High-strength and high-ductility aluminum alloy profile and preparation method thereof

Abstract

The invention relates to the field of aluminum alloys, and particularly discloses a high-strength and high-ductility aluminum alloy profile which comprises the following chemical components in percentage by mass: 0.35-0.75% of Si, less than or equal to 0.3% of Fe, less than or equal to 0.05% of Cu, 0.10-0.30% of Mn, 0.30-0.70% of Mg, less than or equal to 0.05% of Cr, less than or equal to 0.05% of Zn, less than or equal to 0.1% of Ti, less than or equal to 0.05% of other single trace alloy elements, less than or equal to 0.15% of other trace alloy elements and the balance of Al. By the adoption of the technical scheme, components are stable, size precision is high, and surface defects are few.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloys, and particularly to high-strength, high-ductility aluminum alloy profiles and their preparation methods. Background Technology

[0002] 6XXX series aluminum alloys, with their moderate strength, good processing and welding properties, are widely used in the automotive, rail transportation, and construction industries. However, existing technologies still have significant shortcomings in balancing the strength, ductility, dimensional accuracy, and energy consumption of aluminum alloy profiles.

[0003] Existing aluminum alloy profiles lack precise control in composition design, have high impurity element content, and have not coordinated optimization of key processes such as extrusion, heat treatment, and surface treatment. This results in insufficient dimensional accuracy and numerous surface defects, failing to meet the stringent dimensional tolerance and surface quality requirements of automotive applications. Furthermore, the strength and ductility of existing profiles are also insufficient to meet the demands of high-precision assembly.

[0004] Therefore, there is an urgent need for a high-strength, high-ductility aluminum alloy profile with excellent strength and ductility, and its preparation method. Summary of the Invention

[0005] This invention provides a high-strength, high-ductility aluminum alloy profile with stable composition, high dimensional accuracy, and few surface defects, as well as a method for its preparation.

[0006] To solve the above-mentioned technical problems, this application provides the following technical solution: The high-strength and high-ductility aluminum alloy profiles have the following chemical composition by mass fraction: Si 0.35-0.75%, Fe ≤0.3%, Cu ≤0.05%, Mn 0.10-0.30%, Mg 0.30-0.70%, Cr ≤0.05%, Zn ≤0.05%, Ti ≤0.1%, other individual trace alloying elements ≤0.05%, the total of other trace alloying elements ≤0.15%, and the balance being Al.

[0007] Furthermore, the mechanical properties of the aluminum alloy profile meet the following requirements: tensile strength Rm≥265N / mm², specified non-proportional elongation strength Rp0.2≥245N / mm², elongation after fracture A50≥9%, and Webster hardness HW≥14.

[0008] Furthermore, the tensile strength Rm ≥ 265 N / mm², and the non-proportional elongation strength Rp0.2 ≥ 245 N / mm² are specified.

[0009] Furthermore, the aluminum alloy profile is a strip-type thermal insulation profile, and its room temperature longitudinal shear characteristic value and room temperature transverse tensile characteristic value are both ≥24N / mm.

[0010] Furthermore, the room temperature longitudinal shear characteristic value of the aluminum alloy profile is ≥40N / mm.

[0011] A method for preparing high-strength, high-ductility aluminum alloy profiles includes the following steps: S1 Raw Material Preparation and Casting: By mass fraction, Si 0.35-0.75%, Fe ≤0.3%, Cu ≤0.05%, Mn 0.10-0.30%, Mg 0.30-0.70%, Cr ≤0.05%, Zn ≤0.05%, Ti ≤0.1%, other individual trace alloying elements ≤0.05%, total other trace alloying elements ≤0.15%, and the balance is Al. Prepare aluminum ingots, master alloys, and trace alloying elements. Put the aluminum ingots into a melting furnace and heat them to 720-760℃ to melt. Add master alloys and trace alloying elements. After refining and purification, the composition is detected by a spectrometer and adjusted to meet the standards. Then, cast rods are obtained. S2 Extrusion Molding: The casting rod, extrusion cylinder and mold are heated separately, and the three-temperature and one-speed, three-point and one-line production process is strictly controlled to carry out extrusion molding. After extrusion, it is quenched online and cooled to a surface temperature ≤150℃. The quenched profile is straightened, sawed and framed, and then hoisted into an aging furnace, heated to 190-200℃, held for 2-4 hours, and then air-cooled to room temperature. S3 Surface Treatment: The aged profiles are sequentially subjected to water washing, degreasing, water washing, passivation, water washing, pure water washing, drying, spraying, and curing. The spraying adopts a vertical powder spraying process. After curing, the adhesion, hardness, and film thickness of the coating are tested. S4 Deep Processing and Inspection: The strip-insulated profiles undergo sequential processes of toothing, strip insertion, and roll forming; then, the finished products are inspected according to the preset performance and dimensional deviation requirements, and packaged and stored after passing the inspection.

