Aluminum alloy surface hard anodic oxidation film layer and its stage type preparation process

Abstract

The application discloses an aluminum alloy surface anti-abrasion hard anodic oxidation film layer and a stage type preparation process thereof, and the process comprises the following steps: firstly, oil removal, immersion, lightening, neutralization, ultrasonic cleaning and blow drying are performed on the aluminum alloy parts; secondly, the anti-abrasion hard anodic oxidation film layer is formed on the surface of the aluminum alloy parts through hard anodic oxidation; thirdly, ultrasonic cleaning is performed after neutralization; and fourthly, drying is performed after high-temperature sealing of pores. The hard anodic oxidation of the stage type process effectively controls the generation and dissolution time of the oxidation film layer in the hard anodic oxidation process, reduces the roughness of the hard anodic oxidation film layer, and makes the hard anodic oxidation film layer more closely combined with the aluminum alloy parts, so that the surface hardness of the aluminum alloy parts is greatly improved, the hard anodic oxidation film layer has the characteristics of high bonding force, low roughness and high hardness, the anti-abrasion performance of the titanium alloy is improved, the service life of the titanium alloy is prolonged, and the application prospect of the titanium alloy is good in the fields of aerospace and marine equipment, transportation and the like.

Description

Technical Field

[0001] This invention belongs to the field of aluminum alloy surface treatment technology, specifically relating to a wear-resistant and corrosion-resistant hard anodized film layer on aluminum alloy surface and its staged preparation process. Background Technology

[0002] Aluminum alloys have great application potential in marine equipment, aerospace, transportation and building materials decoration, but aluminum alloys themselves have shortcomings in properties such as wear resistance, which greatly limits the application fields of this type of material.

[0003] Aluminum alloys possess excellent properties such as high specific strength, high heat resistance, and high corrosion resistance, leading to their widespread application in marine equipment. However, when used as open-moving components in marine equipment (such as seawater hydraulic transmission systems, offshore helicopter platforms, and drill pipes for oil exploration), aluminum alloys are subjected to long-term seawater corrosion and wear loads. Under the coupled effect of corrosion and wear, the aluminum alloy surface suffers severe damage, significantly impacting the reliability and safety of equipment operation. Hard anodizing of aluminum alloys, forming a dense, corrosion- and wear-resistant protective film on the surface, is an effective way to solve this problem.

[0004] Furthermore, due to their low hardness and poor wear resistance, aerospace aluminum alloys (such as structural components, fasteners, actuators, and transmission components) are prone to wear and scratches under long-term harsh service environments, and are susceptible to failure behaviors such as corrosion, peeling, and cracking, resulting in huge economic losses and posing significant safety hazards to flights. Therefore, there is an urgent need for a protective technology to form a well-bonded, highly dense, and corrosion- and wear-resistant protective film layer on the surface of aluminum alloys to solve the above problems.

[0005] In the transportation sector, lightweighting of vehicles such as automobiles and motorcycles is a significant development trend. Aluminum alloys are widely used in transportation vehicles and their components due to their inherent properties. However, the low hardness and poor wear resistance of conventional aluminum alloys limit their application in vehicles. For example, replacing some cast iron components in an engine with aluminum alloys will cause severe wear on the cylinder walls and piston contact points due to the poor wear resistance of aluminum alloys, significantly reducing engine life. Furthermore, components in rail vehicles, such as brake pads and wheels, are frequently exposed to wear environments; without surface wear-resistant and friction-reducing treatments, the wear rate will increase considerably. These application challenges place higher demands on the wear resistance of aluminum alloys.

[0006] The wear resistance of architectural aluminum alloy profiles is a crucial technical parameter reflecting their resistance to friction and abrasion. Wear resistance primarily refers to a material's ability to resist frictional mechanical forces; it is essentially a reflection of the combined effects of coating hardness, adhesion, and cohesion, directly impacting the service life of the aluminum profile. Therefore, a surface protection technology is urgently needed to improve the corrosion and wear resistance of the aluminum alloy substrate. Summary of the Invention

[0007] The technical problem this invention aims to solve is to address the shortcomings of the prior art by providing a staged preparation process for a wear-resistant hard anodized film on aluminum alloy surfaces. This process employs a staged hard anodizing technique, resulting in a tighter bond between the hard anodized film and the aluminum alloy substrate. This significantly improves the surface hardness of the aluminum alloy and reduces the roughness of the hard anodized film, thereby enhancing the wear and corrosion resistance of the aluminum alloy parts and extending their service life. This solves the application challenges of aluminum alloys in various fields due to their low hardness, poor wear resistance, and poor corrosion resistance.

