A method of treating an aluminum-containing metal and an aluminum-containing metal

Abstract

The application provides a treatment method of aluminum-containing metal and an aluminum-containing metal, and the treatment method comprises a target step, the target step comprises: treating a first aluminum-containing metal by using a target solution to obtain a second aluminum-containing metal, wherein the target solution comprises a mixture of a first solute and a second solute, the mass ratio of the first solute and the second solute in the mixture is (3.2-4.7):1, the first solute is selected from at least one of ammonium hydrogen fluoride and potassium hydrogen fluoride, and the second solute is selected from at least one of sodium hydroxide and potassium hydroxide.

Description

Technical Field

[0001] This application relates to the technical field of metallic materials, and more particularly to a method for processing aluminum-containing metals and aluminum-containing metals. Background Technology

[0002] In recent years, consumers have placed increasingly higher demands on the appearance of portable devices, such as laptops, that use aluminum as their primary structural material. How to achieve color and appearance that meet the requirements of commercial applications using aluminum remains a pressing technical problem to be solved in this field. Summary of the Invention

[0003] The first aspect of this application provides a method for processing aluminum-containing metal, comprising: a target step, the target step comprising: processing a first aluminum-containing metal with a target solution to obtain a second aluminum-containing metal, wherein the target solution comprises a mixture of a first solute and a second solute, the mass ratio of the first solute and the second solute in the mixture being (3.2 to 4.7):1, the first solute being selected from at least one of ammonium bifluoride and potassium bifluoride, and the second solute being selected from at least one of sodium hydroxide and potassium hydroxide.

[0004] In some embodiments, the mass ratio of the first solute to the second solute in the mixture is (3.5 to 4.5):1.

[0005] In some embodiments, the target solution comprises ammonium bifluoride and sodium hydroxide in a mass ratio of 4:1.

[0006] In some embodiments, the first aluminum-containing metal comprises, by mass, 0% ≤ Mg ≤ 2%.

[0007] In some embodiments, the processing temperature is 40°C to 50°C, and the processing time is 150 seconds to 200 seconds; the mixture accounts for 4% to 5.4% of the mass of the target solution.

[0008] In some embodiments, the processing method further includes a targeted oxidation step, by which an oxide film with an average thickness of 10 μm to 13 μm is formed on the second aluminum-containing metal surface.

[0009] In some embodiments, the target oxidation step includes: oxidizing the second aluminum-containing metal in an oxidation tank containing a sulfuric acid solution at a temperature of 10°C to 30°C for 18 to 25 minutes, at a voltage of 12V to 14V, wherein the concentration of the sulfuric acid solution is 190g / L to 210g / L; and controlling the concentration of aluminum ions in the sulfuric acid solution to 7g / L to 10g / L in the target oxidation step; or, the target oxidation step includes: oxidizing the second aluminum-containing metal in an oxidation tank containing a sulfuric acid solution at a temperature of 50°C to 60°C for 10 to 15 minutes, at a voltage of 12V to 14V, wherein the concentration of the sulfuric acid solution is 190g / L to 210g / L; and controlling the concentration of aluminum ions in the sulfuric acid solution to 7g / L to 10g / L in the target oxidation step.

[0010] In some embodiments, the first aluminum-containing metal comprises an aluminum-magnesium-silicon alloy, wherein, based on the mass of the aluminum-magnesium-silicon alloy, the aluminum-magnesium-silicon alloy comprises: 0.3% ≤ Mg ≤ 1%; 0.4% ≤ Si ≤ 1.2%; and 98% ≤ Al ≤ 99.5%.

[0011] A second aspect of this application provides an aluminum-containing metal, which is treated with a target solution comprising a mixture of a first solute and a second solute, wherein the mass ratio of the first solute to the second solute in the mixture is (3.2 to 4.7):1, the first solute being selected from at least one of ammonium bifluoride and potassium bifluoride, and the second solute being selected from at least one of sodium hydroxide and potassium hydroxide.

[0012] In some implementations, the CIE LAB color space containing aluminum metals satisfies: L≥91; -0.5≤a≤0.2; -0.2≤b≤0.5; and in the CIE LAB color space containing aluminum metals, the color difference ΔE between any two points (L1,a1,b1) and (L2,a2,b2) ≤0.81, where ΔE=[(L1-L2)] 2 +(a1-a2) 2 +(b1-b2) 2 ] 1 / 2 .

