Treatment method for aluminum alloy surface with fine texture and matt surface

Abstract

The invention relates to a treatment method for an aluminum alloy surface with fine texture and a matt surface. First, an aluminum alloy surface is chemically polished to have a gloss of between 10 GU and 1000 GU. Then, electrolytic treatment is conducted on the surface of the aluminum alloy subjected to chemical polishing; the operating conditions of the electrolytic treatment include: the current density is in the range of 0.01 A / dm2 to 1.5 A / dm2; the voltage is gradually increased from 0V to 50V; the processing time is in the range of 3 minutes to 30 minutes. Then, anodic treatment is conducted on the surface of the aluminum alloy subjected to electrolytic treatment; operating conditions of the anodic treatment include: a current density in a range of 0.1 A / dm2 to 2.5 A / dm2; the voltage ranges from 10 V to 20 V; the processing time is in the range of 30 minutes to 120 minutes. The anodized aluminum alloy surface may have a unique white ceramic texture that exhibits a fine texture and an aluminum alloy surface with a matt surface.

Description

Technical Field

[0001] This invention relates to a method for treating aluminum alloy surfaces, and more particularly to a method for treating aluminum alloy surfaces with a fine texture and a matte finish, suitable for treating aluminum alloy objects to integrate the texture of ceramics into the aluminum alloy surface, thereby improving the appearance and texture of the product, and the appearance color can be adjusted. Background Technology

[0002] Today's portable electronic products are mostly designed to be thin, light, and compact. Aluminum alloys, with their excellent mechanical properties and light weight, have become a popular material for manufacturing the casings and other mechanical parts of portable electronic products. Aluminum alloy parts are generally treated with surface finishing processes such as anodizing to enhance their aesthetics and durability.

[0003] CN 102312263 A discloses a ceramic oxidation method for aluminum parts, which uses an oxidation solution containing chromic acid, citric acid, nickel sulfate, etc., to form a ceramic film on the surface of the aluminum parts. However, the oxidation solution contains chromic acid, which is not environmentally friendly, and the resulting film is silver-gray and cannot be effectively colored through a dyeing process.

[0004] CN 102834551 A discloses a method for forming substantially white anodic aluminum oxide, which involves immersion treatment to allow two or more solutions to flow into the pores of the anodic oxide layer and react to form a white precipitate. However, this method is time-consuming and complex to operate.

[0005] CN 104428454 B discloses another method for forming a white-looking anodic oxide film, which involves scanning a laser beam onto the anodic oxide film to form an array of uniformly spaced light-diffusing portions (multiple microcracks) within the anodic oxide film, thereby producing a white appearance through a combination of spectral reflection and diffuse reflection. However, this method is costly in terms of equipment and operation, and is not suitable for large-area processing.

[0006] There is currently no surface treatment technology in the industry that can be practically applied to large-area processing of complex aluminum alloy parts to create an aluminum alloy surface with a white ceramic texture. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a method for treating aluminum alloy surfaces with a fine texture and a matte finish, which is suitable for treating aluminum alloy objects and the treated aluminum alloy surface exhibits a fine matte texture while also presenting a ceramic-like aesthetic.

[0008] To address the aforementioned technical problems, one technical solution adopted by this invention is to provide a method for treating an aluminum alloy surface with a fine texture and a matte finish. The method includes: chemically polishing the aluminum alloy surface to achieve a gloss level of 60° between 10 GU and 1000 GU; electrolyzing the chemically polished aluminum alloy surface; and performing a first anodizing treatment on the electrolyzed aluminum alloy surface. The operating conditions for the electrolytic treatment include a current density of 0.01 A / dm³. 2 Up to 1.5A / dm 2 Within the specified range; the voltage gradually increases from 0V to 50V; the processing time ranges from 3 minutes to 30 minutes. The operating conditions for the first anodic treatment include: a current density of 0.1A / dm³. 2 Up to 2.5A / dm 2 Within the range of; voltage within the range of 10V to 20V; processing time within the range of 30 minutes to 120 minutes. According to the CIE L*a*b* color system, the L* value of the aluminum alloy surface after the first anodizing treatment and without dyeing is 77 to 85, the a* value is -0.55 to -0.40, and the b* value is -0.7 to +0.3.

[0009] Furthermore, in an embodiment of the present invention, the electrolysis is carried out in a first treatment solution, the temperature of which is in the range of 20°C to 80°C and the pH value is in the range of 8 to 11. Based on a total weight of 100 wt% of the first treatment solution, the first treatment solution contains 3 wt% to 15 wt% sodium carbonate and 1 wt% to 15 wt% fluoride, wherein the fluoride is selected from the group consisting of sodium fluoride, potassium fluoride, ammonium hydrogen fluoride, and hydrofluoric acid.

