High-strength low-deformation-resistance aluminum alloy profile and preparation and application thereof

Abstract

The invention relates to the technical field of preparation of aluminum alloy profiles, and discloses a high-strength low-deformation-resistance aluminum alloy profile and preparation and application thereof. By reasonably designing alloy components and process parameters, superposition of double strengthening phases is achieved, and therefore the mechanical property of the material is greatly improved. Meanwhile, corrosion resistance reduction caused by high zinc content needs to be avoided, deformation resistance increase caused by solid solution of magnesium and copper elements during high-temperature extrusion is reduced, the extrudable performance of the material is improved, and therefore the requirement for producing high-strength profile products with complex sections is met. The prepared aluminum alloy creatively contains more elements such as zinc, magnesium, silicon and copper at the same time. Through the processes of two-stage homogenization treatment, on-line solid solution extrusion forming, multi-stage aging treatment and the like, superposition of two strengthening phases of ZnMgCu and MgSi can be achieved, corrosion resistance reduction caused by high zinc content is avoided while the strength is improved, deformation resistance is reduced, the extrudable performance is improved, and the method is very suitable for producing high-strength profile products with complex sections.

Description

Technical Field

[0001] The present invention relates to the technical field of the preparation of aluminum alloy profiles, and particularly relates to a high-strength and low-deformation-resistance aluminum alloy profile and its preparation and application. Background Art

[0002] Due to its advantages such as light weight, non-rusting and non-corrosive, and recyclability, aluminum alloy has been widely used in fields such as automobiles and aerospace. However, there are some problems with existing 6-series and 7-series aluminum alloys. For example, only a single-component strengthening phase is used, resulting in insufficient strength; a high zinc content will reduce the corrosion resistance; when magnesium and copper elements are dissolved in the alloy during hot extrusion, it will cause an increase in deformation resistance and reduce the extrudability. Therefore, it is difficult for existing aluminum alloys to simultaneously meet the requirements of high strength, low deformation resistance, and good corrosion resistance, and it is impossible to produce high-strength profiles with complex cross-sections, which restricts the development of automotive lightweighting.

[0003] Some existing 6-series and 7-series aluminum alloys and their preparations can be referred to the Chinese patent literature with publication numbers CN118006975A, CN117867341A, and CN114790528A. Summary of the Invention

[0004] Aiming at the problems existing in the prior art, the purpose of the present invention is to provide an aluminum alloy profile and a preparation method that can simultaneously meet the requirements of high strength, low deformation resistance, and good corrosion resistance, which is conducive to the production of aluminum alloy profiles with complex cross-sections, and further to solve one or more technical problems existing in the prior art, and at least provide a beneficial choice or create conditions.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions.

[0006] A preparation method of a high-strength and low-deformation-resistance aluminum alloy profile, and its preparation steps are as follows: 1) Prepare an aluminum rod, and the alloy composition of the aluminum rod is as follows: magnesium 1.0%-2.0%, silicon 0.5%-1.0%, zinc 1.5%-2.5%, iron less than 0.2%, manganese 0.05%-0.20%, copper 0.2%-0.5%, lanthanum 0.05%-0.15%, tin 0.05%-0.15%, and the balance is aluminum, by weight percentage.

[0007] 2) Homogenization treatment, perform double-stage homogenization treatment on the aluminum rod. The first-stage homogenization temperature is 400°C - 450°C, and the time is 6h - 12h. The second-stage homogenization temperature is 510°C - 560°C, and the time is 4h - 10h.

[0008] 3) Extrusion, extrude the homogenized aluminum rod to obtain an aluminum alloy profile with the required cross-sectional shape. The extrusion exit temperature is above 520°C, and the online quenching cooling rate is greater than 350°C / min.

[0009] 4) Multi-stage aging treatment: The extruded aluminum alloy profiles are subjected to multi-stage aging treatment to improve strength. The temperature of the first-stage aging treatment is 80°C - 100°C, and the time is 2h - 6h. The temperature of the second-stage aging treatment is 120°C - 140°C, and the time is 8h - 20h. The temperature of the third-stage aging treatment is 160°C - 180°C, and the time is 2h - 6h.

