Aluminum material surface treatment process and nano coating material used for same

Abstract

The invention relates to the technical field of surface treatment, and discloses an aluminum material surface treatment process and a nano coating material applied to the process. According to the aluminum material surface treatment process, the aluminum material is subjected to the multiple process steps of pretreatment, furnace charging, vacuumizing, silicon plating, evaporation deposition, cooling and the like, so that the adhesive force of a surface coating of a prepared aluminum material surface treatment process product reaches the level of 0, and the salt fog resistance and the impact resistance are excellent. According to the aluminum material surface treatment process, the nanometer coating material is introduced in the evaporation deposition step, and under the synergistic effect of all components of the nanometer coating material, the comprehensive performance of the surface of a product obtained through the aluminum material surface treatment process is remarkably improved.

Description

Technical Field

[0001] This application relates to the field of surface treatment technology, and in particular to a surface treatment process for aluminum materials and its products. Background Technology

[0002] Due to its lightweight and ease of processing, aluminum is widely used in electronic equipment, automotive parts, and home decoration. To enhance the surface aesthetics and environmental resistance of aluminum, anodizing is often used to form an oxide film on its surface. This improves the aluminum's wear resistance and corrosion resistance to some extent, and the oxide film can also be colored to meet different aesthetic requirements. However, with the widespread application of aluminum and its anodized finish in numerous fields, market demands for surface performance are increasing. After anodizing, aluminum is often coated with a layer of paint using methods such as spraying, dipping, or brushing to seal pores and improve corrosion resistance.

[0003] However, these existing technologies have significant drawbacks. Traditional sealing methods such as spraying, dipping, and brushing are difficult to achieve uniform sealing, resulting in micropores remaining on the aluminum surface. These micropores easily absorb moisture, dust, and sweat, affecting not only aesthetics but also accelerating corrosion. Furthermore, the anodized layer itself has limited salt spray resistance and insufficient impact resistance. Traditional coatings alone cannot pass long-term corrosion and impact tests. Increasing the coating thickness can improve the corrosion resistance and impact resistance of the aluminum surface coating to some extent, but excessive thickness will obscure the natural texture and color of the anodized layer, affecting its decorative properties. Summary of the Invention

[0004] To at least overcome one of the problems existing in the prior art, one objective of this application is to provide an aluminum surface treatment process that, through multiple process steps such as pretreatment, furnace loading, vacuuming, silicon plating, evaporation deposition, and cooling, produces an aluminum surface-treated product with a surface coating that exhibits strong adhesion, excellent salt spray resistance, and superior impact resistance. A second objective of this application is to provide a nano-coating material for this aluminum surface treatment process.

[0005] Therefore, this application adopts the following technical solution: The first aspect of this application provides a surface treatment process for aluminum materials, including the following steps: S1. Pretreatment: Anodize the aluminum material, clean and dry it to obtain anodized aluminum material; S2. Loading and Vacuuming: Place the anodized aluminum material into the vacuum evaporation furnace and evacuate it. S3, Silicon plating: Gas is introduced, and then voltage is applied to deposit the silicon source on the surface of the anodic aluminum material to obtain silicon-plated aluminum material; S4. Evaporation Deposition: Introduce the nano-coating material, turn on the evaporation power supply, and evaporate and deposit the nano-coating material onto the surface of the silicon-coated aluminum material. S5. Cooling: Cool and remove to obtain aluminum surface-treated products.

[0006] In the aluminum surface treatment process of this application, step S1, pretreatment, involves anodizing to form a uniform, porous oxide film on the aluminum surface, providing a good adhesion substrate for subsequent coatings and improving surface hardness and corrosion resistance. Step S2, vacuuming, effectively removes air from the furnace, ensuring the purity of the subsequent processing environment. Step S3, silicon plating, through the control of gas flow and voltage, allows the silicon source to be uniformly deposited on the anodized aluminum surface, forming a dense silicon layer, further enhancing the chemical stability of the aluminum. Step S4, the evaporation and deposition of nano-coating materials on the silicon-plated aluminum surface forms a functional protective layer, further improving the corrosion resistance of the aluminum. The entire process is tightly integrated, with each step working synergistically to ultimately obtain aluminum surface-treated products with strong adhesion, excellent corrosion resistance, and superior impact resistance.

