Antibacterial solution for aluminum alloy, antibacterial aluminum alloy member, and method for producing same

Abstract

The application provides an antibacterial solution for antibacterial treatment of an aluminum alloy after anodic oxidation, the pH value of the antibacterial solution is 5.5-6.5, the antibacterial solution is prepared from raw materials including an antibacterial element source, a complexing agent, sodium carbonate, citric acid, a surfactant and water, wherein the antibacterial element source includes water-soluble salts of silver, copper, zinc and zirconium, and the complexing agent includes thiosulfate. The antibacterial solution is suitable for surface treatment of all anodized aluminum alloy products in existing mass production, does not need to be changed, has low cost, can form an antibacterial layer with excellent antibacterial ability on the oxide film layer, and does not reduce the corrosion resistance of the aluminum alloy part. The application also provides an antibacterial aluminum alloy part and a preparation method thereof.

Description

Technical Field

[0001] This application relates to the field of aluminum alloy technology, specifically to an antibacterial liquid for aluminum alloys, antibacterial aluminum alloy parts, and a method for preparing the same. Background Technology

[0002] Aluminum alloys are a widely used type of non-ferrous metal material, extensively used in automobiles, ships, aviation, and electronic products. With economic development, they are also widely used in everyday consumer goods (such as kitchen knives and cooking utensils) and medical devices. However, aluminum alloys are prone to bacterial growth and corrosion in humid environments, affecting their use and decorative effects. Therefore, research on antibacterial aluminum alloys with antibacterial properties is of great significance.

[0003] Currently, the preparation of antibacterial aluminum alloys generally involves adding antibacterial elements to the anodizing bath during the anodizing surface treatment process, so that the antibacterial elements can be incorporated into the oxide film through alternating current oxidation. However, this method requires modification of the power supply and power lines, resulting in high costs. Summary of the Invention

[0004] In view of this, this application provides an antibacterial liquid for aluminum alloys and the preparation of antibacterial aluminum alloys. By immersing aluminum alloys that have undergone conventional anodizing treatment in this specific antibacterial liquid system, antibacterial aluminum alloys with excellent antibacterial properties can be obtained without modifying existing anodizing production lines, and can be applied on a large scale.

[0005] Specifically, in a first aspect, this application provides an antibacterial liquid for antibacterial treatment of anodized aluminum alloys. The antibacterial liquid is formulated from raw materials comprising an antibacterial element source, a complexing agent, sodium carbonate, citric acid, a surfactant, and water. The antibacterial element source includes water-soluble salts of silver, copper, zinc, and zirconium. The complexing agent includes thiosulfate. The pH value of the antibacterial liquid is 5.5-6.5.

[0006] The oxide film on the surface of anodized aluminum alloy substrates generally has pores. The aforementioned antibacterial solution can be used to coat or immerse anodized aluminum alloy substrates at room temperature to deposit antibacterial substances in the pores of the porous oxide film. Specifically, under appropriate pH conditions provided by sodium carbonate and citric acid, the complexing agent thiosulfate can form stable antibacterial complexes with salts of silver (Ag), copper (Cu), zinc (Zn), and zirconium (Zr). These complexes can remain stable in the antibacterial solution without aggregation in the presence of surfactants. These antibacterial complexes can deposit in the pores of the porous oxide film (especially in micropores), and the antibacterial elements in the complexes can be released persistently and stably without affecting the original corrosion resistance of the aluminum alloy parts. Furthermore, citric acid also plays a certain complexing role, which also helps the aforementioned antibacterial complexes to remain stable in the antibacterial solution.

[0007] The above-mentioned antibacterial solution is applicable to the surface treatment of all existing mass-produced anodized aluminum alloy products. It only needs to be added after the ordinary anodizing process, without modifying the existing anodizing production line. It is low in cost and low in energy consumption, and can be promoted on a large scale. Moreover, the antibacterial layer formed will not reduce the corrosion resistance of the original oxide film.

[0008] In this embodiment, the water-soluble salt of silver includes silver nitrate, and the water-soluble salt of copper includes copper sulfate and / or copper nitrate. The water-soluble salt of zinc includes at least one of zinc sulfate, zinc nitrate, and zinc acetate. The water-soluble salt of zirconium includes at least one of zirconium sulfate, zirconium nitrate, and zirconium acetate. The thiosulfate is selected from at least one of sodium thiosulfate, potassium thiosulfate, ammonium thiosulfate, magnesium thiosulfate, and calcium thiosulfate.