[0013] In some embodiments, the aluminum-containing metal also includes an oxide film disposed on the surface of the aluminum-containing metal, the average thickness of the oxide film being 10 μm to 13 μm. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the sampling points for measuring the color difference ΔE in one embodiment of this application; Figure 2 This is an image of a magnesium-aluminum-silicon alloy according to an embodiment of this application, observed under a microscope. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. The described embodiments should not be regarded as limitations on this application. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0016] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of the particular range. The range defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range.

[0017] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0018] Unless otherwise specified, all steps in this application may be performed sequentially or randomly.

[0019] Unless otherwise specified, the terms used in this application have the common meanings as commonly understood by those skilled in the art.

[0020] Unless otherwise specified, the values ​​of the parameters mentioned in this application can be determined using various testing methods commonly used in the art, for example, according to the testing methods given in this application.

[0021] In recent years, consumers have placed increasingly higher demands on the appearance of portable devices, such as laptops, that use aluminum as their primary structural material. White exteriors, with their simple, elegant, and modern visual qualities, are favored by many consumers. However, how to achieve a white exterior for aluminum-based devices that meets the requirements of commercial applications remains a pressing technical problem to be solved in this field.

[0022] In view of this, a first aspect of this application provides a method for processing aluminum-containing metal, comprising: a target step, the target step comprising: treating a first aluminum-containing metal with a target solution to obtain a second aluminum-containing metal, wherein the target solution comprises a mixture of a first solute and a second solute, the mass ratio of the first solute to the second solute in the mixture being (3.2 to 4.7):1, the first solute being selected from at least one of ammonium bifluoride and potassium bifluoride, and the second solute being selected from at least one of sodium hydroxide and potassium hydroxide. By using the processing method of this application to treat the aluminum-containing metal, an aluminum-containing metal with a nearly white surface can be obtained.

[0023] The possible mechanism is as follows: The aluminum-containing metal is treated with a target solution containing the first and second solutes. A chemical reaction occurs between the target solution and the aluminum-containing metal, and etching creates microstructures on the surface of the metal suitable for diffuse light reflection, resulting in a near-white appearance. During the treatment, fluoride ions in the first solute are primarily used to etch the aluminum-containing metal, while the second solute mainly regulates the fluoride ion concentration in the target solution and the pH of the target solution during etching. By maintaining the mass ratio of the first and second solutes within the aforementioned range, the etching rate can be controlled appropriately, thereby creating microstructures suitable for diffuse light reflection on the surface of the aluminum-containing metal, ultimately resulting in a near-white appearance.

[0024] In this application, "aluminum-containing metal" refers to a metal containing aluminum. The aluminum content in "aluminum-containing metal" can be up to 100%, that is, "aluminum-containing metal" can be pure aluminum.

[0025] In this application, "first aluminum-containing metal" and "second aluminum-containing metal" are terms introduced to clearly describe the state changes of the object before and after treatment, and do not indicate that there is a difference in their chemical composition.

[0026] In this application, the color of aluminum-containing metals is characterized by their color coordinates (L, a, b) in the CIE LAB color space. Here, L is the whiteness value, representing the brightness of the color; a is the red-green hue, representing the color's tendency between red and green; and b is the yellow-blue hue, representing the color's tendency between yellow and blue. The larger the L value, the closer the a value and b value are to 0, and the closer the color is to white.

[0027] In this application, the color coordinates (L, a, b) of the aluminum-containing metal can be measured, for example, by using a colorimeter (e.g., Konica Minolta, CM-700d, etc.) to measure the aluminum-containing metal workpiece (measurement conditions: measuring aperture Φ8mm, light source D65, 10-degree viewing angle, SCI (includes specular reflection) mode). The testing instruments used above are merely exemplary, and those skilled in the art can use any suitable colorimeter for testing.

[0028] In some embodiments, the mass ratio of the first solute to the second solute in the mixture can be (3.5 to 4.5):1. Studies have found that controlling the mass ratio of the first solute to the second solute in the mixture within the above range is beneficial for further improving the L value of the aluminum-containing metal's chromaticity coordinates, thereby making it appear brighter and closer to white. Exemplarily, the mass ratio of the first solute to the second solute in the mixture can be 3.5:1, 3.6:1, 3.7:1, 3.8:1, 3.9:1, 4.0:1, 4.1:1, 4.2:1, 4.3:1, 4.4:1, 4.5:1, or a value within a range of any two of these.

