is formed using the same coating process. The porosity, bonding strength with the substrate, and peel strength with rubber of the comparison coating are tested to ensure that the performance of the repair layer meets the standards;

[0017] S3. Mechanical grinding: The blades that have been cold-sprayed are clamped onto a special milling machine. The blade tip is tightened by the tail center to ensure processing stability. Carbide milling cutters are used to mill the sprayed area to make the surface of the sprayed area consistent with the original design surface of the blade and the dimensions meet the tolerance requirements. Then, sandpaper is used to polish the surface until the surface roughness meets the usage standards to ensure that the aerodynamic performance of the blade is not affected.

[0018] S4. Subsequent protective treatment: In accordance with the original production process of aluminum alloy blades, micro-arc oxidation and painting are carried out in sequence to form a composite protective layer on the blade surface, further improving corrosion resistance and wear resistance.

[0019] The repair layer formed by the cold spray must meet the following core performance indicators: porosity ≤1%, bonding strength with the 2A11 aluminum alloy body not less than 27.5MPa, and peel strength with rubber not less than 3.92kN / m.

[0020] Preferably, the mass ratio of the pure aluminum to Al2O3 mixed powder is (85-95):(5-15). This ratio can take into account both the toughness and wear resistance of the repair layer, and avoid the coating becoming brittle due to an excessively high proportion of Al2O3, or the wear resistance being affected by an excessively low proportion.

[0021] Preferably, the cold spraying process parameters are: spraying temperature 200-400℃, spraying gas pressure 1.5-3.0MPa, and spray gun moving speed 50-150mm / s. This parameter range can ensure that the powder particles obtain sufficient kinetic energy to form a strong mechanical bond with the substrate, while avoiding the impact of high temperature on the substrate.

[0022] Preferably, when there is severe oil residue on the area to be sprayed, pre-clean with an alkaline degreasing agent with a pH of 8-10 for 1-3 minutes, and then clean with alcohol or acetone to improve the surface cleaning effect.

[0023] Preferably, powder drying is carried out in an environment with a vacuum degree of -0.08 to -0.06 MPa and a temperature of 80-120℃ for 1-2 hours, which can effectively prevent powder oxidation and ensure the uniformity of powder feeding during the spraying process.

[0024] Preferably, a laser thickness gauge is used to monitor the thickness of the repair layer in real time during the spraying process. When the thickness reaches 90% of the preset minimum thickness, the spray gun moving speed is increased by 30-50% to achieve fine spraying and reduce coating defects.

[0025] Preferably, water cooling (cooling water flow rate 5-10L / min) is used to cool the milling cutter and the machined area during milling to avoid deformation of the substrate or repair layer caused by the heat of the process;

[0026] The preferred micro-arc oxidation process parameters are: oxidation voltage 300-500V, oxidation current density 5-15A / dm³. 2 The electrolyte temperature is 20-40℃, the oxidation time is 15-40min, and the electrolyte is a sodium silicate-sodium hydroxide composite electrolyte, which can form a dense ceramic protective layer.

[0027] Preferably, after the painting is completed, an additional layer of epoxy zinc-rich primer with a thickness of 5-10μm is applied to easily corroded areas such as the blade edge, blade root and the transition between the blade body, to form a locally reinforced anti-corrosion layer.

[0028] Preferably, after repair, an additional verification step is added: a salt spray resistance test is performed on the blades (salt spray concentration 50-80 mg / m³). 3 The tests include: test duration 1000-1500 hours, sand blowing test (sand particle diameter 0.1-0.3 mm, impact velocity 80-100 m / s), and vibration test (vibration frequency 10-2000 Hz, acceleration 50-100 m / s²). 2 This ensures that the repaired blades meet the requirements for service in harsh environments.

[0029] Compared with the prior art, the present invention provides a cold spraying repair method for aluminum alloy propeller blades, which has the following beneficial effects:

[0030] This invention, through a pretreatment design involving secondary cleaning and targeted removal of oxide film, combined with precise positioning of specialized tooling, effectively removes interfering factors such as oil stains and oxide film from the substrate surface, avoids displacement deviation of the paddle during spraying, and significantly improves the bonding stability between the repair layer and the substrate.

[0031] After spraying, a multi-dimensional inspection method is adopted, including multi-point detection with a thickness gauge, comprehensive appearance inspection, and performance testing of comparative specimens, to fully control the consistency of coating thickness, appearance quality, and core performance, thereby avoiding defects such as peeling and cracking from the source and ensuring the reliability of the repair layer.

