Anodic oxidation process for forged and pressed aluminum material

Abstract

The invention provides an anodic oxidation process for a forged and pressed aluminum material. The anodic oxidation process comprises the following steps that (1) the forged and pressed aluminum material subjected to pretreatment is subjected to oxidation treatment; the voltage of the oxidation treatment is 17.8 to 18.2 V; (2) sequentially carrying out first surface conditioning treatment, second surface conditioning treatment and third surface conditioning treatment on the forged and pressed aluminum material subjected to oxidation treatment in the step (1), and then carrying out post-treatment; the number of times of the first surface conditioning processing and the third surface conditioning processing is greater than or equal to 2. By improving parameters and manufacturing procedures of oxidation treatment and surface conditioning treatment, acid in the forged and pressed aluminum material can be washed out, the phenomenon that white spots exist on the surface of the forged and pressed aluminum material after the anodic oxidation process is solved, and it can be guaranteed that the forged and pressed aluminum material passes a reliability test.

Description

Technical Field

[0001] The invention belongs to the technical field of metal surface treatment and relates to an anodizing process for forged aluminum materials. Background Art

[0002] Aluminum and its alloys have the advantages of high strength, good thermal and electrical conductivity, beautiful color, non-magnetic, corrosion-resistant, good plasticity and formability, and no low-temperature brittleness. It is a non-ferrous metal material with excellent performance. Currently, aluminum and its alloys have been widely used in aerospace, construction, automobiles, mechanical properties and civil decorative hardware; but some properties of aluminum are not ideal, such as hardness, wear resistance and corrosion resistance of the surface properties; in order to overcome the shortcomings of aluminum alloy surface properties, but also to improve the protection, decoration and functionality, anodizing in aluminum surface technology is the most commonly used protection method.

[0003] The anodizing process includes: degreasing-neutralization-chemical polishing-neutralization-alkali washing-neutralization-oxidation-surface adjustment-dyeing-sealing-drying. For sandblasted products, chemical polishing is required, and for bright surface products, chemical polishing is not required. CN116837437A discloses an aluminum alloy anodizing process, firstly, the aluminum alloy is placed in a degreasing tank containing sodium hydroxide solution for ultrasonic degreasing and first water washing, then the aluminum alloy after water washing is placed in a chemical polishing tank filled with polishing liquid for chemical polishing and second water washing, then the aluminum alloy after water washing is placed in a neutralization tank filled with weak alkali solution for neutralization, then the aluminum alloy after washing is placed in an anodizing tank filled with anodizing solution for direct current anodizing and coloring, and then the aluminum alloy is sealed and dried in sequence, wherein the polishing liquid includes phosphoric acid, sulfuric acid, corrosion inhibitor sodium silicate, and consistency regulator hydroxymethyl cellulose, wherein the phosphorus-sulfur ratio is 9-11:1, and the aluminum ion content is 15-35g / L. Although the proportion of anode surface spots on the aluminum alloy treated by the above anodizing process is small, the anodized film has corrosion resistance and wear resistance.

[0004] At present, aluminum raw materials are usually formed by extrusion or forging. However, under the same anodizing parameters, a large number of white spots will appear on the surface of the forged aluminum after dyeing, and the distribution is irregular, with a high defect rate, which greatly affects production efficiency and causes a huge waste of manpower and material resources. After many experiments and characterization verifications by the inventors, it is known that forged aluminum will contain acid before oxidation treatment, and the acid will precipitate during the dyeing process, causing the pH of the local area to drop, resulting in the undesirable phenomenon that the area cannot be dyed normally, which is called acid spitting.

[0005] In summary, an improved anodizing process for forged aluminum is provided, which can not only solve the problem of white spots on the surface of forged aluminum, but also ensure that the forged aluminum can pass the reliability (REL) test. Summary of the invention

[0006] In view of the shortcomings of the prior art, the purpose of the present invention is to provide an anodizing process for forged aluminum materials. By improving the parameters and processes of oxidation treatment and surface conditioning treatment, the acid hidden inside the forged aluminum materials can be washed out, which can not only solve the problem of white spots on the surface of the forged aluminum materials after the anodizing process, but also ensure that the forged aluminum materials pass the reliability test.

[0007] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0008] The present invention provides an anodizing process for forged aluminum material, the anodizing process comprising the following steps:

[0009] (1) Oxidation treatment of the forged aluminum material after pretreatment;

[0010] The voltage of the oxidation treatment is 17.8-18.2V, for example, it can be 17.9V, 17.95V, 18V, 18.05V, 18.1V or 18.15V, but is not limited to the listed values, and other values ​​within the numerical range are also applicable;

[0011] (2) performing a first surface conditioning treatment, a second surface conditioning treatment and a third surface conditioning treatment on the forged aluminum material after the oxidation treatment in step (1), and then performing a post-treatment;

[0012] The number of times of the first table adjustment processing and the third table adjustment processing are both ≥ 2 times, for example, can be 2 times, 3 times or 4 times, etc., but are not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0013] In the present invention, the forged aluminum material includes forged aluminum alloy.