[0029] In some embodiments, the target solution may include ammonium bifluoride and sodium hydroxide in a mass ratio of 4:1. This is beneficial for further increasing the L value of the aluminum-containing metallic color coordinates, thereby making it appear brighter and closer to white.

[0030] In some embodiments, the first aluminum-containing metal, based on its mass, may include: 0% ≤ Mg ≤ 2%. Studies have found that the magnesium content in the first aluminum-containing metal has a certain influence on the b-value of the aluminum-containing metal's chromaticity coordinates. Based on the mass of the first aluminum-containing metal, when the magnesium content exceeds 1%, the b-value of the aluminum-containing metal's chromaticity coordinates increases, meaning the aluminum-containing metal has a more yellowish color. A possible mechanism for this is that excessively high Mg content in the aluminum-containing metal alters the morphology of the microstructure formed through etching, reducing the reflection of short-wavelength blue light and relatively increasing the reflection of long-wavelength yellow light, macroscopically manifesting as an increased b-value. Therefore, controlling the magnesium content in the first aluminum-containing metal within the aforementioned range is beneficial for further making the appearance of the aluminum-containing metal closer to white. For example, the magnesium content in the first aluminum-containing metal, based on its mass, can be 0%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, or a value within a range of any two of these. In some embodiments, the first aluminum-containing metal, based on its mass, may include: 0% ≤ Mg ≤ 1%. This is advantageous for further refining the appearance of the aluminum-containing metal to be closer to white.

[0031] In some embodiments, the processing temperature can be 40°C to 50°C, and the processing time can be 150 seconds to 200 seconds; the mass percentage of the mixture in the target solution can be 4% to 5.4% based on the mass of the target solution. Studies have found that by maintaining the processing temperature and time within the above ranges during the target solution processing, and by maintaining the mass percentage of the mixture of the first and second solutes in the target solution within the above ranges, it is beneficial to further improve the uniformity of the formed microstructure, thereby reducing the color difference ΔE of the color coordinates in different regions, and thus improving the uniformity of white color in different regions of the aluminum-containing metal surface. For example, the processing temperature can be a value between 40°C, 42°C, 44°C, 46°C, 48°C, 50°C, or any two of these values; the processing time can be a value between 150 seconds, 155 seconds, 160 seconds, 165 seconds, 170 seconds, 175 seconds, 180 seconds, 185 seconds, 190 seconds, 195 seconds, 200 seconds, or any two of these values; and the mass percentage of the mixture in the target solution can be 4%, 4.2%, 4.4%, 4.6%, 4.76%, 4.8%, 5%, 5.2%, 5.4%, or any two of these values.

[0032] In this application, the color difference ΔE between any two points (L1,a1,b1) and (L2,a2,b2) of aluminum metal can be calculated as follows: Figure 1 As shown, four sampling points (30mm from the edge) were taken at the edge of the aluminum-containing metal workpiece, and one test point was taken at the center. A colorimeter (e.g., Konica Minolta, CM-700d) was used to measure these five test points (measurement conditions: Φ8mm measuring aperture, D65 light source, 10-degree viewing angle, SCI (including specular reflection) mode). The color difference ΔE between any two points (L1, a1, b1) and (L2, a2, b2) was calculated, where ΔE = [(L1 - L2)]. 2 +(a1-a2) 2 +(b1-b2) 2 ] 1 / 2 .

[0033] In some embodiments, the processing method may further include a targeted oxidation step, which forms an oxide film with an average thickness of 10 μm to 13 μm on the second aluminum-containing metal surface. By performing a targeted oxidation step on the aluminum-containing metal, the corrosion resistance, hardness, and wear resistance of the aluminum-containing metal surface can be improved. Furthermore, studies have found that when the average thickness of the oxide film is less than 10 μm, light interference is easily formed in localized areas, resulting in a iridescent effect when viewed from different angles; additionally, the corrosion resistance, hardness, and wear resistance of the oxide film are also reduced. When the average thickness of the oxide film is greater than 13 μm, it will have a certain impact on the L value, causing it to decrease. For example, the average thickness of the oxide film formed on the second aluminum-containing metal surface by the targeted oxidation step can be a value between 10 μm, 10.5 μm, 11 μm, 11.5 μm, 12 μm, 12.5 μm, 13 μm, or any combination thereof.