[0032] The mechanical grinding process precisely matches the blade profile and size requirements, and the surface roughness after polishing meets the usage standards. The subsequent micro-arc oxidation and painting treatment carried out according to the original process specifications form a synergistic protection system, which greatly enhances the corrosion resistance of the blade.

[0033] The entire repair process covers pretreatment, spraying, inspection, grinding and post-protection. Each step is closely linked and has clear quality control points. The process is highly stable and can achieve efficient and precise repair of aluminum alloy blades, ensuring the performance and long-term service reliability of the repaired blades. Attached Figure Description

[0034] Fig. 1 This is a process flow diagram of a cold spraying repair method for aluminum alloy propeller blades according to the present invention.

[0035] Fig. 2 This is a process flow diagram of a cold spraying repair method for aluminum alloy propeller blades according to the present invention. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] Example 1

[0038] Please see Figs. 1-2 The present invention provides the following technical solution:

[0039] 1. Object to be repaired

[0040] The 2A11 die-forged aluminum alloy marine propeller blades developed localized corrosion on their surface after three years of service, with a corrosion area of ​​approximately 6 cm². 2 The maximum corrosion depth is 0.9 mm, and the original design surface roughness of the propeller blades is Ra≤1.6 μm. The repaired blades are required to meet long-term service requirements in marine environments (salt spray concentration ≥60 mg / m³). 3 (and operating conditions with a speed ≥3000r / min).

[0041] 2. Repair Steps

[0042] S1. Mechanical grinding: Use P120 sandpaper to grind the corroded parts to remove the corrosion layer, damaged paint layer and micro-arc oxidation layer until the fresh 2A11 aluminum alloy substrate is exposed. After grinding, there are no sharp edges or unground areas on the surface.

[0043] S2, Cold spraying:

[0044] S2.1 Surface Inspection: ① Visually confirm that there are no bumps, scratches or abrasions on the area to be sprayed and its surroundings; ② Use a micrometer with an accuracy of 0.01mm to measure and determine that the minimum thickness of the repair layer is 1.1mm.

[0045] S2.2 Pretreatment: ① If the area to be sprayed is heavily contaminated with oil, first pre-clean it with an alkaline degreaser with a pH of 9 for 2 minutes, then clean the area to be sprayed and the surrounding 80mm area with acetone, and blow it dry with compressed air at 0.5MPa. Repeat twice. ② Use 120-grit sandpaper to evenly sand the area to be sprayed until the oxide film is completely removed and the surface is uniformly rough. Blow away the sanding debris.

[0046] S2.3 Spraying Operation: ① Fix the blades to the cold spraying station using a special fixture, clamping the blade root and tip, with the blade profile at a 45° angle to the spraying direction; ② Select 501.1 grade pure aluminum-Al2O3 mixed powder (mass ratio 90:10), sieve it through an 80-mesh screen, and place it in a vacuum drying oven (vacuum degree -0.07MPa, temperature 100℃) to dry for 1.5h; ③ Introduce 1.2MPa compressed gas, check that the spray gun has no water or air leaks, and that the powder feeding system is working normally; ④ Clean the area to be sprayed a second time with acetone and blow it dry; ⑤ Set the cold spraying parameters: spraying temperature 300℃, gas pressure 2.5MPa, spray gun moving speed 100mm / s, powder feeding rate 35g / min, spray until the coating is 1.3mm higher than the substrate; ⑥ Disassemble the parts and clean the excess powder and fixtures from the blade surface;

[0047] S2.4 Post-spraying inspection: ① Five test points were selected on the area to be sprayed using an ultrasonic thickness gauge, with thicknesses of 1.12mm, 1.08mm, 1.15mm, 1.10mm, and 1.09mm, all meeting the requirements; ② The coating was visually inspected to ensure it was continuous and uniform, without defects such as peeling or blistering, and there was no residue in non-sprayed areas; ③ Tests on 2A11 specimens from the same batch showed: porosity 0.7%, bonding strength 31.2MPa, and peel strength from rubber 4.3kN / m;

[0048] S3. Mechanical grinding: The blade is clamped onto a special milling machine, the tail tip is pressed against the blade tip, and the sprayed area is milled with a carbide end mill to make its profile consistent with the original design. Then it is polished with 240# sandpaper, and the final surface roughness Ra=1.3μm.

[0049] S4. Subsequent protective treatment: ① Micro-arc oxidation: Sodium silicate-sodium hydroxide composite electrolyte is used, with an oxidation voltage of 400V and a current density of 10A / dm³. 2 ① Electrolyte temperature 30℃, oxidation time 25min; ② Spraying: spray two coats of anti-corrosion primer and one coat of topcoat according to the original process; ③ Apply 7μm thick epoxy zinc-rich primer to the blade edge and blade root transition area.