[0012] Furthermore, nitrogen degassing is used in the refining and purification process of S1.

[0013] Furthermore, the smelting process in S1 is assisted by ultrasound. When smelting aluminum ingots, the ultrasonic treatment lasts for 6-10 minutes with an ultrasonic frequency of 16-20 kHz and an ultrasonic intensity of 1.00-1.15 kW / cm². After the aluminum ingots are mixed with the intermediate alloy and other elements, the ultrasonic treatment lasts for 8-15 minutes with the same ultrasonic parameters as the smelting stage.

[0014] Furthermore, before spraying in S3, the medium and high gloss powder-coated profiles are polished or sandblasted, and the surface is blown or wiped before being loaded onto the surface; during the loading process, the profiles are spaced ≥5cm apart to prevent accumulation and pressure from causing scratches; the curing temperature is not lower than 190℃ and the time is not lower than 10min.

[0015] The principle and beneficial effects of this scheme are as follows: The mass fraction ratio of each element in this invention allows Si and Mg to form the Mg2Si strengthening phase, improving mechanical properties; Mn refines grains and inhibits recrystallization, Cr optimizes the grain boundary structure, and Ti refines the as-cast microstructure; the content of impurity elements such as Fe, Cu, and Zn is strictly controlled (Fe≤0.3%, Cu≤0.05%, Zn≤0.05%) to avoid the formation of coarse and brittle phases. At the same time, the content of other individual trace alloying elements is limited to ≤0.05%, and the total to ≤0.15%, ensuring compositional uniformity.

[0016] By using a spectrometer for detection and adjustment, the fluctuation of alloy composition is controlled within a very small range, avoiding performance dispersion caused by compositional deviations and ensuring consistency in mass production. The combination of the Mg2Si strengthening phase and the refined grain structure results in a tensile strength ≥265 N / mm², a non-proportional elongation strength ≥245 N / mm², and an elongation after fracture ≥9%, resolving the contradiction in traditional aluminum alloys where increased strength leads to decreased ductility.

[0017] A melting temperature of 720-760℃ ensures that alloying elements are fully dissolved. Two-stage online degassing (argon + chlorine mixed gas + pure argon) efficiently removes hydrogen and impurities from the melt. Ultrasonic-assisted treatment (16-20kHz, 1.00-1.15kW / cm²) breaks up coarse grains and intermetallic compounds through cavitation effect.

[0018] The reduced porosity and inclusion defects in the cast rods increase their density, preventing the risk of fracture due to internal defects during subsequent processing. The ultrasonically assisted treatment results in a uniform microstructure, providing a stable substrate for extrusion molding, reducing uneven deformation during extrusion, and laying the foundation for subsequent dimensional accuracy control.

[0019] Extrusion followed by quenching (cooling to ≤150℃) inhibits premature precipitation of the Mg2Si phase, preventing the formation of a supersaturated solid solution. Rapid quenching suppresses grain growth, avoiding the impact of coarse microstructure on ductility and creating conditions for improved performance after aging treatment.

[0020] Holding at 190-200℃ for 2-4 hours allows the Mg2Si phase to slowly and uniformly precipitate from the supersaturated solid solution, forming a fine-sized (≤50nm) and widely distributed strengthening phase. This composition also avoids the aggregation of grain boundary embrittlement phases. The final product can achieve an elongation at break of up to 13.0% and a Webster hardness ≥15.5HW, far exceeding basic requirements. The widely distributed strengthening phase hinders dislocation movement, reduces fatigue crack initiation and propagation, and extends the service life of the profile in dynamic automotive applications.

