Alloy product with surface antibacterial coating and processing technology

Abstract

The invention relates to an alloy product with a surface antibacterial coating and a processing technology. A matrix aluminum alloy of the alloy product comprises the following components in percentage by mass: 0.25%-0.4% of Si, 2.0%-3.0% of Zn, 0.1%-0.25% of Cu, 0.8%-1.2% of Mg, 0.05%-0.10% of Cr, 0.11%-0.20% of Mn, 0.1%-0.3% of Ti, 0.03%-0.06% of V, 0.01%-0.02% of La, 0.02%-0.05% of Zr, 0.01%-0.03% of Sr and the balance of Al and inevitable impurities. An antibacterial coating is arranged on the surface of the aluminum alloy product and contains antibacterial components formed by compounding copper and silver, so that the adhesive force of the coating is larger than or equal to 10 MPa, the antibacterial rate reaches 99% or above, and the salt spray corrosion resistance protection grade can reach 10 grade.

Description

Technical Field

[0001] This invention belongs to the technical field of aluminum alloy materials and their surface functionalization treatment, specifically relating to an alloy product with a surface antibacterial coating and its processing technology. Background Technology

[0002] Aluminum alloys are widely used in the automotive, medical, and bathroom hardware industries due to their low density, good thermal conductivity, and excellent processability. However, traditional aluminum alloys are often strengthened by a single element (such as Mg or Zn), which can lead to a contradiction where increased strength results in decreased elongation. In addition, aluminum alloys have insufficient antibacterial properties. Traditional antibacterial treatments often use single Ag or copper coatings, which are costly, prone to agglomeration, and have poor adhesion. Furthermore, the micropores in the anodized film are not completely filled, making it difficult to improve wear resistance and corrosion resistance.

[0003] Therefore, there is an urgent need to design an aluminum alloy product with synergistic optimization of matrix components and innovative surface antibacterial process to solve the dual pain points of aluminum alloy mechanical properties and antibacterial properties. Summary of the Invention

[0004] This invention provides an alloy product with a surface antibacterial coating and a processing technology to solve the problems of insufficient mechanical properties, insufficient antibacterial properties, and poor bonding strength of current aluminum alloy products.

[0005] In a first aspect, the present invention relates to an alloy article having a surface antibacterial coating, comprising: The base aluminum alloy composition of the alloy product, by mass percentage, is: Si 0.25%–0.4%, Zn 2.0%–3.0%, Cu 0.1%–0.25%, Mg 0.8%–1.2%, Cr 0.05%–0.10%, Mn 0.11%–0.20%, Ti 0.1%–0.3%, V 0.03%–0.06%, La 0.01%–0.02%, Zr 0.02%–0.05%, Sr 0.01%–0.03%, with the balance being Al and unavoidable impurities; The composition of the base aluminum alloy satisfies the following mass percentage content relationship: 0.30≤Mg / (Zn+Si)≤0.40; 2.0≤Cu / Cr≤5.0; The aluminum alloy product has an antibacterial coating on its surface, which contains an antibacterial component composed of copper and silver.

[0006] Preferably, the composition of the base aluminum alloy satisfies the following mass percentage content relationship: 0.06≤La / Ti≤0.18; Zr / Sr≥1.25.

[0007] Preferably, the average size of the precipitated phases MgZn2 and Al2CuMg in the matrix aluminum alloy is ≤45μm.