[0008] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a staged preparation process of a wear-resistant and corrosion-resistant hard anodized film layer on the surface of aluminum alloy, characterized in that the process includes the following steps:

[0009] Step 1: The aluminum alloy parts are sequentially degreased, impregnated, brightened, neutralized, ultrasonically cleaned, and dried to obtain clean aluminum alloy parts;

[0010] Step 2: Place the clean aluminum alloy parts obtained in Step 1 into a mixed solution of sulfuric acid, organic acid, complexing agent and glycerol for hard anodizing. Use a staged process to adjust the oxide film formation rate and dissolution time, and use compressed air to stir to form a wear-resistant hard anodized film layer on the surface of the aluminum alloy parts.

[0011] Step 3: Neutralize the aluminum alloy parts with the wear-resistant hard anodized film layer on the surface from Step 2 with dilute ammonia water, and then perform ultrasonic cleaning.

[0012] Step 4: After ultrasonic cleaning in Step 3, the aluminum alloy parts with a wear-resistant hard anodized film layer on the surface are sealed at high temperature and then dried.

[0013] The above-mentioned staged preparation process of wear-resistant hard anodized film layer on aluminum alloy surface is characterized in that the mixed solution of sulfuric acid, organic acid, complexing agent and glycerol in step two comprises: sulfuric acid 180g / L~220g / L, organic acid 5g / L~30g / L, complexing agent 2g / L~10g / L, and glycerol 10g / L~30g / L.

[0014] The above-mentioned staged preparation process of wear-resistant hard anodized film on aluminum alloy surface is characterized in that the organic acid in step two is one or a mixture of two or more of oxalic acid, tartaric acid, malic acid, citric acid and dodecyl sulfonic acid.

[0015] The above-mentioned staged preparation process of wear-resistant hard anodized film on aluminum alloy surface is characterized in that the complexing agent in step two is one or a mixture of two or more of sodium pyrophosphate, triethanolamine and EDTA-2Na.

[0016] This invention further promotes a uniform and fine oxide film on the aluminum alloy surface by adding an appropriate amount of organic acid to the electrolyte used in hard anodizing; on the other hand, it balances the complexing and dissociation effects during hard anodizing by adding a complexing agent. The synergistic effect of these two methods reduces the surface roughness of the hard anodized film, significantly increases its surface hardness, and improves its wear and corrosion resistance.

[0017] The aforementioned staged preparation process of the wear-resistant hard anodized film layer on the aluminum alloy surface is characterized in that the staged process in step two is as follows: Stage one, the voltage is increased to 14V and held constant for 5 minutes; Stage two, the current density is controlled to be 0.5A / dm² based on the area S of the aluminum alloy part. 2 ~1A / dm 2 The current I1 is calculated, then adjusted to I1 and kept constant for 20 minutes. The voltage at this time is recorded as U1. In the third stage, the voltage is adjusted to U2 and kept constant for 10 minutes, with U2:U1 = 3:2. In the fourth stage, based on the area S of the aluminum alloy part, the current density is controlled to 2A / dm². 2 ~4A / dm 2 The current I2 is calculated, and then adjusted to I2 and kept constant for 30 minutes. This invention adjusts the growth and dissolution time of the hard anodized layer through a staged process, so that the hard anodized layer has high adhesion, low roughness and high hardness, thereby improving its wear and corrosion resistance.

[0018] The above-mentioned staged preparation process of wear-resistant hard anodized film on aluminum alloy surface is characterized in that the mass concentration of dilute ammonia water in step three is 3%, and the ultrasonic cleaning is deionized water cleaning for 10 minutes.