[0034] In this application, the average thickness of the oxide film formed on the aluminum-containing metal surface can be measured as follows: The thickness of the oxide film formed on the aluminum-containing metal surface is measured using a coating thickness gauge (such as ElektroPhysik, Mini test 600, etc.). To make the results more accurate, the thickness at five different locations can be measured, and the average value is taken as the final result. The testing instruments used above are merely exemplary; those skilled in the art can use any suitable coating thickness gauge for testing.

[0035] In some embodiments, the target oxidation step may include: oxidizing a second aluminum-containing metal in an oxidation bath containing a sulfuric acid solution at a temperature of 10°C to 30°C for 18 to 25 minutes, at a voltage of 12V to 14V, wherein the concentration of the sulfuric acid solution is 190 g / L to 210 g / L; and controlling the concentration of aluminum ions in the sulfuric acid solution to 7 g / L to 10 g / L during the target oxidation step. Through the synergistic effect of the above process parameters, an oxide film with good density, uniformity, and corrosion resistance can be formed. Controlling the concentration of aluminum ions in the sulfuric acid solution within the above range is beneficial for controlling the film formation rate of the oxide film within a suitable range, thereby further improving the structural uniformity of the oxide film. Exemplarily, the second aluminum-containing metal may be oxidized in an oxidation bath containing a sulfuric acid solution for 18 minutes, 19 minutes, 20 minutes, 21 minutes, 22 minutes, 23 minutes, 24 minutes, 25 minutes, or any combination thereof.

[0036] In some embodiments, the target oxidation step may include: oxidizing a second aluminum-containing metal in an oxidation bath containing a sulfuric acid solution at 50°C to 60°C for 10 to 15 minutes, with a voltage of 12V to 14V, wherein the concentration of the sulfuric acid solution is 190 g / L to 210 g / L; and controlling the concentration of aluminum ions in the sulfuric acid solution to 7 g / L to 10 g / L during the target oxidation step. This allows the formation of an oxide film with good density, uniformity, and corrosion resistance. Controlling the concentration of aluminum ions in the sulfuric acid solution within the aforementioned range helps to control the film formation rate of the oxide film within a suitable range, thereby further improving the structural uniformity of the oxide film. Exemplarily, the second aluminum-containing metal may be oxidized in an oxidation bath containing a sulfuric acid solution for 10 minutes, 11 minutes, 12 minutes, 13 minutes, 14 minutes, 15 minutes, or any combination thereof.

[0037] The core of the target oxidation step is to achieve a predetermined oxide film thickness of 10 μm to 13 μm. The above process parameters are for illustrative purposes only and are not mandatory limitations on the process range. Those skilled in the art can reasonably modify these parameters while forming an oxide film of the same thickness.

[0038] In some embodiments, the first aluminum-containing metal may include an aluminum-magnesium-silicon alloy, which, by mass, may include: 0.3% ≤ Mg ≤ 1%; 0.4% ≤ Si ≤ 1.2%; and 98% ≤ Al ≤ 99.5%. The aforementioned aluminum-magnesium-silicon alloy (i.e., 6-series aluminum alloy) has high ductility, meets the requirements of stamping processes, is suitable for the casing of portable devices (e.g., laptops), and also offers high cost-effectiveness. For example, based on the mass of the aluminum-magnesium-silicon alloy, the aluminum-magnesium-silicon alloy may include Mg values ​​of 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, or any two of these values; Si values ​​of 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.1%, 1.2%, or any two of these values; and Al values ​​of 98%, 98.2%, 98.4%, 98.6%, 98.6%, 99%, 99.3%, 99.5%, or any two of these values.

[0039] In some embodiments, the treatment method may further include a degreasing step, which may include: degreasing the aluminum-containing metal for 100 to 150 seconds at 50°C to 55°C using a solution of a weakly alkaline salt with a concentration of 45 g / L to 55 g / L, wherein the weakly alkaline salt is selected from at least one of carbonates and silicates. Performing the above degreasing step helps remove oil stains from the surface of the aluminum-containing metal while reducing over-corrosion or surface damage to the aluminum-containing metal surface.