[0008] Secondly, the present invention relates to a processing technology for the alloy article having a surface antibacterial coating, comprising the following steps: (1) Alloy smelting: Weigh the raw materials according to the composition of the base aluminum alloy, add them to the smelting furnace for smelting, refining and removing impurities, and die casting to obtain aluminum alloy ingots; (2) Extrusion molding: The aluminum alloy ingot is extruded at a temperature of 430-500℃. The extruded aluminum alloy is then air-cooled online. The cooled aluminum alloy is aged at 140-160℃ for 8-12 hours to obtain the base aluminum alloy. (3) Surface pretreatment: The base aluminum alloy is polished, alkaline washed and neutralized in sequence; (4) Anodizing: The pretreated aluminum alloy substrate is placed in a sulfuric acid solution of 190-210 g / L, and the current density is controlled at 1.4-1.6 A / dm³. 2 Oxidize for 25–35 minutes to form a honeycomb-like microporous anodic oxide film with a pore size of 50–80 nm on the surface; after oxidation, rinse with deionized water until pH 6–7, drain and let dry. (5) Antibacterial impregnation: The anodized aluminum alloy is immersed in an antibacterial impregnation solution, which is a mixture containing copper salt, silver salt and deionized water; the immersion is carried out at 50-60℃ and ultrasonically treated for 15-20 minutes, and then placed at 790-890℃ for 30-50 seconds. After the aluminum alloy is baked, it is allowed to cool naturally to 100-120℃, and the ultrasonic immersion and baking are repeated 4-5 times to make the antibacterial components uniformly deposited on the outer layer of micropores. (6) Sealing: The aluminum alloy after antibacterial impregnation is placed in a sealing solution containing 20-25 g / L NiF2 and 0.5-1.0 g / L Ce(NO3)3, and sealed for 30-45 min at the same temperature as antibacterial impregnation to obtain aluminum alloy products with surface antibacterial coating.

[0009] Preferably, in step (3), polishing is performed to make the surface roughness of the aluminum alloy 0.2 to 0.3 μm.

[0010] Preferably, in step (3), the alkaline washing uses a 55-65 g / L NaOH solution and is treated at 55-60°C for 1.5-2.5 min to remove the surface oxide scale; the neutralization uses an HNO3 solution and is treated at room temperature for 1.2-1.8 min until there is no gray or black residue on the surface.

[0011] Preferably, the antibacterial impregnation solution in step (5) consists of sulfuric acid 15-19 g / L, CuSO4·5H2O 8-10 g / L, silver nitrate 20-30 g / L, HNO3 2-5 g / L, and the remainder is deionized water.

[0012] The beneficial effects of this invention are as follows: This invention improves the yield strength, tensile strength, and elongation of the base aluminum alloy by optimizing the composition and content relationship between the components. The resulting aluminum alloy products exhibit excellent tensile strength, yield strength, and elongation properties, with a tensile strength ≥420MPa, a yield strength ≥360MPa, and an elongation ≥10%.

[0013] By adjusting and optimizing the anodizing and antibacterial impregnation processes, and by using a specific antibacterial impregnation solution with appropriate process parameters, repeated ultrasonic and high-temperature baking is performed. This allows silver and copper particles to uniformly fill the micropores of alumina, forming a uniform and dense nano-antibacterial layer on the aluminum alloy surface. The antibacterial layer completely fills the outer layer of the micropores, achieving a thickness of 8–10 nm. This improves the hardness and wear resistance of the alumina micropores, enhances the gloss and antibacterial properties of the aluminum alloy, and results in a coating adhesion ≥10 MPa, an antibacterial rate of over 99%, and a salt spray corrosion protection level of up to level 10. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of a processing flow for preparing an alloy product with a surface antibacterial coating, as disclosed in an embodiment of the present invention. Detailed Implementation

[0016] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. 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.

[0017] Existing aluminum alloys are mostly strengthened by a single element (such as Mg or Zn), which easily leads to the contradiction that increased strength results in decreased elongation. Furthermore, aluminum alloy surfaces lack sufficient antibacterial properties. Traditional antibacterial treatments often use single Ag or copper coatings, which suffer from high costs, easy agglomeration, and poor adhesion. Moreover, the micropores in the anodic oxide film are not completely filled, making it difficult to improve wear resistance and corrosion resistance. This invention provides an alloy product with a surface antibacterial coating and its processing technology, addressing the problems of insufficient mechanical properties, inadequate antibacterial properties, and poor adhesion in current aluminum alloy products.

