Aluminum alloy profile surface highlight corrosion-resistant treatment process

Abstract

The invention discloses an aluminum alloy profile surface highlight corrosion-resistant treatment process which comprises the following steps: S1, pretreatment including degreasing and alkaline etching; s2, anodic oxidation; s3, chemical brightening treatment; s4, surface wiredrawing; s5, carrying out sand blasting; s6, highlight is conducted; s7, treating with a silane coupling agent; s8, carrying out secondary oxidation treatment; s9, performing nano-composite hole sealing; s10, spraying, printing and chemical brightening are used for replacing traditional mechanical polishing, so that the surface of the aluminum alloy profile is smoother, the uniformity of glossiness is improved, scratches possibly generated by mechanical polishing are avoided, stable chemical bonds are formed between the profile and a hole sealing layer through coupling agent treatment, the surface state is optimized, it can be ensured that a hole sealing agent can be attached more firmly, and the service life of the aluminum alloy profile is prolonged. According to the secondary oxidation treatment, an oxidation film is thickened after highlight treatment, the formed highlight surface is not affected, invasion of a corrosion medium is effectively blocked, nano-scale pores in the oxidation film are filled with nano silicon dioxide, a compact hole sealing layer is formed, and therefore the corrosion resistance of the workpiece is improved.

Description

Technical Field

[0001] This invention relates to the field of corrosion-resistant treatment processes for aluminum alloy surfaces, and particularly to a high-gloss corrosion-resistant treatment process for aluminum alloy profiles. Background Technology

[0002] Aluminum alloys are widely used in many fields such as construction, aerospace, and electronics due to their excellent properties, such as light weight, high strength, and good machinability. However, aluminum alloys are susceptible to corrosion in natural environments, which affects their service life and performance. At the same time, for some applications with high appearance requirements, such as electronic product casings and high-end architectural decoration, aluminum alloy profiles need to have a high-gloss finish.

[0003] Traditional surface treatment processes for aluminum alloy profiles include anodizing, electrophoretic coating, sandblasting, and polishing. While these methods have achieved certain results in improving the surface gloss and corrosion resistance of aluminum alloy profiles, they also have some shortcomings. Traditional anodizing, although forming an oxide film on the aluminum alloy surface and improving corrosion resistance to some extent, has a limited thickness and is easily damaged in complex environments. Chemical conversion coatings have poor adhesion and their protective effect is not long-lasting. Spraying processes suffer from problems such as easy coating peeling and affecting the original texture of the aluminum alloy. Furthermore, existing surface treatment processes often struggle to simultaneously guarantee good corrosion resistance while achieving a high-gloss finish, failing to meet market demands for high-performance and high-quality appearance in aluminum alloy profiles.

[0004] Therefore, this application provides a high-gloss corrosion-resistant surface treatment process for aluminum alloy profiles to solve the problems of insufficient corrosion resistance, difficulty in achieving both high gloss effect and corrosion resistance, and complex and costly processes in existing aluminum alloy profile surface treatment processes. Summary of the Invention

[0005] The purpose of this invention is to provide a high-gloss corrosion-resistant treatment process for aluminum alloy profiles, in order to solve the problems of insufficient corrosion resistance, difficulty in achieving both high gloss effect and corrosion resistance, and complex and costly processes in existing aluminum alloy profile surface treatment processes.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A high-gloss corrosion-resistant surface treatment process for aluminum alloy profiles includes the following steps: S1. Pretreatment: The aluminum alloy profile is placed in a degreasing tank for 4-5 minutes to remove oil stains from the surface of the aluminum alloy; the degreased aluminum alloy profile is then placed in an alkaline etching tank for 12-14 minutes to further clean the oil stains and dirt adhering to the surface of the aluminum alloy.

[0007] S2. Anodizing: Turn on the circulating cooling system and the supply and exhaust fans in the anodizing tank, and put the pre-treated aluminum alloy profiles into the anodizing tank for oxidation.

[0008] S3. Chemical brightening treatment: Immerse the aluminum alloy profile in the treatment solution at a temperature of 45~55℃ for 2~3 minutes. After treatment, rinse with pure water for 2~3 minutes to remove residual treatment agent from the surface and prevent contamination in subsequent processes.

[0009] S4. Surface brushing: The aluminum alloy profile is fixed on the brushing machine by the clamping device, the brushing machine is turned on and the surface of the aluminum alloy profile is brushed.

[0010] S5. Sandblasting: Check the liquid channel inside the sandblasting machine, and pre-set the distance and angle of the spray gun. Turn on the sandblasting machine to sandblast the aluminum alloy surface.

[0011] S6. High Gloss: The aluminum alloy is fixed on the worktable of the high gloss machine using a positioning fixture. The machining trajectory of the aluminum alloy is input into the control program of the high gloss machine. The high gloss machine is turned on, so that the milling cutter inside the high gloss machine performs high gloss processing according to the preset program.

[0012] S7. Silane coupling agent treatment: The high-gloss aluminum alloy profile is immersed in a KH-560 silane coupling agent solution with a mass concentration of 0.8~1.2%, and then dried after immersion at room temperature.

