Corrosion-resistant aluminum alloy profile and method for producing the same

Abstract

The application discloses a kind of corrosion-resistant aluminum alloy profiles and preparation method thereof, belong to aluminum alloy preparation field, the first coating is formed on the surface of aluminum alloy profile in the application, and the optimized lanthanum oxide, magnesium powder, yttrium oxide and silicon dioxide are used in combination, can form dense coating on the surface of aluminum alloy profile, and component synergistic effect and play significant corrosion resistance effect.The component of the first coating is pretreated, which can reduce the probability of pitting corrosion, and also helps to improve the compatibility and adhesion of the second coating.In addition, the second coating is provided, and after optimization of the components, the components of the second coating can also adhere to the first coating, with excellent adhesion, without pinholes, bubbles, unevenness and other problems, while obtaining excellent surface appearance of aluminum alloy profile, it can further improve the surface density, further improve the corrosion resistance of aluminum alloy profile, not easily damaged by the environment, improve its service life.

Description

Technical Field

[0001] This invention relates to a method for preparing aluminum alloys, and more specifically, to a corrosion-resistant aluminum alloy profile and its preparation method. Background Technology

[0002] Aluminum alloys are widely used in industrial fields such as automobiles and construction due to their advantages of low density, good ductility, and low cost. However, aluminum and its alloys are chemically reactive, and the effects of humid air and industrial exhaust gases can cause intergranular corrosion, exfoliation corrosion, and stress corrosion. Since intergranular corrosion occurs within the metal, it is often difficult to detect and can lead to sudden structural failure. Exfoliation corrosion causes a significant decrease in material strength, plasticity, and fatigue performance. Stress corrosion, once it occurs, can degrade the load-bearing capacity of aluminum alloy structures, significantly reducing their service life and limiting their application range. Furthermore, aluminum alloys inevitably suffer damage in their service environment, such as impacts from foreign objects or fragments, scratches, or erosion. Corrosion is a common but difficult-to-detect form of damage, and scratches or cracks can interact with the corrosive environment, further accelerating corrosion. Therefore, improving the corrosion resistance of aluminum alloys is of great significance.

[0003] To improve the corrosion resistance of aluminum alloys, existing technologies also involve spraying corrosion-resistant coatings onto the surface of aluminum alloy profiles. These coatings enhance the protection and isolation of the aluminum alloy profile surface, thereby reducing the corrosive effects of the environment. However, existing coatings for aluminum alloy profiles suffer from poor stability and incompatibility with the aluminum alloy profiles, making them prone to corrosion. Summary of the Invention

[0004] Therefore, in order to solve the problems of poor stability, poor compatibility with aluminum alloy profiles, and easy corrosion of existing coatings used in aluminum alloy profiles, this invention provides a corrosion-resistant aluminum alloy profile and its preparation method, the specific technical solution of which is as follows:

[0005] A corrosion-resistant aluminum alloy profile, comprising an aluminum alloy substrate, wherein the surface of the aluminum alloy substrate is provided with a first coating and a second coating, wherein the first coating comprises the following raw materials in parts by weight: 20-25 parts of lanthanum oxide, 12-15 parts of magnesium powder, 10-17 parts of yttrium oxide and 1-5 parts of silicon dioxide.

[0006] The second coating comprises the following raw materials in parts by weight: 30 to 35 parts epoxy resin, 15 to 18 parts ultraviolet absorber, 3 to 7 parts titanium dioxide, 5 to 7 parts boron nitride, 1 to 3 parts cobalt aluminate, 1 to 5 parts polyamide, 1 to 2 parts dispersant, and 1 to 2 parts leveling agent.

[0007] Furthermore, the ultraviolet absorber is at least one of resorcinol monobenzoate and 2-hydroxy-4-n-octyloxybenzophenone.

[0008] Furthermore, the dispersant is at least one of ethylene glycol and sodium hexametaphosphate.

[0009] Furthermore, the leveling agent is one of butyl cellulose or acrylic leveling agents.

[0010] In addition, the present invention also provides a method for preparing a corrosion-resistant aluminum alloy profile, the method comprising the following steps:

[0011] Lanthanum oxide, magnesium powder, yttrium oxide, and silicon dioxide were placed in a ball mill and ball-milled to obtain mixed powder A.