[0009] In this embodiment, the ratio of the total molar amount of antibacterial elements in the antibacterial element source (i.e., the sum of the molar amounts of silver in the water-soluble salt of silver, copper in the water-soluble salt of copper, zinc in the water-soluble salt of zinc, and zirconium in the water-soluble salt of zirconium) to the molar amount of the thiosulfate is (1-10):1. This ensures that silver, copper, zinc, and zirconium ions can be fully complexed by the thiosulfate to form an antibacterial complex with good antibacterial properties. In some embodiments, this ratio is (2-8.5):1.

[0010] In this application, the surfactant includes at least one of sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, and nonylphenol polyoxyethylene ether. These surfactants ensure that thiosulfate complexes of elements such as silver, copper, zinc, and zirconium can exist stably in the system without aggregation, thereby ensuring that these antibacterial complexes can be uniformly deposited in the pores of subsequent porous oxide film layers. Furthermore, these surfactants can significantly improve the affinity of the antibacterial solution for the aluminum alloy oxide film layer, improving the film quality. In some embodiments of this application, the surfactant includes nonylphenol polyoxyethylene ether and sodium dodecyl sulfate.

[0011] In this embodiment, the ratio of the molar amount of the surfactant to the total molar amount of the antibacterial elements in the antibacterial element source is 1:(0.01-1000). This allows the antibacterial solution to better penetrate the pores of the oxide film layer of the anodized aluminum alloy, forming a film on the surface of the pores and restricting the aforementioned antibacterial complex from moving arbitrarily, thereby ensuring that the antibacterial complex can exert its antibacterial effect for a longer period. In some embodiments, this ratio can be 1:(1-100), more preferably 1:(10-100), and most preferably 1:(20-95).

[0012] In some embodiments of this application, the mass ratio of thiosulfate to surfactant is (3-12):1, further, this mass ratio can be (5-10):1, preferably (5-8):1. This facilitates the stable existence of the above-mentioned silver, copper, zinc, and zirconium thiosulfate complexes in the antibacterial solution and allows them to be better deposited in the pores of the aluminum alloy oxide film.

[0013] In this application, the above-mentioned antibacterial solution is obtained by mixing raw materials such as antibacterial element source, complexing agent, sodium carbonate, citric acid, surfactant and water. In the embodiments of this application, relative to the total volume of each raw material, the concentration of water-soluble salt of silver is 5-30 g / L, the concentration of water-soluble salt of copper is 20-200 g / L, the concentration of water-soluble salt of zinc is 5-60 g / L, the concentration of water-soluble salt of zirconium is 3-10 g / L, the concentration of thiosulfate is 10-30 g / L, the concentration of sodium carbonate is 10-20 g / L; the concentration of citric acid is 2-5 g / L, and the concentration of surfactant is 2-5 g / L.

[0014] At this point, the concentrations of the raw materials forming the antibacterial solution are appropriate, especially the concentrations of water-soluble salts of silver, copper, zinc, and zirconium. The resulting antibacterial solution can contain appropriate proportions of silver, copper, zinc, and zirconium thiosulfate complexes, all of which can exist stably without aggregation in the presence of appropriate amounts of surfactants and citric acid. Furthermore, through the synergistic effect of different elemental complexes, excellent antibacterial effects can be achieved when using this antibacterial solution to treat anodized aluminum alloys. In addition, the addition of sodium carbonate and citric acid within the above-mentioned concentration range not only facilitates the reaction between the antibacterial element source and the complexing agent but also ensures that the pH fluctuation of the resulting antibacterial solution is small, making it suitable for surface antibacterial treatment of aluminum alloys and achieving good antibacterial effects.