[0040] In some embodiments, the processing method may further include a sandblasting step, which may include sandblasting the aluminum-containing metal with an abrasive having a mesh size of 150 to 180, wherein the abrasive is selected from at least one of iron sand and zirconium sand. By performing the above sandblasting step, microscopic defects on the surface of the aluminum-containing metal can be removed, the adhesion to the oxide film generated in the subsequent target oxidation step can be improved, and damage to the aluminum-containing metal substrate caused by excessively large abrasives can be reduced. Exemplarily, the mesh size of the abrasive used in the sandblasting process can be a value between 150 mesh, 155 mesh, 160 mesh, 165 mesh, 170 mesh, 175 mesh, 180 mesh, or any combination thereof.

[0041] In some embodiments, the processing method may further include a chemical polishing step, which may include: chemically polishing the aluminum-containing metal with a chemical polishing solution at 75°C to 85°C for 50 to 150 seconds, wherein the chemical polishing solution comprises a mixed solution of phosphoric acid and sulfuric acid with a volume ratio of (2.8:1) to (3.3:1), and the aluminum ion concentration in the chemical polishing solution is controlled at 20 g / L to 30 g / L. Performing the above steps facilitates microscopic leveling of the aluminum-containing metal surface, thereby improving surface gloss. By controlling the aluminum ion concentration in the chemical polishing solution to 20 g / L to 30 g / L, a balance is achieved between the polishing rate and leveling ability, resulting in a uniform, bright surface. If the aluminum ion concentration is too high, the polishing rate will decrease significantly, leading to poor surface gloss. The chemical polishing time can be adaptively adjusted according to the gloss level of the target product.

[0042] In some embodiments, the processing method may further include a descaling step, which may include descaling the aluminum-containing metal with a 10% to 15% (by volume) nitric acid solution at 10°C to 30°C for 100 to 120 seconds. Reaction products generated after the target step may remain on the surface of the aluminum-containing metal, forming ash residue. The descaling step can remove these residual reaction products, reducing their impact on subsequent processes. Using a low-concentration nitric acid solution for descaling can reduce the impact on the aluminum-containing metal substrate while removing ash.

[0043] In some embodiments, the processing method may further include a sealing step, which may include sealing the aluminum-containing metal at 90°C to 100°C for at least 35 minutes using a sealing agent with a mass concentration of 12 g / L to 15 g / L. The sealing agent may be selected from at least one of nickel acetate and nickel sulfate. This sealing step closes the micropores present in the oxide film, thereby further improving the density and corrosion resistance of the oxide film, enabling the final product to meet standards such as wear resistance and salt spray testing.

[0044] In some embodiments, a water washing step can be performed after the above-mentioned target step, target oxidation step, degreasing step, sandblasting step, chemical polishing step, dust removal step and sealing step, so as to remove the residue on the aluminum-containing metal surface.

[0045] A second aspect of this application provides an aluminum-containing metal treated with a target solution comprising a mixture of a first solute and a second solute, wherein the mass ratio of the first solute to the second solute in the mixture is (3.2 to 4.7):1. The first solute is selected from at least one of ammonium bifluoride and potassium bifluoride, and the second solute is selected from at least one of sodium hydroxide and potassium hydroxide. By treating the aluminum-containing metal with the aforementioned target solution, a chemical reaction occurs between the target solution and the aluminum-containing metal, and an etching process forms a microstructure suitable for diffuse light reflection on the surface of the aluminum-containing metal, thereby giving the aluminum-containing metal a near-white appearance.

[0046] In some implementations, the CIE LAB color space containing aluminum metal can satisfy: L≥91; -0.5≤a≤0.2; -0.2≤b≤0.5; in the CIE LAB color space containing aluminum metal, the color difference ΔE between any two points (L1,a1,b1) and (L2,a2,b2) ≤0.81, where ΔE=[(L1-L2)] 2 +(a1-a2) 2 +(b1-b2) 2 ] 1 / 2 As a result, aluminum-containing metals exhibit a near-white appearance, and the color difference between different areas of the aluminum-containing metal is small, resulting in a good appearance and texture.

[0047] In some embodiments, the aluminum-containing metal may further include an oxide film disposed on the surface of the aluminum-containing metal, the average thickness of which can be 10 μm to 13 μm. Studies have found that when the average thickness of the oxide film is less than 10 μm, light interference is easily formed in localized areas, resulting in a iridescent effect when viewed from different angles; furthermore, the corrosion resistance, hardness, and wear resistance of the oxide film are also reduced. When the average thickness of the oxide film is greater than 13 μm, it will have a certain impact on the L value, causing it to decrease. Exemplarily, the average thickness of the oxide film can be a value within the range of 10 μm, 10.5 μm, 11 μm, 11.5 μm, 12 μm, 12.5 μm, 13 μm, or any two of these values.

