An aluminum alloy surface treatment agent, its preparation method and application

Abstract

This invention discloses an aluminum alloy surface treatment liquid, its preparation method, and its application. The aluminum alloy surface treatment liquid is prepared from components comprising the following parts by weight: 65-75 parts fluoride ion etchant, 5-15 parts chelating agent, 10-20 parts leveling agent, and 2-5 parts interfacial active wetting agent. The aluminum alloy surface treated with the liquid of this invention can achieve a uniform and fine matte "frosted" finish. This chemical surface treatment process is applied in small-scale oxidation industries such as pneumatic valve bodies, achieving a uniform matte decorative effect without significantly increasing key sealing performance indicators such as the roughness (Ra) of the valve body's sealing inner hole. Replacing the original mechanical sandblasting matte process, the decorative effect of the valve body surface is more favored by customers, and it can significantly improve production efficiency and reduce production costs.

Description

Technical Field

[0001] This invention belongs to the field of aluminum alloy surface treatment, and particularly relates to an aluminum alloy surface treatment agent, its preparation method and application. Background Technology

[0002] The pretreatment process for aluminum alloy pneumatic valve bodies typically involves mechanical sandblasting followed by chemical surface treatment. Sandblasting primarily covers surface defects such as extrusion striations, providing a uniform surface finish. Mechanical sandblasting is inefficient, especially on small pneumatic valve bodies. The valve body has sealing holes on its working surfaces, requiring manual shielding during sandblasting, further reducing production efficiency. Chemical surface pretreatment technology can significantly improve surface treatment efficiency. While chemical sandblasting has become a mature surface pretreatment method for extruded aluminum profiles, replacing mechanical sandblasting, it is insufficient for functional components with high aesthetic requirements, as conventional chemical sandblasting processes often fail to meet key functional indicators and surface quality requirements. For example, high-quality surface quality on pneumatic valve body components is manifested in the following aspects: First, the roughness of the sealing hole on the working surface has strict requirements. Using general chemical acid etching sandblasting treatment will significantly increase its roughness and reduce the service life of the valve body. Second, the requirements for appearance consistency are higher. After treatment, it is not only required to remove the original forming defects (such as extrusion stripes), but also to achieve a uniform and fine matte surface to achieve a beautiful decorative effect. Summary of the Invention

[0003] To address the shortcomings of existing technologies, the present invention aims to provide an aluminum alloy surface treatment agent, its preparation method, and its application. Using the treatment agent described in this invention for surface chemical pretreatment of aluminum alloy pneumatic valve bodies replaces the mechanical sandblasting pretreatment, significantly improving the production efficiency of surface treatment. Through uniform and consistent surface chemical treatment, the pneumatic valve body surface exhibits a high-end and aesthetically pleasing "matte" finish without significantly increasing the roughness of the valve body's internal working surface, thus meeting its sealing life test requirements.

[0004] The objective of this invention is achieved through the following technical solution:

[0005] An aluminum alloy surface treatment agent is prepared from the following components in parts by weight: 65-75 parts of fluoride ion etchant, 5-15 parts of chelating agent, 10-20 parts of leveling agent and 2-5 parts of interfacial active wetting agent, wherein the interfacial active wetting agent is sodium dicyclohexyl sulfosuccinate.

[0006] Preferably, the fluoride ion etchant is at least one selected from hydrofluoric acid, ammonium bifluoride, ammonium fluoride, fluorosilicic acid, and sodium fluoride.

[0007] Preferably, the chelating agent is at least one selected from the following: tetrasodium aminotrimethylphosphonate (ATMP.Na4), pentasodium aminotrimethylphosphonate, disodium hydroxyethylidene diphosphonate (HEDP.Na2), potassium hydroxyethylidene diphosphonate (HEDP.K2), pentasodium ethylenediaminetetramethylphosphonate (EDTMP.Na5), sodium diethylenetriaminepentamethylphosphonate (DTPMP.Na2), and tetrasodium 2-butane-1,2,4-tricarboxylic acid (PBTCA.Na4).