[0007] Preferably, in step S1, the electrolyte for anodizing is 160-190 g / L sulfuric acid and 2-3 g / L citric acid; the anodizing temperature is 18-21°C; the anodizing voltage is 16-18 V; the anodizing time is 25-40 min; after anodizing, the sample is rinsed with water; and the drying temperature is 70-90°C, with a drying time of 10-15 min. More preferably, in step S1, the electrolyte for anodizing is 170-190 g / L sulfuric acid and 2.5-3 g / L citric acid; the anodizing temperature is 19-21°C; the anodizing voltage is 16.5-18 V; the anodizing time is 30-40 min; after anodizing, the sample is rinsed with water; and the drying temperature is 80-90°C, with a drying time of 12-15 min.

[0008] In step S1, a uniform and porous oxide film is formed on the aluminum surface through anodizing, providing a good adhesion substrate for subsequent coatings. Controlling the drying temperature within the range of 70~90℃ effectively evaporates residual moisture on the aluminum surface after anodizing, while avoiding excessive temperature that could cause the oxide film to crack or structurally damage, thus ensuring the integrity of the oxide film. Drying within 10~15 minutes ensures sufficient evaporation of moisture, while preventing the oxide film from becoming over-dried and brittle due to excessive drying time.

[0009] Preferably, in step S2, the vacuum degree is 0.3~0.6 Pa. More preferably, in step S2, the vacuum degree is 0.4~0.6 Pa. Even more preferably, in step S2, the vacuum degree is 0.45~0.6 Pa.

[0010] Preferably, in step S3, the gas used for ventilation is oxygen and argon, the volumetric flow rate of the oxygen is 80-150 SCCM, the volumetric flow rate of the argon is 100-300 SCCM, the silicon source is selected from a silicon target, the applied voltage is 350-400 V, and the deposition time is 2-8 min. More preferably, in step S3, the gas used for ventilation is oxygen and argon, the volumetric flow rate of the oxygen is 110-150 SCCM, the volumetric flow rate of the argon is 180-300 SCCM, the silicon source is selected from a silicon target, the applied voltage is 350-400 V, and the deposition time is 2-8 min. More preferably, in step S3, the gas used for ventilation is oxygen and argon, the volumetric flow rate of the oxygen is 120~150 SCCM, the volumetric flow rate of the argon is 180~280 SCCM, the silicon source is selected from silicon target material, the applied voltage is 360~400V, and the deposition time is 5~8min.

[0011] In step S3, under a voltage of 350~400V, the gas is effectively ionized, causing the silicon source to be directionally deposited on the surface of the anodic aluminum oxide material under the action of the electric field, forming a uniform silicon coating layer. At the same time, oxygen reacts with some of the silicon source to form silicon oxide, which covers the surface of the anodic aluminum oxide material, improving the density and corrosion resistance of the aluminum surface. Argon gas, as the carrier gas and plasma maintenance gas, has a higher flow rate than oxygen, which plays a role in stabilizing the plasma and promoting the uniform diffusion of the silicon source.

[0012] Preferably, before step S3, a glow discharge cleaning is performed, wherein the voltage applied during glow discharge cleaning is 300-400V, and the glow discharge cleaning time is 2-8 minutes. More preferably, before step S3, a glow discharge cleaning is performed, wherein the voltage applied during glow discharge cleaning is 350-400V, and the glow discharge cleaning time is 4-8 minutes.

[0013] The 300-400V voltage used for glow discharge cleaning before step S3 can excite a stable glow discharge. The generated plasma can efficiently bombard the aluminum surface, removing residual organic contaminants and loose oxide film, and forming a micro-rough structure on the surface. This avoids damage to the substrate caused by excessively high voltage, or insufficient cleaning force caused by excessively low voltage, which would affect the adhesion of subsequent coatings.

[0014] Preferably, in step S4, the current of the evaporation power supply is 650~700A, the distance between the surface of the silicon-plated aluminum material and the nano-coating material is 30~50cm, the evaporation temperature is 150~300℃, and the evaporation deposition time is 5~15min. More preferably, in step S4, the current of the evaporation power supply is 680~700A, the distance between the surface of the silicon-plated aluminum material and the nano-coating material is 40~50cm, the evaporation temperature is 160~300℃, and the evaporation deposition time is 8~15min.

