An aluminum alloy profile having improved fatigue crack growth resistance and a method of making the same

Abstract

The present application relates to aluminum alloy profile, specifically relates to a kind of anti-fatigue crack propagation performance aluminum alloy profile and its preparation method.The preparation method of aluminum alloy profile includes: providing aluminum alloy ingot;The aluminum alloy ingot is treated with homogenization;Aluminum alloy ingot after homogenization treatment is rolled in multiple passes to obtain aluminum alloy rolling plate;The temperature of annealing treatment between passes is 200-350 DEG C;The aluminum alloy rolling plate is treated with solid solution heat treatment and artificial aging treatment, and aluminum alloy plate is obtained;Aluminum alloy plate after artificial aging is treated with creep aging;Aluminum alloy profile is obtained.The present application can produce aluminum alloy profile with high anti-fatigue crack propagation performance by new process method to control profile organization.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy profile technology, specifically to an aluminum alloy profile with fatigue crack propagation resistance and its preparation method. Background Technology

[0002] Creep aging forming, as a manufacturing process for one-time forming of large, integral stiffened panel components, has been widely used in the manufacture of complex multi-curvature structural parts for aerospace applications. Al-Zn-Mg-Cu alloy is an ultra-high strength 7XXX series aluminum alloy. Since its development, it has been widely used in aerospace and rail transportation fields due to its ultra-high strength, excellent hot working properties, and weldability. With the development of the aircraft manufacturing and rail transportation industries, the requirements for aluminum alloy sheets have shifted from focusing solely on strength to a greater emphasis on comprehensive performance indicators such as strength, toughness, corrosion resistance, and damage limit. While the widely used T6 state Al-Zn-Mg-Cu alloy has high strength, its toughness and corrosion resistance are poor. Furthermore, due to its high internal stress, it is prone to warping after processing, leading to a very high scrap rate – a problem that urgently needs to be addressed. Summary of the Invention

[0003] The present invention aims to at least partially solve one of the technical problems in the prior art.

[0004] This invention provides an aluminum alloy profile with high resistance to fatigue crack propagation and its preparation method. By controlling the microstructure of the profile through a novel process, aluminum alloy profiles with high resistance to fatigue crack propagation can be produced. This invention obtains an aluminum alloy ingot through melting and casting; the aluminum alloy ingot undergoes homogenization annealing; then, the homogenized annealed ingot is rolled in multiple passes to obtain an aluminum alloy rolled sheet; subsequently, the aluminum alloy rolled sheet undergoes solution heat treatment, artificial aging, and finally, the aged sheet undergoes creep over-aging forming treatment to obtain the aluminum alloy profile.

[0005] A method for preparing an aluminum alloy profile, comprising:

[0006] Provide aluminum alloy ingots;

[0007] The aluminum alloy ingot is subjected to homogenization treatment;

[0008] The homogenized aluminum alloy ingot is rolled in multiple passes to obtain aluminum alloy rolled plate; the annealing temperature between passes is 200-350℃.

[0009] The aluminum alloy rolled sheet is subjected to solution heat treatment and artificial aging treatment in sequence to obtain an aluminum alloy sheet.

[0010] The aluminum alloy sheet after artificial aging is subjected to creep aging treatment to obtain aluminum alloy profiles.

[0011] According to an embodiment of the present invention, the aluminum alloy ingot is composed of the following by mass percentage: Zn: 4.20-6.20%, Mg: 2.0-2.5%, Cu: 1.1-1.5%, Fe: 0.30-0.39%, Cr: 0.1-0.3%, Ti: 0.01-0.06%, Mn: 0.01-0.06%, Zr: 0.01-0.1%, with the balance being Al.

[0012] According to an embodiment of the present invention, the aluminum alloy ingot is composed of the following by mass percentage: Zn: 5.41%, Mg: 2.34%, Cu: 1.37%, Fe: 0.39%, Cr: 0.26%, Ti: 0.06%, Mn: 0.05%, Zr: 0.01%, with the balance being Al.

[0013] The aluminum alloy ingot can be prepared using conventional methods in the art, such as taking raw materials according to the designed composition and obtaining the aluminum alloy ingot through melting and casting.

[0014] According to an embodiment of the present invention, the homogenization treatment temperature is 410-460℃, and the homogenization treatment time is 30-80h.

[0015] Specifically, the homogenization treatment temperature is 450°C and the homogenization treatment time is 48 hours.