[0018] To address the aforementioned technical problems, embodiments of the present invention provide an alloy product with a surface antibacterial coating, comprising: The base aluminum alloy composition of the alloy product, by mass percentage, is: Si 0.25%–0.4%, Zn 2.0%–3.0%, Cu 0.1%–0.25%, Mg 0.8%–1.2%, Cr 0.05%–0.10%, Mn 0.11%–0.20%, Ti 0.1%–0.3%, V 0.03%–0.06%, La 0.01%–0.02%, Zr 0.02%–0.05%, Sr 0.01%–0.03%, with the balance being Al and unavoidable impurities; The composition of the base aluminum alloy satisfies the following mass percentage content relationship: 0.30≤Mg / (Zn+Si)≤0.40; 2.0≤Cu / Cr≤5.0; The aluminum alloy product has an antibacterial coating on its surface, which contains an antibacterial component composed of copper and silver.

[0019] In one embodiment, the components of the base aluminum alloy satisfy the following mass percentage content relationship: 0.06≤La / Ti≤0.18; Zr / Sr≥1.25.

[0020] In one embodiment, the average size of the precipitated phases MgZn2 and Al2CuMg in the matrix aluminum alloy is ≤45μm.

[0021] Si is a key strengthening element in aluminum alloys. Its core role is to form the Mg2Si strengthening phase with Mg, which effectively hinders dislocation movement and improves the yield strength of the matrix. The Si content should be controlled between 0.25% and 0.4%. If the Si content is below 0.25%, the amount of Mg2Si phase formed is insufficient, and the strengthening effect is weak. If the Si content is above 0.4%, it will reduce the elongation performance and the corrosion resistance of the material.

[0022] The main function of Zn is to synergistically form the MgZn2 precipitate with Mg. The Zn content is set at 2.0% to 3.0%. When the Zn content is below 2.0%, the amount of MgZn2 precipitate is small, and the tensile strength is difficult to guarantee. When the Zn content is above 3.0%, Zn is prone to segregation at the grain boundaries to form a low-melting-point eutectic structure, which leads to defects during subsequent extrusion molding. At the same time, grain boundary segregation will reduce the impact toughness of the material.

[0023] Mg is the core synergistic strengthening element in this invention, and its functions include: forming the Mg₂Si phase with Si, the MgZn₂ phase with Zn, and the Al₂CuMg phase with Cu (a triple strengthening effect). The Mg content is controlled at 0.8%–1.2%. The Cu content is set at 0.1%–0.25%.

[0024] Cr acts as a grain refiner and recrystallization inhibitor. In aluminum alloys, Cr forms the Al7Cr phase (dispersed fine particles), which hinders grain growth and suppresses recrystallization after extrusion, thereby improving the material's strength and corrosion resistance. The Cr content is controlled between 0.05% and 0.10%.

[0025] The main function of manganese (Mn) is to improve the stress corrosion resistance of aluminum alloys, while also working synergistically with chromium (Cr) to refine grains and further inhibit grain growth. The Mn content is set at 0.11%–0.20%.

[0026] Ti is a key grain refiner in the smelting process. In molten aluminum alloy, Ti forms the TiAl3 phase, which acts as a heterogeneous nucleation core, reducing the ingot grain size from 100 μm to below 30 μm, thereby improving subsequent processing and mechanical properties. The Ti content is controlled between 0.1% and 0.3%.

[0027] V is a high-temperature stability modifier. During the subsequent high-temperature baking (790–890°C) process of antibacterial impregnation, V forms the Al10V phase (a high-temperature stable phase). This phase can inhibit the growth of matrix grains, thereby maintaining the mechanical properties of the matrix. The V content is set at 0.03–0.06%.

[0028] La is a rare earth purification element. La can form stable compounds with harmful impurities (such as Fe and Na) in aluminum alloys. These compounds can be removed through refining, thereby purifying grain boundaries and improving the uniformity of the distribution of strengthening phases (MgZn2, Al2CuMg). The La content is controlled between 0.01% and 0.02%.