[0010] In one embodiment, a method for preparing a high-strength and low-deformation-resistance aluminum alloy profile comprises the following preparation steps: 1) Prepare an aluminum rod. The alloy composition of the aluminum rod is as follows: magnesium 1.5%, silicon 0.7%, zinc 2.0%, iron 0.15%, manganese 0.1%, copper 0.3%, lanthanum 0.1%, tin 0.1%, and the balance is aluminum, by weight percentage; 2) Homogenization treatment: The aluminum rod is subjected to two-stage homogenization treatment. The temperature of the first-stage homogenization is 420°C, and the time is 10h. The temperature of the second-stage homogenization is 540°C, and the time is 6h; 3) Extrusion: The homogenized aluminum rod is extruded to obtain an aluminum alloy profile with the required cross-sectional shape. The extrusion outlet temperature is above 520°C, and the online quenching cooling rate is greater than 350°C / min; 4) Multi-stage aging treatment: The temperature of the first-stage aging treatment is 90°C, and the time is 4 hours. The temperature of the second-stage aging treatment is 130°C, and the time is 10 hours. The temperature of the third-stage aging treatment is 170°C, and the time is 4 hours.

[0011] In one embodiment, a method for preparing a high-strength and low-deformation-resistance aluminum alloy profile comprises the following preparation steps: 1) Prepare an aluminum rod. The alloy composition of the aluminum rod is as follows: magnesium 1.8%, silicon 0.8%, zinc 2.3%, iron 0.18%, manganese 0.15%, copper 0.4%, lanthanum 0.15%, tin 0.15%, and the balance is aluminum, by weight percentage; 2) Homogenization treatment: The aluminum rod is subjected to two-stage homogenization treatment. The temperature of the first-stage homogenization is 450°C, and the time is 8h. The temperature of the second-stage homogenization is 560°C, and the time is 5h; 3) Extrusion: The homogenized aluminum rod is extruded to obtain an aluminum alloy profile with the required cross-sectional shape. The extrusion outlet temperature is above 520°C, and the online quenching cooling rate is greater than 350°C / min; 4) Multi-stage aging treatment: The temperature of the first-stage aging treatment is 100°C, and the time is 3 hours. The temperature of the second-stage aging treatment is 140°C, and the time is 8 hours. The temperature of the third-stage aging treatment is 180°C, and the time is 3 hours.

[0012] In one embodiment, a method for preparing a high-strength and low-deformation-resistance aluminum alloy profile is as follows: 1) Prepare an aluminum rod. The alloy composition of the aluminum rod is as follows: magnesium 1.2%, silicon 0.6%, zinc 1.8%, iron 0.12%, manganese 0.08%, copper 0.25%, lanthanum 0.08%, tin 0.08%, and the balance is aluminum, by weight percentage; 2) Homogenization treatment. The aluminum rod is subjected to a two-stage homogenization treatment. The first-stage homogenization temperature is 400°C and the time is 12 h. The second-stage homogenization temperature is 510°C and the time is 10 h; 3) Extrusion. The homogenized aluminum rod is extruded to obtain an aluminum alloy profile with the required cross-sectional shape. The extrusion exit temperature is above 520°C, and the online quenching cooling rate is greater than 350°C / min; 4) Multi-stage aging treatment. The first-stage aging treatment temperature is 80°C and the time is 6 hours; the second-stage aging treatment temperature is 120°C and the time is 20 hours; the third-stage aging treatment temperature is 160°C and the time is 6 hours.