[0015] In some embodiments of this application, the antibacterial solution is prepared from raw materials comprising silver nitrate, copper sulfate, zinc sulfate, zirconium acetate, sodium thiosulfate, sodium carbonate, citric acid, surfactant, and water. The concentrations of silver nitrate, copper sulfate, zinc sulfate, zirconium acetate, sodium carbonate, surfactant, and water are, relative to the total volume of each raw material, as follows: silver nitrate concentration is 5-30 g / L; copper sulfate concentration is 20-200 g / L; zinc sulfate concentration is 5-60 g / L; zirconium acetate concentration is 3-10 g / L; sodium thiosulfate concentration is 10-30 g / L; sodium carbonate concentration is 1-20 g / L; citric acid concentration is 1-20 g / L; and surfactant concentration is 2-5 g / L.

[0016] Secondly, this application provides a method for preparing an antibacterial aluminum alloy part, comprising the following steps:

[0017] Anodizing is performed on an aluminum alloy substrate to deposit a porous oxide film layer on the surface of the aluminum alloy substrate;

[0018] The aluminum alloy substrate with the porous oxide film layer is immersed in the antibacterial solution described in the first aspect of this application for 1-20 minutes at room temperature, and then subjected to nickel sealing treatment to obtain an antibacterial aluminum alloy part.

[0019] In the above method, after anodizing the aluminum alloy substrate, immersing it in the aforementioned antibacterial solution allows the formation of a stable antibacterial layer with excellent and long-lasting antibacterial properties within the pores of the porous oxide film. Antibacterial elements such as Ag, Cu, Zn, and Zr are released stably and persistently without affecting the original corrosion resistance of the aluminum alloy. Therefore, this method can impart antibacterial functionality to the aluminum alloy without affecting its appearance or corrosion resistance.

[0020] The composition of the antibacterial solution in the above method is as described above in this application, and will not be repeated here.

[0021] In some embodiments of this application, the soaking time with the aforementioned antibacterial solution can be 2, 3, 5, 8, 10, 12, 15, 18, or 20 minutes. A suitable soaking time can prevent the formation of an effective antibacterial layer with high coverage due to insufficient soaking time, and can also prevent the dyeing effect of the prior dyeing treatment from being affected by excessive soaking time. Furthermore, the aforementioned "room temperature" specifically refers to a temperature of 20-30°C, and more specifically, 23-27°C.

[0022] In this embodiment of the application, a pretreatment is performed before anodizing the aluminum alloy substrate. The pretreatment sequentially includes alkaline etching, neutralization, and chemical polishing. It is understood that a water rinse is performed after each step to prevent residual solution from the previous step from interfering with the next step. In other words, the pretreatment specifically includes alkaline etching, water rinsing, neutralization, water rinsing, chemical polishing, and water rinsing.

[0023] The purpose of alkaline etching is to remove the passivation layer on the aluminum alloy surface, exposing the fresh aluminum substrate to facilitate subsequent processing. It also removes dirt (especially grease) from the aluminum alloy substrate surface, thus altering the surface texture to some extent. Optionally, the alkaline etching solution used includes sodium hydroxide with a concentration of 50-60 g / L. The etching temperature can be 50-70°C, and the etching time can be 5-20 seconds.

[0024] The purpose of neutralization is to neutralize the alkaline etching solution adsorbed on the aluminum alloy after alkaline etching, and to remove impurities that are insoluble in alkali. Optionally, the neutralizing solution used is nitric acid with a concentration of 180-200 g / L. Furthermore, the neutralization temperature can be 20-28°C, and more specifically 23-27°C; the neutralization time can be 10-20 seconds.

[0025] The purpose of chemical polishing is to improve the surface gloss of aluminum alloys and obtain a smooth and bright appearance. Optionally, the chemical polishing solution used includes the following components in the following volume proportions: 650-750 mL / L of phosphoric acid and 250-350 mL / L of sulfuric acid. Here, phosphoric acid and sulfuric acid refer to commercially available concentrated phosphoric acid and concentrated sulfuric acid; that is, the chemical polishing solution is obtained by mixing commercially available concentrated phosphoric acid and commercially available concentrated sulfuric acid, wherein the volume proportion of commercially available concentrated phosphoric acid in the chemical polishing solution is 650-750 mL / L, and the volume proportion of commercially available concentrated sulfuric acid in the chemical polishing solution is 250-350 mL / L. Optionally, the chemical polishing temperature is 90-95℃, and the time is 5-20 seconds. A higher chemical polishing temperature ensures that the burrs on the surface of the aluminum alloy substrate after the above-mentioned alkaline etching and neutralization treatment are effectively removed.