[0015] In step S4, a current of 650~700A ensures the full evaporation of the nano-coating material while preventing excessive current from causing material decomposition. The distance between the surface of the silicon-plated aluminum material and the outlet end of the nano-coating material is 30~50cm, ensuring uniform distribution of the evaporated nano-coating material and facilitating the formation of a uniform and continuous nano-coating on the surface of the silicon-plated layer. Simultaneously, controlling the temperature to 150~300℃ promotes the diffusion and spreading of the nano-coating material on the surface of the silicon-plated layer, enhances the bonding force between the nano-coating material and the silicon-plated layer, and also prevents excessive temperature from damaging the formed silicon-plated layer.

[0016] In the aluminum surface treatment products obtained by the above steps S1 to S5, the thickness of the silicon coating layer is 30 to 150 nm, and the thickness of the nano coating layer is 5 to 20 nm.

[0017] The second aspect of this application provides a nano-coating material for aluminum surface treatment according to the first aspect of this application, the nano-coating material comprising perfluoroether polymers, nonafluorobutyl ethyl ether, methyl nonafluorobutyl ether, heptafluoropropane derivatives, and fluoroalkyl ethers.

[0018] All components of the nano-coating material are fluorine-containing compounds. Among them, perfluoroether polymers serve as the main film-forming substances, endowing the nano-coating with good mechanical strength and durability. Nonafluorobutyl ethyl ether and methyl nonafluorobutyl ether, as small molecule fluorine ethers, improve the fluidity of the material, which helps the nano-coating material to form a uniform film on the silicon-coated aluminum surface. Heptafluoropropane derivatives and fluoroalkyl ethers help to regulate the flexibility of the nano-coating. Under the synergistic effect of the components, the nano-coating on the aluminum surface has excellent corrosion resistance, flexibility and adhesion, and good compatibility with the silicon-coated layer, significantly improving the overall performance of the aluminum surface.

[0019] Preferably, the perfluoroether polymer contains 68% to 72% fluorine by mass, and has a number-average molecular weight of 9000 to 13000 g / mol. More preferably, the perfluoroether polymer contains 70% to 72% fluorine by mass, and has a number-average molecular weight of 10000 to 13000 g / mol. Even more preferably, the perfluoroether polymer contains 70% to 72% fluorine by mass, and has a number-average molecular weight of 12000 to 13000 g / mol.

[0020] If the fluorine content of perfluoroether polymers is too low, their corrosion resistance and other properties will be poor; if the fluorine content is too high, their compatibility with other components will decrease. A fluorine mass fraction of 68% to 72% ensures that the nano-coating material has good chemical corrosion resistance and low surface energy. The number average molecular weight of perfluoroether polymers is 9,000 to 13,000 g / mol, which avoids the easy wear of the coating caused by too low a number average molecular weight, and also ensures the film-forming properties of the polymer.

[0021] Preferably, the heptafluoropropane derivative is selected from at least one of 1,1,1,2,3,3,3-heptafluoro-2-(ethoxydifluoromethyl)-propane, 1,1,1,2,2,3,3-heptafluoro-3-methoxypropane, and 1,1,1,2,3,3,3-heptafluoro-2-trifluoromethylpropane. More preferably, the heptafluoropropane derivative is selected from at least one of 1,1,1,2,3,3,3-heptafluoro-2-(ethoxydifluoromethyl)-propane and 1,1,1,2,2,3,3-heptafluoro-3-methoxypropane. Even more preferably, the heptafluoropropane derivative is selected from 1,1,1,2,3,3,3-heptafluoro-2-(ethoxydifluoromethyl)-propane.

[0022] Preferably, the fluoroalkyl ether has a C1-C6 straight-chain or branched fluoroalkyl substituent. More preferably, the fluoroalkyl ether has a C2-C6 straight-chain or branched fluoroalkyl substituent. Even more preferably, the fluoroalkyl ether has a C4-C6 straight-chain or branched fluoroalkyl substituent.

[0023] Preferably, the C1-C6 straight-chain or branched fluoroalkyl-substituted fluoroalkyl ethers are selected from at least one of trifluoromethoxytrifluoromethane, hexafluoroisopropylmethyl ether, and perfluorohexylmethyl ether. More preferably, the C1-C6 straight-chain or branched fluoroalkyl-substituted fluoroalkyl ethers are selected from at least one of hexafluoroisopropylmethyl ether and perfluorohexylmethyl ether.