[0014] The anodizing process provided by the present invention can not only quickly wash out the acid hidden in the forged aluminum material by controlling the voltage parameters of the oxidation treatment and combining the process of adjusting the surface, but also facilitate the penetration and fixation of the subsequent dye. The anodizing process can not only solve the problem of white spots on the surface of the forged aluminum material after the anodizing process, but also ensure that the product passes the REL test.

[0015] As a preferred technical solution of the present invention, the pretreatment in step (1) includes degreasing treatment, chemical polishing treatment and alkaline washing treatment performed in sequence.

[0016] Preferably, the degreasing treatment is performed under ultrasound.

[0017] In the present invention, the purpose of the degreasing treatment is to remove grease and impurities on the surface of the aluminum alloy and improve the cleanliness of the surface of the aluminum alloy.

[0018] Preferably, the degreasing agent for the degreasing treatment includes Okuno 161 degreasing agent.

[0019] Preferably, the mass concentration of the degreasing agent is 40-50 g / L, for example, it can be 41 g / L, 42 g / L, 43 g / L, 44 g / L, 45 g / L, 46 g / L, 47 g / L, 48 g / L or 49 g / L, but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0020] Preferably, the temperature of the degreasing treatment is 55-65°C, for example, it can be 56°C, 57°C, 58°C, 59°C, 60°C, 61°C, 62°C, 63°C or 64°C, but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0021] Preferably, the degreasing treatment time is 150-200 s, for example, it can be 155 s, 160 s, 165 s, 170 s, 175 s, 180 s, 185 s, 190 s or 195 s, but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0022] Preferably, the polishing agent for the chemical polishing treatment is a mixture of phosphoric acid and sulfuric acid.

[0023] In the present invention, the purpose of the chemical polishing treatment is to remove impurities and oxides on the surface of the aluminum alloy, provide a good foundation for subsequent anodizing, and help form a more uniform and dense oxide film layer; in addition, for workpieces that need to be dyed, chemical polishing can also improve the surface microstructure, making it easier for the dye to penetrate and evenly adhere to the surface, thereby improving the dyeing effect.

[0024] Preferably, the specific gravity of the polishing agent is 1.7-1.8 g / cm 3 , for example, it can be 1.71 g / cm 3 , 1.72g / cm 3 、1.73g / cm 3 , 1.74g / cm 3 , 1.75g / cm 3 , 1.76g / cm 3 , 1.77g / cm 3 , 1.78g / cm 3 or 1.79 g / cm 3 The above values ​​are not limited to the above values, and other values ​​within the above range are also applicable.

[0025] Preferably, the phosphorus-sulfur ratio of the polishing agent is 6-7, for example, it can be 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8 or 6.9, but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0026] Preferably, the temperature of the chemical polishing treatment is 65-75°C, for example, it can be 66°C, 67°C, 68°C, 69°C, 70°C, 71°C, 72°C, 73°C or 74°C, but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0027] Preferably, the alkali cleaning agent of the alkali cleaning treatment comprises a sodium hydroxide solution.

[0028] In the present invention, the purpose of the alkali washing treatment is that the surface of the aluminum alloy will chemically react with the acidic solution in the previous process, and some acidic residues or reaction products may exist on its surface. Alkaline washing can effectively neutralize and remove these residues to ensure surface cleanliness.

[0029] Preferably, the mass concentration of the alkaline cleaning agent is 45-55 g / L, for example, it can be 46 g / L, 47 g / L, 48 g / L, 49 g / L, 50 g / L, 51 g / L, 52 g / L, 53 g / L or 54 g / L, but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0030] Preferably, the temperature of the alkali washing treatment is 45-55°C, for example, it can be 46°C, 47°C, 48°C, 49°C, 50°C, 51°C, 52°C, 53°C or 54°C, but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0031] Preferably, the alkali washing treatment time is 30-90s, for example, it can be 35s, 40s, 45s, 50s, 55s, 60s, 65s, 70s, 75s, 80s or 85s, but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0032] As a preferred technical solution of the present invention, the degreasing treatment, chemical polishing treatment and alkali washing treatment are all followed by a neutralization treatment.

[0033] In the present invention, the purpose of the neutralization treatment is to more fully remove the residues and make the surface of the aluminum alloy purer, which is beneficial to the subsequent processing and the improvement of product quality.

[0034] Preferably, the neutralizing agent of the neutralization treatment comprises nitric acid.

[0035] Preferably, the mass concentration of the nitric acid is 150-200 g / L, for example, it can be 155 g / L, 160 g / L, 165 g / L, 170 g / L, 175 g / L, 180 g / L, 185 g / L, 190 g / L or 195 g / L, but is not limited to the listed values, and other values ​​within the numerical range are equally applicable.