[0026] In this application, during the anodizing process, the aluminum alloy substrate is used as the anode, graphite as the cathode, and a DC power supply is used for anodizing. The formed oxide film is aluminum oxide. Optionally, the DC power supply voltage is 12-18V. A suitable power supply voltage can ensure the preparation efficiency of the oxide film. Optionally, the anodizing solution used is a sulfuric acid solution with a concentration of 180-200g / L. Optionally, the anodizing temperature can be 10-20℃, and the processing time is 5-50min. Suitable anodizing temperature and time can ensure that the pore size of the oxide film is appropriate, avoiding excessively large pores that would be detrimental to subsequent sealing and ensure the corrosion resistance of the oxide film.

[0027] In some embodiments of this application, after anodizing and before immersion in the antibacterial solution, the method further includes a dyeing treatment in a dyeing tank. The dyeing treatment can enrich and enhance the appearance of the anodized aluminum alloy. The dye in the dyeing tank can be Okuno dye, with a concentration of 1-20 g / L, for example, 10 g / L. The dyeing treatment temperature can be 20-27°C, for example, 22°C, and the dyeing time can be 2-30 min, for example, 5 min.

[0028] In this embodiment, the nickel sealing treatment includes immersion in a nickel acetate solution at 90-98°C for 10-60 minutes, followed by drying. The porous structure of the porous oxide film is highly active, allowing contaminants or corrosive substances to easily enter the pores, and dyes can also easily flow out. The sealing treatment plugs the pores of the oxide film, making the surface denser, enhancing its adhesion, and improving its anti-fouling, corrosion-resistant, and wear-resistant properties. Optionally, the concentration of the nickel acetate solution used is 5-15 g / L. The drying treatment can be carried out in an oven at 80-100°C for 10-30 minutes.

[0029] The preparation method provided in the second aspect of this application is applicable to the surface treatment of all currently mass-produced anodized aluminum alloy products (i.e., suitable for converting all anodized aluminum alloys into antibacterial aluminum alloys), without requiring modifications to existing anodizing production lines, and can impart antibacterial properties to the aluminum alloy without affecting its appearance or corrosion resistance. Furthermore, this method is energy-efficient, easy to operate, and conducive to large-scale promotion.

[0030] The third aspect of this application also provides antibacterial aluminum alloy parts prepared using the preparation method described in the second aspect. Detailed Implementation

[0031] The following are exemplary embodiments of this application. It should be noted that those skilled in the art can make several improvements and modifications without departing from the principles of this application, and these improvements and modifications are also considered to be within the scope of protection of this application.

[0032] The present application will be further described below through specific embodiments. Unless otherwise specified, the reagents used in the following embodiments are all commercially available products.

[0033] Example 1

[0034] A method for preparing an antibacterial aluminum alloy part, comprising:

[0035] (1) Preprocessing

[0036] Take an aluminum alloy shell (aluminum alloy grade is 6013), first place it in a NaOH alkaline etching solution with a concentration of 50-60 g / L, and perform alkaline etching at a temperature of 50-70℃ for 5-20 seconds; after rinsing with water, place it in a nitric acid solution with a concentration of 180-200 g / L, and perform neutralization treatment at a temperature of 25℃ for 10-20 seconds; after rinsing with water, place it in a chemical polishing solution (containing 700 mL / L phosphoric acid and 300 mL / L sulfuric acid), and perform chemical polishing treatment at a temperature of 90-95℃ for 5-20 seconds, and then rinse with water.

[0037] (2) Anodizing

[0038] The pretreated aluminum alloy shell was placed in an anodizing tank containing a sulfuric acid solution with a concentration of 190 g / L. The aluminum alloy shell was used as the anode and graphite as the cathode. Anodizing was performed using a DC power supply with a voltage of 15 V, followed by water washing. The anodizing temperature was 19 °C and the oxidation time was 35 min, forming an aluminum oxide film with a thickness of 12 μm.

[0039] (3) Antibacterial treatment

[0040] The anodized aluminum alloy shell was placed in an antibacterial solution with pH=5.5 and immersed for 5 minutes at room temperature. The antibacterial solution was prepared from the following raw materials and water, and the concentrations of each raw material relative to the total volume were as follows: silver nitrate 6g / L, copper sulfate 30g / L, zinc sulfate 5g / L, zirconium acetate 3g / L, sodium thiosulfate 10g / L, sodium carbonate 2g / L, citric acid 4g / L, and sodium dodecyl sulfate 2.5g / L.