[0012] The mixed powder A is pretreated, dried, and ground to obtain mixed powder B;

[0013] The aluminum alloy substrate is surface treated, and then the mixed powder B is transformed into molten particles at the plasma jet working temperature. After flying 60mm to 100mm with the high-temperature flame stream, it is sprayed onto the surface of the aluminum alloy substrate preheated to 500℃ to 550℃ to form a first coating with a thickness of 100μm to 300μm.

[0014] Epoxy resin, UV absorber, titanium dioxide, boron nitride, cobalt aluminate, polyamide, dispersant, and leveling agent are added to a mixer and mixed. The mixture is then fed into a twin-screw extruder for melt extrusion. The extruded material is then sheeted, cooled to room temperature, crushed, ball-milled, and passed through a 100-200 mesh sieve. A second coating with a thickness of 0.2 mm to 0.8 mm is then formed on the surface of the first coating using an electrostatic spraying process. After cooling to room temperature, a corrosion-resistant aluminum alloy profile is obtained.

[0015] Furthermore, the ball milling process is carried out at a rotation speed of 250 r / min to 500 r / min, and the ball milling time is 1 h to 3 h.

[0016] Furthermore, the average particle size of the mixed powder B is 10 μm to 30 μm.

[0017] Furthermore, the mixed powder B is subjected to ultrasonic vibration treatment before melt coating, and the power of the ultrasonic vibration treatment is 100W to 150W, the vibration-to-break ratio is 1, the vibration is applied for 1 second, the interval is 1 second, and the total vibration time is 60s to 120s.

[0018] Furthermore, the surface treatment includes decontamination, degreasing, and sandblasting roughening.

[0019] Furthermore, mix the material at a speed of 500 r / min to 1000 r / min for 20 min to 30 min.

[0020] Compared with existing technologies, its beneficial effects include:

[0021] 1. This invention forms a first coating on the surface of an aluminum alloy profile by using an optimized combination of lanthanum oxide, magnesium powder, yttrium oxide, and silicon dioxide. This combination forms a dense coating on the surface of the aluminum alloy profile, and the components work synergistically to achieve a significant corrosion resistance effect.

[0022] 2. The components of the first coating of the present invention are pretreated, which helps to improve the compatibility with the aluminum alloy profile interface, thereby making it less likely to peel off, reducing the probability of pitting corrosion, and also promoting corrosion resistance. It also helps to improve the compatibility and adhesion with the second coating. In addition, the ultrasonic vibration before melt coating helps to improve the uniformity of the components, reduce coarse grains, and obtain a coating with better performance.

[0023] 3. The present invention provides a second coating. After the composition is optimized, the composition of the second coating can also adhere to the first coating, and the adhesion is excellent. No problems such as pinholes, bubbles, or unevenness occur. While obtaining an excellent surface appearance of aluminum alloy profiles, it can also further improve the surface density and further synergistically improve the corrosion resistance of aluminum alloy profiles, making them less susceptible to environmental damage and extending their service life. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to its embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the scope of protection of the invention.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0026] According to one embodiment of the present invention, a corrosion-resistant aluminum alloy profile includes an aluminum alloy substrate. The surface of the aluminum alloy substrate is provided with a first coating and a second coating. The first coating includes the following raw materials in parts by weight: 20 to 25 parts of lanthanum oxide, 12 to 15 parts of magnesium powder, 10 to 17 parts of yttrium oxide, and 1 to 5 parts of silicon dioxide.

[0027] The second coating comprises the following raw materials in parts by weight: 30 to 35 parts epoxy resin, 15 to 18 parts ultraviolet absorber, 3 to 7 parts titanium dioxide, 5 to 7 parts boron nitride, 1 to 3 parts cobalt aluminate, 1 to 5 parts polyamide, 1 to 2 parts dispersant, and 1 to 2 parts leveling agent.

[0028] In one embodiment, the ultraviolet absorber is at least one of resorcinol monobenzoate and 2-hydroxy-4-n-octyloxybenzophenone.

[0029] In one embodiment, the dispersant is at least one of ethylene glycol and sodium hexametaphosphate.

[0030] In one embodiment, the leveling agent is one of butyl cellulose or acrylic leveling agents.