[0016] According to an embodiment of the present invention, the temperature at which the homogenized ingot begins rolling is 420-440°C, for example, 420°C, 430°C, or 440°C.

[0017] According to an embodiment of the present invention, the single-pass reduction during the rolling process is 10%-15%.

[0018] According to an embodiment of the present invention, the total reduction in pressure during the rolling process is 70%-90%.

[0019] According to an embodiment of the present invention, during the rolling process, a low-temperature annealing treatment is performed between passes to form a rolling texture that is close to the dislocation slip surface.

[0020] According to an embodiment of the present invention, at least 6 rolling passes are performed.

[0021] According to embodiments of the present invention, the annealing temperature between passes is 200-350°C (e.g., 250-350°C), and the annealing time is preferably 0.5-2 hours to form a rolling texture close to the {111} plane orientation. Studies have found that if the annealing temperature between passes exceeds 350°C, the number and size of precipitated secondary particles increase, the secondary phase tends to coarsen, the yield strength decreases, and the coarser particles lead to stress concentration and microcrack initiation.

[0022] According to an embodiment of the present invention, a 6-pass rolling process is performed, with the deformation amount per pass and the intermediate annealing process as follows:

[0023] The first pass rolls the material from 20mm to 15mm, and then holds it at 250-260℃ for 30-40 minutes.

[0024] The second pass rolls the material from 15mm to 12mm, and then holds it at 270-350℃ for 40-60 minutes.

[0025] The third pass rolls the material from 12mm to 9mm, and then holds it at 300-320℃ for 30-40 minutes.

[0026] The fourth pass rolls the material from 9mm to 6mm, and then holds it at 300-320℃ for 30-40 minutes.

[0027] The fifth pass rolls the material from 6mm to 5mm, and then holds it at 300-320℃ for 40-45 minutes.

[0028] The sixth pass rolls the material from 5mm to 4mm, and then holds it at 250-270℃ for 30-35 minutes.

[0029] According to embodiments of the present invention, the method further includes a step of cold rolling the aluminum alloy sheet obtained by multi-pass rolling; followed by solution treatment after cold rolling. Specifically, the cold rolling includes rolling the aluminum alloy sheet obtained by multi-pass rolling directly from 4mm to 3.5mm without annealing.

[0030] According to an embodiment of the present invention, the solution treatment temperature is 460-480℃ and the solution treatment time is 1-2 hours.

[0031] Specifically, the solution treatment temperature is 470°C and the solution treatment time is 1 hour.

[0032] According to an embodiment of the present invention, the method further includes the step of water cooling the aluminum alloy rolled plate obtained by solution treatment to room temperature; and then performing artificial aging treatment.

[0033] According to an embodiment of the present invention, the temperature for artificial aging is 100-140℃, and the time for artificial aging is 20-25h.

[0034] Specifically, the temperature for artificial aging is 120°C, and the artificial aging time is 24 hours.

[0035] According to an embodiment of the present invention, the creep curvature of the creep aging treatment is 200-400 mm, and the creep temperature is 140-170 °C.

[0036] The present invention also includes aluminum alloy profiles prepared by the above method.

[0037] This invention first uses continuous cold rolling deformation and low-temperature annealing processes to give it typical rolling texture characteristics. Then, through large curvature creep aging forming, it improves the residual stress distribution of aluminum alloy profiles, increases the angle between the actual active slip surfaces of adjacent grains, makes the distribution of geometrically necessary dislocation density within the grains more uniform, and improves the fatigue crack propagation resistance of aluminum alloy profiles. Attached Figure Description

[0038] Figure 1 The dislocation density diagram of the aluminum alloy profile prepared in Example 1;

[0039] Figure 2 The dislocation density diagram of the aluminum alloy profile prepared in Comparative Example 2 is shown.

[0040] Figure 3 EBSD image of fatigue crack propagation in the aluminum alloy sheet prepared in Example 1;

[0041] Figure 4 EBSD image of fatigue crack propagation in the aluminum alloy sheet prepared in Example 2;

[0042] Figure 5 EBSD image of fatigue crack propagation in the aluminum alloy sheet prepared in Example 3;

[0043] Figure 6 EBSD image of fatigue crack propagation in aluminum alloy sheet prepared in Comparative Example 1;

[0044] Figure 7 EBSD image of fatigue crack propagation in aluminum alloy sheet prepared in Comparative Example 2. Detailed Implementation

[0045] The following examples are used to illustrate the present invention, but are not intended to limit the scope of the invention.