[0041] (4) Nickel sealing treatment

[0042] The aluminum alloy shell after the above antibacterial treatment was placed in a sealing tank containing a nickel acetate solution with a concentration of 10 g / L, and nickel sealing was performed at 93°C for 30 min. After washing with water, it was baked in an oven at 90°C for 10-30 min.

[0043] Example 2

[0044] A method for preparing antibacterial aluminum alloy parts, which differs from Example 1 in that: during the antibacterial treatment, the pH value of the antibacterial solution used is 6.0, the soaking time is 2 minutes, and the antibacterial solution is prepared by mixing raw materials and water at the following concentrations relative to the total volume of each raw material: silver nitrate 10 g / L, copper sulfate 20 g / L, zinc sulfate 20 g / L, zirconium acetate 5 g / L, sodium thiosulfate 20 g / L, sodium carbonate 2 g / L, citric acid 3.7 g / L, and sodium dodecyl sulfate 3 g / L.

[0045] Example 3

[0046] A method for preparing an antibacterial aluminum alloy part, which differs from Example 2 in that: after anodizing and before antibacterial treatment, the method further includes: performing a dyeing treatment in a dye bath containing a dye solution of Okuno dye 502 with a concentration of 10 g / L, at a dyeing temperature of 22°C for 5 min.

[0047] Example 4

[0048] A method for preparing antibacterial aluminum alloy parts, which differs from Example 1 in that: during the antibacterial treatment, the pH value of the antibacterial solution used is 6.5, and the soaking time is 20 min. The antibacterial solution is prepared by mixing raw materials and water at the following concentrations relative to the total volume of each raw material: silver nitrate 30 g / L, copper sulfate 200 g / L, zinc sulfate 60 g / L, zirconium acetate 10 g / L, sodium thiosulfate 30 g / L, sodium carbonate 2 g / L, citric acid 3.5 g / L, and sodium dodecyl sulfate 5 g / L.

[0049] Example 5

[0050] A method for preparing an antibacterial aluminum alloy part, which differs from Example 1 in that the antibacterial treatment time is 1 minute.

[0051] To highlight the beneficial effects of the technical solutions in the embodiments of this application, the following comparative examples are provided:

[0052] Comparative Example 1

[0053] A method for preparing an antibacterial aluminum alloy part, which differs from Example 1 in that: the pretreated aluminum alloy shell is directly placed in an oxidizing solution containing sulfuric acid with a concentration of 190 g / L and silver nitrate with a concentration of 2 g / L for anodizing, and anodizing is performed using a 25V AC power supply, followed by nickel sealing treatment.

[0054] Comparative Example 2

[0055] A method for preparing an antibacterial aluminum alloy part, which differs from Example 1 in that the antibacterial treatment involves immersion in an aqueous solution of nano-silver, wherein the nano-silver has a particle size of 2-5 nm.

[0056] Comparative Example 3

[0057] A method for preparing an antibacterial aluminum alloy part, which differs from Example 1 in that the antibacterial solution does not contain sodium thiosulfate.

[0058] Comparative Example 4

[0059] A method for preparing antibacterial aluminum alloy parts, which differs from Example 1 in that the antibacterial element source in the antibacterial solution is only silver nitrate, and does not contain copper sulfate, zinc sulfate and zirconium acetate.

[0060] Comparative Example 5

[0061] A method for preparing an antibacterial aluminum alloy part, which differs from Example 1 in that the antibacterial element source in the antibacterial solution is only copper sulfate.

[0062] Comparative Example 6

[0063] A method for preparing an antibacterial aluminum alloy part, which differs from Example 1 in that the antibacterial element source in the antibacterial solution is only zinc sulfate.

[0064] Comparative Example 7

[0065] A method for preparing an antibacterial aluminum alloy part, which differs from Example 1 in that the antibacterial element source in the antibacterial solution is only zirconium acetate.