[0013] In one embodiment, a method for preparing a high-strength and low-deformation-resistance aluminum alloy profile is as follows: 1) Prepare an aluminum rod. The alloy composition of the aluminum rod is as follows: magnesium 1.6%, silicon 0.9%, zinc 2.2%, iron 0.16%, manganese 0.12%, copper 0.35%, lanthanum 0.12%, tin 0.12%, and the balance is aluminum, by weight percentage; 2) Homogenization treatment. The aluminum rod is subjected to a two-stage homogenization treatment. The first-stage homogenization temperature is 430°C and the time is 9 h. The second-stage homogenization temperature is 530°C and the time is 7 h; 3) Extrusion. The homogenized aluminum rod is extruded to obtain an aluminum alloy profile with the required cross-sectional shape. The extrusion exit temperature is above 520°C, and the online quenching cooling rate is greater than 350°C / min; 4) Multi-stage aging treatment. The first-stage aging treatment temperature is 95°C and the time is 5 hours; the second-stage aging treatment temperature is 135°C and the time is 12 hours; the third-stage aging treatment temperature is 175°C and the time is 5 hours.

[0014] On the other hand, the present invention also provides a high-strength and low-deformation-resistance aluminum alloy profile, which is prepared by using the method for preparing a high-strength and low-deformation-resistance aluminum alloy profile as described above.

[0015] On the other hand, the present invention also provides the application of the high-strength and low-deformation-resistance aluminum alloy profile as described above in automotive profiles with a multi-cavity structure.

[0016] On the other hand, the present invention also provides the application of the high-strength and low-deformation-resistance aluminum alloy profile as described above in an automotive battery tray or an automotive sill beam.

[0017] By reasonably designing the alloy composition and process parameters, the present invention realizes the superposition of dual strengthening phases, thereby greatly improving the mechanical properties of the material. At the same time, it is also necessary to avoid the decrease in corrosion resistance caused by high zinc content, and reduce the increase in deformation resistance caused by the solution of magnesium and copper elements during hot extrusion, and improve the extrudability of the material, so as to meet the requirements for producing high-strength profiles with complex cross-sections.

[0018] The aluminum alloy prepared by the present invention innovatively contains relatively more elements such as zinc, magnesium, silicon, and copper at the same time. Through processes such as two-stage homogenization treatment, on-line solution extrusion forming, and multi-stage aging treatment, the superposition of ZnMgCu and MgSi two strengthening phases can be realized, improving the strength while avoiding the decrease in corrosion resistance caused by high zinc content, and reducing the deformation resistance and improving the extrudability, which is very suitable for producing high-strength profiles with complex cross-sections.

[0019] Compared with the prior art, the present invention has at least the following beneficial effects.

[0020] First, by reasonably designing the alloy composition and process parameters, the present invention realizes the superposition of ZnMgCu and MgSi two strengthening phases, breaking through the limitation of using only single-component strengthening phases in traditional 6-series and 7-series alloys, and greatly improving the mechanical properties of the material.

[0021] Second, the present invention adopts a unique multi-stage aging treatment process, avoiding the decrease in corrosion resistance caused by high zinc content, and ensuring good corrosion resistance while improving the strength.

[0022] Third, the presence of zinc elements inside the alloy greatly reduces the effect of the increase in deformation resistance caused by the solution of magnesium and copper elements inside the alloy during hot extrusion, significantly improving the extrudability of the material. Among alloys with the same strength, the deformation resistance at 500 °C is reduced by about 20%, and the extrusion efficiency can be increased by more than 30%.

[0023] Fourth, the new aluminum alloy prepared by the present invention is very suitable for producing high-strength profiles with complex cross-sections, such as automotive battery trays, sill beams, etc., which is beneficial to automotive lightweighting and energy conservation and emission reduction.

[0024] Some other beneficial effects of the present invention will become more obvious in the following description or be understood in practice. Specific Embodiments

[0025] In order to make the objectives, technical solutions and advantages of the present invention clearer, the following further describes the present invention in detail with reference to embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0026] A method for preparing a high-strength and low-deformation-resistance aluminum alloy profile comprises the following steps:

[0027] I. Preparation of aluminum rods. The alloy composition of the aluminum rods is as follows: magnesium 1.0% - 2.0%, silicon 0.5% - 1.0%, zinc 1.5% - 2.5%, iron less than 0.2%, manganese 0.05% - 0.20%, copper 0.2% - 0.5%, lanthanum 0.05% - 0.15%, tin 0.05% - 0.15%, with the balance being aluminum, by weight percentage.