[0008] Preferably, the leveling agent is at least one selected from sodium nitrate, potassium nitrate, ammonium nitrate, nitric acid, sodium m-nitrobenzenesulfonate, ammonium molybdate, sodium molybdate, and phosphomolybdate.

[0009] The preparation method of the above-mentioned aluminum alloy surface treatment agent includes the following steps: by mass, 65-75 parts of fluorine ion etchant, 5-15 parts of chelating agent, 10-20 parts of leveling agent and 2-5 parts of interfacial active wetting agent are mixed evenly.

[0010] The above-mentioned aluminum alloy surface treatment agent is used in the surface treatment of aluminum profiles in the small anodizing industry, and more preferably in the surface treatment of pneumatic valve bodies.

[0011] The application of the aluminum alloy surface treatment agent in the aluminum profile minor anodizing industry includes the following steps:

[0012] (1) The processed aluminum alloy samples were subjected to vibration grinding pretreatment and chemical polishing treatment in sequence;

[0013] (2) After the polishing treatment is cleaned with water, the sample is immersed in the aqueous solution of the aluminum alloy surface treatment agent to perform a matte "frosted" treatment.

[0014] (3) After the matte “frosted” treatment, the aluminum profile products are obtained by sequentially performing dust removal and brightening, anodizing and oxide film sealing treatment.

[0015] Preferably, the vibration grinding pretreatment method in step (1) is: placing the processed aluminum alloy sample on the vibration grinding automatic line for vibration grinding flattening treatment.

[0016] Preferably, the chemical polishing treatment in step (1) is performed by immersing the vibratory-milled sample in an acidic solution for chemical polishing treatment to remove the natural oxide film, increase surface brightness, and reduce roughness.

[0017] Preferably, the acidic solution is a mixture of phosphoric acid, sulfuric acid and nitric acid in a volume ratio of 7:2:1 or a mixture of phosphoric acid and sulfuric acid in a volume ratio of 2:1.

[0018] Preferably, the temperature of the chemical polishing treatment in step (1) is 95~110℃ and the time is 30~60s.

[0019] Preferably, in the aqueous solution of the aluminum alloy surface treatment agent in step (2), the concentration of the aluminum alloy surface treatment agent is 50~150g / L, more preferably 100~130g / L.

[0020] Preferably, the matte "frosting" treatment in step (2) takes 15-100 seconds and the temperature is 25-40°C; more preferably, the time is 30-60 seconds and the temperature is 33-38°C.

[0021] Preferably, the method for removing ash and brightening in step (3) is as follows: after the matte "frosted" treatment, the surface is washed with water and then immersed in dilute sulfuric acid or dilute nitric acid with added hydrogen peroxide to remove ash and brighten.

[0022] Preferably, the anodizing method in step (3) is as follows: after ash removal, brightening, and water washing, the sample is subjected to sulfuric acid anodizing treatment at a temperature of 18~20℃ for 30~35 min and a current density of 1.1~1.3 A / dm³. 2 The film thickness is controlled at 12~15μm.

[0023] Preferably, the oxide film sealing treatment in step (3) is as follows: after anodizing, the oxide film is washed with water and then treated with a high-temperature nickel-free sealant. The sealant is a commercially available high-temperature nickel-free sealant with the code ZHM-0912 provided by Wuhan Materials Protection Research Institute Co., Ltd. of China Academy of Machinery Science and Technology. The concentration of the sealant is 10~15mL / L, the temperature is 92~95℃, the pH is 6.5~7.0, and the time is 1.5~2min / μm.