[0046] The following aluminum alloy ingots are composed of the following by weight percentage: Zn: 5.41%, Mg: 2.34%, Cu: 1.37%, Fe: 0.39%, Cr: 0.26%, Ti: 0.06%, Mn: 0.05%, Zr: 0.01%, with the balance being Al.

[0047] Raw materials are selected according to the designed composition, and aluminum alloy ingots are obtained through melting and casting.

[0048] Example 1

[0049] This embodiment provides an aluminum alloy profile, the preparation method of which is as follows:

[0050] ① Homogenization treatment: After machining the outer surface of the aluminum alloy ingot, it is homogenized in a heat treatment furnace. The homogenization treatment process is 450℃ / 48h.

[0051] ② Hot rolling: Flat ingots are rolled at 430℃ on a hot rolling mill in 6 passes from 20mm thickness to 4mm thickness, with a total reduction of 80%. Intermediate annealing is performed between each pass. The deformation amount per pass and the intermediate annealing process are as follows:

[0052] The first pass rolls the material from 20mm to 15mm, and then holds it at 250℃ for 30 minutes.

[0053] The second pass rolls the material from 15mm to 12mm, and then holds it at 270℃ for 40 minutes.

[0054] The third pass rolls the material from 12mm to 9mm, and then holds it at 300℃ for 30 minutes.

[0055] The fourth pass rolls the material from 9mm to 6mm, and then holds it at 300℃ for 30 minutes.

[0056] The fifth pass rolls the material from 6mm to 5mm, and then holds it at 300℃ for 40 minutes.

[0057] The sixth pass rolls the material from 5mm to 4mm, and then holds it at 250℃ for 35 minutes.

[0058] ③ Cold rolling: The hot-rolled aluminum alloy sheet obtained in step ② above is rolled directly from 4mm to 3.5mm without annealing.

[0059] ④ Solution heat treatment: Place the cold-rolled hot aluminum alloy sheet into a 470℃ solution furnace and hold for 1 hour for solution heat treatment.

[0060] ⑤ Artificial aging: The aluminum alloy sheet after solution heat treatment is quickly placed in cold water and quenched to room temperature, and then placed in a drying oven for artificial aging at 120℃ / 24 hours to obtain the aluminum alloy sheet in the peak aging state.

[0061] ⑥ Creep aging treatment: The peak-aged aluminum alloy sheet is placed in a lattice mold with a curvature radius of 300 mm. The sheet is brought into contact with the forming surface of the mold under a pressure of 0.10 MPa. The sheet and the mold are then placed together in an autoclave. The autoclave is heated to 153°C, and the forming pressure is gradually increased to 0.5 MPa during the heating process. The temperature is maintained for 10 hours. Finally, the material is unloaded and cooled to room temperature with the autoclave to obtain an aluminum alloy profile with high fatigue crack propagation resistance.

[0062] Example 2

[0063] This embodiment provides an aluminum alloy profile, the preparation method of which is as follows:

[0064] ① Homogenization treatment: After machining the outer surface of the aluminum alloy ingot, it is homogenized in a heat treatment furnace. The annealing process is 450℃ / 48h.

[0065] ② Hot rolling: Flat ingots are rolled at 430℃ on a hot rolling mill in 6 passes from 20mm thickness to 4mm thickness, with a total reduction of 80%. Intermediate annealing is performed between each pass. The deformation amount per pass and the intermediate annealing process are as follows:

[0066] The first pass rolls the material from 20mm to 15mm, and then holds it at 260℃ for 30 minutes.

[0067] The second pass rolls the material from 15mm to 12mm, and then holds it at 350℃ for 60 minutes.

[0068] The third pass rolls the material from 12mm to 9mm, and then holds it at 320℃ for 30 minutes.

[0069] The fourth pass rolls the material from 9mm to 6mm, and then holds it at 320℃ for 40 minutes.

[0070] The fifth pass rolls the material from 6mm to 5mm, and then holds it at 320℃ for 40 minutes.

[0071] The sixth pass rolls the material from 5mm to 4mm, and then holds it at 270℃ for 30 minutes.

[0072] ③ Cold rolling: The hot-rolled aluminum alloy sheet obtained in step ② above is rolled directly from 4mm to 3.5mm without annealing.

[0073] ④ Solution heat treatment: Place the cold-rolled hot aluminum alloy sheet in a solution furnace and hold at 470℃ for 1 hour for solution heat treatment.