[0019] The above-mentioned staged preparation process of wear-resistant hard anodized film on aluminum alloy surface is characterized in that the high-temperature sealing in step four is to soak in nickel acetate solution at 90°C for 30 minutes, and then wash with deionized water; the drying treatment is to blow dry with compressed air.

[0020] In addition, the present invention also discloses a wear-resistant hard anodized film layer on the surface of aluminum alloy prepared by the process described above.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] 1. This invention employs a hard anodizing method to prepare a hard anodized film layer in situ on the surface of a treated, smooth, and clean aluminum alloy part. By adopting a staged process, the generation and dissolution time of the oxide film layer during the hard anodizing process are effectively controlled, thereby adjusting the generation rate of the oxide film layer, greatly reducing the roughness of the hard anodized film layer. Furthermore, the hard anodized film layer is tightly bonded to the aluminum alloy part substrate, significantly improving the surface hardness of the aluminum alloy part. As a result, the hard anodized film layer has high adhesion, low roughness, and high hardness characteristics, improving the wear and corrosion resistance of titanium alloys and increasing their service life.

[0023] 2. This invention uses a staged hard anodizing process to increase the surface hardness of aluminum alloy parts to over 470 HV and reduce the roughness of the hard anodized film to a minimum of 0.21, significantly improving the wear and corrosion resistance of aluminum alloys. It has good application prospects in aerospace and marine equipment, transportation and other fields.

[0024] 3. This invention uses a hard anodizing method, which places aluminum alloy parts in a mixed solution, i.e., an electrolyte, for oxidation. This achieves uniform overall treatment of large-sized and irregularly shaped aluminum alloy parts, improves the uniformity of the hard anodized film, and is simple, economical and convenient.

[0025] 4. In the hard anodizing process, the present invention introduces compressed air into the electrolyte for stirring, which can effectively reduce the concentration gradient and temperature gradient at the interface between the aluminum alloy parts and the electrolyte solution, making the current distribution more uniform and improving the uniformity of the hard anodized film.

[0026] 5. This invention generates an oxide film in situ on the surface of aluminum alloy parts as a wear-resistant film layer through hard anodizing. The reaction cycle is short and the application range is wide.

[0027] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0028] Figure 1 This is a morphological diagram of the wear-resistant hard anodized film layer prepared on the surface of an aluminum alloy part in Embodiment 1 of the present invention.

[0029] Figure 2 This is a morphological diagram of the wear-resistant hard anodized film layer prepared on the surface of an aluminum alloy part in Embodiment 2 of the present invention.

[0030] Figure 3 This is a morphological diagram of the wear-resistant hard anodized film layer prepared on the surface of an aluminum alloy part in Embodiment 3 of the present invention.

[0031] Figure 4 This is a morphological diagram of the wear-resistant hard anodized film layer prepared on the surface of an aluminum alloy part in Embodiment 4 of the present invention.

[0032] Figure 5 This is a morphological diagram of the wear-resistant hard anodized film layer prepared on the surface of an aluminum alloy part in Embodiment 5 of the present invention. Detailed Implementation

[0033] Example 1

[0034] This embodiment includes the following steps:

[0035] Step 1: The aluminum alloy parts are sequentially degreased, impregnated, brightened, neutralized, ultrasonically cleaned, and dried to obtain clean aluminum alloy parts;

[0036] Step 2: Place the clean aluminum alloy parts obtained in Step 1 into a mixed solution of sulfuric acid, oxalic acid, EDTA-2Na, and glycerol for hard anodizing. Use a staged process to adjust the oxide film formation rate and dissolution time, and use compressed air for stirring to form a wear-resistant hard anodized film layer on the surface of the aluminum alloy parts. The mixed solution of sulfuric acid, oxalic acid, EDTA-2Na, and glycerol has the following composition: sulfuric acid 180 g / L, oxalic acid 5 g / L, EDTA-2Na 2 g / L, and glycerol 30 g / L.