[0024] Heptafluoropropane derivatives possess specific fluorinated structures and ether bonds, exhibiting high chemical stability and good compatibility with other fluorinated components. This avoids phase separation caused by incompatibility of coating components. The fluorinated groups in their molecular structure endow the coating with lower surface energy, thereby improving its antifouling effect; the ether bonds, on the other hand, impart a certain degree of flexibility to the molecule, improving the coating's impact resistance. C1-C6 short-chain fluoroalkyl ethers have moderate chain lengths, resulting in better compatibility with other components and avoiding phase separation caused by long chains.

[0025] Preferably, in the raw materials of the nano-coating material, the weight ratio of perfluoroether polymer, nonafluorobutyl ethyl ether, and methyl nonafluorobutyl ether is (18~30):(10~20):(12~25).

[0026] Preferably, in the raw materials of the nano-coating material, the weight ratio of perfluoroether polymer, nonafluorobutyl ethyl ether, methyl nonafluorobutyl ether, and heptafluoropropane derivative is (18~30):(10~20):(12~25):(20~30).

[0027] Preferably, in the raw materials of the nano-coating material, the weight ratio of perfluoroether polymer, nonafluorobutyl ethyl ether, methyl nonafluorobutyl ether, heptafluoropropane derivative, and fluoroalkyl ether is (18~30):(10~20):(12~25):(20~30):(3.5~12).

[0028] In the raw materials of nano-coating materials, through quantitative synergy among the components, the nano-coating achieves an optimal balance in terms of film formation, uniformity, and corrosion resistance, and has good compatibility with the silicon coating layer, giving the aluminum surface coating excellent adhesion, corrosion resistance, and impact resistance.

[0029] Compared with the prior art, this application has at least the following beneficial effects: 1) Through multiple process steps such as pretreatment, furnace loading, vacuuming, glow discharge cleaning, silicon plating, evaporation deposition, and cooling, the surface coating of the aluminum surface treatment products has strong adhesion, excellent corrosion resistance and impact resistance.

[0030] 2) In the aluminum surface treatment process of this application, the evaporation deposition step introduces a nano-coating material. Under the synergistic effect of the components of the nano-coating material, the nano-coating on the aluminum surface has excellent corrosion resistance, impact resistance and adhesion, and has good compatibility with the silicon coating layer, which significantly improves the overall performance of the aluminum surface. Attached Figure Description

[0031] Figure 1 This is a metallographic image of the cross-section of the silicon-coated layer of the aluminum surface treatment product of Example 1, magnified 500 times.

[0032] Figure 2 This is a metallographic image of the cross-section of the nano-coating of the aluminum surface treatment product of Example 1, magnified 1000 times. Detailed Implementation

[0033] The following detailed description of the contents of this application is provided through specific embodiments, comparative examples, and tables, but is not limited to all the arguments and data.

[0034] This application discloses a surface treatment process for aluminum materials, which specifically includes the following steps: S1. Pretreatment: After the aluminum material is hung, it is degreased at 45~65℃ for 60~100s, washed with water, pickled and demolded for 80~120s, washed with water again, and transported to an anodizing tank at 18~21℃ with an electrolyte of 160~190g / L sulfuric acid and 2~3g / L citric acid. A voltage of 16~18V is applied, and anodizing is performed for 25~40min. After washing with water, it is dried at 70~90℃ for 10~15min.

[0035] Regarding step S1, in some specific embodiments, the degreasing temperature can be 45℃, 50℃, 55℃, 60℃, or 65℃, and the degreasing time can be 60s, 65s, 70s, 75s, 80s, 85s, 90s, 95s, or 100s; the pickling and demolding time can be 80s, 85s, 90s, 95s, 100s, 105s, 110s, 115s, or 120s; the anodizing temperature can be 18℃, 19℃, 20℃, or 21℃, and the concentration of sulfuric acid in the anodizing electrolyte is... The concentration of citric acid can be 160 g / L, 165 g / L, 170 g / L, 180 g / L, or 190 g / L; the concentration of citric acid can be 2 g / L, 2.5 g / L, 2.8 g / L, or 3 g / L; the voltage for anodizing can be 16 V, 17 V, or 18 V; the anodizing time can be 25 min, 30 min, 35 min, or 40 min; the drying temperature after anodizing can be 70℃, 75℃, 80℃, 85℃, or 90℃; and the drying time can be 10 min, 12 min, or 15 min.

[0036] S2. Loading and Vacuuming: Place the anodized aluminum material into the vacuum evaporation furnace and evacuate to a vacuum level of 0.3~0.6Pa.

