Corrosion-resistant aluminum alloy profile and preparation method thereof

Abstract

The invention discloses a corrosion-resistant aluminum alloy profile and a preparation method thereof, and belongs to the field of aluminum alloy preparation.A first coating is formed on the surface of the aluminum alloy profile, and optimized lanthanum oxide, magnesium powder, yttrium oxide and silicon dioxide are compounded for use, so that a compact coating can be formed on the surface of the aluminum alloy profile; and the components have a synergistic effect and exert a remarkable corrosion-resistant effect. The components of the first coating are pretreated, so that the probability of pitting corrosion can be reduced, and the compatibility and adhesiveness of the first coating and the second coating can be improved. Besides, the second coating is arranged, after component optimization, components of the second coating can also be attached to the first coating, the adhesive force is excellent, pinholes, bubbles, unevenness and the like are avoided, the surface compactness can be further improved while the excellent surface appearance of the aluminum alloy profile is obtained, the corrosion resistance of the aluminum alloy profile is further improved cooperatively, and the service life of the aluminum alloy profile is prolonged. Environmental damage is not easily caused, and the service life is prolonged.

Description

Technical Field

[0001] The invention relates to a method for preparing an aluminum alloy, and in particular to a corrosion-resistant aluminum alloy profile and a method for preparing the same. Background Art

[0002] Aluminum alloys are widely used in industrial fields such as automobiles and buildings due to their low density, good ductility, and low cost. Aluminum and aluminum alloys have active chemical properties. Due to the effects of humid air and industrial waste gas, aluminum alloys will suffer from intergranular corrosion, exfoliation, and stress corrosion. Since intergranular corrosion occurs inside the metal, it is often difficult to detect and causes sudden damage to structural parts. Exfoliation leads to a significant decrease in the strength, plasticity, and fatigue properties of the material. Once stress corrosion occurs, it will cause the bearing capacity of the aluminum alloy structure to degrade, and thus significantly reduce its service life, resulting in limited application range. In addition, aluminum alloys will inevitably be damaged in the service environment, such as impact by foreign objects or debris, as well as scratches or erosion. In fact, corrosion is one of the common but difficult to detect forms of damage, and damage such as scratches or cracks will interact with the corrosive environment, further accelerating the development of corrosion. Therefore, it is of great significance to improve the corrosion resistance of aluminum alloys.

[0003] In order to improve the corrosion resistance of aluminum alloys, the prior art also has a method of spraying a corrosion-resistant coating on the surface of aluminum alloy profiles to strengthen the protection and isolation effect of the surface of the aluminum alloy profiles through the corrosion-resistant coating, thereby reducing the corrosion effect of the environment on the aluminum alloy profiles. However, the coatings for aluminum alloy profiles in the prior art have poor stability and poor compatibility with aluminum alloy profiles, and are prone to corrosion problems. Summary of the invention

[0004] Based on this, in order to solve the problems of poor stability, poor compatibility with aluminum alloy profiles, and easy corrosion of the coating for aluminum alloy profiles in the prior art, the present invention provides a corrosion-resistant aluminum alloy profile and a preparation method thereof. The specific technical scheme is as follows:

[0005] A corrosion-resistant aluminum alloy profile, comprising an aluminum alloy substrate, a first coating and a second coating being arranged on the surface of the aluminum alloy substrate, 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;

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

[0007] Furthermore, the ultraviolet absorber is at least one of monobenzoic acid resorcinol ester 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 and acrylic leveling agent.

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

[0011] Place lanthanum oxide, magnesium powder, yttrium oxide and silicon dioxide in a ball mill for ball milling to obtain mixed powder A;

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

[0013] The aluminum alloy substrate is subjected to surface treatment, and then the mixed powder B is converted into molten particles at the working temperature of the plasma jet, and then sprayed onto the surface of the aluminum alloy substrate preheated to 500° C. to 550° C. after flying 60 mm to 100 mm with the high-temperature flame flow, to form a first coating with a thickness of 100 μm to 300 μm;

[0014] Epoxy resin, ultraviolet absorber, titanium dioxide, boron nitride, cobalt aluminate, polyamide, dispersant and leveling agent are added to a mixer and mixed, and then sent to a twin-screw extruder for melt extrusion. The extruded material is tableted, cooled to room temperature, crushed, ball-milled and sieved through a 100-200 mesh sieve, and then a second coating with a thickness of 0.2 mm to 0.8 mm is 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.

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

[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-150W, the vibration-off ratio is 1, the vibration is 1s, the interval is 1s, and the total vibration time is 60s-120s.

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

[0019] Furthermore, the mixing is performed at a rotation speed of 500 r / min to 1000 r / min for 20 min to 30 min.