[0037] The staged process is as follows: Stage 1: Increase the voltage to 14V and maintain it for 5 minutes; Stage 2: Based on the area S=0.5dm of the aluminum alloy part... 2 Control current density is 1A / dm 2 The calculated current I1 = 0.5A was then adjusted and held constant for 20 minutes, at which point the voltage was recorded as U1 = 20V; Stage three: The voltage was adjusted to U2 = 30V and held constant for 10 minutes; Stage four: Based on the area S = 0.5dm of the aluminum alloy part... 2 The control current density is 4A / dm 2 The current I2 was calculated to be 2A, and then the current was adjusted to I2 and kept constant for 30 minutes.

[0038] Step 3: Neutralize the aluminum alloy parts with the wear-resistant hard anodized film layer on the surface from Step 2 with 3% dilute ammonia water, and then ultrasonically clean them with deionized water for 10 minutes.

[0039] Step 4: Immerse the aluminum alloy parts with a wear-resistant hard anodized film layer on the surface after ultrasonic cleaning in Step 3 in a nickel acetate solution at 90°C for 30 minutes to seal the holes, then clean them with deionized water and dry them with compressed air at low temperature.

[0040] Figure 1 This is a morphology image of the wear-resistant hard anodized film layer prepared on the surface of the aluminum alloy part in this embodiment. Figure 1 It can be seen that the wear-resistant hard anodized film is relatively flat and uniform, with a small number of corrosion pits and corrosion channels.

[0041] According to the test results, the thickness of the wear-resistant hard anodized film layer prepared on the surface of the aluminum alloy part in this embodiment is about 38.27 μm, the Vickers hardness is about 388.4 HV, and the roughness is about 0.31.

[0042] In this embodiment, the organic acid can also be replaced by one or a mixture of two or more of oxalic acid, tartaric acid, malic acid, citric acid and dodecyl sulfonic acid, other than oxalic acid; the complexing agent can also be replaced by one or a mixture of two or more of sodium pyrophosphate, triethanolamine and EDTA-2Na, other than EDTA-2Na.

[0043] Example 2

[0044] This embodiment includes the following steps:

[0045] Step 1: The aluminum alloy parts are sequentially degreased, impregnated, brightened, neutralized, ultrasonically cleaned, and dried to obtain clean aluminum alloy parts;

[0046] Step 2: Place the clean aluminum alloy parts obtained in Step 1 into a mixed solution of sulfuric acid, oxalic acid, malic acid, EDTA-2Na, sodium pyrophosphate, and glycerol for hard anodizing. Use a staged process to adjust the oxide film formation rate and dissolution time, and use compressed air for stirring to form a wear-resistant hard anodized film layer on the surface of the aluminum alloy parts. The mixed solution of sulfuric acid, oxalic acid, malic acid, EDTA-2Na, sodium pyrophosphate, and glycerol has the following composition: sulfuric acid 180g / L, oxalic acid 5g / L, malic acid 5g / L, EDTA-2Na 2g / L, sodium pyrophosphate 3g / L, and glycerol 15g / L.

[0047] The staged process is as follows: Stage 1: Increase the voltage to 14V and maintain it for 5 minutes; Stage 2: Based on the area S=0.5dm of the aluminum alloy part... 2 Control current density is 1A / dm 2 The calculated current I1 = 0.5A was then adjusted and held constant for 20 minutes. At this point, the voltage was recorded as U1 = 19.2V. In stage three, the voltage was adjusted to U2 = 28.8V and held constant for 10 minutes. In stage four, based on the area S = 0.5dm² of the aluminum alloy part… 2 The control current density is 4A / dm 2 The current I2 was calculated to be 2A, and then the current was adjusted to I2 and kept constant for 30 minutes.

[0048] Step 3: Neutralize the aluminum alloy parts with the wear-resistant hard anodized film layer on the surface from Step 2 with 3% dilute ammonia water, and then ultrasonically clean them with deionized water for 10 minutes.

[0049] Step 4: Immerse the aluminum alloy parts with a wear-resistant hard anodized film layer on the surface after ultrasonic cleaning in Step 3 in a nickel acetate solution at 90°C for 30 minutes to seal the holes, then clean them with deionized water and dry them with compressed air at low temperature.