[0037] In some specific implementations, the vacuum level for step S2 can be 0.3 Pa, 0.4 Pa, 0.5 Pa, or 0.6 Pa.

[0038] S3. Silicon plating: Introduce oxygen and argon, set the oxygen volume flow rate to 80~150SCCM and the argon volume flow rate to 100~300SCCM, apply a voltage of 350~400V, and deposit the silicon source on the surface of the anodic aluminum material for 2~8 minutes to obtain silicon-plated aluminum material.

[0039] Regarding step S3, in some specific embodiments, the oxygen volumetric flow rate can be 80 SCCM, 100 SCCM, 120 SCCM or 150 SCCM, the argon volumetric flow rate can be 100 SCCM, 180 SCCM, 240 SCCM, 280 SCCM or 300 SCCM, the applied voltage can be 350 V, 365 V, 385 V or 400 V, and the deposition time can be 2 min, 5 min, 6 min or 8 min.

[0040] S4. Evaporation Deposition: Introduce the nano-coating material, making the distance between the surface of the silicon-plated aluminum material and the outlet end of the nano-coating material 30~50cm. Turn on the evaporation power supply, set the current of the evaporation power supply to 650~700A, the evaporation temperature to 150~300℃, and evaporate and deposit for 5~15min to evaporate and deposit the nano-coating material onto the surface of the silicon-plated aluminum material.

[0041] Regarding step S4, in some specific implementation schemes, the weight ratio of perfluoroether polymer, nonafluorobutyl ethyl ether, methyl nonafluorobutyl ether, heptafluoropropane derivative, and fluoroalkyl ether in the raw materials of the nano-coating material is (18~30):(10~20):(12~25):(20~30):(3.5~12). Specifically, the amount of perfluoroether polymer can be 18g, 20g, 22g, 25g, 28g, or 30g; the amount of nonafluorobutyl ethyl ether can be 10g, 12g, 15g, 18g, or 20g; the amount of methyl nonafluorobutyl ether can be 12g, 15g, 18g, 20g, 22g, or 25g; the amount of heptafluoropropane derivative can be 20g, 22g, 25g, 28g, or 30g; and the amount of fluoroalkyl ether can be 3.5g, 5g, 7g, 8g, 10g, or 12g. The distance between the surface of the silicon-plated aluminum material and the outlet end of the nano-coating material can be 30cm, 38cm, 43cm or 50cm, the current of the evaporation power supply can be 650A, 665A, 680A, 690A or 700A, the evaporation temperature can be 150℃, 180℃, 250℃ or 300℃, and the evaporation deposition time can be 5min, 9min, 12min or 15min.

[0042] S5. Cooling: After cooling to room temperature, remove the product to obtain the aluminum surface treatment product.

[0043] The aluminum material used in the embodiments and comparative examples of this application is an aluminum alloy substrate; the silicon source is a silicon target with a purity of 99.9%; the perfluoroether polymer has a fluorine mass fraction of 69% and a number average molecular weight of 9000 g / mol.

[0044] Examples and comparative examples of the preparation of nano-coating materials: Preparation Example 1: The preparation method of a nano-coating material has the following steps: 22g of perfluoroether polymer, 13g of nonafluorobutyl ethyl ether, 12g of methyl nonafluorobutyl ether, 20g of 1,1,1,2,3,3,3-heptafluoro-2-(ethoxydifluoromethyl)-propane and 3.5g of perfluorohexyl methyl ether were mixed and stirred to obtain a nano-coating material.

[0045] Preparation Example 2: The preparation method of a nano-coating material has the following steps: 26g of perfluoroether polymer, 13g of nonafluorobutyl ethyl ether, 15g of methyl nonafluorobutyl ether, 22g of 1,1,1,2,3,3,3-heptafluoro-2-(ethoxydifluoromethyl)-propane and 5g of perfluorohexyl methyl ether were mixed and stirred to obtain a nano-coating material.

[0046] Preparation Example 3: The preparation method of a nano-coating material has the following steps: 30g of perfluoroether polymer, 18g of nonafluorobutyl ethyl ether, 23g of methyl nonafluorobutyl ether, 25g of 1,1,1,2,3,3,3-heptafluoro-2-(ethoxydifluoromethyl)-propane and 10g of perfluorohexyl methyl ether were mixed and stirred to obtain a nano-coating material.