[0024] The surface treatment process for pneumatic valve bodies using the aluminum alloy surface treatment agent described in this invention employs a chemical etching method to create a uniform, sandblasted-like surface on the aluminum alloy substrate. This sandblasting effect primarily relies on the chemical bonding of fluoride ions to the aluminum substrate. Fluoride ions have a small radius, resulting in a strong and uniform corrosive reaction, producing a fine and smooth etched surface. Fluoride ions exhibit good corrosiveness to the aluminum matrix in acidic environments. The carriers for fluoride ions are typically ammonium hydrogen fluoride or ammonium fluoride, and sometimes hydrogen fluoride is used directly. Higher fluoride ion concentrations result in better surface uniformity and a stronger matte finish after diffuse reflection. Compared to the sandblasting process for large-area aluminum profiles, the fluoride ion concentration in the chemical pretreatment process for small valve body parts, observed at close range, is 2-3 times higher.

[0025] The etching reaction of fluoride ions becomes uneven with prolonged processing time, resulting in an over-etched, uneven corrosion state on the surface. Therefore, leveling agents are needed to reduce the unevenness of the etching reaction. These leveling agents are oxidizing, and their mechanism of action is similar to the polishing and leveling effect of chemical polishing. They form a solid oxide film on the aluminum alloy surface, and on the other hand, the oxide film is dissolved by the acid. This process repeats, maintaining a balance between oxide film formation and dissolution, resulting in a smooth surface with low roughness. Nitric acid and nitrates are excellent oxidizing leveling agents that do not produce nitrogen oxide gases at room temperature. Molybdates and phosphomolybdates also have good leveling effects.

[0026] Surfactant wetting agents also have a certain corrosion inhibition and leveling effect. Their mechanism of action lies in forming an adsorption film on the aluminum surface. The adsorption film is thicker and denser in depressions, significantly inhibiting the reaction on the aluminum substrate surface, while it is thinner and looser in protrusions, resulting in less reaction inhibition. This reduces the unevenness of the corrosion reaction, achieving a smooth leveling effect. There are many types of surfactants, but few can maintain stable adsorption in high halide ion and oxidizing acidic environments.

[0027] The main function of surfactants is to reduce interfacial tension and increase the wettability of the aluminum substrate surface with the treatment agent. The pretreatment reaction time for a "matte finish" is short (generally within 60 seconds), and workpieces such as valve bodies need to be rapidly and completely wetted by the treatment agent to reduce the unevenness of corrosion, oxidation, and adsorption film formation caused by differences in surface wetting. Increasing wettability at the solid-liquid interface requires the surfactant to exhibit the characteristic adsorption and arrangement of hydrophilic groups facing outwards on the solid surface. Aluminum or alumina surfaces are in a densely positively charged polar state under acidic conditions. Using negatively charged anionic surfactants allows for direct adsorption onto the substrate surface via electrostatic forces, followed by spontaneous interaction of hydrophobic groups to form outward-facing spherical, rod-shaped, or layered micelle structures. Therefore, the wetting agent needs to have good water solubility (above micelle concentration), negatively charged hydrophilic groups that are strongly adsorbed and tightly arranged at the interface, and strong interaction of hydrophobic groups to ensure rapid and complete wetting of the workpiece. Furthermore, in acidic environments with high fluoride ion oxidizing properties, many surfactants lose their original interfacial activity. For example, cationic surfactants may polymerize and precipitate due to the electrochemical effects of fluoride ions; anionic surfactants such as carboxylates, sulfates, and phosphates may dissolve and hydrolyze in acidic environments, losing their activity; and polyoxyethylene chain nonionic surfactants may break down due to the oxidizing properties of the treatment agent, thus losing their activity. Sulfonate-type anionic surfactants with special structures can maintain their wetting activity in this complex environment.

[0028] The "frosting" treatment reaction is extremely vigorous, causing the etched Al, Mg, Fe, and other metal ions to accumulate rapidly. The concentration of free active F ions decreases rapidly due to their combination with Al and Na ions to form insoluble substances like cryolite, leading to premature imbalance and clumping of the treatment agent, rendering it unusable. Adding a suitable chelating agent can complex metal ions, release fluoride ions, and delay the need for liquid replacement due to agent imbalance. Organophosphonates are excellent chelating water treatment agents, exhibiting broad chelating ability for various metal ions even in acidic, high-hardness water. In particular, carboxylic acid-type organophosphonates have outstanding chelating ability for aluminum ions.