[0010] Furthermore, in embodiments of the present invention, the first treatment solution further comprises 5 wt% to 50 wt% glycerol, 0.1 wt% to 10 wt% chelating agent, and 0.1 wt% to 10 wt% additive. The chelating agent is selected from the group consisting of sodium gluconate, ethylenediaminetetraacetic acid, citric acid, and potassium sodium tartrate, and the additive is selected from the group consisting of boric acid, sodium citrate, and triethanolamine.

[0011] Furthermore, in an embodiment of the present invention, the first anodic treatment is performed in a second treatment solution, the temperature of which is in the range of 5°C to 20°C. Based on a total weight of 100 wt% of the second treatment solution, the second treatment solution contains 5% to 25% sulfuric acid, 5 wt% to 20 wt% oxalic acid, or a combination thereof.

[0012] Furthermore, in an embodiment of the present invention, the processing method of the present invention further includes: after performing the first anodizing step, performing a sealing treatment on the aluminum alloy surface that has undergone the first anodizing.

[0013] Furthermore, in embodiments of the present invention, the sealing treatment can be nickel sealing treatment, hot water sealing treatment, or coating sealing treatment; the sealing material used in the coating sealing treatment is a UV-curable or thermosetting material, which includes polyurethane polymer, polycarbonate polymer, aminosiloxane, epoxysiloxane, nano-silicon compound, or any combination thereof.

[0014] Furthermore, in an embodiment of the present invention, the processing method further includes: between the step of performing the first anodizing treatment and the step of performing the sealing treatment, performing a first dyeing treatment on the aluminum alloy surface after the first anodizing treatment. The first anodizing treatment includes forming a porous alumina layer on the aluminum alloy surface, and the first dyeing treatment includes filling at least one dye into a plurality of openings in the porous alumina layer.

[0015] Furthermore, in an embodiment of the present invention, the processing method of the present invention further includes: after performing the sealing process, forming a drilled surface on the aluminum alloy surface that has undergone the sealing process.

[0016] Furthermore, in an embodiment of the present invention, the processing method further includes: after the step of forming the drill cut surface, performing a second anodizing treatment on the drill cut surface, wherein the operating conditions for the second anodizing treatment include a current density of 0.1 A / dm². 2 Up to 1.5A / dm 2 Within the specified range; the voltage is within the range of 10V to 20V; the processing time is within the range of 10 minutes to 60 minutes. Furthermore, the second anodic treatment is carried out in a third treatment solution, the temperature of which is within the range of 5°C to 20°C; and the third treatment solution, based on a total weight of 100wt%, contains 5wt% to 20wt% sulfuric acid, 5wt% to 20wt% oxalic acid, or a combination thereof.

[0017] Furthermore, in an embodiment of the present invention, the processing method of the present invention further includes: after performing the second anodizing step, performing a second staining treatment on the drill cut surface that has undergone the second anodizing.

[0018] Furthermore, in embodiments of the present invention, the method for processing aluminum alloy surfaces with a fine texture and matte finish provided by the present invention can produce an aluminum alloy surface with a unique white ceramic texture by "chemically polishing the aluminum alloy surface (which may have undergone pretreatment such as sandblasting or uniform polishing) to give it a 60° gloss (measured at a 60° angle) between 10 GU and 1000 GU", "electrolytically treating the chemically polished aluminum alloy surface under special conditions", and "performing a first anodizing treatment on the electrolytically treated aluminum alloy surface under special conditions". The white color difference can be controlled by adjusting the operating condition parameters, and the appearance color of the aluminum alloy surface can also be changed as needed. In addition, the processing method of the present invention can be practically applied to large-area processing of complex aluminum alloy parts, and the processed products have high reliability and can directly meet product testing specifications.

[0019] To further understand the features and technical content of the present invention, please refer to the following detailed description and accompanying drawings. However, the drawings provided are for reference and illustration only and are not intended to limit the present invention. Attached Figure Description

[0020] Figure 1 This is a flowchart of the main steps of the method for treating an aluminum alloy surface with a fine texture and matte finish according to the present invention.

[0021] Figure 2 This is a flowchart of the post-processing steps of the method for treating aluminum alloy surfaces with a fine texture and matte finish according to the present invention.

[0022] Figure 3 This is a schematic diagram of the finished product obtained by the method for treating aluminum alloy surfaces with a fine texture and matte finish according to the present invention.

[0023] Figure 4 This is a process diagram illustrating step S108 of the method for treating an aluminum alloy surface with a fine texture and a matte finish according to the present invention.

[0024] Figure 5 This is a schematic diagram of the operating conditions for step S102 of the method for treating an aluminum alloy surface with a fine texture and a matte finish according to the present invention. Detailed Implementation

[0025] The following specific examples illustrate the embodiments of the "method for treating aluminum alloy surfaces with a fine texture and matte finish" disclosed in this invention. Those skilled in the art can understand the advantages and effects of this invention from the content disclosed in this specification. This invention can be implemented or applied through other different specific embodiments, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of this invention. Furthermore, the accompanying drawings of this invention are for simple illustrative purposes only and are not depictions of actual dimensions; this is stated beforehand. The following embodiments will further describe the relevant technical content of this invention in detail, but the disclosed content is not intended to limit the scope of protection of this invention.