[0036] Preferably, the neutralization treatment time is 150-200 s, for example, it can be 155 s, 160 s, 165 s, 170 s, 175 s, 180 s, 185 s, 190 s or 195 s, but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0037] As a preferred technical solution of the present invention, the oxidant for the oxidation treatment in step (1) comprises a mixed solution of sulfuric acid with a mass concentration of 87-92 g / L and oxalic acid with a mass concentration of 15-20 g / L.

[0038] In the present invention, the purpose of the oxidation treatment is to form a dense and hard oxide layer on the surface of the aluminum alloy. The oxidized film layer has good corrosion resistance and wear resistance, and the oxidized film layer can be dyed, which enhances its aesthetics and decorativeness.

[0039] In the present invention, the mass concentration of the sulfuric acid is 87-92 g / L, for example, it can be 87.5 g / L, 88 g / L, 88.5 g / L, 89 g / L, 89.5 g / L, 90 g / L, 90.5 g / L, 91 g / L or 91.5 g / L, and the mass concentration of the oxalic acid is 15-20 g / L, for example, it can be 15.5 g / L, 16 g / L, 16.5 g / L, 17 g / L, 17.5 g / L, 18 g / L, 18.5 g / L, 19 g / L or 19.5 g / L, but is not limited to the listed values, and other values ​​within the numerical range are equally applicable.

[0040] Preferably, the temperature of the oxidation treatment in step (1) is 25-30°C, for example, 26°C, 27°C, 28°C or 29°C, but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0041] Preferably, the soft start time of the oxidation treatment in step (1) is 250-350 s, for example, it can be 260 s, 270 s, 280 s, 290 s, 300 s, 310 s, 320 s, 330 s or 340 s, but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0042] It is worth noting that by further controlling the soft start time parameter range of the oxidation treatment, the white spot defect on the surface of forged aluminum materials can be significantly improved.

[0043] Preferably, the oxidation time of the oxidation treatment in step (1) is 3200-3800 s, for example, it can be 3300 s, 3400 s, 3500 s, 3600 s or 3700 s, but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0044] As a preferred technical solution of the present invention, the surface conditioning agents of the first surface conditioning treatment, the second surface conditioning treatment and the third surface conditioning treatment in step (2) all include TAC SORMAL 121 surface conditioning agent.

[0045] In the present invention, the purpose of the surface conditioning treatment is to remove impurities and residual acid on the surface of the oxide film to reduce the impact on subsequent dyeing. At the same time, the surface conditioning treatment can further organize the microstructure of the oxide film to make it more uniform and dense, which is conducive to the penetration and fixation of the dye.

[0046] Preferably, in step (2), the first surface conditioning treatment, the second surface conditioning treatment and the third surface conditioning treatment are all performed under ultrasound.

[0047] As a preferred technical solution of the present invention, in step (2), the number of times the first table adjustment is processed is 2 times.

[0048] Preferably, the mass concentration of the surface conditioning agent used in the first surface conditioning treatment in step (2) is 55-65 g / L, for example, it can be 56 g / L, 57 g / L, 58 g / L, 59 g / L, 60 g / L, 61 g / L, 62 g / L, 63 g / L or 64 g / L, but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0049] Preferably, the temperature of the first surface conditioning treatment in step (2) is 15-25°C, for example, it can be 16°C, 17°C, 18°C, 19°C, 20°C, 21°C, 22°C, 23°C or 24°C, but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0050] Preferably, the time for the first table adjustment processing in step (2) is 320-400s, for example, it can be 330s, 340s, 350s, 360s, 370s, 380s or 390s, etc., but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0051] As a preferred technical solution of the present invention, the mass concentration of the surface conditioning agent used in the second surface conditioning treatment in step (2) is 15-25 g / L, for example, it can be 16 g / L, 17 g / L, 18 g / L, 19 g / L, 20 g / L, 21 g / L, 22 g / L, 23 g / L or 24 g / L, but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0052] Preferably, the temperature of the second surface conditioning treatment in step (2) is 45-55°C, for example, it can be 46°C, 47°C, 48°C, 49°C, 50°C, 51°C, 52°C, 53°C or 54°C, etc., but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0053] Preferably, the time for the second table adjustment processing in step (2) is 150-200s, for example, it can be 155s, 160s, 165s, 170s, 175s, 180s, 185s, 190s or 195s, etc., but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0054] As a preferred technical solution of the present invention, the third table adjustment processing in step (2) is performed twice.