[0020] Compared with the prior art, the beneficial effects include:

[0021] 1. The present invention forms a first coating on the surface of the aluminum alloy profile, and the optimized lanthanum oxide, magnesium powder, yttrium oxide and silicon dioxide are compounded and used to form a dense coating on the surface of the aluminum alloy profile, and the components act synergistically and exert a significant corrosion resistance effect.

[0022] 2. The components of the first coating of the present invention are pretreated, which can help improve the compatibility with the interface of the aluminum alloy profile, thereby making it less likely to fall off, reducing the probability of pitting, and promoting corrosion resistance. It also helps to improve the compatibility and adhesion with the second coating. In addition, 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 sets a second coating. After the composition is optimized, the composition of the second coating can also adhere to the first coating with excellent adhesion, without pinholes, bubbles, unevenness and other problems. While obtaining an excellent surface appearance of the aluminum alloy profile, it can also further improve the surface density, further synergistically improve the corrosion resistance of the aluminum alloy profile, make it less susceptible to environmental damage, and increase its service life. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with its embodiments. It should be understood that the specific implementation methods described herein are only used to explain the present invention and do not limit the scope of protection of the present invention.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0026] A corrosion-resistant aluminum alloy profile in one embodiment of the present invention comprises an aluminum alloy substrate, a first coating and a second coating are provided on the surface of the aluminum alloy substrate, 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;

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

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

[0032] Place lanthanum oxide, magnesium powder, yttrium oxide and silicon dioxide in a ball mill for ball milling to obtain mixed powder A;

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

[0034] The aluminum alloy substrate is subjected to surface treatment, and then the mixed powder B is converted into molten particles at the working temperature of the plasma jet, and then sprayed onto the surface of the aluminum alloy substrate preheated to 500° C. to 550° C. after flying 60 mm to 100 mm with the high-temperature flame flow, to form a first coating with a thickness of 100 μm to 300 μm;

[0035] Epoxy resin, ultraviolet absorber, titanium dioxide, boron nitride, cobalt aluminate, polyamide, dispersant and leveling agent are added to a mixer and mixed, and then sent to a twin-screw extruder for melt extrusion. The extruded material is tableted, cooled to room temperature, crushed, ball-milled and sieved through a 100-200 mesh sieve, and then a second coating with a thickness of 0.2 mm to 0.8 mm is 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.

[0036] In one embodiment, the rotation speed of the ball milling treatment 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: adding the mixed powder A to the silane coupling agent, stirring at a temperature of 45°C to 65°C and a rotation speed of 100r / min to 200r / min for 1h to 2h.

[0038] In one embodiment, the liquid-to-material 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 power of the ultrasonic vibration treatment is 100W-150W, the vibration ratio is 1, the vibration is 1s, the interval is 1s, and the total vibration time is 60s-120s.

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

[0042] In one embodiment, the mixing is carried out at a rotation speed of 500 r / min to 1000 r / min for 20 min to 30 min.

[0043] The above scheme can obtain an aluminum alloy profile with significant corrosion resistance as a whole by optimizing the first coating and the second coating and improving the process.

[0044] The embodiments of the present invention will be described in detail below with reference to specific examples.

[0045] Embodiment 1:

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

[0047] According to 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 a speed of 300 r / min for 2 hours to obtain a mixed powder A;

[0048] The mixed powder A was added to the silane coupling agent at a material-liquid ratio of 5 g / 10 mL, stirred at 60° C. and 100 r / min for 2 h, dried, and ground to obtain a mixed powder B with an average particle size of 30 μm;

[0049] The aluminum alloy substrate is subjected to surface treatment, wherein the surface treatment includes decontamination, degreasing and sandblasting roughening, and then the mixed powder B is converted into molten particles at the plasma jet working temperature, and subjected to ultrasonic vibration treatment, wherein the power of the ultrasonic vibration treatment is 100W to 150W, the vibration-off ratio is 1, the vibration is applied for 1s, the interval is 1s, and the total vibration time is 60s to 120s, and the mixed powder B is sprayed onto the surface of the aluminum alloy substrate preheated to 500°C after flying 80mm with the high-temperature flame flow, to form a first coating with a thickness of 150μm;

[0050] According to weight, 35 parts of epoxy resin, 16 parts of monobenzoic acid resorcinol ester, 5 parts of titanium dioxide, 5 parts of boron nitride, 2 parts of cobalt aluminate, 3 parts of polyamide, 2 parts of ethylene glycol and 1 part of acrylic leveling agent were added to a mixer and mixed at a speed of 500 r / min for 20 minutes. The materials were then sent to a twin-screw extruder for melt extrusion. The extruded materials were tableted, cooled to room temperature, crushed, ball-milled and sieved through a 150-mesh sieve, and then a second coating with a thickness of 0.5 mm was formed on the surface of the first coating through an electrostatic spraying process. After cooling to room temperature, a corrosion-resistant aluminum alloy profile was obtained.