[0013] S8. Secondary oxidation treatment: The aluminum alloy profile treated with silane coupling agent is placed in an oxidation tank for secondary oxidation treatment. The oxide film is thickened on the basis of the first oxide film to improve corrosion resistance, while not affecting the high gloss effect.

[0014] S9. Nanocomposite sealing involves suspending aluminum alloy profiles into a sealing tank to seal the micropores of the oxide film layer, forming a dense oxide film. The tank solution is composed of sealing agent and water in a 2:17 ratio. The sealing agent is composed of the following parts by weight: 20-25 parts organic solvent, 20-23 parts nickel acetate, 15-17 parts sodium dodecylbenzenesulfonate, 3-5 parts hexamethylenediamine, and 1.5-2.5 parts nano silica; wherein the organic solvent is composed of methyltrichlorosilane and phenyltrichlorosilane in a mass ratio of 1:1.

[0015] S10. Spraying and printing: Spraying and screen printing are performed on aluminum alloys that have undergone sealing treatment to further improve the decorative and protective properties of the surface.

[0016] As a preferred embodiment of the present invention, in step S1, the bath solution in the degreasing tank is an acidic degreasing agent, and its components are as follows: , , and water, among which , , The content of each component is 2-3%; the solution in the alkaline etching tank is a mixture of NaOH and water at a mass ratio of 1:12; a rinsing process is set between and after the degreasing and alkaline etching steps, with pure water as the rinsing solution and a rinsing time of 2-3 minutes to remove residual degreasing agent and alkaline etching solution from the surface.

[0017] As a preferred embodiment of the present invention, in step S2, the solution in the oxidation tank is... It is mixed with water at a mass ratio of 1:10, and the oxidation time is 25~30 minutes.

[0018] As a preferred embodiment of the present invention, in step S3, the treatment liquid is composed of the following components by weight percentage: 60-70% phosphoric acid (85% by mass), 5-8% nitric acid (68% by mass), 10-15% sulfuric acid (98% by mass), 2-3% urea, and the remainder being water.

[0019] In a preferred embodiment of the present invention, in step S7, the soaking time is 2-3 minutes, the drying temperature is 50-60°C, and the drying time is 5-8 minutes.

[0020] As a preferred embodiment of the present invention, in step S8, the solution in the oxidation tank is... It is mixed with water at a mass ratio of 1:10, and the oxidation time is 10~12 minutes.

[0021] As a preferred embodiment of the present invention, in step S9, the temperature of the sealing solution in the sealing tank is 70~75℃, and the sealing time is the oxide film thickness × 1.1 min.

[0022] Compared with the prior art, the beneficial effects of the present invention are: 1. In this invention, the aluminum alloy profile after high-gloss treatment is treated with a silane coupling agent, thereby forming chemical bonds between the aluminum alloy surface and the subsequent sealing agent. This overcomes the limitation of the sealing layer relying on physical adsorption to bond with the substrate, significantly improving adhesion and reducing the risk of coating peeling. At the same time, the silane coupling agent can fill the tiny defects on the oxide film surface, and together with the pore-sealing effect of the sealing agent, further reduce the channels for corrosive media intrusion and improve overall corrosion resistance. In addition, the silane coupling agent molecules can optimize the micro-state of the aluminum alloy profile surface without damaging the structure and performance of the oxide film and high-gloss surface. It is compatible with the parameter requirements of processes such as anodizing and high-gloss treatment, and the operation is simple without adding extra complex equipment costs.

[0023] 2. This invention further thickens the initial oxide film through a secondary oxidation process without compromising its integrity. This enhances the ability to effectively block corrosive media such as water and salt, significantly extending the service life of the profile. The thicker oxide film formed by secondary oxidation provides a more sufficient pore structure for subsequent sealing processes, allowing the sealing agent to more fully fill the pores and further enhancing the density of the oxide film. Simultaneously, compared to primary oxidation, the film layer after secondary oxidation bonds more tightly with the surface textures formed by wire drawing and sandblasting, reducing the risk of coating peeling in subsequent spraying and printing processes and improving the stability of the entire process. Existing processes often result in blurred high-gloss surfaces due to thickened oxide films. This process, however, performs secondary oxidation after high-gloss treatment, with optimized parameters that only thicken the oxide film layer below the high-gloss surface, without affecting the already formed high-gloss surface finish. This solves the industry pain point of balancing improved corrosion resistance and high-gloss retention, meeting the stringent requirements of electronic product casings, high-end decorations, and other demanding aesthetic applications.

[0024] 3. In this invention, the use of nanocomposite sealing significantly improves the density of the sealing layer compared to traditional sealing agents that only seal the micropores of the oxide film. The addition of nano-silica allows for deep filling of the nanoscale pores of the oxide film. Combined with an organic resin-based system, this significantly blocks the intrusion channels of corrosive media. Simultaneously, the synergistic effect of nano-silica and the sealing agent components forms a denser protective layer. Combined with the thickened oxide film from secondary oxidation, this further extends the salt spray corrosion resistance time, solving the problem of short-lasting protection with traditional sealing agents and improving production efficiency. Furthermore, the uniform dispersion of nano-silica does not damage the microscopic smoothness of the high-gloss surface and exhibits good compatibility with subsequent spraying processes, balancing appearance and protective performance to meet the needs of high-end applications.