[0029] The main functions of Zr are to refine grain size and improve corrosion resistance. Zr forms the ZrAl3 phase, which not only helps Ti refine grain size but also forms a dense oxide film (ZrO2) on the aluminum alloy surface, reducing the corrosion rate. The Zr content is set at 0.02% to 0.05%.

[0030] Sr is a casting performance improver. Sr can refine the primary phases (such as Si phase) in the casting process, reduce porosity and defects in the ingot, and reduce the tendency for hot cracking. The Sr content is controlled at 0.01% to 0.03%.

[0031] The relationship 0.30 ≤ Mg / (Zn+Si) ≤ 0.40 is the core guarantee for the "equilibrium formation of the triple strengthening phase". Controlling the Mg / (Zn+Si) ratio between 0.30 and 0.40 ensures that Mg reacts with Zn and Si to form sufficient MgZn2 and Mg2Si phases. A small amount of free Mg can improve the toughness of the material. For the first time, a balance between sufficient strengthening phase formation and toughness is achieved through controlling the ratio of Mg to Zn and Si.

[0032] The relationship 2.0 ≤ Cu / Cr ≤ 5.0 is key to the synergistic effect of grain refinement and matrix strengthening. The Cu / Cr ratio is controlled between 2.0 and 5.0. Cu acts as the Al2CuMg strengthening phase, while Cr refines the grains. By optimizing the Cu / Cr ratio, the matrix grain size is stabilized at 25–35 μm, ensuring the tensile strength of the aluminum alloy matrix.

[0033] 0.06≤La / Ti≤0.18, the La / Ti ratio is controlled between 0.06 and 0.18. The role of La is to purify impurities and also has a certain effect on refining grains. The role of Ti is to refine grains. When La / Ti is controlled between 0.06 and 0.18, their coordinating effect can be better exerted and the elongation performance can be improved.

[0034] With a Zr / Sr ratio ≥ 1.25, Zr enhances corrosion resistance, while Sr improves casting performance. By controlling the Zr / Sr ratio, the contradiction between improved casting performance and decreased corrosion resistance is resolved. This fully utilizes ZrAl3 to pin dislocations, neutralize Fe impurities, reduce crack sources, and effectively improve the ingot yield.

[0035] Secondly, the present invention relates to a processing technology for the aluminum alloy product having a surface antibacterial coating, comprising the following steps: (1) Alloy smelting: Weigh the raw materials according to the composition of the base aluminum alloy, add them to the smelting furnace for smelting, refining and removing impurities, and die casting to obtain aluminum alloy ingots; (2) Extrusion molding: The aluminum alloy ingot is extruded at a temperature of 430-500℃. The extruded aluminum alloy is then air-cooled online. The cooled aluminum alloy is aged at 140-160℃ for 8-12 hours to obtain the base aluminum alloy. (3) Surface pretreatment: The base aluminum alloy is polished, alkaline washed and neutralized in sequence; (4) Anodizing: The pretreated aluminum alloy substrate is placed in a sulfuric acid solution of 190-210 g / L, and the current density is controlled at 1.4-1.6 A / dm³. 2 Oxidize for 25–35 minutes to form a honeycomb-like microporous anodic oxide film with a pore size of 50–80 nm on the surface; after oxidation, rinse with deionized water until pH 6–7, drain and let dry. (5) Antibacterial impregnation: The anodized aluminum alloy is immersed in an antibacterial impregnation solution, which is a mixture containing copper salt, silver salt and deionized water; the immersion is carried out at 50-60℃ and ultrasonically treated for 15-20 minutes, and then placed at 790-890℃ for 30-50 seconds. After the aluminum alloy is baked, it is allowed to cool naturally to 100-120℃, and the ultrasonic immersion and baking are repeated 4-5 times to make the antibacterial components uniformly deposited on the outer layer of micropores. (6) Sealing: The aluminum alloy after antibacterial impregnation is placed in a sealing solution containing 20-25 g / L NiF2 and 0.5-1.0 g / L Ce(NO3)3, and sealed for 30-45 min at the same temperature as antibacterial impregnation to obtain aluminum alloy products with surface antibacterial coating.