[0051] Embodiment 2:

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

[0053] According to 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 a speed of 350 r / min for 3 hours to obtain a mixed powder A;

[0054] The mixed powder A was added to the silane coupling agent at a material-liquid ratio of 5 g / 10 mL, and the mixture was stirred at a temperature of 65° C. and a speed of 150 r / min for 2 h, dried, and ground to obtain a mixed powder B with an average particle size of 30 μm;

[0055] The aluminum alloy substrate is subjected to surface treatment, the surface treatment including decontamination, degreasing and sandblasting roughening, and then the mixed powder B is converted into molten particles at the plasma jet working temperature, and ultrasonic vibration treatment is performed, and the power of the ultrasonic vibration treatment is 100W-150W, the vibration ratio is 1, the vibration is 1s, the interval is 1s, and the total vibration time is 60s-120s, and the high-temperature flame flow flies 100mm and then sprays onto the surface of the aluminum alloy substrate preheated to 520°C to form a first coating with a thickness of 150μm;

[0056] According to weight, 32 parts of epoxy resin, 17 parts of monobenzoic acid resorcinol ester, 7 parts of titanium dioxide, 6 parts of boron nitride, 3 parts of cobalt aluminate, 4 parts of polyamide, 2 parts of sodium hexametaphosphate and 1 part of acrylic leveling agent were added to a mixer and mixed at a speed of 500 r / min for 25 minutes. The materials were then sent to a twin-screw extruder for melt extrusion. The extruded materials were tableted, cooled to room temperature, crushed, ball-milled and sieved through a 150-mesh sieve. A second coating with a thickness of 0.5 mm was formed on the surface of the first coating through an electrostatic spraying process. After cooling to room temperature, a corrosion-resistant aluminum alloy profile was obtained.

[0057] Embodiment 3:

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

[0059] According to 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 a speed of 300 r / min for 3 hours to obtain a mixed powder A;

[0060] The mixed powder A was added to the silane coupling agent at a material-liquid ratio of 5 g / 10 mL, stirred at 65° C. and 200 r / min for 2 h, dried, and ground to obtain a mixed powder B with an average particle size of 30 μm.

[0061] The aluminum alloy substrate is subjected to surface treatment, wherein the surface treatment includes decontamination, degreasing and sandblasting roughening, and then the mixed powder B is converted into molten particles at the plasma jet working temperature, and subjected to ultrasonic vibration treatment, wherein the power of the ultrasonic vibration treatment is 100W to 150W, the vibration-off ratio is 1, the vibration is applied for 1s, the interval is 1s, and the total vibration time is 60s to 120s, and the mixed powder B is sprayed onto the surface of the aluminum alloy substrate preheated to 510°C after flying 100mm with the high-temperature flame flow, to form a first coating with a thickness of 150μm;

[0062] According to weight, 35 parts of epoxy resin, 18 parts of monobenzoic acid resorcinol ester, 6 parts of titanium dioxide, 7 parts of boron nitride, 3 parts of cobalt aluminate, 3 parts of polyamide, 1 part of sodium hexametaphosphate and 2 parts of acrylic leveling agent were added to a mixer and mixed at a speed of 500 r / min for 30 minutes. The materials were then sent to a twin-screw extruder for melt extrusion. The extruded materials were tableted, cooled to room temperature, crushed, ball-milled and sieved through a 150-mesh sieve, and then a second coating with a thickness of 0.5 mm was formed on the surface of the first coating through an electrostatic spraying process. After cooling to room temperature, a corrosion-resistant aluminum alloy profile was obtained.

[0063] Comparative Example 1:

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

[0065] Comparative Example 2:

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

[0067] Comparative Example 3:

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

[0069] Comparative Example 4:

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

[0071] Comparative Example 5:

[0072] The difference between Comparative Example 5 and Example 3 is that no pretreatment is performed in Comparative Example 5, and the rest is the same as Example 3.

[0073] Comparative Example 6:

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

[0075] Comparative Example 7:

[0076] The difference between Comparative Example 7 and Example 3 is that the first coating layer is not provided in Comparative Example 7, and the other aspects are 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 are not added to the raw materials for preparing the second coating in Comparative Example 8, and the rest is the same as Example 3.

[0079] Comparative Example 9:

[0080] The difference between Comparative Example 9 and Example 3 is that no resorcinol monobenzoate is added in Comparative Example 9, and the rest is the same as Example 3.