[0025] 4. In this invention, chemical brightening treatment replaces polishing devices for polishing. Chemical brightening treatment after oxidation results in more uniform polishing. Polishing devices rely on mechanical grinding, which can easily lead to uneven polishing in certain areas (such as residual burrs or differences in gloss) on irregularly shaped or complex cross-section profiles. Chemical brightening treatment, however, selectively dissolves burrs and protrusions on the oxidized surface using an acidic solution, ensuring uniform application across the entire surface of the profile. It is particularly suitable for complex structures such as curved and hollow shapes, avoiding the blind spots of mechanical polishing. Furthermore, the grinding wheel of a polishing device may cause localized thinning or scratches on the oxide film, while chemical brightening treatment only requires gentle grinding. Chemical brightening treatment can dissolve surface defects and completely preserve the initial oxide film structure, laying a more stable foundation for subsequent secondary oxidation. Furthermore, polishing equipment requires debugging of dual drive motors, positioning fixtures, etc., which is complex to operate and has high equipment maintenance costs. Chemical brightening treatment only requires room temperature immersion, without complex equipment, and can be seamlessly connected with the original water washing process, reducing equipment investment and production time. Moreover, there is no abrasive residue on the surface after chemical brightening treatment, and the micropores are more regular, which can enhance the consistency of subsequent wire drawing texture and improve the uniformity of bath solution adsorption during secondary oxidation. The synergistic effect with subsequent processes is better than mechanical polishing. Attached Figure Description

[0026] Figure 1 This is a process flow diagram of the high-gloss corrosion-resistant surface treatment of aluminum alloy profiles according to the present invention; Figure 2 Here is a scanning electron microscope image of the surface of the aluminum alloy profile prepared in Example 1; Figure 3 The image shows a scanning electron microscope (SEM) image of the surface of the aluminum alloy profile prepared in Comparative Example 3. Detailed Implementation

[0027] 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.

[0028] Applying silane coupling agent treatment to the surface of high-gloss aluminum alloy profiles significantly improves the adhesion between the sealing layer and the aluminum alloy substrate. By using the silane coupling agent, chemical bonds are formed between the aluminum alloy surface and the subsequent sealing agent, rather than relying solely on physical adsorption. This improvement effectively reduces the risk of coating peeling and fills minor defects in the oxide film surface with the silane coupling agent, enhancing overall sealing performance. Compared to traditional technologies, this process effectively prevents corrosive media from penetrating the aluminum alloy surface, improving corrosion resistance.

[0029] Secondary oxidation treatment enhances the corrosion resistance of aluminum alloy profiles by further thickening the film layer on the basis of the initial oxide film, significantly improving the service life of the profiles. This process can enhance the sealing performance of the oxide film without damaging the integrity of the film layer, thereby effectively blocking the intrusion of corrosive media such as moisture and salt. Through this thickening treatment, the overall density and corrosion resistance of the oxide film are significantly improved. The thicker oxide film formed by secondary oxidation provides a more ample pore structure for subsequent sealing processes, allowing the sealing agent to fill the pores more thoroughly. This further improves the film's density and enhances its protective performance. Simultaneously, compared to primary oxidation, the film layer after secondary oxidation bonds more tightly to surface textures such as wire drawing and sandblasting, reducing the risk of coating peeling during subsequent processes like spraying and printing. This improves the stability of the entire process. Furthermore, traditional processes often blur the high-gloss surface when thickening the oxide film, affecting surface finish. This process, however, performs secondary oxidation after high-gloss treatment. Through parameter optimization, the oxide film layer is thickened only below the high-gloss surface, ensuring that the high-gloss surface maintains its original smoothness and visual effect. This successfully resolves the contradiction between improved corrosion resistance and high-gloss surface preservation. This innovative process meets the stringent appearance requirements of applications such as electronic product casings and high-end decorations, becoming the industry's best solution for balancing corrosion resistance and surface finish.

[0030] Traditional sealing agents typically only seal the micropores in oxide films. However, by using nanocomposite sealing technology combined with the application of nano-silica, these nanoscale pores in the oxide film can be deeply filled, significantly improving the density of the sealing layer. This improvement effectively blocks the intrusion channels of corrosive media, significantly enhancing the protective performance of aluminum alloy profiles. Simultaneously, the synergistic effect of nano-silica and the organic resin-based system in the sealing agent forms a denser protective layer, significantly improving the corrosion resistance of the oxide film. Combined with the oxide film thickened by a secondary oxidation process, this composite sealing technology effectively extends salt spray corrosion resistance time, solving the problem of the short-lasting protective effect of traditional sealing agents, thereby improving production efficiency and product quality. Furthermore, nano-silica has excellent dispersibility and uniformity, and can be compatible with subsequent spraying processes without compromising the microscopic smoothness of the high-gloss surface, ensuring that surface finish is unaffected. This allows the technology to not only meet high-end appearance requirements but also maintain excellent protective performance.