[0028] II. Homogenization treatment. The aluminum rods are subjected to two - stage homogenization treatment. The temperature of the first - stage homogenization is 400°C - 450°C, and the time is 6h - 12h. The temperature of the second - stage homogenization is 510°C - 560°C, and the time is 4h - 10h.

[0029] The purpose of the two - stage homogenization is to ensure that most of the magnesium and all of the zinc and copper elements complete solid solution through the first - stage homogenization treatment, avoiding the eutectic over - burning defect caused by direct high temperature. Then, through the second - stage homogenization treatment, all of the magnesium and silicon elements complete solid solution, and the uniform distribution of the iron phase is promoted.

[0030] III. Extrusion. The homogenized aluminum rods are extruded to obtain aluminum alloy profiles with the required cross - sectional shape. Online solution treatment is carried out during the extrusion process. The extrusion outlet temperature is guaranteed to be above 520°C, and the online quenching cooling rate is greater than 350°C / min.

[0031] IV. Multi - stage aging treatment. The aluminum alloy profiles obtained by extrusion are subjected to multi - stage aging treatment to improve the strength. The temperature of the first - stage aging treatment is 80°C - 100°C, and the time is 2h - 6h. The temperature of the second - stage aging treatment is 120°C - 140°C, and the time is 8h - 20h. The temperature of the third - stage aging treatment is 160°C - 180°C, and the time is 2h - 6h.

[0032] The purpose of the multi - stage aging treatment is to first promote the precipitation of the internal ZnMgCu strengthening phase and the MgSi pre - β" phase through the low - temperature first and second - stage aging, and then promote the coarsening and disconnection of the ZnMg strengthening phase at the grain boundaries through the third - stage aging, improving the corrosion resistance of the material, and promoting the transformation of the MgSi pre - β" phase to the β" phase, synchronously increasing the strengthening effect of the MgSi strengthening phase.

[0033] Through the above process, the present invention realizes the superposition of two strengthening phases, ZnMgCu and MgSi, thereby greatly improving the mechanical properties of the material. At the same time, the unique multi - stage aging treatment process avoids the decrease in corrosion resistance caused by a high zinc content. Moreover, the presence of zinc elements inside the alloy greatly reduces the increase in deformation resistance caused by the solid solution of magnesium and copper elements inside the alloy during high - temperature extrusion, significantly improving the extrudability of the material.

[0034] To better demonstrate the progressiveness of the present invention, Examples 1-4 and Comparative Examples 1-6 are formed by defining the alloy composition and preparation process. The alloy compositions and preparation process parameters of Examples 1-4 and Comparative Examples 1-6 are shown in Table 1. In each example and comparative example, except for the different parameters shown in Table 1, other parameters are default to be the same.