[0050] Figure 2 This is a morphology image of the wear-resistant hard anodized film layer prepared on the surface of the aluminum alloy part in this embodiment. Figure 2 It can be seen that the wear-resistant hard anodized film is relatively flat and uniform, with a large number of corrosion pits.

[0051] According to the test results, the thickness of the wear-resistant hard anodized film layer prepared on the surface of the aluminum alloy part in this embodiment is about 40.3 μm, the Vickers hardness is about 390.78 HV, and the roughness is about 0.21.

[0052] Example 3

[0053] This embodiment includes the following steps:

[0054] Step 1: The aluminum alloy parts are sequentially degreased, impregnated, brightened, neutralized, ultrasonically cleaned, and dried to obtain clean aluminum alloy parts;

[0055] Step 2: Place the clean aluminum alloy parts obtained in Step 1 into a mixed solution of sulfuric acid, citric acid, tartaric acid, EDTA-2Na, and glycerol for hard anodizing. Use a staged process to adjust the oxide film formation rate and dissolution time, and use compressed air for stirring to form a wear-resistant hard anodized film layer on the surface of the aluminum alloy parts. The mixed solution of sulfuric acid, citric acid, tartaric acid, EDTA-2Na, and glycerol has the following composition: sulfuric acid 190 g / L, citric acid 3 g / L, tartaric acid 2 g / L, EDTA-2Na 2 g / L, and glycerol 20 g / L.

[0056] The staged process is as follows: Stage 1: Increase the voltage to 14V and maintain it for 5 minutes; Stage 2: Based on the area S=0.5dm of the aluminum alloy part... 2 Control current density is 1A / dm 2 The calculated current I1 = 0.5A was then adjusted and held constant for 20 minutes. At this point, the voltage was recorded as U1 = 20.3V. In stage three, the voltage was adjusted to U2 = 30.5V and held constant for 10 minutes. In stage four, based on the area S = 0.5dm² of the aluminum alloy part... 2Control current density is 3A / dm 2 The current I2 was calculated to be 1.5A, and then the current was adjusted to I2 and kept constant for 30 minutes.

[0057] Step 3: Neutralize the aluminum alloy parts with the wear-resistant hard anodized film layer on the surface from Step 2 with 3% dilute ammonia water, and then ultrasonically clean them with deionized water for 10 minutes.

[0058] Step 4: Immerse the aluminum alloy parts with a wear-resistant hard anodized film layer on the surface after ultrasonic cleaning in Step 3 in a nickel acetate solution at 85°C for 30 minutes to seal the holes, then clean them with deionized water and dry them with compressed air at low temperature.

[0059] Figure 3 This is a morphology image of the wear-resistant hard anodized film layer prepared on the surface of the aluminum alloy part in this embodiment. Figure 3 It can be seen that the wear-resistant hard anodized film is relatively flat and uniform, with many corrosion pits.

[0060] According to the test results, the thickness of the wear-resistant hard anodized film layer prepared on the surface of the aluminum alloy part in this embodiment is about 38.73 μm, the Vickers hardness is about 411.65 HV, and the roughness is about 0.52.

[0061] Example 4

[0062] This embodiment includes the following steps:

[0063] Step 1: The aluminum alloy parts are sequentially degreased, impregnated, brightened, neutralized, ultrasonically cleaned, and dried to obtain clean aluminum alloy parts;

[0064] Step 2: The clean aluminum alloy parts obtained in Step 1 are placed in a mixed solution of sulfuric acid, oxalic acid, tartaric acid, dodecyl sulfonic acid, sodium pyrophosphate, triethanolamine, and glycerol for hard anodizing. A staged process is used to adjust the oxide film formation rate and dissolution time, assisted by compressed air stirring, to form a wear-resistant hard anodized film layer on the surface of the aluminum alloy parts. The mixed solution of sulfuric acid, oxalic acid, tartaric acid, dodecyl sulfonic acid, sodium pyrophosphate, triethanolamine, and glycerol has the following composition: sulfuric acid 200 g / L, oxalic acid 5 g / L, tartaric acid 5 g / L, dodecyl sulfonic acid 5 g / L, sodium pyrophosphate 3 g / L, triethanolamine 2.5 g / L, and glycerol 20 g / L.