[0047] Preparation Example 4: The preparation method of a nano-coating material has the following steps: 22g of perfluoroether polymer, 13g of nonafluorobutyl ethyl ether, 12g of methyl nonafluorobutyl ether, 20g of 1,1,1,2,2,3,3-heptafluoro-3-methoxypropane and 3.5g of perfluorohexyl methyl ether were mixed and stirred to obtain a nano-coating material.

[0048] Preparation Example 5: The preparation method of a nano-coating material has the following steps: 26g of perfluoroether polymer, 15g of nonafluorobutyl ethyl ether, 24g of methyl nonafluorobutyl ether, 23g of 1,1,1,2,2,3,3-heptafluoro-3-methoxypropane and 9g of perfluorohexyl methyl ether were mixed and stirred to obtain a nano-coating material.

[0049] Preparation of Comparative Example 1: The preparation method of a nano-coating material has the following steps: 22g of perfluoroether polymer, 13g of nonafluorobutyl ethyl ether, 12g of methyl nonafluorobutyl ether, 32g of 1,1,1,2,3,3,3-heptafluoro-2-(ethoxydifluoromethyl)-propane and 3.5g of perfluorohexyl methyl ether were mixed and stirred to obtain a nano-coating material.

[0050] Preparation of Comparative Example 2: The preparation method of a nano-coating material has the following steps: 22g of perfluoroether polymer, 13g of nonafluorobutyl ethyl ether, 12g of methyl nonafluorobutyl ether and 3.5g of perfluorohexyl methyl ether were mixed and then stirred to obtain a nano-coating material.

[0051] It is particularly important to emphasize that, unless otherwise specified, the raw materials, reagents or devices used in this application can be obtained from conventional commercial sources.

[0052] Based on the aluminum surface treatment process of this application, the following examples and comparative examples are provided: Example 1

[0053] This application discloses a surface treatment process for aluminum materials, which specifically includes the following steps: S1. Pretreatment: After the aluminum material is hung, it is degreased at 45℃ for 80s, washed with water, pickled and demolded for 120s, washed with water again, and transported to an anodizing tank at 18℃ with an electrolyte of 190g / L sulfuric acid and 3g / L citric acid. A voltage of 16V is applied, and anodizing is performed for 35min. After washing with water, it is dried at 75℃ for 12min.

[0054] S2. Loading and Vacuuming: Place the anodized aluminum material into the vacuum evaporation furnace and evacuate it to a vacuum level of 0.4 Pa.

[0055] S3. Silicon plating: Introduce oxygen and argon, set the oxygen volume flow rate to 85 SCCM and the argon volume flow rate to 180 SCCM, and apply a voltage of 350V to deposit the silicon source on the surface of the anodic aluminum material for 6 minutes to obtain silicon-plated aluminum material.

[0056] S4. Evaporation Deposition: Import the nano-coating material prepared in Example 1, and make the distance between the silicon-coated aluminum material surface and the nano-coating material 40cm. Turn on the evaporation power supply, set the current of the evaporation power supply to 680A, the evaporation temperature to 250℃, and evaporate and deposit for 9min to evaporate and deposit the nano-coating material onto the silicon-coated aluminum material surface.

[0057] S5. Cooling: After cooling to room temperature, remove the product to obtain the aluminum surface treatment product. Example 2

[0058] An aluminum surface treatment process is the same as in Example 1, except that the nano-coating material in step S4 of Example 2 is the same as the nano-coating material prepared in Example 2. Example 3

[0059] An aluminum surface treatment process is the same as in Example 1, except that the nano-coating material in step S4 of Example 3 is the same as the nano-coating material prepared in Example 3. Example 4

[0060] An aluminum surface treatment process is the same as in Example 1, except that the nano-coating material in step S4 of Example 4 is the same as the nano-coating material prepared in Example 4. Example 5

[0061] An aluminum surface treatment process is the same as in Example 1, except that the nano-coating material in step S4 of Example 5 is the same as the nano-coating material prepared in Example 5.

[0062] Comparative Example 1: An aluminum surface treatment process is the same as in Example 1, except that step S3 is omitted in Comparative Example 1.

[0063] Comparative Example 2: An aluminum surface treatment process is the same as in Example 1, except that the evaporation temperature in step S4 of Comparative Example 2 is 130°C.

[0064] Comparative Example 3: An aluminum surface treatment process is the same as in Example 1, except that the nano-coating material in step S4 of Comparative Example 3 is the same as the nano-coating material prepared in Comparative Example 1.