[0021] By refining the grains with Mn and Ti elements and using ultrasonic treatment to break up coarse grains, and without obvious coarse second-phase aggregation at the grain boundaries, the fine and uniform grains reduce stress concentration, resulting in more uniform deformation of the profile under stress and further improving elongation after fracture, meeting the bending and stamping processing requirements of automotive-grade products. The refined grains and pure grain boundaries improve the toughness of the profile, enabling the product to absorb more energy in sudden scenarios such as impacts, thus enhancing safety.

[0022] This invention enables profiles to possess excellent cutting, drilling, and welding properties through precise component control and uniform microstructure. During processing, tool wear is minimal, processing accuracy is easily controlled, and product processing costs are reduced. At the same time, high ductility allows the profiles to adapt to cold bending and stamping processes for complex shapes without the need for additional heat treatment softening, thereby improving production efficiency.

[0023] The low impurity content and dense coating protection make the profiles resistant to corrosion, discoloration, and coating peeling in harsh environments such as high temperature, high humidity, and salt spray, adapting to the product usage requirements of different climatic regions. The stable composition and microstructure ensure a uniform coefficient of thermal expansion, resulting in minimal deformation during high and low temperature cycling, preventing changes in assembly clearances or structural failures caused by thermal deformation. While maintaining high strength, high-precision dimensional control allows for thin-walled profile designs, reducing product weight and lowering costs.

[0024] The refined grain structure and dispersed reinforcing phase give the profile excellent vibration resistance, making it less prone to fatigue damage or structural loosening due to vibration during product use, thus ensuring the stability and safety of the product connection.

[0025] The aluminum alloy profiles of this application have a tensile strength ≥265 N / mm² and a specified non-proportional elongation strength ≥245 N / mm², fully meeting the mechanical property requirements of 6061 alloy in T6 condition in GB / T6982-2006 (tensile strength ≥260 N / mm², specified non-proportional elongation strength ≥240 N / mm²). Simultaneously, the elongation after fracture (A50) of this application is ≥9%, significantly better than the national standard requirement for 6061 alloy in T6 condition (A50 ≥6%), achieving a perfect balance between high strength and high ductility, and solving the industry pain point that traditional 6xxx series aluminum alloys experience a decrease in ductility with increased strength.

[0026] The room temperature longitudinal shear characteristic value surpasses that of 6061 and 6063 alloys: The room temperature longitudinal shear characteristic value of the strip-type thermal insulation profile in this application is ≥40N / mm (actually reaching 50N / mm), which not only far exceeds its own set requirement of ≥24N / mm, but also significantly surpasses the conventional level of similar products of 6061 and 6063 alloys. This advantage stems from the synergistic effect of precise composition design and process, ensuring that the thermal insulation profile has stronger structural stability and shear resistance in load-bearing scenarios, meeting the stringent mechanical requirements of assembly.

[0027] In the traditional preparation of 6xxx series aluminum alloys, homogenization treatment (holding at 550-560℃ for 4-6 hours) is a key step to eliminate component segregation in the cast ingot and ensure the uniformity of subsequent properties. However, this step is energy-intensive and time-consuming. This application omits this step through two core innovations: first, it precisely controls the proportions of elements such as Si, Mg, Mn, and Ti to form a stable alloy system and reduce component segregation in the as-cast microstructure; second, it employs ultrasonic-assisted treatment (16-20kHz, 1.00-1.15kW / cm²) during the melting and casting stage to break up coarse grains and intermetallic compounds through cavitation, while simultaneously using a nitrogen degassing process to effectively improve the uniformity and density of the cast ingot microstructure.

[0028] Despite the absence of homogenization treatment, the aluminum alloy profiles prepared in this application maintain excellent performance, with tensile strength ≥275MPa and elongation after fracture ≥12%, and all mechanical properties are no less than those of products produced using traditional processes. This significantly reduces production energy consumption and time costs, achieving a synergistic improvement in environmental protection and economic efficiency, aligning with the industry trend of green manufacturing.