[0036] In one embodiment, the polishing in step (3) results in a surface roughness of 0.2 to 0.3 μm for the aluminum alloy.

[0037] In one embodiment, the alkaline washing in step (3) uses a 55-65 g / L NaOH solution and is treated at 55-60°C for 1.5-2.5 min to remove the surface oxide scale; the neutralization uses an HNO3 solution and is treated at room temperature for 1.2-1.8 min until there is no gray or black residue on the surface.

[0038] In one embodiment, the antibacterial impregnation solution in step (5) consists of sulfuric acid 15-19 g / L, CuSO4·5H2O 8-10 g / L, silver nitrate 20-30 g / L, HNO3 2-5 g / L, and the remainder is deionized water.

[0039] Traditional antibacterial coatings often use a single Ag (high cost, prone to aggregation) or a single Cu (low antibacterial efficiency). This invention uses a Cu-Ag compound to achieve "synergistic antibacterial effect + cost optimization": Ag has high antibacterial efficiency (inhibition rate of over 95% against Escherichia coli), but it is prone to forming aggregated particles with a size exceeding 100nm; Cu has long-lasting antibacterial effect and can inhibit Ag aggregation (Cu particles can act as dispersion cores for Ag particles, controlling the Ag particle size to 20-50nm). After compounding, the antibacterial rate of the antibacterial coating is increased to 99%.

[0040] Step (4) Anodizing: The sulfuric acid concentration is 190–210 g / L. Below 190 g / L, the oxide film grows slowly (film thickness ≤ 10 μm); above 210 g / L, the film layer is easily dissolved. The current density is 1.4–1.6 A / dm², ensuring sufficient film density (porosity ≥ 5%). A time of 25–35 min can achieve a film thickness of 12–15 μm, with the pore size controlled at 50–80 nm. Through precise control of sulfuric acid concentration, current density, and time, the directional design of the micropore size (50–80 nm) is achieved, providing a "carrier" for the uniform deposition of antibacterial particles.

[0041] The pore size of the anodic oxide film is 50–80 nm. If the pore size is less than 50 nm, Cu and Ag particles have difficulty entering the micropores, resulting in poor coating adhesion. If the pore size is greater than 80 nm, impurities are easily left inside the micropores, and the antibacterial particles are not firmly deposited, leading to a decrease in antibacterial rate after washing. A pore size of 50–80 nm allows the antibacterial particles to completely fill the outer layer of the micropores, forming an "anchoring effect," which improves adhesion while ensuring the compactness of the film.

[0042] Step (5) Antibacterial impregnation (ultrasound at 50-60℃ for 15-20 min, bake at 790-890℃ for 30-50 s, repeat 4-5 times). Components of the antibacterial impregnation solution (sulfuric acid 15-19 g / L, CuSO4·5H2O 8-10 g / L, silver nitrate 20-30 g / L, HNO3 2-5 g / L): Controlling the concentration of Cu and Ag ions ensures the combination of copper and silver in the coating, achieving the optimal antibacterial effect.

[0043] Ultrasonic treatment (50–60℃, 15–20 min): This enhances ion activity and ensures uniform distribution of Cu and Ag ions. Repeated immersion and ultrasonic baking (4–5 times) allows silver and copper particles to uniformly fill the micropores of alumina, forming a uniform and dense nano-antibacterial layer on the aluminum alloy surface. The antibacterial layer thickness reaches 8–10 nm, completely filling the outer layer of the micropores and forming a uniform and dense nano-coating. This improves the hardness and wear resistance of the alumina micropores, enhances the gloss and antibacterial properties of the aluminum alloy, and achieves a coating adhesion ≥10 MPa and an antibacterial rate of 99%.