[0031] In addition, the present invention also provides a method for preparing a corrosion-resistant aluminum alloy profile, the method comprising the following steps:

[0032] Lanthanum oxide, magnesium powder, yttrium oxide, and silicon dioxide were placed in a ball mill and ball-milled to obtain mixed powder A.

[0033] The mixed powder A is pretreated, dried, and ground to obtain mixed powder B;

[0034] The aluminum alloy substrate is surface treated, and then the mixed powder B is transformed into molten particles at the plasma jet working temperature. After flying 60mm to 100mm with the high-temperature flame stream, it is sprayed onto the surface of the aluminum alloy substrate preheated to 500℃ to 550℃ to form a first coating with a thickness of 100μm to 300μm.

[0035] Epoxy resin, UV absorber, titanium dioxide, boron nitride, cobalt aluminate, polyamide, dispersant, and leveling agent are added to a mixer and mixed. The mixture is then fed into a twin-screw extruder for melt extrusion. The extruded material is then sheeted, cooled to room temperature, crushed, ball-milled, and passed through a 100-200 mesh sieve. A second coating with a thickness of 0.2 mm to 0.8 mm is then formed on the surface of the first coating using an electrostatic spraying process. After cooling to room temperature, a corrosion-resistant aluminum alloy profile is obtained.

[0036] In one embodiment, the ball milling speed is 250 r / min to 500 r / min, and the ball milling time is 1 h to 3 h.

[0037] In one embodiment, the pretreatment is as follows: adding mixed powder A to the silane coupling agent and stirring at a temperature of 45°C to 65°C and a rotation speed of 100 r / min to 200 r / min for 1 h to 2 h.

[0038] In one embodiment, the ratio of the mixed powder A to the silane coupling agent is (1-5) g / 10 mL.

[0039] In one embodiment, the average particle size of the mixed powder B is 10 μm to 30 μm.

[0040] In one embodiment, the mixed powder B is subjected to ultrasonic vibration treatment before melt coating, and the ultrasonic vibration treatment power is 100W to 150W, the vibration-to-break ratio is 1, the vibration is applied for 1 second, the interval is 1 second, and the total vibration time is 60s to 120s.

[0041] In one embodiment, the surface treatment includes decontamination, degreasing, and sandblasting roughening.

[0042] In one embodiment, the material is mixed at a speed of 500 r / min to 1000 r / min for 20 min to 30 min.

[0043] The above solution, through optimization of the first and second coatings and combined with process improvements, can achieve aluminum alloy profiles with significantly improved corrosion resistance.

[0044] The implementation schemes of the present invention will now be described in detail with reference to specific embodiments.

[0045] Example 1:

[0046] A method for preparing a corrosion-resistant aluminum alloy profile includes the following steps:

[0047] By weight, 22 parts of lanthanum oxide, 13 parts of magnesium powder, 15 parts of yttrium oxide and 3 parts of silicon dioxide were placed in a ball mill and ball-milled at 300 r / min for 2 h to obtain mixed powder A;

[0048] Add mixed powder A to the silane coupling agent at a material-to-liquid ratio of 5g / 10mL, stir at 100r / min for 2h at 60℃, dry, and grind to obtain mixed powder B with an average particle size of 30μm.

[0049] The aluminum alloy substrate is surface treated, including decontamination, degreasing, and sandblasting roughening. Then, at the working temperature of plasma jet, the mixed powder B is transformed into molten particles, which are then subjected to ultrasonic vibration treatment. The ultrasonic vibration treatment power is 100W to 150W, the vibration ratio is 1, the vibration is applied for 1 second, the interval is 1 second, and the total vibration time is 60s to 120s. After flying 80mm with the high-temperature flame stream, the particles are sprayed onto the surface of the aluminum alloy substrate preheated to 500℃ to form a first coating with a thickness of 150μm.

[0050] By weight, 35 parts epoxy resin, 16 parts resorcinol monobenzoate, 5 parts titanium dioxide, 5 parts boron nitride, 2 parts cobalt aluminate, 3 parts polyamide, 2 parts ethylene glycol, and 1 part acrylic leveling agent are added to a mixer and mixed at 500 r / min for 20 min. The mixture is then fed into a twin-screw extruder for melt extrusion. The extruded material is then sheeted, cooled to room temperature, crushed, ball-milled, and passed through a 150-mesh sieve. A second coating with a thickness of 0.5 mm is then formed on the surface of the first coating using an electrostatic spraying process. After cooling to room temperature, a corrosion-resistant aluminum alloy profile is obtained.