[0026] Unless otherwise defined, the terms used herein have the same meaning as commonly understood by those skilled in the art. Materials involved in the embodiments are commercially available or prepared according to prior art, unless otherwise specified. Process methods involved in the embodiments are conventionally used in the art, unless otherwise specified.

[0027] It should be understood that although the steps in the method flowchart are described in a specific order herein, this does not require or imply that these steps must be performed in that specific order, or that all steps must be performed to achieve the desired result. Optionally, multiple steps may be combined into one step, or a single step may be broken down into multiple steps.

[0028] See Figure 1 As shown, this embodiment of the invention provides a method for treating an aluminum alloy surface with a fine texture and a matte finish, which mainly includes: step S100, chemically polishing the aluminum alloy surface; step S102, electrolyzing the chemically polished aluminum alloy surface; and step S104, performing a first anodizing treatment on the electrolyzed aluminum alloy surface. Specifically, the treatment method of this invention is a surface treatment method for aluminum alloy objects, and mainly uses electrolytic treatment under special conditions combined with anodizing treatment to integrate the ceramic texture into the aluminum alloy surface and give it a color-adjustable appearance.

[0029] The aforementioned aluminum alloy parts may be made of 5000 series (e.g., 5052), 6000 series (e.g., 6063), or 7000 series (e.g., 7075) aluminum alloys, and may be formed into desired shapes (e.g., sheet metal) by die casting, extrusion, forging, or machining, thereby enabling their use in the appearance components of electronic products, such as housings. However, the present invention is not limited to the examples described above.

[0030] The following text will combine Figure 3 and Figure 5 The steps of the processing method of the present invention are described in detail.

[0031] In step S100, the aluminum alloy object can be placed in a chemical polishing solution to eliminate minute fine lines on the aluminum alloy surface, making the surface smoother and brighter. In embodiments of the present invention, the aluminum alloy surface after chemical polishing can have a gloss level between 10 GU and 1000 GU (measured at a 60° angle). The chemical polishing solution may contain phosphoric acid or a combination of phosphoric acid and sulfuric acid, but the present invention is not limited thereto.

[0032] In practical applications, the present invention may also include a pretreatment step, i.e., pretreatment of the aluminum alloy surface before chemical polishing. The pretreatment method varies depending on the purpose, and may include sandblasting, degreasing, pickling, and alkaline washing steps, and the above steps may be performed sequentially.

[0033] Furthermore, the sandblasting material can be rounded steel gravel, iron sand, or zirconium sand. Degreasing can be performed by immersing the aluminum alloy object in a 50°C solution containing a degreasing agent for 1 to 3 minutes. Pickling can be performed by immersing the aluminum alloy object in a 20°C to 40°C solution containing an acid pickling agent for 1 to 3 minutes. Alkaline cleaning can be performed by immersing the aluminum alloy object in a 40°C to 60°C solution containing an alkaline cleaning agent for 0.5 to 2 minutes. However, the above descriptions are merely feasible embodiments and are not intended to limit the invention.

[0034] In step S102, the aluminum alloy object may be placed in a first treatment solution containing an alkaline agent and subjected to electrolytic treatment under specific conditions. The temperature of the first treatment solution is in the range of 20°C to 80°C and the pH value is in the range of 8 to 11. Based on a total weight of 100 wt%, the first treatment solution contains 3 wt% to 15 wt% sodium carbonate and 1 wt% to 15 wt% fluoride; the fluoride may be selected from the group consisting of sodium fluoride, potassium fluoride, ammonium hydrogen fluoride, and hydrofluoric acid. In embodiments of the present invention, the first treatment solution may further contain 0.1 wt% to 10 wt% chelating agent and 0.1 wt% to 10 wt% additive; the chelating agent may be selected from the group consisting of sodium gluconate, ethylenediaminetetraacetic acid, citric acid, and potassium sodium tartrate, and the additive may be selected from the group consisting of boric acid, sodium citrate, and triethanolamine. If necessary, the first treatment solution may further contain 5 wt% to 50 wt% glycerol. However, the present invention is not limited to the examples described above.

[0035] Cooperate Figure 3 and Figure 5 As shown, during the electrolytic treatment process, the aluminum alloy object 1 being treated serves as the anode, and the cathode is made of corrosion-resistant materials (such as stainless steel plate, carbon plate, titanium plate, lead-antimony plate, etc.). A certain current and a gradually increasing voltage are applied to form a well-adhered first porous alumina layer 2 on the aluminum alloy surface 100. Specifically, the operating conditions for the electrolytic treatment include: a current density of 0.01 A / dm³. 2Up to 1.5A / dm 2 Within a certain range; the voltage gradually increases from 0V to the target voltage Vt, which can be 10-50V; the processing time is within the range of 3 to 30 minutes.