[0044] The embodiments of the present invention are described in detail below. The base aluminum alloy composition of Embodiments 1 to 4 and Comparative Examples 1 to 4 is shown in Table 1.

[0045] Table 1: Composition of the base aluminum alloy in Examples 1-4 and Comparative Examples 1-4

[0046] The process parameters used in the preparation of aluminum alloy products in Examples 1-4 and Comparative Examples 5-7 of this invention are shown in Table 2.

[0047] Table 2: Process parameters used in the preparation methods of Examples 1-4 and Comparative Examples 5-7

[0048] The process parameters used to prepare aluminum alloy products in Comparative Examples 1 to 4 were the same as those in Example 1.

[0049] The base aluminum alloys used in the preparation of aluminum alloy products in Comparative Examples 5-7 were the same as those in Example 2.

[0050] Compared to the processing technology of Example 2, the processing technology of Comparative Example 5 changed the anodizing process parameters, Comparative Example 6 changed the composition of the antibacterial impregnation solution, and Comparative Example 7 did not undergo ultrasonic treatment. See Table 2 for details.

[0051] The mechanical properties of the aluminum alloy products of Examples 1-4 and Comparative Examples 1-4 were measured, and the results are shown in Table 3.

[0052] Table 3: Mechanical property data of Examples 1-4 and Comparative Examples 1-4

[0053] As can be seen from Table 3, the aluminum alloy products prepared by the present invention have excellent tensile strength, yield strength and elongation properties, with tensile strength ≥420MPa, yield strength ≥360MPa and elongation ≥10%.

[0054] Compared with Examples 1-4, Comparative Examples 1-4 changed the component content and did not satisfy the relationship between the contents of each component, thus failing to give full play to the synergistic effect between the components, and the mechanical properties of the alloy were significantly reduced.

[0055] According to relevant standards such as JIS Z2801-2000 "Antibacterial processed products - Test methods and antibacterial effects" and GB / T2591-2003 "Test methods and antibacterial effects of antibacterial plastics", the bactericidal rate of the alloy products obtained in Examples 1-2 and Comparative Examples 5-7 of this invention was determined to be effective against common bacteria (Escherichia coli and Staphylococcus aureus) in daily life. The incubation time was set to 6 minutes.

[0056] The CASS test was conducted according to GB / T12967.3-2008 "Test Methods for Anodized Films of Aluminum and Aluminum Alloys - Part 3: Copper Accelerated Acetic Acid Salt Spray Test (CASS Test)". The salt spray corrosion resistance test time was set according to GB / T5237.2-2017 "Aluminum Alloy Building Profiles - Part 2: Anodized Profiles", and the alloy products obtained in Examples 1-2 and Comparative Examples 5-7 of this invention were tested for salt spray corrosion resistance. The results are shown in Table 4.

[0057] Table 4: Antibacterial and corrosion resistance data of Examples 1-2 and Comparative Examples 5-7

[0058] As can be seen from Table 4, the aluminum alloy products prepared by this invention, through adjustment and optimization of the anodizing and antibacterial impregnation processes, and by using a specific antibacterial impregnation solution with matching antibacterial impregnation process parameters, and repeatedly undergoing multiple ultrasonic and high-temperature baking processes, allow silver and copper particles to uniformly fill the micropores of alumina, forming a uniform and dense nano-antibacterial layer on the surface of the aluminum alloy, completely filling the outer layer of the micropores, achieving an antibacterial rate of over 99%, and a salt spray corrosion protection level of up to level 10.

[0059] Compared to Examples 1-2, Comparative Examples 5-7 changed the anodic oxidation parameters, the antibacterial impregnation solution composition, and the ultrasonic treatment process, and were unable to form a stable antibacterial coating, resulting in a significant decrease in antibacterial and corrosion resistance properties.