[0055] Preferably, the mass concentration of the surface conditioning agent used in the third surface conditioning treatment in step (2) is 55-65 g / L, for example, it can be 56 g / L, 57 g / L, 58 g / L, 59 g / L, 60 g / L, 61 g / L, 62 g / L, 63 g / L or 64 g / L, but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0056] Preferably, the temperature of the third surface conditioning treatment in step (2) is 15-25°C, for example, it can be 16°C, 17°C, 18°C, 19°C, 20°C, 21°C, 22°C, 23°C or 24°C, but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0057] Preferably, the time for the third table adjustment processing in step (2) is 320-400s, for example, it can be 330s, 340s, 350s, 360s, 370s, 380s or 390s, etc., but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0058] It is worth noting that by controlling the relevant parameters of the first surface conditioning treatment, the second surface conditioning treatment and the third surface conditioning treatment, the white spot defect on the surface of the forged aluminum material can be significantly improved.

[0059] As a preferred technical solution of the present invention, the post-treatment in step (2) includes dyeing treatment, sealing treatment and drying treatment performed in sequence.

[0060] Preferably, the temperature of the dyeing treatment is 25-35°C, for example, it can be 26°C, 27°C, 28°C, 29°C, 30°C, 31°C, 32°C, 33°C or 34°C, but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0061] In the present invention, there is no specific limitation on the dyeing agent used for dyeing treatment, and those skilled in the art can select the dyeing agent according to actual needs.

[0062] In the present invention, the purpose of the dyeing treatment is to enhance the aesthetics and decorativeness of the aluminum alloy surface.

[0063] Preferably, the sealing treatment temperature is 85-95°C, for example, it can be 86°C, 87°C, 88°C, 89°C, 90°C, 91°C, 92°C, 93°C or 94°C, but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0064] In the present invention, the sealing agent used for the sealing treatment is not specifically limited, and those skilled in the art can select it according to actual needs.

[0065] In the present invention, the purpose of the pore sealing treatment is to seal the oxide film pores, fix the dye molecules in the film pores, and prevent them from escaping, thereby maintaining the durability of the color, and also enhancing the corrosion resistance and wear resistance of the aluminum alloy.

[0066] Preferably, the sealing treatment time is 2000-3000 s, for example, it can be 2100 s, 2200 s, 2300 s, 2400 s, 2500 s, 2600 s, 2700 s, 2800 s or 2900 s, but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0067] Preferably, the temperature of the drying treatment is 75-85°C, for example, it can be 76°C, 77°C, 78°C, 79°C, 80°C, 81°C, 82°C, 83°C or 84°C, but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0068] Preferably, the drying treatment time is 1000-1500s, for example, it can be 1050s, 1100s, 1150s, 1200s, 1250s, 1300s, 1350s, 1400s or 1450s, but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0069] In the present invention, the purpose of the drying treatment is to remove moisture on the surface or inside of the aluminum alloy.

[0070] As a preferred technical solution of the present invention, the anodizing process comprises the following steps:

[0071] (1) Oxidation treatment of the forged aluminum material after pretreatment;

[0072] The pre-treatment includes degreasing treatment, chemical polishing treatment and alkali washing treatment performed in sequence, and neutralization treatment is performed after the degreasing treatment, chemical polishing treatment and alkali washing treatment;

[0073] The oxidant of the oxidation treatment includes a mixed solution of sulfuric acid with a mass concentration of 87-92 g / L and oxalic acid with a mass concentration of 15-20 g / L; the temperature of the oxidation treatment is 25-30°C, the voltage is 17.8-18.2V, the soft start time is 250-350s, and the oxidation time is 3200-3800s;

[0074] (2) performing a first surface conditioning treatment, a second surface conditioning treatment and a third surface conditioning treatment on the forged aluminum material after the oxidation treatment in step (1), and then performing a post-treatment;

[0075] The surface conditioning agents of the first surface conditioning treatment, the second surface conditioning treatment and the third surface conditioning treatment all include TAC SORMAL121 surface conditioning agent; the first surface conditioning treatment, the second surface conditioning treatment and the third surface conditioning treatment are all performed under ultrasound;

[0076] The mass concentration of the surface conditioning agent used in the first surface conditioning treatment is 55-65 g / L; the number of the first surface conditioning treatment is ≥ 2 times; the temperature of the first surface conditioning treatment is 15-25° C., and the time is 320-400 seconds;

[0077] The mass concentration of the surface conditioning agent used in the second surface conditioning treatment is 15-25 g / L; the temperature of the second surface conditioning treatment is 45-55° C., and the time is 150-200 seconds;

[0078] The mass concentration of the surface conditioning agent used in the third surface conditioning treatment is 55-65g / L; the number of the third surface conditioning treatment is ≥2 times; the temperature of the third surface conditioning treatment is 15-25°C, and the time is 320-400s;

[0079] The post-treatment includes dyeing treatment, sealing treatment and drying treatment performed in sequence.

[0080] Compared with the prior art, the present invention has the following beneficial effects:

[0081] (1) The anodizing process provided by the present invention can not only quickly wash out the acid hidden in the forged aluminum material by controlling the relevant parameters of the oxidation treatment and the surface conditioning treatment, but also facilitate the subsequent penetration and fixation of the dye.