[0029] In summary, the present invention achieves excellent strength and ductility. Attached Figure Description

[0030] Figure 1 This is a flowchart of Example 1 of the method for preparing high-strength, high-ductility aluminum alloy profiles; Figure 2 This is a flowchart of the casting process in Example 1; Figure 3 The test report for Example 1 (above); Figure 4 The test report for Example 1 is shown below. Detailed Implementation

[0031] The following detailed description illustrates the specific implementation method: A method for preparing high-strength, high-ductility aluminum alloy profiles (e.g.) Figure 1 (As shown), including the following steps: Melting and casting (S1, such as) Figure 2As shown): Prepare raw materials according to the above chemical composition ratio. Heat aluminum ingots in a melting furnace to 740℃ to melt. Add a slag remover at 0.25% of the aluminum ingot mass to remove slag. During aluminum ingot melting, ultrasonically treat for 8 minutes (frequency 18kHz, intensity 1.10kW / cm²), then add intermediate alloys and other elements, mix, and continue ultrasonic treatment for 12 minutes (parameters as above). Degas with nitrogen (flow rate 2.5m³ / t aluminum melt). Analyze the composition using a spectrometer. If the composition does not meet the standards, reprocess the raw material. Once the composition meets the standards, cast φ120mm ingots, which are then cut to length / machined to obtain the finished ingots.

[0032] Extrusion (S2): The finished cast ingot is heated to 480℃, the extrusion cylinder to 460℃, and the die to 470℃. Strict control of the three temperatures and one speed, and the three-point-one-line production process is maintained. The extrusion speed is 15-25 m / min. After extrusion, the material is quenched by spraying or strong air cooling until the surface temperature is below 150℃. Aging Treatment: The quenched profile is placed in an aging furnace, heated to 200℃ and held for 2 hours, then removed from the furnace and cooled to room temperature by air.

[0033] Surface treatment (S3): The following steps were performed in sequence: water washing (5 min), degreasing (40℃, 10 min), water washing (5 min), passivation (25℃, 8 min), water washing (5 min), pure water washing (5 min), drying (120℃, 30 min), vertical powder spraying (coating thickness 70 μm), and curing (190℃, 18 min). After curing, the coating adhesion, hardness, and film thickness were tested.

[0034] Deep processing (S4): The strip-threading process is adopted, which involves sequentially opening teeth, threading strips, and rolling compounding. Then, the finished products are inspected according to the specified performance and dimensional deviation requirements. After passing the inspection, they are packaged and stored.

[0035] Example 2 The difference between this embodiment and Embodiment 1 is that: in the aging treatment, the temperature is raised to 200℃ and held for 3 hours; in the surface treatment, the coating thickness is 60μm, the curing temperature is 200℃, and the holding time is 15 minutes. The remaining steps and parameters are the same as in Embodiment 1.

[0036] Example 3 The difference between this embodiment and Embodiment 1 is that the melting temperature is 720℃, the ultrasonic treatment time is 6 minutes during the melting stage and 8 minutes after mixing, and the aging treatment is heated to 185℃ and held for 4 hours. The remaining steps and parameters are the same as in Embodiment 1.

[0037] Comparative Example 1 (Changing Aging Process Parameters) The difference between this comparative example and Example 1 is that the composition of Mg is 0.55-0.62%, Si is 0.38-0.42%, Cu is <0.005%, Mn is <0.005%, Cr is <0.005%, Zn is <0.005%, and Ti is 0.015-0.02%, which conforms to the composition range of 6063 in the national standard GB / T3190-2008. The sample is heated to 185-250℃ in an aging furnace, held at that temperature for 0-4 hours, then cooled at a rate of 5-80℃ / h to a temperature not exceeding 160℃ before being removed from the furnace and cooled to room temperature.

[0038] Comparative Example 2 (changing the control range of ingredients) The difference between this comparative example and Example 1 is that the Fe content in the chemical composition is 0.5% and the Cu content is 0.1%, which exceeds the range of "Fe ≤ 0.3% and Cu ≤ 0.05%" defined in this invention. The remaining steps and parameters are the same as in Example 1.

[0039] Comparative Example 3 The difference between this comparative example and Example 1 is that: Mg 0.55-0.62%, Si 0.38-0.42%, Cu <0.005%, Mn <0.005%, Cr <0.005%, Zn <0.005%, and Ti 0.015-0.02%, which conforms to the composition range of 6063 in the national standard GB / T3190-2008. The remaining steps and parameters are the same as in Example 1.

[0040] Comparative Example 4 The composition is as follows: Mg 0.95-1.02%, Si 0.65-0.72%, Cu 0.25-0.30%, Fe 0.20-0.25%, Mn 0.10-0.15%, Cr 0.15%, Zn < 0.005%, Ti 0.015-0.02%, which conforms to the composition range of 6061 in the national standard GB / T3190-2008.