[0048] Example The present invention will be described in more detail below through embodiments. It should be understood that the embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in the art.

[0049] Example 1 An aluminum-magnesium-silicon alloy is prepared, comprising 99% Al, 0.4% Mg, and 0.4% Si by weight. The alloy is then processed through the following steps: (1) Degreasing steps Remove the protective film from the surface of the aluminum-magnesium-silicon alloy, place it in a degreasing tank for 120 seconds, and degrease it at a temperature of 50°C. The degreasing solution used in the degreasing step is an aqueous sodium carbonate solution with a concentration of 50 g / L.

[0050] (2) Target Steps The aluminum-magnesium-silicon alloy obtained in step (1) was etched using a target solution containing ammonium bifluoride and sodium hydroxide. The concentration of ammonium bifluoride in the target solution was 30 g / L, the concentration of sodium hydroxide was 7.5 g / L, the processing temperature was 55 °C, and the processing time was 220 seconds.

[0051] (3) Ash removal steps The aluminum-magnesium-silicon alloy obtained in step (2) was treated for 110 seconds at room temperature using a 15% nitric acid solution.

[0052] (4) Chemical polishing step The aluminum-magnesium-silicon alloy obtained in step (3) was chemically polished for 80 seconds at 80°C using a chemical polishing solution, wherein the chemical polishing solution included a mixed solution of phosphoric acid and sulfuric acid, the concentration of phosphoric acid was 940 g / L, the concentration of sulfuric acid was 294 g / L, and the concentration of aluminum ions was controlled at 25 g / L.

[0053] (5) Target oxidation step The aluminum-magnesium-silicon alloy obtained in step (4) was oxidized for 25 minutes at 25°C in an oxidation tank containing sulfuric acid solution, with a voltage of 13V. The concentration of the sulfuric acid solution was 200g / L. In the target oxidation step, the concentration of aluminum ions in the sulfuric acid solution was controlled to 8g / L.

[0054] Oxide film thickness testing The average thickness of the oxide film formed on the surface of the aluminum-magnesium-silicon alloy was tested using the following method: A coating thickness gauge (ElektroPhysik, Mini test 600) was used to measure the thickness of the oxide film on the aluminum-magnesium-silicon alloy surface. To ensure accuracy, the thickness was measured at five different locations, and the average value was taken as the final result. The measured average thickness of the oxide film on the aluminum-magnesium-silicon alloy surface was 12 μm.

[0055] (6) Sealing steps At 95°C, the aluminum-magnesium-silicon alloy obtained in step (4) was sealed for 40 minutes using a sealing agent with a mass concentration of 13 g / L. The sealing agent was nickel acetate.

[0056] Testing of aluminum-magnesium-silicon alloys CIE color coordinates The CIE color coordinates of aluminum-magnesium-silicon alloys were measured using the following method: A colorimeter (Konica Minolta, CM-700d) was used to measure the aluminum-magnesium-silicon alloy workpiece (measurement conditions: measuring aperture Φ8mm, light source D65, 10-degree viewing angle, SCI (includes specular reflection) mode). The results are shown in Table 1.

[0057] Example 2 The aluminum-magnesium-silicon alloy was treated in the same manner as in Example 1, except that the mass ratio of the first solute to the second solute was adjusted according to Table 1 below, and the target oxidation steps were performed as follows: The aluminum-magnesium-silicon alloy was oxidized for 13 minutes at 50°C in the oxidation tank containing sulfuric acid solution, with a voltage of 13V, wherein the concentration of the sulfuric acid solution was 200g / L; in the target oxidation step, the concentration of aluminum ions in the sulfuric acid solution was controlled to 8g / L.

[0058] The thickness of the oxide film formed on the surface of the aluminum-magnesium-silicon alloy was measured in the same manner as in Example 1. The average thickness of the oxide film formed in Example 2 was measured to be 12.4 μm.

[0059] Examples 3-5 The aluminum-magnesium-silicon alloy was treated in the same manner as in Example 1, except that the types of the first and second solutes and the mass ratio of the first solute to the second solute were adjusted according to Table 1 below.