[0082] (2) The anodizing process provided by the present invention can not only solve the problem of white spots on the surface of forged aluminum materials after the anodizing process, but also ensure that the product passes the REL test; wherein the yield rate of the product is ≥97%. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] Figure 1 is a Keyence microscope image of the aluminum material obtained after the anodizing process provided in Example 1;

[0084] Figure 2 This is a Keyence microscope image of the aluminum material obtained after the anodizing process provided in Example 5. DETAILED DESCRIPTION

[0085] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0086] In the following embodiments and comparative examples, the specific materials of the dye and the sealant are not limited, and those skilled in the art can purchase them commercially according to their needs.

[0087] Example 1

[0088] This embodiment provides an anodizing process for forged aluminum material, the anodizing process comprising the following steps:

[0089] (1) subjecting the forged aluminum material to degreasing treatment, chemical polishing treatment and alkali washing treatment in sequence, and neutralization treatment is performed after the degreasing treatment, chemical polishing treatment and alkali washing treatment;

[0090] The degreasing treatment is carried out under ultrasound; the degreasing agent of the degreasing treatment is Aoye 161 degreasing agent with a mass concentration of 45g / L; the temperature of the degreasing treatment is 60°C and the time is 180s;

[0091] The polishing agent for chemical polishing is a mixture of phosphoric acid and sulfuric acid; the specific gravity of the polishing agent is 1.77 g / cm 3 , the phosphorus-sulfur ratio is 6.6; the temperature of the chemical polishing treatment is 70°C;

[0092] The alkaline cleaning agent for the alkaline cleaning treatment is a sodium hydroxide solution with a mass concentration of 50g / L; the temperature of the alkaline cleaning treatment is 50°C and the time is 60s;

[0093] The neutralizing agent for the neutralization treatment is nitric acid with a mass concentration of 180 g / L; the time for the neutralization treatment is 180 s;

[0094] (2) performing oxidation treatment on the forged aluminum material after treatment in step (1);

[0095] The oxidant of the oxidation treatment includes a mixed solution of sulfuric acid with a mass concentration of 90g / L and oxalic acid with a mass concentration of 17g / L; the temperature of the oxidation treatment is 27°C, the voltage is 18V, the soft start time is 300s, and the oxidation time is 3500s;

[0096] (3) performing a first surface conditioning treatment, a second surface conditioning treatment, and a third surface conditioning treatment on the forged aluminum material after the treatment in step (2);

[0097] The surface conditioning agents of the first surface conditioning treatment, the second surface conditioning treatment and the third surface conditioning treatment are all TAC SORMAL 121 surface conditioning agent; the first surface conditioning treatment, the second surface conditioning treatment and the third surface conditioning treatment are all performed under ultrasound;

[0098] The mass concentration of the surface conditioning agent used in the first surface conditioning treatment is 60 g / L; the number of the first surface conditioning treatment is 2 times; the temperature of the first surface conditioning treatment is 20° C., and the time is 360 seconds;

[0099] The mass concentration of the surface conditioning agent used in the second surface conditioning treatment is 20 g / L; the temperature of the second surface conditioning treatment is 50° C. and the time is 180 s;

[0100] The mass concentration of the surface conditioning agent used in the third surface conditioning treatment is 60 g / L; the number of the third surface conditioning treatment is 2 times; the temperature of the third surface conditioning treatment is 20° C., and the time is 360 seconds;

[0101] (4) sequentially performing dyeing, sealing and drying treatments on the forged aluminum material after the treatment in step (3);

[0102] The temperature of the dyeing treatment is 30°C; the mass concentration of the sealing agent used in the sealing treatment is 13g / L; the temperature of the sealing treatment is 90°C and the time is 2400s; the temperature of the drying treatment is 80°C and the time is 1200s.

[0103] Figure 1 The Keyence microscope image of the aluminum material obtained by the anodizing process provided in this embodiment is Figure 1 It can be seen that the surface of the obtained aluminum material has no white spots. The anodizing process provided by the present invention can solve the problem of white spots on the surface of the forged aluminum material after the anodizing process.

[0104] The forged aluminum material obtained in this embodiment was subjected to REL performance test, and ORT test was performed using salt spray tester (YHYW-020), constant temperature and humidity liquid circulation tester (ELK-CTH-01), ATEC high and low temperature test box (CHALLENGE1000C), ATLAS UV tester and other test instruments, and whether the reliability test was passed was determined according to the corresponding machine model control requirements required by the market. If the reliability test was passed, it was recorded as OK, and if the reliability test failed, it was recorded as NG. The test results are shown in Table 1.

[0105] Table 1

[0106]

[0107] It can be seen from Table 1 that the aluminum material obtained by the improved anodizing process can pass the REL test.

