High-toughness al-mg-si series aluminum alloy and preparation method and application thereof

Abstract

The application discloses a kind of high tough Al-Mg-Si series aluminum alloy and its preparation method and application, it is related to aluminum alloy material technical field.The chemical elements of Al-Mg-Si series aluminum alloy is added with certain content Nd and Ce element, Ce element can hinder dislocation movement and subgrain boundary migration merger, inhibit the growth of recrystallized grain, and then refine deformation structure, improve deformation mechanical property.Nd can retain more small-angle grain boundary, promote subgrain boundary precipitated phase morphology tends to round and distribution discrete.Therefore, the Al-Mg-Si series aluminum alloy provided by the application can ensure good toughness, corrosion resistance and welding performance while improving the strength of Al-Mg-Si series aluminum alloy, and the comprehensive performance is more excellent.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy materials technology, and more specifically, to a high-strength and high-toughness Al-Mg-Si aluminum alloy, its preparation method, and its application. Background Technology

[0002] Aluminum alloys are a common type of alloy material with wide applications in various fields. Based on the main alloying elements, aluminum alloys can be classified into series 1 to 8. Series 6 aluminum alloys primarily contain Al, Mg, and Si, and are therefore also known as Al-Mg-Si aluminum alloys. Al-Mg-Si aluminum alloys possess high strength and toughness, along with excellent resistance to stress corrosion, making them widely used in the automotive, electronics, and building materials industries.

[0003] Currently, 6-series aluminum alloys, represented by grades such as 6061, 6005, and 6082, are the main materials for aluminum alloy profiles used in rail transportation, new energy vehicles, and other fields. These alloys possess excellent extrusion processing properties, as well as good corrosion resistance and weldability; however, their strength is relatively low, making it difficult to meet the increasingly stringent performance requirements of aluminum alloy profiles in rail transportation, new energy vehicles, and other fields. Therefore, simultaneously improving the strength, toughness, corrosion resistance, and weldability of 6-series aluminum alloys is one of the common goals pursued in this field.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a high-strength and high-toughness Al-Mg-Si aluminum alloy, its preparation method, and its application.

[0006] This invention is implemented as follows:

[0007] In a first aspect, the present invention provides a high-strength and high-toughness Al-Mg-Si aluminum alloy, comprising, by mass percentage: 1.1%≤Mg≤1.4%, 1.3%≤Si≤1.8%, 0.5%≤Cu≤1.5%, 0.5%≤Zn≤1.5%, 0.05%≤Mn≤0.25%, 0.05%≤Cr≤0.25%, 0.02%≤Ce≤0.2%, 0.02%≤Nd≤0.2%, 0.05%≤Ce+Nd≤0.25%, Fe≤0.2%, with each other impurity element having a single content ≤0.05%, the total amount of other impurity elements ≤0.12%, and the balance being Al.

[0008] Secondly, the present invention provides a method for preparing a high-strength and high-toughness Al-Mg-Si aluminum alloy as described in the foregoing embodiments, comprising melting raw materials of each element in proportion to obtain a melt, and then semi-continuously casting the melt through a crystallizer to obtain an ingot. The semi-continuous casting process also includes applying an ultrasonic field to the melt in the crystallizer.

[0009] Thirdly, the present invention provides the application of a high-strength and high-toughness Al-Mg-Si aluminum alloy as described in the foregoing embodiments or a high-strength and high-toughness Al-Mg-Si aluminum alloy prepared by any of the foregoing embodiments in any of the fields of automobiles, electronics or building materials.

[0010] The present invention has the following beneficial effects:

[0011] This invention provides a high-strength and high-toughness Al-Mg-Si aluminum alloy, its preparation method, and its applications. By adding a certain amount of Nd and Ce elements to the chemical elements of the Al-Mg-Si aluminum alloy, Ce can hinder dislocation movement and subgrain boundary migration and merging, suppress the growth of recrystallized grains, thereby refining the deformed microstructure and improving its mechanical properties. Nd can retain more small-angle grain boundaries, promoting the morphology of precipitates at subgrain boundaries to become more rounded and dispersed. Therefore, the Al-Mg-Si aluminum alloy provided by this invention can improve the strength of the Al-Mg-Si aluminum alloy while ensuring good toughness, corrosion resistance, and weldability, resulting in superior overall performance. Detailed Implementation

[0012] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0013] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0014] In a first aspect, the present invention provides a high-strength and high-toughness Al-Mg-Si aluminum alloy, comprising, by mass percentage: 1.1%≤Mg≤1.4%, 1.3%≤Si≤1.8%, 0.5%≤Cu≤1.5%, 0.5%≤Zn≤1.5%, 0.05%≤Mn≤0.25%, 0.05%≤Cr≤0.25%, 0.02%≤Ce≤0.2%, 0.02%≤Nd≤0.2%, 0.05%≤Ce+Nd≤0.25%, Fe≤0.2%, with each other impurity element having a single content ≤0.05%, the total amount of other impurity elements ≤0.12%, and the balance being Al.