[0031] Replacing traditional mechanical polishing with chemical brightening treatment can significantly improve the surface quality of aluminum alloy profiles and solve the problems existing in traditional polishing processes. Chemical brightening treatment uses an acidic solution to uniformly treat the oxide film surface, which can effectively remove surface defects such as burrs and protrusions. Through selective dissolution, it avoids the uneven polishing phenomenon (such as burr residue and gloss difference) that is easy to occur during mechanical grinding. This method is especially suitable for processing complex structures such as arcs and hollows, avoiding the "blind spots" that are difficult to reach in mechanical polishing. Furthermore, the grinding of traditional polishing devices may cause localized thinning of the oxide film or even scratches, while chemical brightening treatment only gently dissolves surface defects, completely preserving the structure of the oxide film. This provides a more stable foundation for subsequent secondary oxidation. In contrast, chemical brightening treatment not only protects the integrity of the film layer but also avoids problems caused by mechanical wear. At the same time, chemical brightening treatment is simple to operate, requiring no complex debugging or equipment maintenance. Traditional polishing devices require dual drive motors, positioning fixtures, and other equipment, making operation cumbersome and maintenance costs high. Chemical brightening treatment only requires immersion at room temperature, which can be seamlessly integrated with existing water washing processes, reducing equipment investment and production time. After chemical brightening treatment, there is no abrasive residue on the surface, and the micropores are more regular. This not only helps improve the consistency of the subsequent wire drawing texture but also enhances the uniform adsorption of the bath solution during secondary oxidation, improving the synergistic effect of subsequent processes.

[0032] like Figure 1 As shown, a high-gloss corrosion-resistant surface treatment process for aluminum alloy profiles includes the following steps: S1. Pretreatment: The aluminum alloy profile is placed in a degreasing tank for 4-5 minutes to remove oil stains from the surface of the aluminum alloy; the degreased aluminum alloy profile is then placed in an alkaline etching tank for 12-14 minutes to further clean the oil stains and dirt adhering to the surface of the aluminum alloy. S2. Anodizing: Turn on the circulating cooling system and the supply and exhaust fans in the anodizing tank, and put the pre-treated aluminum alloy profiles into the anodizing tank for oxidation; S3. Chemical brightening treatment: Immerse the aluminum alloy profile in the treatment solution at a temperature of 45~55℃ for 2~3 minutes. After treatment, rinse with pure water for 2~3 minutes to remove residual treatment agent from the surface and prevent contamination in subsequent processes. S4. Surface brushing: The aluminum alloy profile is fixed on the brushing machine by the clamping device, the brushing machine is turned on and the surface of the aluminum alloy profile is brushed. S5. Sandblasting: Check the liquid channel inside the sandblasting machine, and pre-set the distance and angle of the spray gun. Turn on the sandblasting machine to sandblast the aluminum alloy surface. S6. High Gloss: Fix the aluminum alloy on the high gloss machine worktable using a positioning fixture, input the aluminum alloy processing trajectory into the high gloss machine's control program, turn on the high gloss machine, and let the milling cutter inside the high gloss machine perform high gloss processing according to the preset program; S7. Silane coupling agent treatment: The high-gloss aluminum alloy profile is immersed in a KH-560 silane coupling agent solution with a mass concentration of 0.8~1.2%, and then dried after immersion at room temperature; S8. Secondary oxidation treatment: The aluminum alloy profile treated with silane coupling agent is placed in an oxidation tank for secondary oxidation treatment. The oxide film is thickened on the basis of the first oxide film to improve corrosion resistance, while not affecting the high gloss effect. S9. Nanocomposite sealing: An aluminum alloy profile is suspended into a sealing tank to seal the micropores of the oxide film layer, forming a dense oxide film. The tank solution is composed of a sealing agent and water in a 2:17 ratio. The sealing agent is composed of the following parts by weight: 20-25 parts organic solvent, 20-23 parts nickel acetate, 15-17 parts sodium dodecylbenzenesulfonate, 3-5 parts hexamethylenediamine, and 1.5-2.5 parts nano silica. The organic solvent is composed of methyltrichlorosilane and phenyltrichlorosilane in a 1:1 mass ratio. S10. Spraying and printing: Spraying and screen printing are performed on aluminum alloys that have undergone sealing treatment to further improve the decorative and protective properties of the surface.

[0033] All raw materials used in this invention are commercially available.

[0034] Example 1:

[0035] A high-gloss corrosion-resistant surface treatment process for aluminum alloy profiles includes the following steps: S1. Pretreatment: The aluminum alloy profile is placed in a degreasing tank for 5 minutes to remove oil stains from the surface of the aluminum alloy, and then rinsed with pure water for 3 minutes; the degreased aluminum alloy profile is placed in an alkaline etching tank for 14 minutes to further clean the oil stains and dirt attached to the surface of the aluminum alloy, and then rinsed with pure water for 3 minutes. S2. Anodizing: Turn on the circulating cooling system and exhaust fans in the anodizing tank, and place the pre-treated aluminum alloy profile into the anodizing tank for oxidation. The solution in the anodizing tank is... It is mixed with water at a mass ratio of 1:10, and the oxidation time is 30 minutes. S3. Chemical brightening treatment: The aluminum alloy profile is placed in the treatment solution, which is composed of the following by weight percentages: 70% phosphoric acid (85% concentration), 8% nitric acid (68% concentration), 15% sulfuric acid (98% concentration), 3% urea, and water as the remainder. The treatment temperature is 55℃, and the time is 3 minutes. After treatment, the surface is rinsed with pure water for 3 minutes to remove any residual treatment agent and prevent contamination in subsequent processes. S4. Surface brushing: The aluminum alloy profile is fixed on the brushing machine by the clamping device, the brushing machine is turned on and the surface of the aluminum alloy profile is brushed. S5. Sandblasting: Check the liquid channel inside the sandblasting machine, and pre-set the distance and angle of the spray gun. Turn on the sandblasting machine to sandblast the aluminum alloy surface. S6. High Gloss: Fix the aluminum alloy on the high gloss machine worktable using a positioning fixture, input the aluminum alloy processing trajectory into the high gloss machine's control program, turn on the high gloss machine, and let the milling cutter inside the high gloss machine perform high gloss processing according to the preset program; S7. Silane coupling agent treatment: The high-gloss aluminum alloy profile is immersed in a 1.2% KH-560 silane coupling agent solution at room temperature for 3 minutes, and then dried at 60℃ for 8 minutes. S8. Secondary oxidation treatment: The aluminum alloy profile treated with silane coupling agent is placed in an oxidation tank for secondary oxidation treatment, wherein the solution in the oxidation tank is... It is mixed with water at a mass ratio of 1:10 and the oxidation time is 12 minutes. It further thickens the oxide film on the basis of the first oxide film, improves corrosion resistance, and does not affect the high gloss effect. S9. Nanocomposite sealing: The aluminum alloy profile is suspended into the sealing tank to seal the micropores of the oxide film layer and form a dense oxide film. The temperature of the sealing tank liquid is 75℃ and the sealing time is oxide film thickness × 1.1min. The sealing tank solution is composed of a sealing agent and water in a ratio of 2:17. The sealing agent is composed of the following parts by weight: 20 parts organic solvent, 20 parts nickel acetate, 15 parts sodium dodecylbenzenesulfonate, 3 parts hexamethylenediamine, and 1.5 parts nano silica; wherein the organic solvent is composed of methyltrichlorosilane and phenyltrichlorosilane in a mass ratio of 1:1. S10. Spraying and printing: Spraying and screen printing are performed on aluminum alloys that have undergone sealing treatment to further improve the decorative and protective properties of the surface.

[0036] Example 2:

[0037] A high-gloss corrosion-resistant surface treatment process for aluminum alloy profiles includes the following steps: S1. Pretreatment: The aluminum alloy profile is placed in a degreasing tank for 4 minutes to remove oil stains from the surface of the aluminum alloy, and then rinsed with pure water for 2 minutes; the degreased aluminum alloy profile is placed in an alkaline etching tank for 12 minutes to further clean the oil stains and dirt attached to the surface of the aluminum alloy, and then rinsed with pure water for 2 minutes. S2. Anodizing: Turn on the circulating cooling system and exhaust fans in the anodizing tank, and place the pre-treated aluminum alloy profile into the anodizing tank for oxidation. The solution in the anodizing tank is... It is mixed with water at a mass ratio of 1:10, and the oxidation time is 25 minutes. S3. Chemical brightening treatment: The aluminum alloy profile is placed in the treatment solution, which is composed of the following by weight percentages: 60% phosphoric acid (85% concentration), 5% nitric acid (68% concentration), 10% sulfuric acid (98% concentration), 2% urea, and water as the remainder. The treatment temperature is 45℃, and the time is 2 minutes. After the treatment, the surface is rinsed with pure water for 2 minutes to remove any residual treatment agent and prevent contamination in subsequent processes. S4. Surface brushing: The aluminum alloy profile is fixed on the brushing machine by the clamping device, the brushing machine is turned on and the surface of the aluminum alloy profile is brushed. S5. Sandblasting: Check the liquid channel inside the sandblasting machine, and pre-set the distance and angle of the spray gun. Turn on the sandblasting machine to sandblast the aluminum alloy surface. S6. High Gloss: Fix the aluminum alloy on the high gloss machine worktable using a positioning fixture, input the aluminum alloy processing trajectory into the high gloss machine's control program, turn on the high gloss machine, and let the milling cutter inside the high gloss machine perform high gloss processing according to the preset program; S7. Silane coupling agent treatment: The high-gloss aluminum alloy profile is immersed in a KH-560 silane coupling agent solution with a mass concentration of 0.8% for 2 minutes at room temperature, and then dried at 50℃ for 5 minutes. S8. Secondary oxidation treatment: The aluminum alloy profile treated with silane coupling agent is placed in an oxidation tank for secondary oxidation treatment, wherein the solution in the oxidation tank is... It is mixed with water at a mass ratio of 1:10 and the oxidation time is 10 minutes. It further thickens the oxide film on the basis of the first oxide film, improves corrosion resistance, and does not affect the high gloss effect. S9. Nanocomposite sealing: The aluminum alloy profile is suspended into the sealing tank to seal the micropores of the oxide film layer and form a dense oxide film. The temperature of the liquid in the sealing tank is 70℃ and the sealing time is oxide film thickness × 1.1min. The sealing tank solution is composed of a sealing agent and water in a ratio of 2:17. The sealing agent is composed of the following parts by weight: 20 parts organic solvent, 20 parts nickel acetate, 15 parts sodium dodecylbenzenesulfonate, 3 parts hexamethylenediamine, and 1.5 parts nano silica; wherein the organic solvent is composed of methyltrichlorosilane and phenyltrichlorosilane in a mass ratio of 1:1. S10. Spraying and printing: Spraying and screen printing are performed on aluminum alloys that have undergone sealing treatment to further improve the decorative and protective properties of the surface.