[0108] Example 2

[0109] This embodiment provides an anodizing process for forged aluminum material, except that step (2) and step (3) are adjusted as follows:

[0110] (2) performing oxidation treatment on the forged aluminum material after treatment in step (1);

[0111] The oxidant of the oxidation treatment includes a mixed solution of sulfuric acid with a mass concentration of 87 g / L and oxalic acid with a mass concentration of 20 g / L; the temperature of the oxidation treatment is 25°C, the voltage is 18.2V, the soft start time is 350s, and the oxidation time is 3800s;

[0112] (3) performing a first surface conditioning treatment, a second surface conditioning treatment, and a third surface conditioning treatment on the forged aluminum material after the treatment in step (2);

[0113] The surface conditioning agents of the first surface conditioning treatment, the second surface conditioning treatment and the third surface conditioning treatment are all TAC SORMAL 121 surface conditioning agent; the first surface conditioning treatment, the second surface conditioning treatment and the third surface conditioning treatment are all performed under ultrasound;

[0114] The mass concentration of the surface conditioning agent used in the first surface conditioning treatment is 55 g / L; the number of the first surface conditioning treatment is 2 times; the temperature of the first surface conditioning treatment is 25° C., and the time is 400 s;

[0115] The mass concentration of the surface conditioning agent used in the second surface conditioning treatment is 15 g / L; the temperature of the second surface conditioning treatment is 55° C. and the time is 150 s;

[0116] The mass concentration of the surface conditioning agent used in the third surface conditioning treatment is 55 g / L; the number of the third surface conditioning treatment is 2 times; the temperature of the third surface conditioning treatment is 25° C., and the time is 400 s;

[0117] Other conditions are the same as those in Example 1.

[0118] Example 3

[0119] This embodiment provides an anodizing process for forged aluminum material, except that step (2) and step (3) are adjusted as follows:

[0120] (2) performing oxidation treatment on the forged aluminum material after treatment in step (1);

[0121] The oxidant of the oxidation treatment includes a mixed solution of sulfuric acid with a mass concentration of 92g / L and oxalic acid with a mass concentration of 15g / L; the temperature of the oxidation treatment is 30°C, the voltage is 17.5V, the soft start time is 250s, and the oxidation time is 3200s;

[0122] (3) performing a first surface conditioning treatment, a second surface conditioning treatment, and a third surface conditioning treatment on the forged aluminum material after the treatment in step (2);

[0123] The surface conditioning agents of the first surface conditioning treatment, the second surface conditioning treatment and the third surface conditioning treatment are all TAC SORMAL 121 surface conditioning agent; the first surface conditioning treatment, the second surface conditioning treatment and the third surface conditioning treatment are all performed under ultrasound;

[0124] The mass concentration of the surface conditioning agent used in the first surface conditioning treatment is 65 g / L; the number of the first surface conditioning treatment is 2 times; the temperature of the first surface conditioning treatment is 15° C., and the time is 320 seconds;

[0125] The mass concentration of the surface conditioning agent used in the second surface conditioning treatment is 25 g / L; the temperature of the second surface conditioning treatment is 45° C., and the time is 200 s;

[0126] The mass concentration of the surface conditioning agent used in the third surface conditioning treatment is 65 g / L; the number of the third surface conditioning treatment is 2 times; the temperature of the third surface conditioning treatment is 15° C., and the time is 320 seconds;

[0127] Other conditions are the same as in Example 1.

[0128] Example 4

[0129] This embodiment provides an anodizing process for forged aluminum material. Except that the soft start time of the oxidation treatment in step (2) is 180 seconds, other conditions are the same as those in Embodiment 1.

[0130] Example 5

[0131] This embodiment provides an anodizing process for forged aluminum material. Except that the soft start time of the oxidation treatment in step (2) is 420 s, other conditions are the same as those in Embodiment 1.

[0132] Example 6

[0133] This embodiment provides an anodizing process for forged aluminum materials. Except that the mass concentration of the surface conditioning agent used in the first surface conditioning treatment and the third surface conditioning treatment in step (3) is 40 g / L, other conditions are the same as those in Example 1.

[0134] Example 7

[0135] This embodiment provides an anodizing process for forged aluminum material. Except that the temperature of the first surface conditioning treatment and the third surface conditioning treatment in step (3) is 35° C., other conditions are the same as those in Embodiment 1.

[0136] Example 8

[0137] This embodiment provides an anodizing process for forged aluminum material. Except that the temperature of the second surface conditioning treatment in step (3) is 35° C., other conditions are the same as those in Embodiment 1.

[0138] Comparative Example 1

[0139] This comparative example provides an anodizing process for forged aluminum material. Except that the voltage of the oxidation treatment in step (2) is 17.5 V, other conditions are the same as those in Example 1.