[0041] Preparation process: After melting and casting, homogenization treatment is performed, followed by extrusion and online quenching (535℃, water spray + strong wind cooling to below 150℃). The aging treatment is "heated to 185℃ and held for 4 hours, then naturally cooled to 140℃ in the furnace, and then naturally cooled to room temperature after being taken out of the furnace". Ultrasonic assistance, secondary degassing and the surface treatment process of this invention were not performed.

[0042] Comparative Example 5 (Traditional T6 Aging Process) The difference between this comparative example and Example 1 is that the aging treatment uses the traditional T6 process, which involves "heating to 175°C and holding for 8 hours, then allowing it to cool naturally to room temperature after removal from the furnace". The remaining steps and parameters are the same as in Example 1.

[0043] The aluminum alloy profiles prepared in each embodiment and comparative example were subjected to performance tests. The test items and methods are as follows: Mechanical properties: Tensile strength Rm, specified non-proportional extension strength Rp0.2, and elongation after fracture A are tested according to GB / T 228.1-2021. 50 Test the Webster hardness (HW) according to YS / T 420.

[0044] Corrosion resistance: Conduct a neutral salt spray test (500h) according to GB / T 10125-2021 and observe the corrosion.

[0045] The test results are shown in Table 1: Table 1 Performance test results of each embodiment and comparative example (all under T6 conditions, some results are shown below). Figure 3 , Figure 4 (As shown) project Tensile strength Rm (MPa) Elongation after fracture (A50%) Webster hardness HW Grain size (grade) <![CDATA[Longitudinal shear resistance eigenvalue at room temperature (A 50 N / mm)]]> Salt spray test (500h) Example 1 278 13.2 15.8 7.5 50 No obvious corrosion Example 2 282 13.0 16.0 7.3 50 No obvious corrosion Example 3 275 13.5 15.5 7.8 50 No obvious corrosion Comparative Example 1 224 10.5 14.2 7.0 24 Minor pitting Comparative Example 2 204 9.8 14.0 6.5 24 Obvious pitting Comparative Example 3 225 9.2 13.8 6.0 25 Localized corrosion Comparative Example 4 265 8.5 15.5 6.8 25 Slight corrosion Comparative Example 5 260 9.0 14.3 7.0 24 Minor pitting As can be seen from the table above, the tensile strength of Examples 1-3 is ≥275MPa, the specified non-proportional elongation strength is ≥249MPa, the elongation after fracture is ≥12%, and the Webster hardness is ≥15.5HW, which is significantly better than the comparative examples. They fully meet the mechanical property requirements of 6061 alloy in the T6 condition in GB / T6982-2006 (tensile strength ≥260N / mm², specified non-proportional elongation strength ≥240N / mm²). Furthermore, the elongation after fracture A of this application... 50 ≥12%, significantly better than the national standard requirement for 6061 alloy in T6 condition (elongation after fracture A). 50 With a strength of ≥6%, it achieves a perfect balance between high strength and high ductility, solving the industry pain point that traditional 6xxx series aluminum alloys experience a decrease in ductility as strength increases.

[0046] The room temperature longitudinal shear characteristic value is superior to that of 6061 and 6063 alloys: The room temperature longitudinal shear characteristic value of the strip-type thermal insulation profile of this application is 50 N / mm, which is significantly better than the conventional level of similar products of 6061 and 6063 alloys.

[0047] Corrosion resistance: The examples showed no significant corrosion after 500 hours of salt spray testing, while Comparative Examples 2-4 all showed varying degrees of corrosion, indicating that the component control and surface treatment process of the present invention effectively improved corrosion resistance.

[0048] In summary, this invention, through precise composition control, ultrasonic-assisted melting and other technical means, synergistically improves the strength, ductility and corrosion resistance of aluminum alloy profiles, while reducing production energy consumption. Its overall performance is superior to existing technologies and traditional process products, and fully meets the needs of automotive applications.