[0029] Controlling variations in time and temperature during the matte finishing process is crucial. Because the matte reaction is highly exothermic, when processing large workpieces at once, the treatment agent temperature can rise significantly (3-5°C) within a short period. In continuous processing, the temperature of subsequent treatment agents may not have enough time to cool down to within the process range, resulting in substandard valve body surface condition and roughness. Therefore, the matte finishing tank should ideally be equipped with the same temperature control system as the anodizing tank. Alternatively, depending on the actual situation, the processing time can be appropriately reduced to mitigate the adverse effects of the intensified temperature rise and reaction.

[0030] Compared with the prior art, the beneficial effects of the present invention include:

[0031] The "matte finish" treatment process provided by this invention results in a valve body surface with a consistent matte finish (see appendix). Figure 2 The surface finish is highly decorative. Simultaneously, the key data obtained (internal roughness, diameter, surface gloss) achieve a high pass rate (reaching 100%), improving efficiency and saving costs. This is significantly superior to the existing general chemical treatment processes used in Comparative Examples 1-4 (see appendix). Figure 1 ). Attached Figure Description

[0032] Figure 1 The images shown are photographs of a 6063 aluminum alloy pneumatic valve body treated with the aluminum alloy surface treatment agent described in Comparative Example 1, where Figure A and Figure B represent different components of the valve body.

[0033] Figure 2 The images shown are photographs of a 6063 aluminum alloy pneumatic valve body treated with the aluminum alloy surface treatment agent described in Example 1, where Figure A and Figure B represent different components of the valve body.

[0034] Figure 3 The images show the surface condition of the 6063 aluminum alloy pneumatic valve body after vibratory grinding, with Figure A and Figure B representing different components of the valve body. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0036] The sodium dicyclohexyl sulfosuccinate used in the examples and comparative examples was purchased from Solvay, a Belgian chemical group, and distributed by Guangmo New Material Technology (Shanghai) Co., Ltd.

[0037] Example 1

[0038] An aluminum alloy surface treatment agent is obtained by uniformly mixing the following components in parts by weight: 70 parts ammonium bifluoride, 10 parts tetrasodium 2-phosphonobutane-1,2,4-tricarboxylate (PBTCA.Na4), 15 parts sodium nitrate and 4 parts sodium dicyclohexyl sulfosuccinate.

[0039] The surface treatment of the 6063 aluminum alloy pneumatic valve body is performed using the aluminum alloy surface treatment agent described in Example 1, and the steps are as follows:

[0040] Vibratory grinding pretreatment → Cleaning → Di-acid polishing → Water washing × 2 → Matte "matte" treatment → Water washing → Dust removal (brightening) → Water washing → Anodizing → Water washing × 3 → Sealing.

[0041] Vibratory grinding pretreatment utilizes green alumina triangular abrasive to vibrate and grind the valve body parts, thereby automatically deburring and initially removing extrusion stripes.

[0042] The acid polishing solution consists of sulfuric acid (98%) and phosphoric acid (85%) in a 2:1 (volume ratio) ratio, and chemical polishing additive ZHM-1110 provided by Wuhan Materials Protection Research Institute Co., Ltd. of China Academy of Machinery Science and Technology. The concentration of the additive in the tank is 15g / L.

[0043] The matte finish treatment solution was prepared by mixing the aluminum alloy surface treatment agent prepared in Example 1 with water to a concentration of 120 g / L for use in the tank. The process conditions were: temperature 35°C, time 35 s.

[0044] The ash removal and brightening process uses a mixed solution of 98% concentrated sulfuric acid (150 g / L) and 30% hydrogen peroxide (80 g / L).

[0045] The anodizing process uses a standard sulfuric acid bath with a 98% concentrated sulfuric acid concentration of 200 g / L. The oxidation process conditions are: current density 1.2 A / dm³. 2 The temperature was 20±1℃ and the time was 35min.