[0036] In an embodiment of the present invention, the current density for electrolysis can be 0.01 A / dm³. 2 0.05A / dm 2 0.1A / dm 2 0.5A / dm 2 1.0A / dm 2 Or 1.5A / dm 2 The electrolysis treatment time can be 3 minutes, 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes or 30 minutes.

[0037] In step S104, the aluminum alloy object may be placed in a second treatment solution containing an acidic agent and subjected to a first anodizing treatment under specific conditions, the temperature of which is in the range of 5°C to 20°C. The second treatment solution contains, by weight 100wt%, 5wt% to 25wt% sulfuric acid, 5wt% to 20wt% oxalic acid, or a combination thereof.

[0038] like Figure 3 As shown, in the first anodizing process, the aluminum alloy object 1 being treated serves as the anode, and the cathode is made of corrosion-resistant materials (such as stainless steel plate, carbon plate, titanium plate, lead-antimony plate, etc.). A certain current and voltage are applied to form a well-adhered second porous alumina layer 3 on the aluminum alloy surface 100. Specifically, the operating conditions for the first anodizing process include: a current density of 0.1 A / dm³. 2 Up to 2.5A / dm 2 Within the range of; voltage within the range of 10V to 20V; processing time within the range of 30 minutes to 120 minutes.

[0039] In an embodiment of the present invention, the current density of the first anodic treatment can be 0.01 A / dm³. 2 0.05A / dm 2 0.1A / dm 2 0.5A / dm 2 1.0A / dm 2 1.5A / dm 2 2.0A / dm 2 Or 2.5A / dm 2The voltage for the first anodizing treatment can be 10V, 11V, 12V, 13V, 14V, 15V, 16V, 17V, 18V, 19V, or 20V. The duration of the first anodizing treatment can be 30 minutes, 35 minutes, 40 minutes, 45 minutes, 50 minutes, 55 minutes, 60 minutes, 65 minutes, 70 minutes, 75 minutes, 80 minutes, 85 minutes, 90 minutes, 95 minutes, 100 minutes, 105 minutes, 110 minutes, 115 minutes, or 120 minutes.

[0040] Furthermore, the second porous alumina layer 3 is located between the aluminum alloy surface 100 and the first porous alumina layer 2, wherein the first porous alumina layer 2 is thinner and the second porous alumina layer 3 is thicker. Additionally, the first porous alumina layer 2 and the second porous alumina layer 3 have different pore structures (such as pore shape, size, or aspect ratio), different pore arrangements, and different porosities. It is worth noting that the aluminum alloy surface 100 after the first anodizing treatment can have a unique white ceramic texture; according to the CIE L*a*b* color system, the L* value of the aluminum alloy surface 100 after the first anodizing treatment and without dyeing is 77 to 85, the a* value is -0.55 to -0.40, and the b* value is -0.7 to +0.3.

[0041] See again Figure 1 As shown, the processing method of the present invention may further include: step S105, dyeing the aluminum alloy surface after the first anodizing treatment; and step S106, sealing the aluminum alloy surface after the first anodizing treatment. Dyeing can change the appearance color of the aluminum alloy surface, while sealing can provide sufficient protection for the aluminum alloy surface and ensure that the dyed aluminum alloy surface does not fade or change color.

[0042] In step S105, the aluminum alloy object can be placed in a dyeing solution containing dye to dye the aluminum alloy surface after the first anodizing treatment. After dyeing, excess dye on the aluminum alloy surface can be removed by washing with water. The dye suitable for step S105 can be Okuno dye, but the present invention is not limited thereto.

[0043] like Figure 3 As shown, during the dyeing process, the dye in the dyeing solution can be deposited in the pores of the first porous alumina layer 2 and the second porous alumina layer 3, causing a color change on the aluminum alloy surface 100. The portion of the dye remaining outside the pores of the first porous alumina layer 2 can be easily removed by washing water.

[0044] In practical applications, a second pickling process can be performed on the aluminum alloy surface after the first anodizing treatment before dyeing. The second pickling can be performed by immersing the CE cut surface after the second anodizing treatment in a solution containing 5-15wt% nitric acid for 1-3 minutes at a solution temperature of 20-35℃.

[0045] In step S106, the dyed aluminum alloy surface can be brought into contact with a sealing material containing a sealing agent (contact time is controllable) for sealing treatment. The sealing treatment can be nickel sealing, hot water sealing, or coating sealing. Coating sealing may include curing the sealing material under UV irradiation or heating conditions, thereby allowing the dye to adhere firmly to the aluminum alloy surface without peeling off. Specifically, the sealing material used in coating sealing is a UV-curable or thermosetting material, including polyurethane polymers, polycarbonate polymers (such as polycarbonate), aminosiloxanes, epoxysiloxanes, nano-silicon compounds, or any combination thereof. Suitable contact methods for the sealing material in step S106 include coating. However, the present invention is not limited to the examples described above.