[0050] S5. Post-repair verification: Salt spray test (60mg / m²) was conducted on the blades. 3 The tests included 1200h, sand blowing test (sand particles 0.2mm, 90m / s), and vibration test (frequency 50-1800Hz, acceleration 80m / s²). 2After the test, the blades showed no coating peeling or substrate corrosion, and the surface accuracy met the requirements.

[0051] 3. Repair effect

[0052] After repair, the blade profile accuracy error is ≤0.05mm, the surface roughness Ra=1.3μm, and the performance of the repair layer meets the following requirements: porosity 0.7%, bonding strength 31.2MPa, and peel strength from rubber 4.3kN / m. After 12 months of marine environment simulation test, there is no obvious corrosion or wear, and it can be put into normal service.

[0053] Example 2

[0054] 1. Object to be repaired

[0055] The fan blades of the 2A11 die-forged aluminum alloy aircraft engine show localized wear on their surface due to airflow impact, with a wear area of ​​approximately 4 cm². 2 The maximum wear depth is 0.6 mm, and the repaired part must withstand vibration frequencies of 10-2000 Hz and salt spray concentrations of 50 mg / m³. 3 The service environment.

[0056] 2. Repair Steps

[0057] S1. Mechanical grinding: Use a manual grinding wheel to grind the worn areas, remove the worn layer and damaged protective layer, and expose the fresh substrate;

[0058] S2, Cold spraying:

[0059] S2.1 Surface inspection: No visible damage is observed. Use calipers to measure and determine the minimum thickness of the repair layer to be 0.8 mm.

[0060] S2.2 Pretreatment: Clean the area to be sprayed and the surrounding 60mm area with alcohol, blow dry with compressed air, and sand with 120-grit sandpaper to remove the oxide film;

[0061] S2.3 Spraying Operation: ① Fix the blades in the tooling to ensure stable positioning; ② Mix the powder in a mass ratio of 85:15, sieve through a 100-mesh sieve, and dry in a vacuum drying oven (-0.06MPa, 110℃) for 1 hour; ③ Cold spraying parameters: temperature 250℃, pressure 2.0MPa, spray gun moving speed 120mm / s, spray until the coating is 1.0mm higher than the substrate; ④ Monitor in real time with a laser thickness gauge. When the thickness reaches 0.72mm, increase the spray gun moving speed by 40% to 168mm / s;

[0062] S2.4 Post-coating inspection: Thickness meets standard, coating has no defects, specimen testing: porosity 0.9%, bond strength 28.7MPa, peel strength 4.0kN / m;

[0063] S3. Mechanical grinding: After milling, polish with 320# sandpaper to achieve Ra = 1.1μm;

[0064] S4. Subsequent protection: micro-arc oxidation (voltage 350V, time 20min, electrolyte temperature 25℃), spray painting, and edge coating with 6μm epoxy zinc-rich primer.

[0065] S5. Verification Test: Salt Spray Resistance Test (50mg / m³) 3 1500h), vibration test (acceleration 70m / s²) 2 All were qualified.

[0066] 3. Repair effect

[0067] After repair, the worn parts of the propeller blade were completely restored, the surface accuracy met the standards, and the repair layer had excellent wear resistance and vibration resistance, meeting the requirements for use in aero engines.

[0068] Example 3

[0069] 1. Object to be repaired

[0070] The 2A11 die-forged aluminum alloy blade has a corrosion depth of 0.7mm and requires a post-repair bonding strength of ≥27.5MPa and a porosity of ≤1%.

[0071] 2. Repair Steps

[0072] S1. Mechanical grinding: Sanding with a sander belt exposes the fresh substrate;

[0073] S2, Cold spraying: Mixed powder ratio 95:5, spraying temperature 380℃, pressure 2.8MPa, spray gun moving speed 80mm / s, powder drying conditions 80℃, 2h (vacuum degree -0.08MPa);

[0074] S3. Mechanical grinding: Polish with 400# sandpaper after milling, Ra=1.0μm;

[0075] S4. Subsequent protection: micro-arc oxidation (voltage 480V, time 35min), painting;

[0076] S5. Testing: The porosity of the repair layer is 0.8%, and the bonding strength is 29.3 MPa, which meets the requirements.

[0077] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Any adjustments or improvements made by those skilled in the art to process parameters, material selection, etc., without departing from the principles of the present invention, should be considered within the scope of protection of the present invention.