[0046] The oxide film was sealed using a nickel-free high-temperature sealing process. The sealing bath solution consisted of environmentally friendly high-temperature nickel-free sealing additive ZHM-0912 provided by Wuhan Materials Protection Research Institute Co., Ltd. of China National Machinery Industry Corporation, diluted with water at a concentration of 15 g / L. The process conditions were: temperature 92℃, pH 6.9, and time 22 min.

[0047] Example 2

[0048] An aluminum alloy surface treatment agent is obtained by uniformly mixing the following components in parts by weight: 70 parts ammonium bifluoride, 10 parts ethylenediaminetetramethylenephosphonate pentasodium salt (EDTMP.Na5), 15 parts sodium nitrate and 4 parts dicyclohexyl sulfosuccinate sodium salt.

[0049] The surface treatment of the 6063 aluminum alloy pneumatic valve body was carried out using the aluminum alloy surface treatment agent described in Example 2, and the steps were the same as in Example 1.

[0050] Example 3

[0051] An aluminum alloy surface treatment agent is obtained by uniformly mixing the following components in parts by weight: 70 parts ammonium bifluoride, 10 parts tetrasodium 2-phosphonobutane-1,2,4-tricarboxylate (PBTCA.Na4), 15 parts sodium nitrate and 2 parts sodium dicyclohexyl sulfosuccinate.

[0052] The surface treatment of the 6063 aluminum alloy pneumatic valve body was carried out using the aluminum alloy surface treatment agent described in Example 3, and the steps were the same as in Example 1.

[0053] Example 4

[0054] An aluminum alloy surface treatment agent is obtained by uniformly mixing the following components in parts by weight: 70 parts ammonium bifluoride, 10 parts tetrasodium 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTCA.Na4), 15 parts sodium nitrate, 2 parts disodium cashew ether sulfosuccinate and 2 parts dicyclohexyl sulfosuccinate.

[0055] The surface treatment of the 6063 aluminum alloy pneumatic valve body was carried out using the aluminum alloy surface treatment agent described in Example 4, and the steps were the same as in Example 1.

[0056] Example 5

[0057] An aluminum alloy surface treatment agent is obtained by uniformly mixing the following components in parts by weight: 70 parts ammonium bifluoride, 10 parts tetrasodium 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTCA.Na4), 15 parts sodium nitrate and 4 parts disodium cashew phenolate sulfosuccinate sesquiester.

[0058] The surface treatment of the 6063 aluminum alloy pneumatic valve body was carried out using the aluminum alloy surface treatment agent described in Example 5, and the steps were the same as in Example 1.

[0059] Comparative Example 1

[0060] An aluminum alloy surface treatment agent is obtained by uniformly mixing the following components in parts by weight: 70 parts ammonium bifluoride, 15 parts sodium nitrate and 4 parts sodium dicyclohexyl sulfosuccinate.

[0061] The surface treatment of the 6063 aluminum alloy pneumatic valve body was carried out using the aluminum alloy surface treatment agent described in Comparative Example 1, and the steps were the same as in Example 1.

[0062] Comparative Example 2

[0063] An aluminum alloy surface treatment agent is obtained by uniformly mixing the following components in parts by weight: 70 parts ammonium bifluoride, 10 parts disodium ethylenediaminetetraacetate, 15 parts sodium nitrate and 4 parts sodium dicyclohexyl sulfosuccinate.

[0064] The surface treatment agent of aluminum alloy described in Comparative Example 2 was used to treat the surface of the 6063 aluminum alloy pneumatic valve body, and the steps were the same as in Example 1.

[0065] Comparative Example 3

[0066] An aluminum alloy surface treatment agent is obtained by uniformly mixing the following components in parts by weight: 70 parts ammonium bifluoride, 10 parts tetrasodium 2-phosphonobutane-1,2,4-tricarboxylate (PBTCA.Na4), 15 parts sodium nitrate and 4 parts sodium dodecylbenzenesulfonate.