[0038] Example 3:

[0039] A high-gloss corrosion-resistant surface treatment process for aluminum alloy profiles includes the following steps: S1. Pretreatment: The aluminum alloy profile is placed in a degreasing tank for 4.5 minutes to remove oil stains from the surface of the aluminum alloy, and then rinsed with pure water for 2.5 minutes; the degreased aluminum alloy profile is placed in an alkaline etching tank for 13 minutes to further clean the oil stains and dirt attached to the surface of the aluminum alloy, and then rinsed with pure water for 2.5 minutes. S2. Anodizing: Turn on the circulating cooling system and exhaust fans in the anodizing tank, and place the pre-treated aluminum alloy profile into the anodizing tank for oxidation. The solution in the anodizing tank is... It is mixed with water at a mass ratio of 1:10, and the oxidation time is 27 minutes. S3. Chemical brightening treatment: The aluminum alloy profile is immersed in a treatment solution, which is composed of the following by weight percentages: 65% phosphoric acid (85% concentration), 6% nitric acid (68% concentration), 12% sulfuric acid (98% concentration), 2% urea, and water as the remainder. The treatment temperature is 50℃, and the time is 2 minutes. After treatment, the surface is rinsed with pure water for 2.5 minutes to remove any residual treatment agent and prevent contamination in subsequent processes. S4. Surface brushing: The aluminum alloy profile is fixed on the brushing machine by the clamping device, the brushing machine is turned on and the surface of the aluminum alloy profile is brushed. S5. Sandblasting: Check the liquid channel inside the sandblasting machine, and pre-set the distance and angle of the spray gun. Turn on the sandblasting machine to sandblast the aluminum alloy surface. S6. High Gloss: Fix the aluminum alloy on the high gloss machine worktable using a positioning fixture, input the aluminum alloy processing trajectory into the high gloss machine's control program, turn on the high gloss machine, and let the milling cutter inside the high gloss machine perform high gloss processing according to the preset program; S7. Silane coupling agent treatment: The high-gloss aluminum alloy profile is immersed in a 1.0% KH-560 silane coupling agent solution at room temperature for 2 minutes and then dried at 55℃ for 6 minutes. S8. Secondary oxidation treatment: The aluminum alloy profile treated with silane coupling agent is placed in an oxidation tank for secondary oxidation treatment, wherein the solution in the oxidation tank is... It is mixed with water at a mass ratio of 1:10 and the oxidation time is 11 minutes. It further thickens the oxide film on the basis of the first oxide film, improves corrosion resistance, and does not affect the high gloss effect. S9. Nanocomposite sealing: The aluminum alloy profile is suspended into the sealing tank to seal the micropores of the oxide film layer and form a dense oxide film. The temperature of the liquid in the sealing tank is 72℃ and the sealing time is oxide film thickness × 1.1min. The sealing tank solution is composed of a sealing agent and water in a ratio of 2:17. The sealing agent is composed of the following parts by weight: 20 parts organic solvent, 20 parts nickel acetate, 15 parts sodium dodecylbenzenesulfonate, 3 parts hexamethylenediamine, and 1.5 parts nano silica; wherein the organic solvent is composed of methyltrichlorosilane and phenyltrichlorosilane in a mass ratio of 1:1. S10. Spraying and printing: Spraying and screen printing are performed on aluminum alloys that have undergone sealing treatment to further improve the decorative and protective properties of the surface.

[0040] Example 4:

[0041] A high-gloss corrosion-resistant surface treatment process for aluminum alloy profiles includes the following steps: S1. Pretreatment: The aluminum alloy profile is placed in a degreasing tank for 5 minutes to remove oil stains from the surface of the aluminum alloy, and then rinsed with pure water for 3 minutes; the degreased aluminum alloy profile is placed in an alkaline etching tank for 14 minutes to further clean the oil stains and dirt attached to the surface of the aluminum alloy, and then rinsed with pure water for 3 minutes. S2. Anodizing: Turn on the circulating cooling system and exhaust fans in the anodizing tank, and place the pre-treated aluminum alloy profile into the anodizing tank for oxidation. The solution in the anodizing tank is... It is mixed with water at a mass ratio of 1:10, and the oxidation time is 30 minutes. S3. Chemical brightening treatment: The aluminum alloy profile is placed in the treatment solution, which is composed of the following by weight percentages: 70% phosphoric acid (85% concentration), 8% nitric acid (68% concentration), 15% sulfuric acid (98% concentration), 3% urea, and water as the remainder. The treatment temperature is 55℃, and the time is 3 minutes. After treatment, the surface is rinsed with pure water for 3 minutes to remove any residual treatment agent and prevent contamination in subsequent processes. S4. Surface brushing: The aluminum alloy profile is fixed on the brushing machine by the clamping device, the brushing machine is turned on and the surface of the aluminum alloy profile is brushed. S5. Sandblasting: Check the liquid channel inside the sandblasting machine, and pre-set the distance and angle of the spray gun. Turn on the sandblasting machine to sandblast the aluminum alloy surface. S6. High Gloss: Fix the aluminum alloy on the high gloss machine worktable using a positioning fixture, input the aluminum alloy processing trajectory into the high gloss machine's control program, turn on the high gloss machine, and let the milling cutter inside the high gloss machine perform high gloss processing according to the preset program; S7. Silane coupling agent treatment: The high-gloss aluminum alloy profile is immersed in a 1.2% KH-560 silane coupling agent solution at room temperature for 3 minutes, and then dried at 60℃ for 8 minutes. S8. Secondary oxidation treatment: The aluminum alloy profile treated with silane coupling agent is placed in an oxidation tank for secondary oxidation treatment, wherein the solution in the oxidation tank is... It is mixed with water at a mass ratio of 1:10 and the oxidation time is 12 minutes. It further thickens the oxide film on the basis of the first oxide film, improves corrosion resistance, and does not affect the high gloss effect. S9. Nanocomposite sealing: The aluminum alloy profile is suspended into the sealing tank to seal the micropores of the oxide film layer and form a dense oxide film. The temperature of the sealing tank liquid is 75℃ and the sealing time is oxide film thickness × 1.1min. The sealing tank solution is composed of a sealing agent and water in a ratio of 2:17. The sealing agent is composed of the following parts by weight: 25 parts organic solvent, 23 parts nickel acetate, 17 parts sodium dodecylbenzenesulfonate, 5 parts hexamethylenediamine, and 2.5 parts nano silica; wherein the organic solvent is composed of methyltrichlorosilane and phenyltrichlorosilane in a mass ratio of 1:1. S10. Spraying and printing: Spraying and screen printing are performed on aluminum alloys that have undergone sealing treatment to further improve the decorative and protective properties of the surface.

[0042] Comparative Example 1: The difference from Example 1 is that the silane coupling agent treatment step is removed.

[0043] Comparative Example 2: The difference from Example 1 is that the secondary oxidation treatment is removed.

[0044] Comparative Example 3: The difference from Example 1 is that the nano-silica in the sealing agent is removed.

[0045] Comparative Example 4: The difference from Example 1 is that the chemical brightening treatment is replaced with mechanical polishing.

[0046] The high-gloss, corrosion-resistant aluminum alloy profiles obtained in Examples 1, 2, 3, and 4 and Comparative Examples 1, 2, 3, and 4 were used to prepare samples. Their properties were tested and the test results were recorded. ASTM D523 was used as the reference standard. A gloss meter was used to test the gloss of the samples. The test angle was 20°, and the test was performed 5 times. The arithmetic mean was taken. The corrosion resistance was determined using the GB / T20854-2007 method. The results are shown in Table 1.

[0047] Table 1: Test results for gloss and corrosion resistance of aluminum alloy profiles

[0048] As shown in Table 1, in general, the aluminum alloy profiles treated in Examples 1, 2, 3, and 4 have better gloss and corrosion resistance compared to Comparative Examples 1, 2, 3, and 4.

[0049] Chemical brightening treatment replaces traditional mechanical polishing. An acidic solution selectively dissolves burrs and protrusions on the oxide film surface, resulting in a smoother surface, improved gloss uniformity, and avoidance of scratches that can occur with mechanical grinding. This ensures the integrity of the high-gloss texture and preserves the complete oxide film structure, providing a stable foundation for subsequent protective processes and indirectly enhancing the material's corrosion resistance. Silane coupling agent treatment forms stable chemical bonds between the profile and the sealing layer, optimizing the surface condition and ensuring stronger adhesion of the sealing agent and coating. This reduces gloss loss due to coating peeling. Simultaneously, the silane coupling agent fills micro-defects in the oxide film, working synergistically with the sealing process to further seal corrosion channels and improve corrosion resistance. Secondary oxidation treatment thickens the oxide film after high-gloss treatment without affecting the already formed high-gloss surface, ensuring consistent gloss. The thickened oxide film more effectively blocks the intrusion of corrosive media. Working together with the primary oxide film, it significantly extends salt spray corrosion resistance time and greatly improves corrosion resistance. Finally, the nanocomposite sealing technology fills the nanoscale pores in the oxide film with nano-silica to form a dense sealing layer, ensuring that the smoothness and gloss of the high-gloss surface are not affected. This dense sealing layer can effectively isolate corrosive media such as moisture and salt, forming a double protection with the oxide film, greatly improving corrosion resistance and solving the problem of the short-lasting protective effect of traditional sealing agents.

[0050] Figure 2 and Figure 3 The images show scanning electron microscope (SEM) images of the aluminum alloy profiles prepared in Example 1 and Comparative Example 3, respectively. The images reveal significant differences in the surface microstructure of the two samples. The sample containing nano-silica exhibits a continuous and dense morphology, while the sample without nano-silica shows obvious micropores and microcracks, poor film integrity, and a loose structure. Nano-silica effectively blocks the pores of the oxide film; its nano-size allows it to fill even the smallest pores, a physical sealing effect that cannot be achieved solely by nickel acetate hydrolysis products. Furthermore, the nanoparticles act as a framework and reinforcing phase during the curing process of the sealing agent, significantly improving the mechanical strength of the sealing layer and preventing cracks caused by stress shrinkage during drying and curing, forming a composite barrier. Without nano-silica, the sealing layer relies solely on organic matter and nickel salts, resulting in a significant decrease in density, continuity, and mechanical strength, making it prone to defects.