[0060] Comparative Examples 1-2 The aluminum-magnesium-silicon alloy was treated in the same manner as in Example 1, except that the mass ratio of the first solute to the second solute was adjusted according to Table 1 below.

[0061] The color coordinates of the aluminum-magnesium-silicon alloys in Examples 2-5 and Comparative Examples 1-2 were measured using the same test method as in Example 1, and the results are shown in Table 1.

[0062] Table 1

[0063] As can be seen from Table 1, the mass ratio of the first solute to the second solute in Comparative Examples 1 and 2 is not within the range of this application, so the L value is relatively low. However, the mass ratio of the first solute to the second solute in Examples 1-5 is within the above range, and exhibits a more white effect.

[0064] Example 6 The aluminum-magnesium-silicon alloy was processed in the same manner as in Example 1, except that in Example 6, the aluminum-magnesium-silicon alloy comprised 97% Al, 2.5% Mg, and 0.4% Si by mass.

[0065] Examples 7-8 The aluminum-magnesium-silicon alloy was processed in the same manner as in Example 1, except that the oxide film thickness was adjusted by changing the oxidation time in the target oxidation step, as shown in Table 2 below.

[0066] The color coordinates of the aluminum-magnesium-silicon alloys in Examples 6 to 8 were measured using the same test method as in Example 1, and the results are shown in Table 2 below.

[0067] Table 2

[0068] As can be seen from Example 6 in Table 2, when the magnesium content in the aluminum-magnesium-silicon alloy is too high, the b value will increase; as can be seen from Example 7, when the average thickness of the oxide film is too small, a iridescent effect will appear under visual observation; as can be seen from Example 8, when the average thickness of the oxide film is too high, it will affect the L value.

[0069] Example 9 The aluminum-magnesium-silicon alloy was treated in the same manner as in Example 1, except that... (2) Target Steps The aluminum-magnesium-silicon alloy obtained in step (1) was etched using a target solution containing ammonium bifluoride and sodium hydroxide. The concentration of ammonium bifluoride in the target solution was 40 g / L, the concentration of sodium hydroxide was 10 g / L, the processing temperature was 45 °C, and the processing time was 180 seconds.

[0070] Measurement of color difference ΔE Measure the color difference ΔE using the following method: (e.g.) Figure 1 As shown, four sampling points (30mm from the edge) and one test point were taken at the center of the aluminum-magnesium-silicon alloy workpiece. A colorimeter (Konica Minolta, CM-700d) was used to measure these five test points (measurement conditions: Φ8mm measuring aperture, D65 light source, 10-degree viewing angle, SCI (including specular reflection) mode). The color difference ΔE between any two points (L1, a1, b1) and (L2, a2, b2) was calculated, where ΔE = [(L1 - L2)]. 2 +(a1-a2) 2 +(b1-b2) 2 ] 1 / 2The aluminum-magnesium-silicon alloy workpieces in Example 1 were tested and compared in the same manner, and the maximum color difference ΔE value was calculated. The corresponding two color coordinates are shown in Table 3 below.

[0071] Example 10 The aluminum-magnesium-silicon alloy was treated in the same manner as in Example 1, except that... (2) Target Steps The aluminum-magnesium-silicon alloy obtained in step (1) was etched using a target solution containing ammonium bifluoride and sodium hydroxide. The concentration of ammonium bifluoride in the target solution was 33.5 g / L, the concentration of sodium hydroxide was 8.3 g / L, the processing temperature was 40 °C, and the processing time was 150 seconds.

[0072] The color difference ΔE of the aluminum-magnesium-silicon alloy workpiece in Example 10 was measured in the same manner as in Example 9. The maximum color difference ΔE value was calculated, and the corresponding two color coordinates are shown in Table 3 below.

[0073] Example 11 The aluminum-magnesium-silicon alloy was treated in the same manner as in Example 1, except that... (2) Target Steps The aluminum-magnesium-silicon alloy obtained in step (1) was etched using a target solution containing ammonium bifluoride and sodium hydroxide. The concentration of ammonium bifluoride in the target solution was 45 g / L, the concentration of sodium hydroxide was 11.25 g / L, the processing temperature was 50 °C, and the processing time was 200 seconds.

[0074] The color difference ΔE of the aluminum-magnesium-silicon alloy workpiece in Example 11 was measured in the same manner as in Example 9. The maximum color difference ΔE value was calculated, and the corresponding two color coordinates are shown in Table 3 below.