[0140] Comparative Example 2

[0141] This comparative example provides an anodizing process for forged aluminum material. Except that the voltage of the oxidation treatment in step (2) is 19V, other conditions are the same as those in Example 1.

[0142] Comparative Example 3

[0143] This comparative example provides an anodizing process for forged aluminum material. Except that the voltage of the oxidation treatment in step (2) is 17.5 V and the soft start time is 180 s, other conditions are the same as those in Example 1.

[0144] Comparative Example 4

[0145] This comparative example provides an anodizing process for forged aluminum material. Except that the number of times of the first surface conditioning treatment and the third surface conditioning treatment in step (3) are both once, other conditions are the same as those in Example 1.

[0146] Comparative Example 5

[0147] This comparative example provides an anodizing process for forged aluminum material. Except that the number of times of the first surface conditioning treatment and the third surface conditioning treatment in step (3) are both once, other conditions are the same as those of comparative example 3.

[0148] Figure 2 This is a Keyence microscope image of the aluminum material obtained by the anodizing process provided in this comparative example. Figure 2 It was found that the obtained aluminum material had white spot defects on its surface.

[0149] For the anodizing process provided in the above embodiments and comparative examples, 240 pieces of forged aluminum materials were processed, and the number of good appearance products (whether white spots were present) was counted, and the yield was calculated (yield = number of good products / total input). The results are shown in Table 2.

[0150] Table 2

[0151]

[0152]

[0153] From Table 2, we can see that:

[0154] (1) The anodizing process provided in Examples 1-3 of the present invention can quickly wash out the acid inside the forged aluminum material, which can not only solve the problem of white spots on the surface of the forged aluminum material after the anodizing process, but also ensure that the product passes the REL test; wherein the yield of the product is ≥97%;

[0155] (2) By comparing Example 1 with Examples 4-5, it can be seen that when the soft start time of the oxidation treatment is too short, the oxidation reaction cannot be fully carried out, which will cause the oxide film to be unevenly distributed on the surface of the workpiece, and the local film layer will be too thin or defective, resulting in an increase in the defective rate of white spots on the surface of the forged aluminum material; when the soft start time of the oxidation treatment is too long, the oxide film is affected by too much heat during the formation process, causing the film layer performance to decrease, resulting in an increase in the risk of white spots on the surface of the forged aluminum material;

[0156] (3) By comparing Example 1 with Examples 6-8, it can be seen that when the mass concentration of the surface conditioning agent used in the first surface conditioning treatment and the third surface conditioning treatment is too low or the temperature is too high, the structure of the anodized film layer will change, thereby affecting the performance of the film layer, all of which will lead to the defect of white spots on the surface of the forged aluminum material; when the temperature of the second surface conditioning treatment is too low, the reaction rate between the surface conditioning agent and the oxide film will be slowed down, affecting the overall performance of the film layer, resulting in an increase in the defect rate of white spots on the surface of the forged aluminum material;

[0157] (4) From the comparison between Example 1 and Comparative Examples 1-5, it can be seen that only by simultaneously regulating the relevant parameters of the oxidation treatment and the process of the surface conditioning treatment can the defect rate of white spots on the surface of forged aluminum materials be significantly improved.

[0158] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. An anodizing process for forged aluminum, characterized in that: The anodizing process comprises the following steps: (1) Oxidation treatment of the forged aluminum material after pretreatment; The voltage of the oxidation treatment is 17.8-18.2V; (2) performing a first surface conditioning treatment, a second surface conditioning treatment and a third surface conditioning treatment on the forged aluminum material after the oxidation treatment in step (1) in sequence, and then performing a post-treatment; The number of times of the first table adjustment processing and the third table adjustment processing are both ≥2 times.

2. The anodizing process according to claim 1, characterized in that: The pretreatment in step (1) includes degreasing treatment, chemical polishing treatment and alkaline washing treatment performed in sequence; Preferably, the degreasing treatment is carried out under ultrasound; Preferably, the degreasing agent for the degreasing treatment includes Okuno 161 degreasing agent; Preferably, the mass concentration of the degreasing agent is 40-50 g / L; Preferably, the temperature of the degreasing treatment is 55-65°C; Preferably, the degreasing treatment time is 150-200s; Preferably, the polishing agent for the chemical polishing treatment is a mixture of phosphoric acid and sulfuric acid; Preferably, the specific gravity of the polishing agent is 1.7-1.8 g / cm 3 ; Preferably, the phosphorus-sulfur ratio of the polishing agent is 6-7; Preferably, the temperature of the chemical polishing treatment is 65-75°C; Preferably, the alkaline cleaning agent of the alkaline cleaning treatment comprises a sodium hydroxide solution; Preferably, the mass concentration of the alkaline cleaning agent is 45-55 g / L; Preferably, the temperature of the alkali washing treatment is 45-55°C; Preferably, the alkali washing treatment time is 30-90s.