[0074] ⑤ Artificial aging: The aluminum alloy sheet after solution heat treatment is quickly placed in cold water and quenched to room temperature, and then placed in a drying oven for artificial aging at 120℃ / 24 hours to obtain the aluminum alloy sheet in the peak aging state.

[0075] ⑥ Creep aging treatment: The peak-aged aluminum alloy sheet is placed in a lattice mold with a curvature radius of 600 mm. The sheet is brought into contact with the forming surface of the mold under a pressure of 0.1 MPa. The sheet and the mold are then placed together in an autoclave. The autoclave is heated to 153°C, and the forming pressure is gradually increased to 0.5 MPa during the heating process. The temperature is maintained for 10 hours. Finally, the material is unloaded and cooled to room temperature with the autoclave to obtain an aluminum alloy profile with high fatigue crack propagation resistance.

[0076] Example 3

[0077] This embodiment provides an aluminum alloy profile, the preparation method of which is as follows:

[0078] ① Homogenization treatment: After machining the outer surface of the aluminum alloy ingot, it is homogenized in a heat treatment furnace. The annealing process is 450℃ / 48h.

[0079] ② Hot rolling: Flat ingots are rolled at 430℃ on a hot rolling mill in 6 passes from 20mm thickness to 4mm thickness, with a total reduction of 80%. Intermediate annealing is performed between each pass. The deformation amount per pass and the intermediate annealing process are as follows:

[0080] The first pass rolls the material from 20mm to 15mm, and then holds it at 260℃ for 30 minutes.

[0081] The second pass rolls the material from 15mm to 12mm, and then holds it at 350℃ for 60 minutes.

[0082] The third pass rolls the material from 12mm to 9mm, and then holds it at 320℃ for 30 minutes.

[0083] The fourth pass rolls the material from 9mm to 6mm, and then holds it at 320℃ for 40 minutes.

[0084] The fifth pass rolls the material from 6mm to 5mm, and then holds it at 320℃ for 40 minutes.

[0085] The sixth pass rolls the material from 5mm to 4mm, and then holds it at 270℃ for 30 minutes.

[0086] ③ Cold rolling: The hot-rolled aluminum alloy sheet obtained in step ② above is rolled directly from 4mm to 3.5mm without annealing.

[0087] ④ Solution heat treatment: Place the cold-rolled hot aluminum alloy sheet in a solution furnace and hold at 470℃ for 1 hour for solution heat treatment.

[0088] ⑤ Artificial aging: The aluminum alloy sheet after solution heat treatment is quickly placed in cold water and quenched to room temperature, and then placed in a drying oven for artificial aging at 120℃ / 24 hours to obtain the aluminum alloy sheet in the peak aging state.

[0089] ⑥ Creep aging treatment: The peak-aged aluminum alloy sheet is placed in a lattice mold with a curvature radius of 1800 mm. The sheet is brought into contact with the forming surface of the mold under a pressure of 0.10 MPa. The sheet and the mold are then placed together in an autoclave. The autoclave is heated to 153°C, and the forming pressure is gradually increased to 0.5 MPa during the heating process. The temperature is maintained for 10 hours. Finally, the material is unloaded and cooled to room temperature with the autoclave to obtain an aluminum alloy profile with high fatigue crack propagation resistance.

[0090] Comparative Example 1

[0091] This comparative example provides an aluminum alloy profile, the preparation method of which is as follows:

[0092] ① Homogenization annealing: After machining the outer surface of the aluminum alloy ingot, it is homogenized in a heat treatment furnace. The annealing process is 450℃ / 48h.

[0093] ② Hot rolling: Flat ingots are rolled at 430℃ on a hot rolling mill in 6 passes from 20mm thickness to 4mm thickness, with a total reduction of 80%. Intermediate annealing is performed between each pass. The deformation amount per pass and the intermediate annealing process are as follows:

[0094] The first pass rolls the material from 20mm to 15mm, and then holds it at 360℃ for 30 minutes.

[0095] The second pass rolls the material from 15mm to 12mm, and then holds it at 350℃ for 60 minutes.

[0096] The third pass rolls the material from 12mm to 9mm, and then holds it at 320℃ for 30 minutes.

[0097] The fourth pass rolls the material from 9mm to 6mm, and then holds it at 320℃ for 40 minutes.

[0098] The fifth pass rolls the material from 6mm to 5mm, and then holds it at 320℃ for 40 minutes.