[0075] Table 3

[0076] As can be seen from Table 3, compared with Example 1, the processing temperature, processing time, and mass ratio of the mixture of the first solute and the second solute in the target solution in Examples 9 to 11 are within the above range, which can further reduce the color difference ΔE value and improve the uniformity of whiteness.

[0077] The aluminum-magnesium-silicon alloy obtained in Example 9 was observed under a confocal microscope, and the results are as follows: Figure 2 As shown, from Figure 2 As can be seen, the aluminum-magnesium-silicon alloy has a uniform microstructure, which enables it to exhibit a near-white effect in different regions.

[0078] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, and improvements made within the spirit and scope of this application are included within the scope of protection of this application.

Claims

1. A method for processing aluminum-containing metal, comprising: The target step includes: treating a first aluminum-containing metal with a target solution to obtain a second aluminum-containing metal, wherein the target solution comprises a mixture of a first solute and a second solute, the mass ratio of the first solute to the second solute in the mixture being (3.2 to 4.7):1, the first solute being selected from at least one of ammonium bifluoride and potassium bifluoride, and the second solute being selected from at least one of sodium hydroxide and potassium hydroxide.

2. The processing method according to claim 1, wherein The mass ratio of the first solute to the second solute in the mixture is (3.5 to 4.5):

1.

3. The processing method according to claim 1 or 2, wherein The target solution comprises ammonium bifluoride and sodium hydroxide in a mass ratio of 4:

1.

4. The processing method according to any one of claims 1 to 3, wherein, The processing method satisfies at least one of the following: (1) Based on the mass of the first aluminum-containing metal, the first aluminum-containing metal comprises: 0% ≤ Mg ≤ 2%; (2) The processing temperature is 40°C to 50°C and the processing time is 150 seconds to 200 seconds; the mass percentage of the mixture in the target solution is 4% to 5.4% based on the mass of the target solution.

5. The processing method according to any one of claims 1 to 3, wherein The processing method further includes a target oxidation step, through which an oxide film with an average thickness of 10 μm to 13 μm is formed on the second aluminum-containing metal surface.

6. The processing method according to claim 5, wherein, The target oxidation step includes: oxidizing the second aluminum-containing metal for 18 to 25 minutes at 10°C to 30°C in an oxidation tank containing a sulfuric acid solution, with a voltage of 12V to 14V, wherein the concentration of the sulfuric acid solution is 190g / L to 210g / L; in the target oxidation step, the concentration of aluminum ions in the sulfuric acid solution is controlled to be 7g / L to 10g / L, or The target oxidation step includes: oxidizing the second aluminum-containing metal in an oxidation tank containing a sulfuric acid solution at a temperature of 50°C to 60°C for 10 to 15 minutes, with a voltage of 12V to 14V, wherein the concentration of the sulfuric acid solution is 190g / L to 210g / L; and controlling the concentration of aluminum ions in the sulfuric acid solution to 7g / L to 10g / L during the target oxidation step.

7. The processing method according to claim 1, wherein, The first aluminum-containing metal includes an aluminum-magnesium-silicon alloy, which, based on the mass of the aluminum-magnesium-silicon alloy, comprises: 0.3%≤Mg≤1%; 0.4%≤Si≤1.2%; and 98%≤Al≤99.5%.

8. An aluminum-containing metal, wherein, The aluminum-containing metal is treated with a target solution comprising a mixture of a first solute and a second solute, wherein the mass ratio of the first solute to the second solute in the mixture is (3.2 to 4.7):1, the first solute being selected from at least one of ammonium bifluoride and potassium bifluoride, and the second solute being selected from at least one of sodium hydroxide and potassium hydroxide.

9. The aluminum-containing metal according to claim 8, wherein, The CIE LAB color space for aluminum-containing metals satisfies: L≥91; -0.5≤a≤0.2; -0.2≤b≤0.5; In the CIE LAB color space of the aluminum-containing metal, the color difference ΔE between any two points (L1,a1,b1) and (L2,a2,b2) is ≤0.81, where ΔE=[(L1-L2)] 2 +(a1-a2) 2 +(b1-b2) 2 ] 1 / 2 .

10. The aluminum-containing metal according to claim 8 or 9, wherein, The aluminum-containing metal also includes an oxide film disposed on the surface of the aluminum-containing metal, the average thickness of the oxide film being 10 μm to 13 μm.

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