[0035] Table 1. Comparison of alloy compositions and preparation processes of Examples 1-4 and Comparative Examples 1-6 Type Magnesium Silicon Zinc Iron Manganese Copper Lanthanum Tin Two-stage homogenization treatment Multi-stage aging treatment Example 1 1.5 0.7 2 0.15 0.1 0.3 0.1 0.1 First stage: 420 °C, 10 hours; Second stage: 540 °C, 6 hours First stage: 90 °C, 4 hours; Second stage: 130 °C, 10 hours; Third stage: 170 °C, 4 hours Example 2 1.8 0.8 2.3 0.18 0.15 0.4 0.15 0.15 First stage: 450 °C, 8 hours; Second stage: 560 °C, 5 hours First stage: 100 °C, 3 hours; Second stage: 140 °C, 8 hours; Third stage: 180 °C, 3 hours Example 3 1.2 0.6 1.8 0.12 0.08 0.25 0.08 0.08 First stage: 400 °C, 12 hours; Second stage: 510 °C, 10 hours First stage: 80 °C, 6 hours; Second stage: 120 °C, 20 hours; Third stage: 160 °C, 6 hours Example 4 1.6 0.9 2.2 0.16 0.12 0.35 0.12 0.12 First stage: 430 °C, 9 hours; Second stage: 530 °C, 7 hours First stage: 95 °C, 5 hours; Second stage: 135 °C, 12 hours; Third stage: 175 °C, 5 hours Comparative example 1 1.8 0.8 2.3 0.18 0.15 0.4 0.15 0.15 First stage: 450 °C, 8 hours First stage: 100 °C, 3 hours; Second stage: 140 °C, 8 hours; Third stage: 180 °C, 3 hours Comparative example 2 1.8 0.8 2.3 0.18 0.15 0.4 0.15 0.15 First stage: 450 °C, 8 hours; Second stage: 560 °C, 5 hours First stage: 100 °C, 3 hours; Second stage: 140 °C, 8 hours Comparative example 3 1.8 0.8 2.3 0.18 0.15 0.4 0.15 0.15 First stage: 450 °C, 8 hours; Second stage: 560 °C, 5 hours First stage: 100 °C, 3 hours; Second stage: 180 °C, 3 hours Comparative example 4 1.8 0.8 2.3 0.18 0.15 0.4 0.15 0.15 First stage: 450 °C, 8 hours; Second stage: 560 °C, 5 hours First stage: 140 °C, 8 hours; Second stage: 180 °C, 3 hours Comparative example 5 1.7 0.05 2.2 0.17 0.15 0.35 0.14 0.13 First stage: 450 °C, 8 hours; Second stage: 560 °C, 5 hours First stage: 100 °C, 3 hours; Second stage: 140 °C, 8 hours; Third stage: 180 °C, 3 hours Comparative example 6 1.9 0.7 2.4 0.2 0.12 0.38 0 0 First stage: 450 °C, 8 hours; Second stage: 560 °C, 5 hours First stage: 100 °C, 3 hours; Second stage: 140 °C, 8 hours; Third stage: 180 °C, 3 hours

[0036] The product properties of the aluminum alloy profiles prepared in each example and comparative example are shown in Table 2.

[0037] Table 2. Comparison of product properties of Examples 1-4 and Comparative Examples 1-6 Type Tensile strength (MPa) Yield strength (MPa) Elongation rate (%) Intergranular corrosion grade Example 1 369 339 12.5 2 Example 2 388 353 11.8 2 Example 3 362 332 12.9 2 Example 4 375 348 12.3 2 Comparative example 1 351 320 12.2 2 Comparative example 2 344 301 13.5 1 Comparative example 3 347 312 12.8 2 Comparative example 4 359 321 11.9 3 Comparative example 5 315 289 13.5 2 Comparative example 6 372 328 9.5 4

[0038] It can be seen from Table 1 and Table 2 that when the double-stage homogenization process is changed to a single-stage homogenization process, the tensile strength and yield strength of the product both decrease significantly (Comparative Example 1); when the multi-stage aging treatment is changed to a two-stage aging treatment, the tensile strength and yield strength of the product also both decrease significantly, and even the corrosion resistance decreases (Comparative Examples 2-4); when the silicon content is lower than the lower limit, the tensile strength and yield strength of the product will decrease significantly (Comparative Example 5); when the lanthanum and tin contents are lower than the lower limit, the elongation and corrosion resistance of the product will decrease significantly (Comparative Example 6).

[0039] In the present invention, the decrease in the deformation resistance is shown in Table 3.

[0040] Table 3. Extrusion deformation resistance in Examples 1-4 Type Maximum breakthrough pressure Mpa Average extrusion speed m / min Yield strength Mpa after aging Example 1 266 5.9 339 Example 2 272 5.5 353 Example 3 264 6.1 332 Example 4 268 5.7 348 6082 alloy 281 5.2 284 6013 alloy 292 4.4 332 6110 alloy 299 3.2 376

[0041] It can be seen from Table 3 that in alloys of the same strength, the deformation resistance at 500 °C is reduced by about 20%, and the extrusion efficiency can be increased by more than 30%.

[0042] It should be noted that the technical features of the above examples can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above examples are described. However, as long as these combinations of technical features do not conflict, they should be considered to be within the scope described in this specification.