[0049] The above are merely embodiments of the present invention. The invention is not limited to the fields covered by these embodiments. Commonly known structures and characteristics in the solutions are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are aware of all existing technologies in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, under the guidance of this application, improve and implement this solution in combination with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several changes and improvements without departing from the structure of the present invention. These should also be considered within the scope of protection of the present invention, and will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. High-strength, high-ductility aluminum alloy profiles, with the following chemical composition by mass fraction: Si 0.35-0.75%, Fe ≤0.3%, Cu ≤0.05%, Mn 0.10-0.30%, Mg 0.30-0.70%, Cr ≤0.05%, Zn ≤0.05%, Ti ≤0.1%, other individual trace alloying elements ≤0.05%, total other trace alloying elements ≤0.15%, balance Al.

2. The high-strength, high-ductility aluminum alloy profile according to claim 1, characterized in that, The mechanical properties of the aluminum alloy profiles meet the following requirements: tensile strength Rm≥265N / mm², and specified non-proportional elongation strength Rp0.2≥245N / mm².

3. The high-strength, high-ductility aluminum alloy profile according to claim 2, characterized in that, The mechanical properties of the aluminum alloy profile satisfy: elongation after fracture A 50 ≥9%, Webster hardness HW≥14.

4. The high-strength, high-ductility aluminum alloy profile according to claim 3, characterized in that, The aluminum alloy profile is a strip-type thermal insulation profile, with both the longitudinal shear characteristic value and the transverse tensile characteristic value at room temperature ≥24N / mm.

5. The high-strength, high-ductility aluminum alloy profile according to claim 4, characterized in that, The room temperature longitudinal shear characteristic value of the aluminum alloy profile is ≥40N / mm.

6. A method for preparing a high-strength, high-ductility aluminum alloy profile, comprising the following steps: S1 Raw Material Preparation and Casting: By mass fraction, Si 0.35-0.75%, Fe ≤0.3%, Cu ≤0.05%, Mn 0.10-0.30%, Mg 0.30-0.70%, Cr ≤0.05%, Zn ≤0.05%, Ti ≤0.1%, other individual trace alloying elements ≤0.05%, total other trace alloying elements ≤0.15%, and the balance is Al. Prepare aluminum ingots, master alloys, and trace alloying elements. Put the aluminum ingots into a melting furnace and heat them to 720-760℃ to melt. Add master alloys and trace alloying elements. After refining and purification, the composition is detected by a spectrometer and adjusted to meet the standards. Then, cast rods are obtained. S2 Extrusion Molding: The casting rod, extrusion cylinder and mold are heated separately, and the three-temperature and one-speed, three-point and one-line production process is strictly controlled to carry out extrusion molding. After extrusion, it is quenched online and cooled to a surface temperature ≤150℃. The quenched profile is straightened, sawed, framed and hoisted into an aging furnace, heated to 190-200℃, held for 2-4 hours, and then air-cooled to room temperature. S3 Surface Treatment: The aged profiles are sequentially subjected to water washing, degreasing, water washing, passivation, water washing, pure water washing, drying, spraying, and curing. The spraying adopts a vertical powder spraying process. After curing, the adhesion, hardness, and film thickness of the coating are tested. S4 Deep Processing and Inspection: The strip-insulated profiles undergo sequential processes of toothing, strip insertion, and roll forming; then, the finished products are inspected according to the preset performance and dimensional deviation requirements, and packaged and stored after passing the inspection.

7. The high-strength, high-ductility aluminum alloy profile according to claim 6, characterized in that, Nitrogen gas is used for refining and purification in S1.

8. The high-strength, high-ductility aluminum alloy profile according to claim 7, characterized in that, In S1, the smelting process is ultrasonically assisted. When smelting aluminum ingots, ultrasonic treatment is performed for 6-10 minutes with an ultrasonic frequency of 16-20 kHz and an ultrasonic intensity of 1.00-1.15 kW / cm². After the aluminum ingots are mixed with the intermediate alloy and other elements, ultrasonic treatment is performed for 8-15 minutes with the same ultrasonic parameters as in the smelting stage.

9. The high-strength, high-ductility aluminum alloy profile according to claim 8, characterized in that, Before spraying S3, the medium and high gloss powder-coated profiles are polished or sandblasted. Before being loaded onto the surface, the surface is blown or wiped. During the loading process, the profiles are spaced ≥5cm apart to prevent accumulation and pressure that could cause scratches. The curing temperature is not lower than 190℃ and the time is not lower than 10min.

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