[0065] The staged process is as follows: Stage 1: Increase the voltage to 14V and maintain it for 5 minutes; Stage 2: Based on the area S=2dm of the aluminum alloy part... 2 The control current density is 0.5 A / dm. 2The calculated current I1 = 1A was then adjusted and held constant for 20 minutes, at which point the voltage was recorded as U1 = 17V; Stage three: The voltage was adjusted to U2 = 25.5V and held constant for 10 minutes; Stage four: Based on the area S = 2dm of the aluminum alloy part... 2 Control current density is 3A / dm 2 The current I2 was calculated to be 6A, and then the current was adjusted to I2 and kept constant for 30 minutes.

[0066] Step 3: Neutralize the aluminum alloy parts with the wear-resistant hard anodized film layer on the surface from Step 2 with 3% dilute ammonia water, and then ultrasonically clean them with deionized water for 10 minutes.

[0067] Step 4: Immerse the aluminum alloy parts with a wear-resistant hard anodized film layer on the surface after ultrasonic cleaning in Step 3 in a nickel acetate solution at 85°C for 30 minutes to seal the holes, then clean them with deionized water and dry them with compressed air at low temperature.

[0068] Figure 4 This is a morphology image of the wear-resistant hard anodized film layer prepared on the surface of the aluminum alloy part in this embodiment. Figure 4 It can be seen that the wear-resistant hard anodized film is relatively flat and uniform, with a large number of corrosion pits.

[0069] According to the test results, the thickness of the wear-resistant hard anodized film layer prepared on the surface of the aluminum alloy part in this embodiment is about 38.58 μm, the Vickers hardness is about 470.5 HV, and the roughness is about 0.39.

[0070] Example 5

[0071] This embodiment includes the following steps:

[0072] Step 1: The aluminum alloy parts are sequentially degreased, impregnated, brightened, neutralized, ultrasonically cleaned, and dried to obtain clean aluminum alloy parts;

[0073] Step 2: The clean aluminum alloy parts obtained in Step 1 are placed in a mixed solution of sulfuric acid, oxalic acid, malic acid, dodecyl sulfonic acid, sodium pyrophosphate, triethanolamine, EDTA-2Na, and glycerol for hard anodizing. A staged process is used to adjust the oxide film formation rate and dissolution time, assisted by compressed air stirring, to form a wear-resistant hard anodized film layer on the surface of the aluminum alloy parts. The mixed solution of sulfuric acid, oxalic acid, malic acid, dodecyl sulfonic acid, sodium pyrophosphate, triethanolamine, EDTA-2Na, and glycerol has the following composition: sulfuric acid 220 g / L, oxalic acid 15 g / L, malic acid 5 g / L, dodecyl sulfonic acid 10 g / L, sodium pyrophosphate 3 g / L, triethanolamine 3 g / L, EDTA-2Na 4 g / L, and glycerol 10 g / L.

[0074] The staged process is as follows: Stage 1: Increase the voltage to 14V and maintain it for 5 minutes; Stage 2: Based on the area S=2dm of the aluminum alloy part... 2 The control current density is 0.5 A / dm. 2 The calculated current I1 = 1A was then adjusted and held constant for 20 minutes. At this point, the voltage was recorded as U1 = 25.5V. In stage three, the voltage was adjusted to U2 = 36.8V and held constant for 10 minutes. In stage four, based on the area S = 2dm² of the aluminum alloy part… 2 Control current density is 2A / dm 2 The current I2 was calculated to be 4A, and then the current was adjusted to I2 and kept constant for 30 minutes.

[0075] Step 3: Neutralize the aluminum alloy parts with the wear-resistant hard anodized film layer on the surface from Step 2 with 3% dilute ammonia water, and then ultrasonically clean them with deionized water for 10 minutes.

[0076] Step 4: Immerse the aluminum alloy parts with a wear-resistant hard anodized film layer on the surface after ultrasonic cleaning in Step 3 in a nickel acetate solution at 85°C for 30 minutes to seal the holes, then clean them with deionized water and dry them with compressed air at low temperature.