[0066] Comparative Example 8

[0067] A method for preparing an antibacterial aluminum alloy part, which differs from Example 1 in that: the pH value of the antibacterial solution is 8; wherein, when preparing the antibacterial solution, the concentration of sodium carbonate relative to the total volume of each raw material is 4 g / L, and the concentration of citric acid relative to the total volume of each raw material is 2 g / L.

[0068] Comparative Example 9

[0069] A method for preparing an antibacterial aluminum alloy part, which differs from Example 1 in that the antibacterial treatment temperature is 60°C.

[0070] To strongly support the beneficial effects of the technical solutions in the embodiments of this application, the following performance tests were conducted.

[0071] Antibacterial effect test:

[0072] According to the method described in national standard GB / T31402, the antibacterial effect of the antibacterial aluminum alloy parts obtained in each embodiment and comparative example was tested, and the results are shown in Table 1 below.

[0073] Table 1 Summary of antibacterial rates of the workpieces in each embodiment and comparative example

[0074]

[0075]

[0076] As shown in Table 1, immersing the anodized aluminum alloy in the antibacterial solution provided in this application embodiment achieves a good antibacterial effect without affecting the effect of the previous dyeing process. However, the corrosion resistance of the oxide film layer introduced by the treatment method in Comparative Example 1 may be affected (see Table 2 below). Furthermore, the comparison of the antibacterial effects between Example 1 and Comparative Example 2 shows that the antibacterial effect obtained by immersing in the solution of nano-silver is significantly lower than that of the antibacterial solution in this application embodiment.

[0077] A comparison of Example 1 and Comparative Examples 4-7 shows that the antibacterial solution prepared using water-soluble salts containing Ag, Cu, Zn, and Zr exhibits a significantly higher antibacterial effect on aluminum alloys than salts using Ag, Cu, Zn, or Zr alone. This demonstrates that the antibacterial complex of Ag, Cu, Zn, and Zr can have a synergistic effect. Furthermore, a comparison of Example 1 and Comparative Examples 8-9 illustrates that to achieve a better antibacterial effect, the pH and operating temperature of the antibacterial solution should be controlled within an appropriate range.

[0078] This application also conducted neutral salt spray tests and boiling water tests on the antibacterial aluminum alloy parts of each embodiment and comparative example, and the results are summarized in Table 2 below.

[0079] The neutral salt spray test involved placing the samples from each example and comparative example in a salt spray chamber at 35°C, face up. A salt solution containing 5% sodium chloride and with a pH of 6.5-7.2 was continuously sprayed through a spray device, allowing the sprayed solution to settle onto the aluminum alloy composite material being tested. The spray pressure was 0.07-0.17 MPa, and the spray rate was 1.5 ± 0.5 mL / hour (with a funnel area of ​​80 cm²). 2 After 48 hours, observe whether there is any corrosion or discoloration on the product surface. Observe the degree of corrosion and discoloration of the film layer and score it accordingly from 0 to 10. 0 points means no corrosion or discoloration, and 10 points means complete corrosion and discoloration of the entire surface.

[0080] The boiling water test involves placing the test samples of each embodiment and comparative example in a constant temperature water bath at 80℃±2℃ for 30 minutes. After wiping with a lint-free cloth, the samples are left at room temperature for 4 hours. The surface of the product is then observed for any corrosion or discoloration. The degree of corrosion and discoloration of the film layer is observed and scored from 0 to 10, with 0 indicating no corrosion or discoloration and 10 indicating complete corrosion and discoloration of the entire surface.

[0081] Table 2 summarizes the salt spray and boiling water test results of the workpieces in each embodiment and comparative example.

[0082] Neutral salt spray test results Boiling water test results Example 1 0 0 Example 2 0 0 Example 3 0 0 Example 4 1 1 Example 5 0 0 Comparative Example 1 3 2 Comparative Example 2 0 0 Comparative Example 3 0 0 Comparative Example 4 0 0 Comparative Example 5 0 0 Comparative Example 6 0 0 Comparative Example 7 0 0 Comparative Example 8 7 7 Comparative Example 9 2 1

[0083] Table 2 shows that the antibacterial elements introduced through alternating current oxidation in Comparative Example 1 resulted in poor water boiling and neutral salt spray resistance test results for the aluminum alloy parts, indicating that this process severely affects the corrosion resistance of the workpiece. A comparison between Comparative Examples 8-9 and Example 1 shows that the pH value and operating temperature of the antibacterial solution provided in this application should be controlled within a suitable range to avoid affecting the corrosion resistance of the oxide film formed after anodizing.