[0078] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0079] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A cold spraying repair method for aluminum alloy propeller blades, characterized in that, The method includes the following steps: S1. Mechanical grinding: Grind the corroded parts of the blades until the fresh aluminum alloy substrate is exposed. S2. Cold spraying: Perform the following sub-steps in sequence: S2.1 Surface Inspection: ① Visually confirm that there are no visible damages such as bumps, scratches, or abrasions on the area to be sprayed and its surroundings; ② Use tools with the required precision to measure the dimensions of the area to be sprayed and determine the minimum thickness of the repair layer; S2.2 Preprocessing: ① Surface cleaning: Clean the area to be sprayed and the surrounding area with alcohol or acetone, and then dry with compressed air; ②Oxide film removal: Use sandpaper to evenly sand the area to be sprayed, and blow away the surface debris after sanding; S2.3 Spraying Operation: ① Clamping: The blades are fixed to the spraying station using special tooling to ensure stable positioning; ②Powder preparation: Select a mixture of pure aluminum and Al2O3 powder, sieve it through a sieve, and then dry it in a drying oven; ③ Spray gun test: Check the spray gun for leaks of water and air by introducing compressed air; ④ Clean the area to be sprayed a second time and blow it dry; ⑤ Set the process parameters according to the thickness of the repair layer and the shape of the blade surface, and spray powder onto the area to be coated until the coating is higher than the surrounding substrate surface; ⑥ After the spraying is completed, remove the blades and clean the protective tooling and excess powder; S2.4 Post-coating inspection: ① Use a thickness gauge to select multiple evenly distributed detection points on the area to be sprayed; ② Visually inspect the coating to ensure it is continuous and uniform, without peeling or cracking defects, and that there is no coating residue in non-sprayed areas; ③ On aluminum alloy specimens from the same batch as the blades, the porosity, bonding strength, and peel strength from rubber of the comparative coatings formed by the same process were tested. S3. Mechanical grinding: The blade is clamped onto a special milling machine and milled to make the sprayed area conform to the blade profile and size requirements. Then, it is polished with sandpaper until the surface roughness meets the usage standards. S4. Subsequent protective treatment: Micro-arc oxidation and painting are carried out in sequence according to the original process specifications for aluminum alloy blades.

2. The cold spraying repair method for aluminum alloy propeller blades according to claim 1, characterized in that, The mass ratio of pure aluminum to Al2O3 mixed powder described in S2.3 is (85-95):(5-15).

3. The cold spraying repair method for aluminum alloy propeller blades according to claim 1, characterized in that, The cold spraying process parameters described in S2.3 are: spraying temperature 200-400℃, spraying gas pressure 1.5-3.0MPa, and spray gun moving speed 50-150mm / s.

4. The cold spraying repair method for aluminum alloy propeller blades according to claim 1, characterized in that, In the surface cleaning operation described in S2.2, if there is severe oil residue on the area to be sprayed, pre-clean with an alkaline degreasing agent with a pH of 8-10 for 1-3 minutes, and then perform the alcohol or acetone cleaning step.

5. The cold spraying repair method for aluminum alloy propeller blades according to claim 1, characterized in that, The specific conditions for powder drying described in S2.3 are: drying oven temperature 80-120℃, drying time 1-2h, and drying environment is a vacuum environment with a vacuum degree of -0.08 to -0.06MPa.

6. The cold spraying repair method for aluminum alloy propeller blades according to claim 1, characterized in that, During the spraying process described in S2.3, a laser thickness gauge is used to monitor the thickness of the repair layer in real time. When the monitored thickness reaches 90% of the preset minimum thickness, the spray gun moving speed is increased by 30-50%.

7. The cold spraying repair method for aluminum alloy propeller blades according to claim 1, characterized in that, During the milling process described in S3, water cooling is used to cool the milling cutter and the blade machining area, with a cooling water flow rate of 5-10 L / min.

8. The cold spraying repair method for aluminum alloy propeller blades according to claim 1, characterized in that, The micro-arc oxidation process parameters described in S4 are: oxidation voltage 300-500V, oxidation current density 5-15A / dm³. 2 The electrolyte temperature is 20-40℃, the oxidation time is 15-40 min, and the electrolyte is a sodium silicate-sodium hydroxide composite electrolyte.

9. The cold spraying repair method for aluminum alloy propeller blades according to claim 1, characterized in that, The method also includes S5, post-repair verification step: the sprayed blades are subjected to salt spray test, sandblasting test and vibration test. After the test, the blades show no coating peeling or substrate corrosion.

10. The cold spraying repair method for aluminum alloy propeller blades according to claim 1, characterized in that, After the painting process described in S4 is completed, an additional layer of epoxy zinc-rich primer with a thickness of 5-10μm is applied to the blade edge, the transition area between the blade root and the blade body.

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