[0067] The surface treatment of the 6063 aluminum alloy pneumatic valve body was carried out using the aluminum alloy surface treatment agent described in Comparative Example 3, and the steps were the same as in Example 1.

[0068] Comparative Example 4

[0069] An aluminum alloy surface treatment agent is obtained by uniformly mixing the following components in parts by weight: 70 parts ammonium bifluoride, 15 parts sodium nitrate and 4 parts sodium dodecylbenzenesulfonate.

[0070] The surface treatment of the 6063 aluminum alloy pneumatic valve body was carried out using the aluminum alloy surface treatment agent described in Comparative Example 3, and the steps were the same as in Example 1.

[0071] To test the stability advantages of the matte finish process of the present invention, 3L of bath solution was prepared according to the matte finish process described in each embodiment and comparative example. 100 JJ4V210 valve bodies (provided by Ningbo Jialing Pneumatic Machinery Co., Ltd., valve body size: 50mm×35mm×22mm) were continuously processed under each process. The final pass rate of the valve body surface treatment line (pass rate after sealing treatment) was evaluated by measuring the average inner hole roughness, diameter, surface gloss, feel, visual appearance, and stability of the bath solution (data after "matte finish" treatment).

[0072] The pneumatic valve bodies treated in Examples 1-5 and Comparative Examples 1-4 were tested for various parameters. The test results are shown in Table 1, and are as follows:

[0073] (1) Surface roughness measurement: The roughness Ra of the working surface of the valve body's inner bore was tested using a portable roughness tester (Mitutoyo SJ-210, Japan) according to the instructions. The acceptable standard is: after matte "frosted" treatment, the roughness Ra of the valve body's inner bore is ≤0.250μm. (Anodizing, sealing, and other processes increase the roughness index by about 0.01μm. After oxidation and sealing, the final sample's inner bore roughness is ≤0.350μm.)

[0074] (2) Measurement of inner diameter: The inner diameter D of the valve body is measured using a dial gauge vernier caliper (manufactured in bulk, with an accuracy of 0.01 mm and a range of 0~150 mm). Acceptance criteria: After matte finishing, the inner diameter of the valve body is 10.380±0.01 mm (original machine tool drilling inner diameter is 10.400±0.01 mm). After oxidation and sealing, the final valve body inner diameter is 10.400±0.02 mm.

[0075] (3) Gloss measurement; The gloss of the valve body surface was measured using a KOSJI gloss meter (model: MG6-SM, range 0~999GU). Acceptance standard: gloss value of 350~370GU after the sealing process.

[0076] (4) Visual inspection and tactile examination: After the sealing process is completed, observe the valve body at a visual distance of about 20cm under general indoor inspection lighting, and gently rub the valve body surface with bare hands. The valve body surface should have a uniform, defect-free matte "frosted" finish, with consistent matte diffuse reflection. It should feel smooth and delicate, without any obvious coarse texture.

[0077]

[0078]

[0079] A comparison of the data in the tables of Example 1 and Comparative Examples 1, 2, 3, and 4 reveals that the selection of chelating agents and surfactants in this invention plays a crucial role in the success of the "matte" pretreatment process for the valve body. The use of organophosphonate chelating agents substantially improves the roughness of the valve body's internal pores and the lifespan of the bath solution. The use of acid-resistant, oxidation-resistant, and fluorine-resistant surfactants significantly improves the matte appearance and feel. The valve body without chelating agents (Comparative Example 1) and with the addition of general complexing agents (Comparative Example 2) and surfactants (Comparative Examples 3 and 4) exhibits low pass rates for key valve body parameters (pore roughness and diameter), and fails to meet customer requirements regarding the required "matte" appearance, bath solution stability, and service life.