[0084] The above description is an exemplary embodiment of this application. It should be noted that those skilled in the art can make several improvements and modifications without departing from the principles of this application, and these improvements and modifications are also considered to be within the scope of protection of this application.

Claims

1. An antibacterial solution, characterized in that, This antibacterial solution is used for antibacterial treatment of anodized aluminum alloys. It is formulated from raw materials including an antibacterial element source, a complexing agent, sodium carbonate, citric acid, a surfactant, and water. The antibacterial element source includes water-soluble salts of silver, copper, zinc, and zirconium. The complexing agent includes thiosulfate. The surfactant includes at least one of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, and nonylphenol polyoxyethylene ether. The ratio of the molar amount of the surfactant to the total molar amount of the antibacterial element in the antibacterial element source is 1:(0.01-1000). The pH value of the antibacterial solution is 5.5-6.

5.

2. The antibacterial solution as described in claim 1, characterized in that, The water-soluble salt of silver includes silver nitrate; the water-soluble salt of copper includes copper sulfate and / or copper nitrate; the water-soluble salt of zinc includes at least one of zinc sulfate, zinc nitrate, and zinc acetate; the water-soluble salt of zirconium includes at least one of zirconium sulfate, zirconium nitrate, and zirconium acetate; and the thiosulfate includes at least one of sodium thiosulfate, potassium thiosulfate, ammonium thiosulfate, magnesium thiosulfate, and calcium thiosulfate.

3. The antibacterial solution as described in claim 1, characterized in that, The ratio of the total molar amount of antibacterial elements in the antibacterial element source to the molar amount of the thiosulfate is (1-10):

1.

4. The antibacterial solution according to any one of claims 1-3, characterized in that, Relative to the total volume of each raw material, the concentration of the water-soluble salt of silver is 5-30 g / L; the concentration of the water-soluble salt of copper is 20-200 g / L; the concentration of the water-soluble salt of zinc is 5-60 g / L; the concentration of the water-soluble salt of zirconium is 3-10 g / L; the concentration of the thiosulfate is 10-30 g / L; the concentration of the sodium carbonate is 1-20 g / L; the concentration of the citric acid is 1-20 g / L; and the concentration of the surfactant is 2-5 g / L.

5. A method for preparing an antibacterial aluminum alloy part, characterized in that, Includes the following steps: Anodizing is performed on an aluminum alloy substrate to deposit a porous oxide film layer on the surface of the aluminum alloy substrate; The aluminum alloy substrate with the porous oxide film layer is immersed in the antibacterial solution as described in any one of claims 1-4 for 1-20 minutes at room temperature, and then subjected to nickel sealing treatment to obtain an antibacterial aluminum alloy part.

6. The preparation method according to claim 5, characterized in that, The anodic oxidation process uses an oxidizing solution comprising a sulfuric acid solution with a concentration of 180-200 g / L; the anodic oxidation process uses a DC power supply with a voltage of 12-18 V; the anodic oxidation process is carried out at a temperature of 10-20 °C for 5-50 min.

7. The preparation method according to claim 5, characterized in that, The nickel sealing process includes immersing the sample in a nickel acetate solution at a temperature of 90-98°C for 10-60 minutes, followed by drying.

8. The preparation method according to any one of claims 5-7, characterized in that, Before the aluminum alloy substrate is anodized, a pretreatment is performed, which includes alkaline etching, neutralization, and chemical polishing in sequence. The alkaline etching solution used in the alkaline etching includes sodium hydroxide with a concentration of 50-60 g / L, and the temperature of the alkaline etching solution is 50-70℃, with a time of 5-20 seconds. The neutralizing solution used for neutralization is nitric acid with a concentration of 180-200 g / L, and the neutralization temperature is 20-28°C, with a time of 10-20 seconds. The chemical polishing solution used in the chemical polishing process comprises the following components in the following volume proportions: 650-750 mL / L of phosphoric acid and 250-350 mL / L of sulfuric acid. The chemical polishing temperature is 90-95℃ and the time is 5-20 seconds.

9. An antibacterial aluminum alloy part prepared by the preparation method according to any one of claims 5-8.

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