[0051] In summary, the aluminum alloy profiles treated by this invention not only significantly improve gloss and appearance quality, but also effectively extend corrosion resistance, meeting the dual requirements of high-end products for aesthetics and functionality.

[0052] The above are merely specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent substitutions, or modifications made based on the present invention to solve essentially the same technical problems and achieve essentially the same technical effects are all covered within the protection scope of the present invention.

Claims

1. A high-gloss corrosion-resistant surface treatment process for aluminum alloy profiles, characterized in that, The process includes pretreatment, anodizing, chemical brightening, surface brushing, sandblasting, high gloss, silane coupling agent treatment, secondary oxidation, nanocomposite sealing, spraying, and printing. The specific steps are as follows: S1. Pretreatment: The aluminum alloy profile is placed in a degreasing tank for 4-5 minutes to remove oil stains from the surface of the aluminum alloy; the degreased aluminum alloy profile is then placed in an alkaline etching tank for 12-14 minutes to further clean the oil stains and dirt adhering to the surface of the aluminum alloy. S2. Anodizing: Turn on the circulating cooling system and the supply and exhaust fans in the anodizing tank, and put the pre-treated aluminum alloy profiles into the anodizing tank for oxidation; S3. Chemical brightening treatment: Immerse the aluminum alloy profile in the treatment solution at a temperature of 45~55℃ for 2~3 minutes. After treatment, rinse with pure water for 2~3 minutes. S4. Surface brushing: The aluminum alloy profile is fixed on the brushing machine by the clamping device, the brushing machine is turned on and the surface of the aluminum alloy profile is brushed. S5. Sandblasting: Check the liquid channel inside the sandblasting machine, and pre-set the distance and angle of the spray gun. Turn on the sandblasting machine to sandblast the aluminum alloy surface. S6. High Gloss: Fix the aluminum alloy on the high gloss machine worktable using a positioning fixture, input the aluminum alloy processing trajectory into the high gloss machine's control program, turn on the high gloss machine, and let the milling cutter inside the high gloss machine perform high gloss processing according to the preset program; S7. Silane coupling agent treatment: The high-gloss aluminum alloy profile is immersed in a KH-560 silane coupling agent solution with a mass concentration of 0.8~1.2%, and then dried after immersion at room temperature; S8. Secondary oxidation treatment: The aluminum alloy profile treated with silane coupling agent is placed in an oxidation tank for secondary oxidation treatment. S9. Nanocomposite sealing involves suspending aluminum alloy profiles into a sealing tank to seal the micropores of the oxide film layer, forming a dense oxide film. The tank solution is composed of sealing agent and water in a 2:17 ratio. The sealing agent is composed of the following parts by weight: 20-25 parts organic solvent, 20-23 parts nickel acetate, 15-17 parts sodium dodecylbenzenesulfonate, 3-5 parts hexamethylenediamine, and 1.5-2.5 parts nano silica; wherein the organic solvent is composed of methyltrichlorosilane and phenyltrichlorosilane in a mass ratio of 1:

1. S10. Spraying and printing: Spraying and screen printing on aluminum alloys that have undergone sealing treatment.

2. The high-gloss corrosion-resistant surface treatment process for aluminum alloy profiles according to claim 1, characterized in that, In step S1, the solution in the degreasing tank is an acidic degreasing agent, and its components are... , , and water, among which , , The content of each component is 2-3%; the solution in the alkaline etching tank is a mixture of NaOH and water at a mass ratio of 1:12; a rinsing process is set between the degreasing and alkaline etching steps and after the alkaline etching step, with pure water as the rinsing solution and a rinsing time of 2-3 minutes.

3. The high-gloss corrosion-resistant surface treatment process for aluminum alloy profiles according to claim 1, characterized in that, In step S2, the solution in the oxidation tank is... It is mixed with water at a mass ratio of 1:10, and the oxidation time is 25~30 minutes.

4. The high-gloss corrosion-resistant surface treatment process for aluminum alloy profiles according to claim 1, characterized in that, In S3, the treatment solution is composed of the following components by weight percentage: 60-70% phosphoric acid (85% by mass), 5-8% nitric acid (68% by mass), 10-15% sulfuric acid (98% by mass), 2-3% urea, and the remainder is water.

5. The high-gloss corrosion-resistant surface treatment process for aluminum alloy profiles according to claim 1, characterized in that, In step S7, the soaking time is 2-3 minutes, the drying temperature is 50-60℃, and the drying time is 5-8 minutes.

6. The high-gloss corrosion-resistant surface treatment process for aluminum alloy profiles according to claim 1, characterized in that, In step S8, the solution in the oxidation tank is It is mixed with water at a mass ratio of 1:10, and the oxidation time is 10~12 minutes.

7. The high-gloss corrosion-resistant surface treatment process for aluminum alloy profiles according to claim 1, characterized in that, In S9, the temperature of the sealing solution in the sealing tank is 70~75℃, and the sealing time is the oxide film thickness × 1.1 min.

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