[0051] Example 2:

[0052] A method for preparing a corrosion-resistant aluminum alloy profile includes the following steps:

[0053] By weight, 23 parts of lanthanum oxide, 12 parts of magnesium powder, 17 parts of yttrium oxide and 2 parts of silicon dioxide were placed in a ball mill and ball-milled at 350 r / min for 3 h to obtain mixed powder A;

[0054] Add mixed powder A to the silane coupling agent at a material-to-liquid ratio of 5g / 10mL, stir at 150r / min for 2h at 65℃, dry, and grind to obtain mixed powder B with an average particle size of 30μm.

[0055] The aluminum alloy substrate is surface treated, including decontamination, degreasing, and sandblasting roughening. Then, at the working temperature of plasma jet, the mixed powder B is transformed into molten particles, which are then subjected to ultrasonic vibration treatment. The ultrasonic vibration treatment power is 100W to 150W, the vibration ratio is 1, the vibration is applied for 1 second, the interval is 1 second, and the total vibration time is 60s to 120s. After flying 100mm with the high-temperature flame stream, the particles are sprayed onto the surface of the aluminum alloy substrate preheated to 520℃ to form a first coating with a thickness of 150μm.

[0056] By weight, 32 parts epoxy resin, 17 parts resorcinol monobenzoate, 7 parts titanium dioxide, 6 parts boron nitride, 3 parts cobalt aluminate, 4 parts polyamide, 2 parts sodium hexametaphosphate, and 1 part acrylic leveling agent are added to a mixer and mixed at 500 r / min for 25 min. The mixture is then fed into a twin-screw extruder for melt extrusion. The extruded material is then sheeted, cooled to room temperature, crushed, ball-milled, and passed through a 150-mesh sieve. A second coating with a thickness of 0.5 mm is then formed on the surface of the first coating using an electrostatic spraying process. After cooling to room temperature, a corrosion-resistant aluminum alloy profile is obtained.

[0057] Example 3:

[0058] A method for preparing a corrosion-resistant aluminum alloy profile includes the following steps:

[0059] By weight, 25 parts of lanthanum oxide, 13 parts of magnesium powder, 16 parts of yttrium oxide and 5 parts of silicon dioxide were placed in a ball mill and ball-milled at 300 r / min for 3 h to obtain mixed powder A;

[0060] Add mixed powder A to the silane coupling agent at a material-to-liquid ratio of 5g / 10mL, stir at 200r / min for 2h at 65℃, dry, and grind to obtain mixed powder B with an average particle size of 30μm.

[0061] The aluminum alloy substrate is surface treated, including decontamination, degreasing, and sandblasting roughening. Then, at the working temperature of plasma jet, the mixed powder B is transformed into molten particles, which are then subjected to ultrasonic vibration treatment. The ultrasonic vibration treatment power is 100W to 150W, the vibration ratio is 1, the vibration is applied for 1 second, the interval is 1 second, and the total vibration time is 60s to 120s. After flying 100mm with the high-temperature flame stream, the particles are sprayed onto the surface of the aluminum alloy substrate preheated to 510℃ to form a first coating with a thickness of 150μm.

[0062] By weight, 35 parts epoxy resin, 18 parts resorcinol monobenzoate, 6 parts titanium dioxide, 7 parts boron nitride, 3 parts cobalt aluminate, 3 parts polyamide, 1 part sodium hexametaphosphate, and 2 parts acrylic leveling agent are added to a mixer and mixed at 500 r / min for 30 min. Then, the mixture is fed into a twin-screw extruder for melt extrusion. The extruded material is then sheeted, cooled to room temperature, crushed, ball-milled, and passed through a 150-mesh sieve. A second coating with a thickness of 0.5 mm is then formed on the surface of the first coating through an electrostatic spraying process. After cooling to room temperature, a corrosion-resistant aluminum alloy profile is obtained.

[0063] Comparative Example 1:

[0064] The difference between Comparative Example 1 and Example 3 is that lanthanum oxide was not added to the raw materials for preparing the first coating in Comparative Example 1, while the rest is the same as in Example 3.