[0077] Figure 5 This is a morphology image of the wear-resistant hard anodized film layer prepared on the surface of the aluminum alloy part in this embodiment. Figure 5 It can be seen that the wear-resistant hard anodized film is relatively flat and uniform, but contains a large number of corrosion pits and cracks.

[0078] According to the test results, the thickness of the wear-resistant hard anodized film layer prepared on the surface of the aluminum alloy part in this embodiment is about 38.07 μm, the Vickers hardness is about 405.8 HV, and the roughness is about 0.26.

[0079] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any way. Any simple modifications, alterations, and equivalent changes made to the above embodiments based on the inventive essence shall still fall within the protection scope of the present invention.

Claims

1. A staged preparation process for a wear-resistant and corrosion-resistant hard anodized film on aluminum alloy surfaces, characterized in that, The process includes the following steps: Step 1: The aluminum alloy parts are sequentially degreased, impregnated, brightened, neutralized, ultrasonically cleaned, and dried to obtain clean aluminum alloy parts; Step Two: The clean aluminum alloy parts obtained in Step One are placed in a mixed solution of sulfuric acid, organic acid, complexing agent, and glycerol for hard anodizing. A staged process is used to adjust the oxide film formation rate and dissolution time, assisted by compressed air stirring, to form a wear-resistant hard anodized film layer on the surface of the aluminum alloy parts. The staged process is as follows: Stage One: The voltage is increased to 14V and held constant for 5 minutes; Stage Two: Based on the area S of the aluminum alloy parts, the current density is controlled at 0.5A / dm². 2 ~1A / dm 2 The current I1 is calculated, then adjusted to I1 and kept constant for 20 minutes. The voltage at this time is recorded as U1. In the third stage, the voltage is adjusted to U2 and kept constant for 10 minutes, with U2:U1 = 3:

2. In the fourth stage, based on the area S of the aluminum alloy part, the current density is controlled to 2A / dm². 2 ~4A / dm 2 The current I2 is calculated, and then the current is adjusted to I2 and kept constant for 30 minutes. Step 3: Neutralize the aluminum alloy parts with the wear-resistant hard anodized film layer on the surface from Step 2 with dilute ammonia water, and then perform ultrasonic cleaning. Step 4: After ultrasonic cleaning in Step 3, the aluminum alloy parts with a wear-resistant hard anodized film layer on the surface are sealed at high temperature and then dried.

2. The staged preparation process of the wear-resistant hard anodized film layer on the aluminum alloy surface according to claim 1, characterized in that, The mixed solution of sulfuric acid, organic acid, complexing agent and glycerol mentioned in step two consists of: sulfuric acid 180g / L~220g / L, organic acid 5g / L~30g / L, complexing agent 2g / L~10g / L, and glycerol 10g / L~30g / L.

3. The staged preparation process of the wear-resistant hard anodized film layer on the aluminum alloy surface according to claim 1, characterized in that, The organic acid mentioned in step two is one or a mixture of two or more of oxalic acid, tartaric acid, malic acid, citric acid and dodecyl sulfonic acid.

4. The staged preparation process of the wear-resistant hard anodized film layer on the aluminum alloy surface according to claim 1, characterized in that, The complexing agent mentioned in step two is one or a mixture of two or more of sodium pyrophosphate, triethanolamine, and EDTA-2Na.

5. The staged preparation process of the wear-resistant hard anodized film layer on the aluminum alloy surface according to claim 1, characterized in that, The mass concentration of the dilute ammonia water mentioned in step three is 3%, and the ultrasonic cleaning is performed with deionized water for 10 minutes.

6. The staged preparation process of the wear-resistant hard anodized film layer on the aluminum alloy surface according to claim 1, characterized in that, The high-temperature sealing in step four involves immersing the sample in a nickel acetate solution at 90°C for 30 minutes, followed by rinsing with deionized water; the drying process involves blowing the sample with compressed air.

7. A wear-resistant hard anodized film layer on the surface of an aluminum alloy prepared by the process described in any one of claims 1 to 6.

Images