[0081] Comparative Example 10:

[0082] The difference between Comparative Example 10 and Example 3 is that no second coating layer is provided in Comparative Example 10, and the rest 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 (ie, the 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: drop 2 mL of 40 wt % sulfuric acid on the surface of the sample, keep it at 25° C. for 24 hours, and observe the apparent blistering corrosion phenomenon of the aluminum alloy profile.

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

[0086] Table 1: Performance test results

[0087]

[0088] From the data in Table 1, it can be seen that the aluminum alloy profile samples of the present application were kept at 25°C for 24 hours, and there was no obvious change on the surface during the acid and alkali immersion test, and no corrosion, shedding, or penetration problems occurred. However, the aluminum alloy substrate that was not treated with the first coating and the second coating was severely corroded, indicating that the aluminum alloy profile treated with the first coating and the second coating of the present application has significant corrosion resistance and can meet the daily corrosion resistance requirements.

[0089] In order to further verify the effects of the first coating and the second coating of the present application on the performance of the aluminum alloy profile, the following test was also conducted. The results are shown in Table 2.

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

[0091] Table 2: Corrosion resistance results

[0092]

[0093] From the data analysis of Table 2, it can be seen that after the composition and process optimization, the present application can obtain an aluminum alloy profile with significant corrosion resistance, and there are no pinholes, bubbles, unevenness and other problems on the surface of the aluminum alloy profile. The difference between Comparative Examples 1 to 4 and Example 3 is that the raw materials for preparing the first coating in Comparative Examples 1 to 4 are different, but it can be clearly seen that the acid resistance, alkali resistance and salt spray resistance in Comparative Examples 1 to 4 are all worse than those in Example 3; the difference between Comparative Examples 5 to 6 and Example 3 is that the raw material processing process for preparing the first coating is different, and it can be seen that after the optimization of the process, the adhesion and corrosion resistance of the coating are promoted; Comparative Example 7 does not set the first coating, and the adhesion of the second coating and the corrosion resistance of the aluminum alloy profile are significantly reduced, indicating that setting the first coating helps to improve the adhesion of the second coating; the difference between Comparative Examples 8 to 9 and Example 3 is that the composition of the second coating is different, but it can also affect the corrosion resistance, and Comparative Example 10 does not set the second coating, but the corrosion resistance is poor, indicating that the present application can play a more significant corrosion resistance role under the synergistic effect of the first coating and the second coating.

[0094] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described 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 above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A corrosion-resistant aluminum alloy profile, comprising 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 layer includes the following raw materials in parts by weight: 30 to 35 parts of epoxy resin, 15 to 18 parts of ultraviolet absorber, 3 to 7 parts of titanium dioxide, 5 to 7 parts of boron nitride, 1 to 3 parts of cobalt aluminate, 1 to 5 parts of polyamide, 1 to 2 parts of dispersant and 1 to 2 parts of leveling agent.

2. The corrosion-resistant aluminum alloy profile according to claim 1, characterized in that: The ultraviolet absorber is at least one of monobenzoic acid resorcinol ester 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 and 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 according to any one of claims 1 to 4, and the preparation method comprises the following steps: Place lanthanum oxide, magnesium powder, yttrium oxide and silicon dioxide in a ball mill for ball milling to obtain mixed powder A; The mixed powder A is pretreated, dried, and ground to obtain a mixed powder B; The aluminum alloy substrate is subjected to surface treatment, and then the mixed powder B is converted into molten particles at the working temperature of the plasma jet, and then sprayed onto the surface of the aluminum alloy substrate preheated to 500° C. to 550° C. after flying 60 mm to 100 mm with the high-temperature flame flow, to form a first coating with a thickness of 100 μm to 300 μm; Epoxy resin, ultraviolet absorber, titanium dioxide, boron nitride, cobalt aluminate, polyamide, dispersant and leveling agent are added to a mixer and mixed, and then sent to a twin-screw extruder for melt extrusion. The extruded material is tableted, cooled to room temperature, crushed, ball-milled and sieved through a 100-200 mesh sieve, and then a second coating with a thickness of 0.2 mm to 0.8 mm is 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.

6. The preparation method according to claim 5, characterized in that: The rotation speed of the ball milling treatment is 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 mixed powder B is subjected to ultrasonic vibration treatment before melt coating, and the power of the ultrasonic vibration treatment is 100W-150W, the vibration-off ratio is 1, the vibration is 1s, the interval is 1s, and the total vibration time is 60s-120s.

9. The preparation method according to claim 5, characterized in that: The surface treatment includes desmearing, degreasing and sandblasting roughening.

10. The preparation method according to claim 5, characterized in that: Mix the materials at a speed of 500 r / min to 1000 r / min for 20 to 30 min.

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