[0043] The above embodiments merely represent several implementation manners of the present invention. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several variations and improvements can be made, and these all fall within the protection scope of the present invention. The parts not described in the specific embodiments are all prior art or common general knowledge.

[0044] In addition, it should be noted that in the description of the present invention, the detailed description of the preferred implementation methods of the present invention and the included embodiments can more easily understand the content of the present invention. Unless otherwise defined, all the technologies and scientific terms used in the present invention have the same meanings as those commonly understood by those of ordinary skill in the art to which the present invention pertains. When there is a contradiction, the definition in this specification shall prevail.

[0045] In the present invention, the term "prepared from" is synonymous with "comprising". The terms "comprising", "including", "having", "containing" or any other variation thereof used in the present invention are intended to cover non-exclusive inclusion. For example, a composition, step, method, article or device containing the listed elements is not necessarily limited to those elements, but may include other elements not expressly listed or elements inherent to such composition, step, method, article or device.

[0046] In the present invention, when an equivalent, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper preferred values and lower preferred values, it should be understood that all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value are specifically disclosed, regardless of whether the range is separately disclosed. For example, when the range "1 to 5" is disclosed, the described range should be interpreted as including ranges "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described in the present invention, unless otherwise stated, the range is intended to include its end values and all integers and fractions within the range.

[0047] Furthermore, the indefinite articles "a" and "an" before an element or component of the present invention do not limit the quantity requirement (i.e., the number of occurrences) of the element or component. Therefore, "a" or "an" should be interpreted as including one or at least one, and the singular form of an element or component also includes the plural form, unless the quantity clearly refers to the singular form.

Claims

1. A method for preparing a high-strength and low-deformation-resistance aluminum alloy profile, characterized in that: The preparation steps are as follows: 1) preparing an aluminum rod, the alloy composition of the aluminum rod is as follows: magnesium 1.0%-2.0%, silicon 0.5%-1.0%, zinc 1.5%-2.5%, iron less than 0.2%, manganese 0.05%-0.20%, copper 0.2%-0.5%, lanthanum 0.05%-0.15%, tin 0.05%-0.15%, and the balance is aluminum, calculated by weight percentage; 2) Homogenization treatment: the aluminum rod is subjected to a two-stage homogenization treatment, the first-stage homogenization temperature is 400℃-450℃, the time is 6h-12h, and the second-stage homogenization temperature is 510℃-560℃, the time is 4h-10h; 3) Extrusion: Extrude the homogenized aluminum rod to obtain aluminum alloy profiles with the required cross-sectional shape. The extrusion outlet temperature is above 520°C, and the online quenching cooling rate is greater than 350°C / min; 4) Multi-stage aging treatment: The extruded aluminum alloy profiles are subjected to multi-stage aging treatment to improve their strength. The primary aging treatment temperature is 80℃-100℃, the time is 2h-6h, the secondary aging treatment temperature is 120℃-140℃, the time is 8h-20h, and the tertiary aging treatment temperature is 160℃-180℃, the time is 2h-6h.

2. The method for preparing a high-strength and low-deformation-resistance aluminum alloy profile according to claim 1, characterized in that: The preparation steps are as follows: 1) preparing an aluminum rod, the alloy composition of the aluminum rod is as follows: 1.5% magnesium, 0.7% silicon, 2.0% zinc, 0.15% iron, 0.1% manganese, 0.3% copper, 0.1% lanthanum, 0.1% tin, and the balance is aluminum, calculated by weight percentage; 2) Homogenization treatment: the aluminum rod is subjected to a two-stage homogenization treatment, the first-stage homogenization temperature is 420°C, the time is 10 hours, and the second-stage homogenization temperature is 540°C, the time is 6 hours; 3) Extrusion: Extrude the homogenized aluminum rod to obtain aluminum alloy profiles with the required cross-sectional shape. The extrusion outlet temperature is above 520°C, and the online quenching cooling rate is greater than 350°C / min; 4) Multi-stage aging treatment, the first-stage aging treatment temperature is 90℃, the time is 4 hours; the second-stage aging treatment temperature is 130℃, the time is 10 hours; the third-stage aging treatment temperature is 170℃, the time is 4 hours.