[0099] The sixth pass rolls the material from 5mm to 4mm, and then holds it at 400℃ for 30 minutes.

[0100] ③ Cold rolling: The hot-rolled aluminum alloy sheet obtained in step ② above is rolled directly from 4mm to 3.5mm without annealing.

[0101] ④ Solution treatment: Place the cold-rolled hot aluminum alloy sheet in a solution furnace and hold at 470℃ for 1 hour for solution heat treatment.

[0102] ⑤ Aging: The aluminum alloy sheet after solution heat treatment is quickly placed in cold water for quenching to room temperature, and then placed in a drying oven for artificial aging at 120℃ / 24 hours to obtain the aluminum alloy sheet in the peak aging state.

[0103] Comparative Example 2

[0104] This comparative example provides an aluminum alloy profile, the preparation method of which is as follows:

[0105] ① Homogenization annealing: After machining the outer surface of the aluminum alloy ingot, it is homogenized in a heat treatment furnace. The annealing process is 450℃ / 48h.

[0106] ② Hot rolling: Flat ingots are rolled at 430℃ on a hot rolling mill in 6 passes from 20mm thickness to 4mm thickness, with a total reduction of 80%. Intermediate annealing is performed between each pass. The deformation amount per pass and the intermediate annealing process are as follows:

[0107] The first pass rolls the material from 20mm to 15mm, and then holds it at 400℃ for 125 minutes.

[0108] The second pass rolls the material from 15mm to 12mm, and then holds it at 400℃ for 60 minutes.

[0109] The third pass rolls the material from 12mm to 9mm, and then holds it at 400℃ for 30 minutes.

[0110] The fourth pass rolls the material from 9mm to 6mm, and then holds it at 400℃ for 40 minutes.

[0111] The fifth pass rolls the material from 6mm to 5mm, and then holds it at 400℃ for 40 minutes.

[0112] The sixth pass rolls the material from 5mm to 4mm, and then holds it at 400℃ for 30 minutes.

[0113] ③ Cold rolling: The hot-rolled aluminum alloy sheet obtained in step ② above is rolled directly from 4mm to 3.5mm without annealing.

[0114] ④ Solution treatment: Place the cold-rolled hot aluminum alloy sheet in a solution furnace and hold at 470℃ for 1 hour for solution heat treatment.

[0115] ⑤ Aging: The aluminum alloy sheet after solution heat treatment is quickly placed in cold water and quenched to room temperature, and then placed in a drying oven for artificial aging at 120℃ / 24 hours to obtain the aluminum alloy sheet in the peak aging state.

[0116] ⑥ Artificial aging: The aluminum alloy sheet in the peak aging state is placed directly into a hot autoclave, heated to 153°C and held for 10 hours; then cooled to room temperature with the autoclave.

[0117] Characteristic tests of Examples 1-3 and Comparative Examples 1-2

[0118] 1) Fatigue crack propagation rate analysis

[0119] The aluminum alloy profiles prepared in Examples 1-3 and Comparative Examples 1-2 were subjected to fatigue crack propagation tests on an MTS Landmark material testing machine.

[0120] The fatigue crack propagation resistance of the aluminum alloy profiles obtained in the examples and comparative examples is listed in Table 1. The material constant n in Table 1 reflects the fatigue crack propagation rate of the sample in the steady-state crack propagation region. A larger n value indicates a higher fatigue crack propagation rate and poorer fatigue crack propagation resistance. Table 1 clearly shows that the aluminum alloy profiles prepared in the examples have a lower n value, meaning they exhibit higher fatigue crack propagation resistance.

[0121] Table 1

[0122] Example 1 3.98±0.19 Example 2 4.34±0.24 Example 3 4.65±0.32 Comparative Example 1 5.54±0.48 Comparative Example 2 5.04±0.51

[0123] Figure 1 The dislocation density diagram of the aluminum alloy profile prepared in Example 1; Figure 2 The dislocation density diagram is shown for the aluminum alloy profile prepared in Comparative Example 2.

[0124] contrast Figure 1 and Figure 2 It can be seen that the dislocation density in Example 1, which underwent creep aging treatment, is greater, and the ρ within the crystal is higher. GND As the number of cells increases, the resistance encountered during fatigue crack propagation increases, and the crack propagation rate decreases, indicating that... Figure 1 It has higher resistance to fatigue crack propagation.