[0046] like Figure 3 As shown, during the sealing process, a sealing material can be applied to bring it into contact with the aluminum alloy surface 100, forming a transparent sealing layer 4 on the first porous alumina layer 2 and sealing its pores. With the presence of the transparent sealing layer 4, the dye can be stably retained within the pores of the first porous alumina layer 2 for a long period.

[0047] It should be noted that, depending on the product appearance requirements, the processing method of the present invention can skip the dyeing process in step S105 after completing the first anodizing process in step S104, and directly proceed to the sealing process in step S106.

[0048] like Figure 3 As shown, after the above steps are completed, the finished product Z is obtained, which includes an aluminum alloy object 1, a first porous alumina layer 2, a second porous alumina layer 3, and a transparent sealing layer 4. The aluminum alloy object 1 has an aluminum alloy surface 100, and the first porous alumina layer 2, the second porous alumina layer 3, and the transparent sealing layer 4 are formed on the aluminum alloy surface 100. The second porous alumina layer 3 is located between the aluminum alloy surface 100 and the first porous alumina layer 2, and the transparent sealing layer 4 covers the first porous alumina layer 2.

[0049] See Figure 2As shown, the present invention may further include a post-processing step, i.e., post-processing the aluminum alloy surface after the sealing process. In an embodiment of the present invention, the present invention may further include: step S108, forming a drilled surface on the sealed aluminum alloy surface; step S110, performing a second anodizing treatment on the drilled surface; and step S112, performing a second dyeing treatment on the drilled surface after the second anodizing treatment.

[0050] Cooperate Figure 4 As shown, in step S108, the finished product Z can be partially drilled (e.g., edge drilled) in the presence of cutting oil, and the resulting drilled surface CE can have a gloss level between 200 GU and 1000 GU (measured at an angle of 60°).

[0051] In step S110, the second anodic treatment can employ approximately the same treatment solution and operating conditions as the first anodic treatment, differing only in that the treatment solution may contain a lower concentration of sulfuric acid, and the second anodic treatment can be completed in a shorter time. Specifically, the treatment solution for the second anodic treatment may contain 5 wt% to 20 wt% sulfuric acid, 5 wt% to 20 wt% oxalic acid, or a combination thereof. The duration of the second anodic treatment is in the range of 10 to 60 minutes. Furthermore, the operating conditions for the second anodic treatment may include a current density of 0.1 A / dm³. 2 Up to 1.5A / dm 2 Within the range of; voltage within the range of 10V to 20V; processing time within the range of 10 minutes to 60 minutes.

[0052] In step S112, the finished product Z can be placed in a dyeing solution containing dye, and the drill-cut surface CE after the second anodizing treatment can be dyed at a temperature of 45-60°C for 3-20 minutes. After dyeing, excess dye on the drill-cut surface CE can be removed by washing with water. The dye suitable for step S112 can be Okuno dye, but the present invention is not limited thereto.

[0053] In practical applications, the CE (Ceramic Edge) facets can be pretreated before the second anodizing treatment. The pretreatment method varies depending on the purpose and may include surface degreasing and a first pickling step, which can be performed sequentially. Additionally, the CE facets after the second anodizing treatment can be pickled a second time before dyeing; and the dyed CE facets can be sealed after dyeing.

[0054] Furthermore, surface degreasing can be performed by immersing the treated finished product Z with the drilled facet CE in a 50°C solution containing a degreasing agent for 3 minutes to remove surface dirt and oil stains. A first pickling can be performed by immersing the treated finished product Z with the drilled facet CE in a 30°C solution containing a pickling agent for 1 minute to remove surface oxides and contaminants. A second pickling can be performed by immersing the drilled facet CE, which has undergone a second anodizing treatment, in a solution containing 5-15 wt% nitric acid for 1-3 minutes at a solution temperature of 20-35°C. Sealing can be performed using nickel sealing at a temperature of 90°C for 30-40 minutes; alternatively, nickel-free sealing can be used, such as color fixing or spraying. However, the above descriptions are merely feasible embodiments and are not intended to limit the invention.