[0065] Comparative Example 2:

[0066] The difference between Comparative Example 2 and Example 3 is that magnesium powder was not added to the raw materials for preparing the first coating in Comparative Example 2, while the rest is the same as in Example 3.

[0067] Comparative Example 3:

[0068] The difference between Comparative Example 3 and Example 3 is that yttrium oxide was not added to the raw materials for preparing the first coating in Comparative Example 3, but the rest is the same as in Example 3.

[0069] Comparative Example 4:

[0070] The difference between Comparative Example 4 and Example 3 is that silicon dioxide was not added to the raw materials for preparing the first coating in Comparative Example 4, but the rest is the same as in Example 3.

[0071] Comparative Example 5:

[0072] The difference between Comparative Example 5 and Example 3 is that Comparative Example 5 did not undergo pretreatment, but otherwise it was the same as Example 3.

[0073] Comparative Example 6:

[0074] The difference between Comparative Example 6 and Example 3 is that Comparative Example 6 was not subjected to ultrasonic vibration treatment, but otherwise it was the same as Example 3.

[0075] Comparative Example 7:

[0076] The difference between Comparative Example 7 and Example 3 is that Comparative Example 7 does not have a first coating, but otherwise it is the same as Example 3.

[0077] Comparative Example 8:

[0078] The difference between Comparative Example 8 and Example 3 is that boron nitride and cobalt aluminate were not added to the raw materials for preparing the second coating in Comparative Example 8, but otherwise the same as in Example 3.

[0079] Comparative Example 9:

[0080] The difference between Comparative Example 9 and Example 3 is that Comparative Example 9 did not contain resorcinol monobenzoate, but otherwise it was the same as Example 3.

[0081] Comparative Example 10:

[0082] The difference between Comparative Example 10 and Example 3 is that Comparative Example 10 does not have a second coating, but otherwise it is the same as Example 3.

[0083] The performance of the aluminum alloy profile samples prepared in Examples 1 to 3 was tested, with the aluminum alloy substrate as a blank control (i.e., aluminum alloy substrate without the first coating and the second coating). The results are shown in Table 1 below.

[0084] The test method for acid corrosion resistance is as follows: 2 mL of 40 wt% sulfuric acid is dropped onto the surface of the sample and kept at 25°C for 24 hours. The apparent blistering corrosion phenomenon of the aluminum alloy profile is then observed.

[0085] The test method for resistance to alkaline corrosion is as follows: drop 0.1 standard concentration sodium hydroxide onto the surface of the sample, keep it at 25℃ for 24 hours, and observe the blistering corrosion phenomenon on the film surface.

[0086] Table 1: Performance Test Apparent Results

[0087]

[0088] As shown in Table 1, the aluminum alloy profile samples of this application showed no significant changes on the surface during acid and alkali immersion tests after being kept at 25°C for 24 hours. No corrosion, peeling, or penetration issues were observed. However, the aluminum alloy substrates that had not undergone the first and second coating treatments were severely corroded. This indicates that the aluminum alloy profiles treated with the first and second coatings of this application have significant corrosion resistance and can meet the daily corrosion resistance requirements.

[0089] To further verify the effects of the first and second coatings of this application on the performance of aluminum alloy profiles, the following experiments were conducted. The results are shown in Table 2.

[0090] The coating adhesion test method refers to GB / T5210-2006 "Paints and Varnishes - Pull-off Adhesion Test"; the acid resistance test method refers to GB / T9274-1988 "Paints and Varnishes - Determination of Resistance to Liquid Media", using a 5% sulfuric acid solution at room temperature. The alkali resistance test method refers to GB / T9274-1988 "Paints and Varnishes - Determination of Resistance to Liquid Media", using a 4% sodium hydroxide solution at room temperature. Salt spray corrosion resistance is tested using a salt spray test chamber, and the test method refers to CNSH20404158 "Salt Spray Test Standard".