[0080] Table 1 also shows that: the organophosphate containing polycarboxylic acids (Example 1) has a better chelating effect and a higher valve body surface treatment pass rate than the amino phosphate (Example 2); the carboxylic acid-sulfonate surfactant (Example 1) is also more effective than the cashew phenol-sulfonate composite surfactant (Example 5). A certain amount of surfactant needs to be added (comparing Example 1 and Example 3) to achieve a better wetting effect.

[0081] Figure 1 The image shows a photograph of a 6063 aluminum alloy pneumatic valve body treated with the aluminum alloy surface treatment agent described in Comparative Example 1. Figure 1 It can be seen that the surface of the sand grains has lost its luster and feels rough to the touch.

[0082] Figure 2 The image shown is a photograph of a 6063 aluminum alloy pneumatic valve body treated with the aluminum alloy surface treatment agent described in Example 1. Figure 2 It can be seen that its surface has a consistent matte finish, making it highly decorative.

[0083] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. An aluminum alloy surface treatment agent, characterized in that, It is prepared from the following components in parts by weight: 65-75 parts of fluoride ion etchant, 5-15 parts of chelating agent, 10-20 parts of leveling agent and 2-5 parts of surfactant wetting agent, wherein the surfactant wetting agent is sodium dicyclohexyl sulfosuccinate. The fluoride ion etching agent is ammonium bifluoride; The chelating agent is at least one of ethylenediaminetetramethylenephosphonate pentasodium and 2-phosphonobutane-1,2,4-tricarboxylic acid tetrasodium; The leveling agent is sodium nitrate.

2. The method for preparing the aluminum alloy surface treatment agent according to claim 1, characterized in that, The process includes the following steps: Mix 65-75 parts of fluoride ion etchant, 5-15 parts of chelating agent, 10-20 parts of leveling agent and 2-5 parts of surfactant wetting agent evenly by weight.

3. The application of the aluminum alloy surface treatment agent according to claim 1 in the surface treatment of aluminum profiles in the small anodizing industry.

4. The application according to claim 3, characterized in that, Includes the following steps: (1) The processed aluminum alloy samples were subjected to vibration grinding pretreatment and chemical polishing treatment in sequence; (2) After the polishing treatment is cleaned with water, the sample is immersed in the aqueous solution of the aluminum alloy surface treatment agent to perform a matte finish treatment; (3) After the matte finish treatment, the aluminum profile products are obtained by sequentially performing dust removal and brightening, anodizing and oxide film sealing treatment.

5. The application according to claim 4, characterized in that, The pretreatment method of vibration grinding in step (1) is as follows: the processed aluminum alloy sample is placed on the automatic vibration grinding line for vibration grinding. The chemical polishing process described in step (1) is as follows: the sample that has passed the vibration grinding is immersed in an acidic solution for chemical polishing to remove the natural oxide film, increase the surface brightness, and reduce the roughness; The temperature of the chemical polishing treatment in step (1) is 95~110℃ and the time is 30~60s.

6. The application according to claim 4 or 5, characterized in that, In step (2), the concentration of the aluminum alloy surface treatment agent in the aqueous solution is 50~150g / L; The matte finish treatment in step (2) takes 15 to 100 seconds and is carried out at a temperature of 25 to 40°C.

7. The application according to claim 6, characterized in that, The method for removing dust and achieving gloss in step (3) is as follows: after matte surface treatment, wash with water and immerse in dilute sulfuric acid or dilute nitric acid with added hydrogen peroxide to remove dust and achieve gloss. The anodizing method described in step (3) is as follows: after ash removal, brightening, and water washing, the sample is subjected to sulfuric acid anodizing treatment at a temperature of 18~20℃ for 30~35 min and a current density of 1.1~1.3 A / dm³. 2 The film thickness is controlled at 12~15μm; The oxide film sealing treatment in step (3) is as follows: after anodizing, the oxide film is washed with water and then treated with a high-temperature nickel-free sealing agent. The concentration of the sealing agent is 10~15mL / L, the temperature is 92~95℃, the pH is 6.5~7.0, and the time is 1.5~2min / μm.

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