[0055] Specific example 1

[0056] The 6063 aluminum alloy object was sandblasted using rounded steel pebbles (grit size 120#). Subsequently, the aluminum alloy object underwent surface degreasing (50°C, 3 minutes) to remove surface dirt and oil stains. Next, the aluminum alloy object was acid-washed (30°C, 1 minute) to remove surface oxides and contaminants. Then, the aluminum alloy object was alkaline-washed (60°C, 0.5 minutes) to improve surface cleanliness. Finally, the aluminum alloy object was chemically polished using a phosphoric acid-based chemical polishing solution at 85°C to 95°C to remove surface contaminants and increase surface gloss and uniformity; the chemically polished aluminum alloy surface had a gloss level between 40 GU and 100 GU (measured at a 60° angle). Subsequently, the aluminum alloy parts are subjected to electrolytic treatment in a solution with a temperature of 20°C to 40°C and a pH of 8 to 11, containing 5 wt% to 10 wt% sodium carbonate and 5 wt% to 10 wt% sodium fluoride; operating conditions include a current density of 0.01 A / dm³. 2 The voltage was gradually increased from 0.1V to 35V; the processing time ranged from 3 to 30 minutes. Subsequently, the aluminum alloy object underwent anodizing, with the treatment solution temperature ranging from 5°C to 20°C, containing 15wt% sulfuric acid, 15wt% oxalic acid, or a combination thereof; operating conditions included a current density of 1A / dm³. 2 The voltage is 14V to 19V; the processing time is between 30 and 60 minutes. Afterwards, the aluminum alloy parts are pickled (temperature 20-35℃, time 1-3 minutes, nitric acid concentration in the treatment solution 5-15%). Then, the aluminum alloy parts are dyed using Okuno dye (temperature 45-60℃, dyeing time 3-20 minutes). Finally, the aluminum alloy parts are sealed (temperature 90℃, time 30-40 minutes).

[0057] Specific example 2

[0058] The 5052 or 6063 aluminum alloy parts were sandblasted using rounded steel pebbles (grit size 120#). Following this, the aluminum alloy parts underwent surface degreasing (50°C, 3 minutes) to remove surface dirt and oil. Next, the aluminum alloy parts were acid-washed (30°C, 1 minute) to remove surface oxides and contaminants. Then, the aluminum alloy parts were alkaline-washed (60°C, 0.5 minutes) to improve surface cleanliness. Finally, the aluminum alloy parts were chemically polished using a phosphoric acid-based chemical polishing solution at 85°C to 95°C to remove surface contaminants and increase surface gloss and uniformity; the chemically polished aluminum alloy surface had a gloss level between 40 GU and 1000 GU (measured at a 60° angle). Subsequently, the aluminum alloy parts are subjected to electrolytic treatment in a solution with a temperature of 40°C to 75°C and a pH of 8 to 11, containing 5 wt% to 10 wt% sodium carbonate and 5 wt% to 10 wt% sodium fluoride; operating conditions include a current density of 0.1 A / dm³. 2 The voltage was gradually increased from 0.1V to 40V; the processing time ranged from 3 to 30 minutes. Subsequently, the aluminum alloy object underwent anodizing, with the treatment solution temperature ranging from 5°C to 20°C, containing 15wt% sulfuric acid, 15wt% oxalic acid, or a combination thereof; operating conditions included a current density of 0.1-1.5A / dm³. 2 The voltage is 14V to 19V; the processing time is between 30 and 60 minutes. Afterwards, the aluminum alloy parts are pickled (temperature 20-35℃, time 1-3 minutes, nitric acid concentration in the treatment solution 5-15%). Then, the aluminum alloy parts are dyed using Okuno dye (temperature 45-60℃, dyeing time 3-20 minutes). Finally, the aluminum alloy parts are sealed (temperature 90℃, time 30-40 minutes).

[0059] Specific example 3

[0060] The 5052 or 6063 aluminum alloy parts were sandblasted using rounded steel pebbles (grit size 120#). Subsequently, the aluminum alloy parts underwent surface degreasing (50°C, 3 minutes) to remove surface dirt and oil. Next, the aluminum alloy parts were acid-washed (30°C, 1 minute) to remove surface oxides and contaminants. Then, the aluminum alloy parts were alkaline-washed (60°C, 0.5 minutes) to improve surface cleanliness. Finally, the aluminum alloy parts were chemically polished using a phosphoric acid-based chemical polishing solution at 85°C to 95°C to remove surface contaminants and increase surface gloss and uniformity; the chemically polished aluminum alloy surface had a gloss level between 40 GU and 100 GU (measured at a 60° angle). Subsequently, the aluminum alloy object undergoes electrolytic treatment in a solution at a temperature of 25°C to 40°C and a pH of 8 to 11, containing 3 wt% to 15 wt% sodium carbonate, 1 wt% to 10 wt% sodium fluoride, 0.1 wt% to 5 wt% sodium gluconate, 0.1 wt% to 5 wt% boric acid, and 15 wt% to 45 wt% glycerol; operating conditions include a current density of 0.01 A / dm³. 2 The voltage was gradually increased from 0.1V to 35V; the processing time ranged from 3 to 30 minutes. Subsequently, the aluminum alloy object underwent anodizing, with the treatment solution temperature ranging from 5°C to 20°C, containing 15wt% sulfuric acid, 15wt% oxalic acid, or a combination thereof; operating conditions included a current density of 0.01-1.5A / dm³. 2 The voltage is 14V to 19V; the processing time is between 30 and 60 minutes. Afterwards, the aluminum alloy parts are pickled (temperature 20-35℃, time 1-3 minutes, nitric acid concentration in the treatment solution 5-15%). Then, the aluminum alloy parts are dyed using Okuno dye (temperature 45-60℃, dyeing time 3-20 minutes). Finally, the aluminum alloy parts are sealed (temperature 90℃, time 30-40 minutes).