[0091] Table 2: Corrosion Resistance Results

[0092]

[0093] Analysis of the data in Table 2 shows that, through optimization of composition and process, this application can obtain aluminum alloy profiles with significantly improved corrosion resistance, and the surface of the aluminum alloy profiles does not exhibit problems such as pinholes, bubbles, or unevenness. The difference between Comparative Examples 1-4 and Example 3 lies in the different raw materials used to prepare the first coating in Comparative Examples 1-4. However, it is clearly evident that the acid resistance, alkali resistance, and salt spray resistance of Comparative Examples 1-4 are all inferior to those of Example 3. The difference between Comparative Examples 5-6 and Example 3 lies in the different processing techniques used to prepare the first coating. It can be seen that process optimization promotes the adhesion and corrosion resistance of the coating. Comparative Example 7 did not have a first coating, and the adhesion of the second coating and the corrosion resistance of the aluminum alloy profile decreased significantly, indicating that the first coating helps improve the adhesion of the second coating. The difference between Comparative Examples 8-9 and Example 3 lies in the different composition of the second coating, but this also affects the corrosion resistance. Comparative Example 10 did not have a second coating, but the corrosion resistance was poor, indicating that this application can achieve a more significant corrosion resistance effect through the synergistic effect of the first and second coatings.

[0094] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0095] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A corrosion-resistant aluminum alloy profile, wherein the corrosion-resistant aluminum alloy profile comprises an aluminum alloy substrate, characterized in that, The surface of the aluminum alloy substrate is provided with a first coating and a second coating, wherein the first coating comprises the following raw materials in parts by weight: 20 to 25 parts of lanthanum oxide, 12 to 15 parts of magnesium powder, 10 to 17 parts of yttrium oxide, and 1 to 5 parts of silicon dioxide; The second coating comprises the following raw materials in parts by weight: 30 to 35 parts epoxy resin, 15 to 18 parts ultraviolet absorber, 3 to 7 parts titanium dioxide, 5 to 7 parts boron nitride, 1 to 3 parts cobalt aluminate, 1 to 5 parts polyamide, 1 to 2 parts dispersant, and 1 to 2 parts leveling agent.

2. The corrosion-resistant aluminum alloy profile according to claim 1, characterized in that, The ultraviolet absorber is at least one of resorcinol monobenzoate and 2-hydroxy-4-n-octyloxybenzophenone.

3. The corrosion-resistant aluminum alloy profile according to claim 1, characterized in that, The dispersant is at least one of ethylene glycol and sodium hexametaphosphate.

4. The corrosion-resistant aluminum alloy profile according to claim 1, characterized in that, The leveling agent is one of butyl cellulose or acrylic leveling agents.

5. A method for preparing a corrosion-resistant aluminum alloy profile, characterized in that, The preparation method is used to prepare the corrosion-resistant aluminum alloy profile as described in any one of claims 1 to 4, and the preparation method includes the following steps: Lanthanum oxide, magnesium powder, yttrium oxide, and silicon dioxide were placed in a ball mill and ball-milled to obtain mixed powder A. The mixed powder A is pretreated by adding the mixed powder A to a silane coupling agent, stirring at a temperature of 45°C to 65°C and a speed of 100 r / min to 200 r / min for 1 h to 2 h, then drying and grinding to obtain mixed powder B. The aluminum alloy substrate is surface treated, and then the mixed powder B is transformed into molten particles at the plasma jet working temperature. After flying 60mm~100mm with the high-temperature flame stream, it is sprayed onto the surface of the aluminum alloy substrate preheated to 500℃~550℃ to form a first coating with a thickness of 100μm~300μm. Epoxy resin, UV absorber, titanium dioxide, boron nitride, cobalt aluminate, polyamide, dispersant, and leveling agent are added to a mixer and mixed. The mixture is then fed into a twin-screw extruder for melt extrusion. The extruded material is then sheeted, cooled to room temperature, crushed, ball-milled, and passed through a 100-200 mesh sieve. A second coating with a thickness of 0.2 mm to 0.8 mm is then formed on the surface of the first coating using an electrostatic spraying process. After cooling to room temperature, a corrosion-resistant aluminum alloy profile is obtained.

6. The preparation method according to claim 5, characterized in that, The ball milling process is carried out at a rotation speed of 250 r / min to 500 r / min, and the ball milling time is 1 h to 3 h.

7. The preparation method according to claim 5, characterized in that, The average particle size of the mixed powder B is 10 μm to 30 μm.

8. The preparation method according to claim 5, characterized in that, The surface treatment includes decontamination, degreasing, and sandblasting roughening.

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