3. The anodizing process according to claim 2, characterized in that: The degreasing treatment, chemical polishing treatment and alkali washing treatment are all followed by a neutralization treatment; Preferably, the neutralizing agent of the neutralization treatment comprises nitric acid; Preferably, the mass concentration of the nitric acid is 150-200 g / L; Preferably, the neutralization treatment time is 150-200s.

4. The anodizing process according to any one of claims 1 to 3, characterized in that: The oxidant of the oxidation treatment in step (1) comprises a mixed solution of sulfuric acid with a mass concentration of 87-92 g / L and oxalic acid with a mass concentration of 15-20 g / L; Preferably, the temperature of the oxidation treatment in step (1) is 25-30°C; Preferably, the soft start time of the oxidation treatment in step (1) is 250-350s; Preferably, the oxidation time of the oxidation treatment in step (1) is 3200-3800s.

5. The anodizing process according to any one of claims 1 to 4, characterized in that: Step (2) the surface conditioning agents of the first surface conditioning treatment, the second surface conditioning treatment and the third surface conditioning treatment all include TAC SORMAL 121 surface conditioning agent; Preferably, in step (2), the first surface conditioning treatment, the second surface conditioning treatment and the third surface conditioning treatment are all performed under ultrasound.

6. The anodizing process according to any one of claims 1 to 5, characterized in that: Step (2) The number of times the first table is processed is 2 times; Preferably, the mass concentration of the surface conditioning agent used in the first surface conditioning treatment in step (2) is 55-65 g / L; Preferably, the temperature of the first surface conditioning treatment in step (2) is 15-25°C; Preferably, the time for the first table adjustment processing in step (2) is 320-400s.

7. The anodizing process according to any one of claims 1 to 6, characterized in that: Preferably, the mass concentration of the surface conditioning agent used in the second surface conditioning treatment in step (2) is 15-25 g / L; Preferably, the temperature of the second surface conditioning treatment in step (2) is 45-55°C; Preferably, the time for the second table adjustment processing in step (2) is 150-200s.

8. The anodizing process according to any one of claims 1 to 7, characterized in that: The number of times the third table call processing is performed in step (2) is 2 times; Preferably, the mass concentration of the surface conditioning agent used in the third surface conditioning treatment in step (2) is 55-65 g / L; Preferably, the temperature of the third surface conditioning treatment in step (2) is 15-25°C; Preferably, the time for the third table adjustment processing in step (2) is 320-400s.

9. The anodizing process according to any one of claims 1 to 8, characterized in that: The post-treatment in step (2) includes dyeing, sealing and drying in sequence; Preferably, the temperature of the dyeing treatment is 25-35°C; Preferably, the sealing treatment temperature is 85-95°C; Preferably, the sealing treatment time is 2000-3000s; Preferably, the drying temperature is 75-85°C; Preferably, the drying process takes 1000-1500 seconds.

10. The anodizing process according to any one of claims 1 to 9, characterized in that: The anodizing process comprises the following steps: (1) Oxidation treatment of the forged aluminum material after pretreatment; The pre-treatment includes degreasing treatment, chemical polishing treatment and alkali washing treatment performed in sequence, and neutralization treatment is performed after the degreasing treatment, chemical polishing treatment and alkali washing treatment; The oxidant of the oxidation treatment includes a mixed solution of sulfuric acid with a mass concentration of 87-92 g / L and oxalic acid with a mass concentration of 15-20 g / L; the temperature of the oxidation treatment is 25-30°C, the voltage is 17.8-18.2V, the soft start time is 250-350s, and the oxidation time is 3200-3800s; (2) performing a first surface conditioning treatment, a second surface conditioning treatment and a third surface conditioning treatment on the forged aluminum material after the oxidation treatment in step (1) in sequence, and then performing a post-treatment; The surface conditioning agents of the first surface conditioning treatment, the second surface conditioning treatment and the third surface conditioning treatment all include TAC SORMAL 121 surface conditioning agent; the first surface conditioning treatment, the second surface conditioning treatment and the third surface conditioning treatment are all performed under ultrasound; The mass concentration of the surface conditioning agent used in the first surface conditioning treatment is 55-65 g / L; the number of the first surface conditioning treatment is ≥ 2 times; the temperature of the first surface conditioning treatment is 15-25° C., and the time is 320-400 seconds; The mass concentration of the surface conditioning agent used in the second surface conditioning treatment is 15-25 g / L; the temperature of the second surface conditioning treatment is 45-55° C., and the time is 150-200 seconds; The mass concentration of the surface conditioning agent used in the third surface conditioning treatment is 55-65g / L; the number of the third surface conditioning treatment is ≥2 times; the temperature of the third surface conditioning treatment is 15-25°C, and the time is 320-400s; The post-treatment includes dyeing treatment, sealing treatment and drying treatment performed in sequence.

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