3. The method for preparing a high-strength and low-deformation-resistance aluminum alloy profile according to claim 1, characterized in that: The preparation steps are as follows: 1) preparing an aluminum rod, the alloy composition of the aluminum rod is as follows: 1.8% magnesium, 0.8% silicon, 2.3% zinc, 0.18% iron, 0.15% manganese, 0.4% copper, 0.15% lanthanum, 0.15% tin, and the balance is aluminum, calculated by weight percentage; 2) Homogenization treatment: the aluminum rod is subjected to a two-stage homogenization treatment, the first-stage homogenization temperature is 450°C, the time is 8 hours, and the second-stage homogenization temperature is 560°C, the time is 5 hours; 3) Extrusion: Extrude the homogenized aluminum rod to obtain aluminum alloy profiles with the required cross-sectional shape. The extrusion outlet temperature is above 520°C, and the online quenching cooling rate is greater than 350°C / min; 4) Multi-stage aging treatment, the first-stage aging treatment temperature is 100℃, the time is 3 hours; the second-stage aging treatment temperature is 140℃, the time is 8 hours; the third-stage aging treatment temperature is 180℃, the time is 3 hours.

4. The method for preparing a high-strength and low-deformation-resistance aluminum alloy profile according to claim 1, characterized in that: The preparation steps are as follows: 1) preparing an aluminum rod, the alloy composition of the aluminum rod is as follows: 1.2% magnesium, 0.6% silicon, 1.8% zinc, 0.12% iron, 0.08% manganese, 0.25% copper, 0.08% lanthanum, 0.08% tin, and the balance is aluminum, calculated by weight percentage; 2) Homogenization treatment: the aluminum rod is subjected to a two-stage homogenization treatment, the first-stage homogenization temperature is 400°C, the time is 12h, and the second-stage homogenization temperature is 510°C, the time is 10h; 3) Extrusion: Extrude the homogenized aluminum rod to obtain aluminum alloy profiles with the required cross-sectional shape. The extrusion outlet temperature is above 520°C, and the online quenching cooling rate is greater than 350°C / min; 4) Multi-stage aging treatment, the first-stage aging treatment temperature is 80℃, the time is 6 hours; the second-stage aging treatment temperature is 120℃, the time is 20 hours; the third-stage aging treatment temperature is 160℃, the time is 6 hours.

5. The method for preparing a high-strength and low-deformation-resistance aluminum alloy profile according to claim 1, characterized in that: The preparation steps are as follows: 1) preparing an aluminum rod, the alloy composition of the aluminum rod is as follows: 1.6% magnesium, 0.9% silicon, 2.2% zinc, 0.16% iron, 0.12% manganese, 0.35% copper, 0.12% lanthanum, 0.12% tin, and the balance is aluminum, calculated by weight percentage; 2) Homogenization treatment: the aluminum rod is subjected to a two-stage homogenization treatment, the first-stage homogenization temperature is 430°C, the time is 9 hours, and the second-stage homogenization temperature is 530°C, the time is 7 hours; 3) Extrusion: Extrude the homogenized aluminum rod to obtain aluminum alloy profiles with the required cross-sectional shape. The extrusion outlet temperature is above 520°C, and the online quenching cooling rate is greater than 350°C / min; 4) Multi-stage aging treatment, the first-stage aging treatment temperature is 95℃, the time is 5 hours; the second-stage aging treatment temperature is 135℃, the time is 12 hours; the third-stage aging treatment temperature is 175℃, the time is 5 hours.

6. A high-strength and low-deformation-resistance aluminum alloy profile, characterized in that: The high-strength and low-deformation-resistance aluminum alloy profile is prepared by the preparation method of any one of claims 1 to 5.

7. Application of the high-strength and low-deformation-resistance aluminum alloy profile as claimed in claim 6 to automobile profiles with a multi-cavity structure.

8. Application of the high-strength and low-deformation-resistance aluminum alloy profile as claimed in claim 6 to an automobile battery tray or an automobile door sill beam.