[0065] Comparative Example 4: An aluminum surface treatment process is the same as in Example 1, except that the nano-coating material in step S4 of Comparative Example 4 is the same as the nano-coating material prepared in Comparative Example 2.

[0066] Material performance testing: The aluminum surface-treated products obtained in Examples 1-5 and Comparative Examples 1-4 were subjected to various performance tests, and the test methods are as follows: Test method for silicon coating and nano-coating thickness: After the aluminum surface treatment products are inlaid, ground and polished, they are observed and photographed under a metallographic microscope, and the average thickness of 5 positions in the corresponding film layer is taken as the corresponding film layer thickness.

[0067] Adhesion (Cross-cut test): According to GB / T 9286 standard, the adhesion of the surface coating of aluminum surface treatment products is tested. The test results are divided into 6 levels, from 0 to 5. The smaller the number, the higher the level and the stronger the coating adhesion.

[0068] Salt spray resistance: Tested according to the copper-accelerated acetic acid salt spray test in GB / T 10125-2021 standard.

[0069] Impact resistance: Under environmental conditions of 21~25℃ and 45~55%RH, the sample is placed in a test chamber at (-30±2)℃ for more than 4 hours. Then, a 500g solid iron ball is dropped from a height of 500mm above the impact surface to conduct a ball impact test. 3~5 points covering each area are selected for the test. The test is completed within 20 seconds after the sample is removed from the low temperature chamber.

[0070] The test performance of the aluminum surface treatment products of Examples 1-5 and Comparative Examples 1-4 is shown in Table 1 below:

[0071] The aluminum surface treatment products in Examples 1-5 involve multiple process steps such as pretreatment of aluminum, furnace loading, vacuuming, silicon plating, evaporation deposition, and cooling. This results in a surface coating with strong adhesion, reaching level 0. After salt spray testing, the surface shows no pitting, red rust, or other corrosion defects. After impact resistance testing, the surface shows no shrinkage, cracking, peeling, or loosening. The products exhibit excellent corrosion resistance and impact resistance.

[0072] Compared with Example 1, Comparative Example 1 omits step S3, while maintaining the same other process conditions. The results show that the adhesion of the nano-coating in Comparative Example 1 drops to level 2. After salt spray testing, the surface shows no pitting, red rust, or other corrosion defects. However, after impact resistance testing, slight cracking appears on the surface, indicating a significant decrease in impact resistance. This may be because Comparative Example 1 omits step S3, meaning that instead of a silicon-plated layer, a nano-coating is deposited on the anodic aluminum surface. This reduces the bonding force between the nano-coating and the aluminum surface, thereby decreasing the adhesion and impact resistance of the coating on the aluminum surface.

[0073] Compared with Example 1, the evaporation temperature in step S4 of Comparative Example 2 was 130°C, while other process conditions were the same as in Example 1. The results showed that the adhesion of the nano-coating in Comparative Example 2 decreased to level 1. After a salt spray test, sporadic pitting occurred. After an impact resistance test, no shrinkage, cracking, peeling, or loosening was observed on the surface, indicating a decrease in both adhesion and corrosion resistance. This may be because the evaporation temperature in step S4 of Comparative Example 2 was too low, resulting in less nano-coating material deposited on the silicon-coated aluminum surface, uneven deposition, and insufficient bonding between the nano-coating and the silicon-coated layer, leading to a decrease in the adhesion and corrosion resistance of the nano-coating.

[0074] Compared with Example 1, Comparative Example 3 used the same nano-coating material as Example 1 in step S4, while other process conditions remained the same. The results showed that the nano-coating of Comparative Example 3 achieved a level 0 adhesion. After salt spray testing, the surface showed no pitting, red rust, or other corrosion defects. After impact resistance testing, the surface showed no shrinkage, cracking, peeling, or loosening, demonstrating excellent corrosion resistance and impact resistance. The weight ratio of 1,1,1,2,3,3,3-heptafluoro-2-(ethoxydifluoromethyl)-propane in Comparative Example 1 exceeded the dosage range of the present application. While the adhesion, corrosion resistance, and impact resistance of the aluminum surface treatment product in Comparative Example 3 were largely unaffected, the excessive use of 1,1,1,2,3,3,3-heptafluoro-2-(ethoxydifluoromethyl)-propane resulted in unnecessary material waste.