[0061] Specific example 4

[0062] The 5052 or 6063 aluminum alloy parts were sandblasted using rounded steel pebbles (grit size 120#). Following this, the aluminum alloy parts underwent surface degreasing (50°C, 3 minutes) to remove surface dirt and oil. Next, the aluminum alloy parts were acid-washed (30°C, 1 minute) to remove surface oxides and contaminants. Then, the aluminum alloy parts were alkaline-washed (60°C, 0.5 minutes) to improve surface cleanliness. Finally, the aluminum alloy parts were chemically polished using a 95°C phosphoric acid-based chemical polishing solution to remove surface contaminants and increase surface gloss and uniformity; the chemically polished aluminum alloy surface had a gloss level between 40 GU and 100 GU (measured at a 60° angle). Subsequently, the aluminum alloy object undergoes electrolytic treatment in a solution with a temperature of 40°C to 75°C and a pH of 8 to 11, containing 3 wt% to 15 wt% sodium carbonate, 1 wt% to 10 wt% sodium fluoride, 0.1 wt% to 5 wt% sodium gluconate, 0.1 wt% to 5 wt% boric acid, and 15 wt% to 45 wt% glycerol; operating conditions include a current density of 0.1 A / dm³. 2 The voltage was gradually increased from 0.1V to 35V; the processing time ranged from 3 to 30 minutes. Subsequently, the aluminum alloy object underwent anodizing, with the treatment solution temperature ranging from 5°C to 20°C, containing 15wt% sulfuric acid, 15wt% oxalic acid, or a combination thereof; operating conditions included a current density of 0.01-1.5A / dm³. 2 The voltage is 14V to 19V; the processing time is between 30 and 60 minutes. Afterwards, the aluminum alloy parts are pickled (temperature 20-35℃, time 1-3 minutes, nitric acid concentration in the treatment solution 5-15%). Then, the aluminum alloy parts are dyed using Okuno dye (temperature 45-60℃, dyeing time 3-20 minutes). Finally, the aluminum alloy parts are sealed (temperature 90℃, time 30-40 minutes).

[0063] Specific example 5

[0064] The treated product of one of Examples 1-4 is subjected to drilling to form a drilled surface with a gloss level between 200 GU and 1000 GU (measured at a 60° angle). Subsequently, the treated product undergoes surface degreasing (at 50°C for 3 minutes) to remove surface dirt and oil. Then, the treated product is subjected to pickling (at 30°C for 1 minute) to remove surface oxides and contaminants. Finally, the treated product is anodized in a solution at a temperature of 5°C to 20°C, containing 15 wt% sulfuric acid, 15 wt% oxalic acid, or a combination thereof; operating conditions include a current density of 0.01-1.5 A / dm³. 2The voltage is 10V to 20V; the processing time is between 10 and 60 minutes. Afterwards, the aluminum alloy parts are pickled (temperature 20-35℃, time 1-3 minutes, nitric acid concentration in the treatment solution 5-15%). Then, the aluminum alloy parts are dyed using Okuno dye (temperature 45-60℃, dyeing time 3-20 minutes). Finally, the aluminum alloy parts are sealed (temperature 90℃, time 30-40 minutes).

[0065] Beneficial effects of the embodiments

[0066] The present invention provides a method for treating aluminum alloy surfaces with a fine texture and matte finish. This method involves "chemically polishing the aluminum alloy surface to achieve a gloss level between 10 GU and 1000 GU (measured at a 60° angle)," "electrolytically treating the chemically polished aluminum alloy surface under special conditions," and "performing a first anodizing treatment on the electrolytically treated aluminum alloy surface under special conditions." This process produces an aluminum alloy surface with a unique white ceramic texture. The white color difference can be controlled by adjusting operating parameters, and the appearance color of the aluminum alloy surface can be changed as needed. Furthermore, the method of the present invention can be practically applied to large-area processing of complex aluminum alloy parts, and the finished product has high reliability and can directly meet product testing specifications.

[0067] The content disclosed above is only a preferred and feasible embodiment of the present invention, and is not intended to limit the scope of protection of the claims of the present invention. Therefore, all equivalent technical changes made based on the content of the present invention specification and drawings are included within the scope of protection of the claims of the present invention.