[0060] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. An alloy product with a surface antibacterial coating, characterized in that, include: The base aluminum alloy composition of the alloy product, by mass percentage, is: Si 0.25%–0.4%, Zn 2.0%–3.0%, Cu 0.1%–0.25%, Mg 0.8%–1.2%, Cr 0.05%–0.10%, Mn 0.11%–0.20%, Ti 0.1%–0.3%, V 0.03%–0.06%, La 0.01%–0.02%, Zr 0.02%–0.05%, Sr 0.01%–0.03%, with the balance being Al and unavoidable impurities; The composition of the base aluminum alloy satisfies the following mass percentage content relationship: 0.30≤Mg / (Zn+Si)≤0.40; 2.0≤Cu / Cr≤5.0; The aluminum alloy product has an antibacterial coating on its surface, which contains an antibacterial component composed of copper and silver.

2. The alloy product with an antibacterial coating according to claim 1, characterized in that, The composition of the base aluminum alloy also satisfies the following mass percentage content relationship: 0.06≤La / Ti≤0.18; Zr / Sr≥1.

25.

3. The alloy product with an antibacterial surface coating according to claim 1, characterized in that, The average size of the precipitated phases MgZn2 and Al2CuMg in the matrix aluminum alloy is ≤45μm.

4. A processing method for preparing an alloy article with a surface antibacterial coating as described in any one of claims 1 to 3, characterized in that: Includes the following steps: (1) Alloy smelting: Weigh the raw materials according to the composition of the base aluminum alloy, add them to the smelting furnace for smelting, refining and removing impurities, and die casting to obtain aluminum alloy ingots; (2) Extrusion molding: The aluminum alloy ingot is extruded at a temperature of 430-500℃. The extruded aluminum alloy is then air-cooled online. The cooled aluminum alloy is aged at 140-160℃ for 8-12 hours to obtain the base aluminum alloy. (3) Surface pretreatment: The base aluminum alloy is polished, alkaline washed and neutralized in sequence; (4) Anodizing: The pretreated aluminum alloy substrate is placed in a sulfuric acid solution of 190-210 g / L, and the current density is controlled at 1.4-1.6 A / dm³. 2 Oxidize for 25–35 minutes to form a honeycomb-like microporous anodic oxide film with a pore size of 50–80 nm on the surface; after oxidation, rinse with deionized water until pH 6–7, drain and let dry. (5) Antibacterial impregnation: The anodized aluminum alloy is immersed in an antibacterial impregnation solution, which is a mixture containing copper salt, silver salt and deionized water; the immersion is carried out at 50-60℃ and ultrasonically treated for 15-20 minutes, and then placed at 790-890℃ for 30-50 seconds. After the aluminum alloy is baked, it is allowed to cool naturally to 100-120℃, and the ultrasonic immersion and baking are repeated 4-5 times to make the antibacterial components uniformly deposited on the outer layer of micropores. (6) Sealing: The aluminum alloy after antibacterial impregnation is placed in a sealing solution containing 20-25 g / L NiF2 and 0.5-1.0 g / L Ce(NO3)3, and sealed for 30-45 min at the same temperature as antibacterial impregnation to obtain aluminum alloy products with surface antibacterial coating.

5. The processing technology according to claim 4, characterized in that, In step (3), polishing is performed to make the surface roughness of the aluminum alloy 0.2 to 0.3 μm.

6. The processing technology according to claim 4, characterized in that, In step (3), the alkaline washing uses a 55-65 g / L NaOH solution and is treated at 55-60°C for 1.5-2.5 min to remove the surface oxide scale; the neutralization uses an HNO3 solution and is treated at room temperature for 1.2-1.8 min until there is no gray or black residue on the surface.

7. The processing technology according to claim 4, characterized in that, The antibacterial impregnation solution in step (5) consists of sulfuric acid 15-19 g / L, CuSO4·5H2O 8-10 g / L, silver nitrate 20-30 g / L, HNO3 2-5 g / L, and the remainder is deionized water.

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