[0075] Compared to Example 1, Comparative Example 4 used the same nano-coating material as Comparative Example 2 in step S4, while maintaining the same process conditions. The results showed that the adhesion of the nano-coating in Comparative Example 4 decreased to level 1. After a salt spray test, sporadic pitting occurred, and the surface showed slight relaxation after an impact resistance test. This indicates a decline in adhesion, corrosion resistance, and impact resistance. This may be because the nano-coating material used in step S4 of Comparative Example 4, which was prepared using the same nano-coating material as Comparative Example 2, lacked the heptafluoropropane derivative. Heptafluoropropane derivatives possess specific fluorinated structures and ether bonds, which can improve compatibility with other fluorinated components and enhance the coating's impact resistance. The lack of the auxiliary effect of the heptafluoropropane derivative in the aluminum surface treatment process of Comparative Example 4 led to an overall decrease in its adhesion, corrosion resistance, and impact resistance.

[0076] Obviously, the above embodiments of this application are merely examples for clearly illustrating this application, and are not intended to limit the implementation of this application. For those skilled in the art, other variations or modifications can be made based on the above description. Any obvious variations or modifications derived from the technical solutions of this application are still within the protection scope of this application.

Claims

1. An aluminum material surface treatment process characterized by, The method comprises the following steps: S1, pretreatment: anodizing, cleaning and drying the aluminum material to obtain an anodized aluminum material; S2, furnace loading and vacuumizing: placing the anodized aluminum material into a vacuum evaporation furnace and vacuumizing; S3, silicon plating: passing gas, and then applying voltage to make the silicon source deposit on the surface of the anodized aluminum material to obtain a silicon-plated aluminum material; S4, nano-coating evaporation deposition: introducing nano-coating material, and starting an evaporation power source to evaporate and deposit the nano-coating material on the surface of the silicon-plated aluminum material; S5, cooling: cooling and taking out to obtain an aluminum material surface treatment process product. In step S1, the drying temperature is 70-90℃, and the drying time is 10-15 min.

2. The aluminum material surface treatment process according to claim 1, characterized by, In step S2, the vacuum degree of the vacuum is 0.3-0.6 Pa.

3. The aluminum material surface treatment process according to claim 1, characterized by, In step S3, the gas for aeration is oxygen and argon, the volume flow rate of the oxygen is 80-150 SCCM, the volume flow rate of the argon is 100-300 SCCM, the applied voltage is 350-400 V, and the deposition time is 2-8 min.

4. The aluminum material surface treatment process according to claim 1, characterized by, Before step S3, glow cleaning is further performed, the applied voltage for the glow cleaning is 300-400 V, and the glow cleaning time is 2-8 min.

5. The aluminum material surface treatment process according to claim 1, wherein In step S4, the current of the evaporation power source is 650-700 A, the distance between the surface of the silicon-plated aluminum material and the discharge end of the nano-coating material is 30-50 cm, the evaporation temperature is 150-300℃, and the evaporation deposition time is 5-15 min.

6. The aluminum material surface treatment process according to claim 1, wherein The nano-coating material comprises perfluoroether polymer, nonafluorobutyl ethyl ether, methyl nonafluorobutyl ether, heptafluoropropane derivative and fluoroalkyl ether.

7. A nano-coating material for use in the process for treating the surface of aluminum material according to any one of claims 1 to 6, characterized in that, The mass fraction of fluorine in the perfluoroether polymer is 68%-72%, and the number average molecular weight of the perfluoroether polymer is 9000-13000 g / mol.

8. The nanocoating material of claim 7, wherein, The heptafluoropropane derivative is at least one selected from 1,1,1,2,3,3,3-heptafluoro-2-(ethoxydifluoromethyl)-propane, 1,1,1,2,2,3,3-heptafluoro-3-methoxypropane and 1,1,1,2,3,3,3-heptafluoro-2-trifluoromethylpropane; 9. The nanocoating material of claim 7, wherein, And / or, the fluoroalkyl ether has a linear or branched fluoroalkyl substituent group with C1-C6. The raw material comprises the following components in parts by weight:

10. The nanocoating material of claim 7, wherein, perfluoroether polymer 18-30 parts; nonafluorobutyl ethyl ether 10-20 parts; methyl nonafluorobutyl ether 12-25 parts; heptafluoropropane derivative 20-30 parts; fluoroalkyl ether 3.5-12 parts. ​

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