[0125] Figure 3 The image shows the EBSD (electron backscattering diffraction) pattern of fatigue crack propagation in the aluminum alloy sheet prepared in Example 1. Figure 4 EBSD image of fatigue crack propagation in the aluminum alloy sheet prepared in Example 2; Figure 5 EBSD image of fatigue crack propagation in the aluminum alloy sheet prepared in Example 3; Figure 6 EBSD image of fatigue crack propagation in aluminum alloy sheet prepared in Comparative Example 1; Figure 7 EBSD image of fatigue crack propagation in aluminum alloy sheet prepared in Comparative Example 2.

[0126] contrast Figure 3-7 It can be seen that the angles at which fatigue cracks penetrate the open slip surfaces of adjacent grains differ greatly among the five samples. The total deflection angle of the fatigue crack penetrating the grain boundary in Sample 1 is 581.7°, while that in Comparative Example 1 is 383.4°. The total deflection angles of the fatigue cracks penetrating the grain boundary in Samples 2, 3, and 2 are 474.4°, 468.2°, and 440.3°, respectively. The total deflection angle of the fatigue crack in Sample 1 is larger than that of the other samples, requiring more energy to penetrate these grain boundaries. The total deflection angle of the fatigue crack in Sample 1 is the smallest, indicating the least resistance when the fatigue crack penetrates the grain boundary. Therefore, Sample 1 exhibits the greatest resistance in terms of grain boundary resistance, followed by Samples 2, 3, and 2, with Sample 1 exhibiting the least resistance.

[0127] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A method for preparing an aluminum alloy profile, characterized in that, include: An aluminum alloy ingot is provided; the aluminum alloy ingot is composed of the following by weight percentage: Zn: 4.20-6.20%, Mg: 2.0-2.5%, Cu: 1.1-1.5%, Fe: 0.30-0.39%, Cr: 0.1-0.3%, Ti: 0.01-0.06%, Mn: 0.01-0.06%, Zr: 0.01-0.1%, with the balance being Al; The aluminum alloy ingot is subjected to homogenization treatment; The homogenized aluminum alloy ingot is rolled in multiple passes to obtain aluminum alloy rolled plates; the annealing temperature between passes is 200-350℃, and the annealing time is 0.5-2h, in order to form a rolling texture close to the {111} plane orientation; during the rolling process, the total reduction is 70%-90%; The aluminum alloy sheet obtained by multiple rolling processes is cold rolled; after cold rolling, it is solution treated; the aluminum alloy sheet obtained by solution treatment is water cooled to room temperature; and then artificial aging treatment is performed to obtain aluminum alloy sheet in the peak aging state; the temperature of artificial aging is 100-140℃ and the time of artificial aging is 20-25h. The aluminum alloy sheet after artificial aging is subjected to creep aging treatment, wherein the creep curvature of the creep aging treatment is 200-400mm and the creep temperature is 140-170℃; thus, aluminum alloy profiles are obtained.

2. The method for preparing the aluminum alloy profile according to claim 1, characterized in that, The aluminum alloy ingot is composed of the following by mass percentage: Zn: 5.41%, Mg: 2.34%, Cu: 1.37%, Fe: 0.39%, Cr: 0.26%, Ti: 0.06%, Mn: 0.05%, Zr: 0.01%, with the balance being Al.

3. The method for preparing the aluminum alloy profile according to claim 1 or 2, characterized in that, The homogenization treatment temperature is 410-460℃, and the homogenization treatment time is 30-80h.

4. The method for preparing the aluminum alloy profile according to claim 1 or 2, characterized in that, The rolling process consists of 6 passes, with the following parameters for deformation per pass and intermediate annealing: The first pass rolls the material from 20mm to 15mm, and then holds it at 250-260℃ for 30-40 minutes. The second pass rolls the material from 15mm to 12mm, and then holds it at 270-350℃ for 40-60 minutes. The third pass rolls the material from 12mm to 9mm, and then holds it at 300-320℃ for 30-40 minutes. The fourth pass rolls the material from 9mm to 6mm, and then holds it at 300-320℃ for 30-40 minutes. The fifth pass rolls the material from 6mm to 5mm, and then holds it at 300-320℃ for 40-45 minutes. The sixth pass rolls the material from 5mm to 4mm, and then holds it at 250-270℃ for 30-35 minutes.

5. The method for preparing the aluminum alloy profile according to claim 1 or 2, characterized in that, The solution treatment temperature is 460-480℃, and the solution treatment time is 1-2 hours.

6. An aluminum alloy profile, characterized in that, It is prepared by the method of any one of claims 1-5.

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