Claims

1. A method for treating an aluminum alloy surface with a fine texture and matte finish, characterized in that, The method for treating the aluminum alloy surface with a fine texture and matte finish includes: The aluminum alloy surface is chemically polished to achieve a gloss level of 60° between 10 GU and 1000 GU. The aluminum alloy surface, after chemical polishing, is subjected to electrolytic treatment, wherein the operating conditions for the electrolytic treatment include a current density of 0.01 A / dm³. 2 Up to 1.5A / dm 2 Within the range; voltage gradually increases from 0V to 50V; processing time ranges from 3 minutes to 30 minutes; and The aluminum alloy surface treated by the electrolysis is subjected to a first anodizing treatment, wherein the operating conditions for the first anodizing treatment include: a current density of 0.1 A / dm³. 2 Up to 2.5A / dm 2 Within the specified range; voltage within the range of 10V to 20V; processing time within the range of 30 minutes to 120 minutes; According to the CIE L*a*b* color system, the L* value of the aluminum alloy surface after the first anodizing treatment is 77 to 85, the a* value is -0.55 to -0.40, and the b* value is -0.7 to +0.

3.

2. The method for treating an aluminum alloy surface with a fine texture and matte finish according to claim 1, characterized in that, The electrolysis is carried out in a first treatment solution, the temperature of which is in the range of 20°C to 80°C and the pH value is in the range of 8 to 11; the first treatment solution contains 3 wt% to 15 wt% sodium carbonate and 1 wt% to 15 wt% fluoride, based on a total weight of 100 wt% of the first treatment solution, the first treatment solution containing 3 wt% to 15 wt% sodium carbonate and 1 wt% to 15 wt% fluoride, the fluoride being selected from the group consisting of sodium fluoride, potassium fluoride, ammonium hydrogen fluoride and hydrofluoric acid.

3. The method for treating an aluminum alloy surface with a fine texture and matte finish according to claim 2, characterized in that, The first treatment solution further comprises 5 wt% to 50 wt% glycerol, 0.1 wt% to 10 wt% chelating agent and 0.1 wt% to 10 wt% additive; the chelating agent is selected from the group consisting of sodium gluconate, ethylenediaminetetraacetic acid, citric acid and potassium sodium tartrate, and the additive is selected from the group consisting of boric acid, sodium citrate and triethanolamine.

4. The method for treating an aluminum alloy surface with a fine texture and matte finish according to claim 1, characterized in that, The first anodic treatment is carried out in a second treatment solution, the temperature of which is in the range of 5°C to 20°C; the second treatment solution contains 5% to 25% sulfuric acid, 5% to 20% oxalic acid or a combination thereof, based on a total weight of 100 wt%.

5. The method for treating an aluminum alloy surface with a fine texture and matte finish according to claim 1, characterized in that, After the first anodizing step, the method further includes: sealing the aluminum alloy surface that has undergone the first anodizing.

6. The method for treating an aluminum alloy surface with a fine texture and matte finish according to claim 5, characterized in that, The sealing treatment is nickel sealing treatment, hot water sealing treatment, or coating sealing treatment; the sealing material used in the coating sealing treatment is a UV-curable or thermosetting material, which includes polyurethane polymer, polycarbonate polymer, aminosiloxane, epoxysiloxane, nano-silicon compound, or any combination thereof.

7. The method for treating an aluminum alloy surface with a fine texture and matte finish according to claim 5, characterized in that, Between the first anodizing step and the sealing step, the method further includes: performing a first dyeing treatment on the aluminum alloy surface that has undergone the first anodizing treatment; wherein the first anodizing treatment includes forming a porous alumina layer on the aluminum alloy surface, and the first dyeing treatment includes filling at least one dye into a plurality of openings in the porous alumina layer.

8. A method for treating an aluminum alloy surface with a fine texture and matte finish according to any one of claims 5 to 7, characterized in that, After performing the sealing process, the method further includes forming a drilled surface on the aluminum alloy surface that has undergone the sealing process.

9. The method for treating an aluminum alloy surface with a fine texture and matte finish according to claim 8, characterized in that, Following the step of forming the drill cut surface, the method further includes: performing a second anodizing treatment on the drill cut surface, wherein the operating conditions for the second anodizing treatment include: a current density of 0.1 A / dm². 2 Up to 1.5A / dm 2 Within the range of; voltage within the range of 10V to 20V; processing time within the range of 10 minutes to 60 minutes; wherein, the second anodic treatment is carried out in a third treatment solution, the temperature of the third treatment solution being within the range of 5°C to 20°C; and based on the total weight of the third treatment solution being 100wt%, the third treatment solution contains 5wt% to 20wt% sulfuric acid, 5wt% to 20wt% oxalic acid, or a combination thereof.

10. The method for treating an aluminum alloy surface with a fine texture and matte finish according to claim 9, characterized in that, Following the second anodizing step, the method further includes: performing a second staining treatment on the drill cut surface that has undergone the second anodizing.

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