[0015] The Al-Mg-Si aluminum alloy provided by this invention has an elemental composition that, compared to existing conventional Al-Mg-Si aluminum alloys, increases the content of Mg, Si, and Cu, while also increasing the content of Zn, which is beneficial for improving the strength and toughness of the aluminum alloy. Furthermore, the combination of Mn, Cr, Nd, and Ce elements helps to refine the as-cast and deformed microstructures of the aluminum alloy. Moreover, by reducing the individual and total content of impurity elements, the adverse effects of impurities in the Al-Mg-Si aluminum alloy provided by this invention are reduced, which helps to improve the purity of the melt after smelting and reduce the number of coarse and sharp second phases.

[0016] In optional embodiments, the content, by mass percentage, includes: 1.2% ≤ Mg ≤ 1.3%, 1.5% ≤ Si ≤ 1.6%, 1.0% ≤ Cu ≤ 1.2%, 1.0% ≤ Zn ≤ 1.2%, 0.12% ≤ Mn ≤ 0.15%, 0.12% ≤ Cr ≤ 0.15%, 0.05% ≤ Ce ≤ 0.08%, and 0.05% ≤ Nd ≤ 0.08%.

[0017] 0.10%≤Ce+Nd≤0.14%, Fe≤0.15%, the content of other impurity elements is ≤0.03% for each individual element, the total amount of other impurity elements is ≤0.11%, and the balance is Al.

[0018] In optional embodiments, the Al-Mg-Si aluminum alloy provided by the present invention is preferably suitable for aluminum alloy ingots with a diameter of 100 to 300 mm, so as to achieve better mechanical properties of the aluminum alloy ingots.

[0019] Secondly, the present invention provides a method for preparing a high-strength and high-toughness Al-Mg-Si aluminum alloy as described in the foregoing embodiments, comprising melting raw materials of each element in proportion to obtain a melt, and then semi-continuously casting the melt through a crystallizer to obtain an ingot. The semi-continuous casting process also includes applying an ultrasonic field to the melt in the crystallizer.

[0020] By controlling the elemental composition of Al-Mg-Si aluminum alloys, especially the content of Nd and Ce, and by applying an ultrasonic field to the melt in the crystallizer during the semi-continuous casting process, not only can the as-cast microstructure of the aluminum alloy be refined, but it is also convenient to control the size, quantity, morphology and distribution of precipitated phases during heat treatment, so as to ensure that Al-Mg-Si aluminum alloys have better comprehensive properties.

[0021] In an optional embodiment, to more clearly illustrate the preparation method of the aforementioned high-strength and high-toughness Al-Mg-Si aluminum alloy provided by the present invention, it includes the following steps:

[0022] S01. Smelting: Smelting raw materials of various elements in proportion to obtain a melt.

[0023] In optional embodiments, the raw materials for the melt include pure Al, pure Mg, pure Zn, AlCu master alloy, AlSi master alloy, AlCr master alloy, AlMn master alloy, AlCe master alloy, and AlNd master alloy. All raw materials for the melt can be commercially available alternatives.

[0024] In an optional embodiment, the smelting process includes adding pure Al, pure Zn, AlCu master alloy, AlSi master alloy, AlCr master alloy, and AlMn master alloy into a smelting furnace for smelting at a smelting temperature of 750–800°C; after complete melting, adding AlCe master alloy and AlNd master alloy and stirring thoroughly; after complete melting, letting stand for 20–25 minutes, then adding pure Mg and stirring thoroughly; after complete melting, performing the following operations in sequence: adding refining agent, degassing for 10–20 minutes, removing slag, letting stand for 20–30 minutes, and adding refining agent.

[0025] By melting each raw material in batches, the role of each raw material can be fully utilized, and burn-off can be effectively reduced.

[0026] S02, Semi-continuous casting: The melt obtained in step S01 is poured into the crystallizer for semi-continuous casting.

[0027] In an optional implementation, because casting speeds that are too low can easily lead to cold shut defects and reduced production efficiency, while casting speeds that are too high can easily lead to an increase in porosity defects, a greater tendency for hot cracking, and an increased risk of run-out in aluminum alloys, the casting speed for semi-continuous casting is 40–90 mm / min, for example, any value or a range between any two of 40 mm / min, 50 mm / min, 60 mm / min, 70 mm / min, 80 mm / min, or 90 mm / min.

[0028] In an optional implementation, excessively low cooling water flow rate can lead to coarse microstructure and low ingot density, while excessively high cooling water flow rate can increase the tendency for cold shuts and hot cracks. Therefore, the cooling water flow rate for semi-continuous casting is 25–70 L / min, for example, any value or a range between any two of 25 L / min, 30 L / min, 40 L / min, 50 L / min, 60 L / min, or 70 L / min.

[0029] In an optional implementation, because excessively low casting temperatures can lead to increased porosity and oxide film defects, while excessively high casting temperatures can exacerbate surface defects such as increased feathery crystals, increased hot cracking tendency, and the exacerbation of scratches and segregation. Therefore, the casting temperature for semi-continuous casting is 680–740°C. This casting temperature, for example, can be any value or a range between any two of 680°C, 690°C, 700°C, 710°C, 720°C, 730°C, or 740°C.

[0030] In an optional implementation, the process of applying the ultrasonic field includes placing an ultrasonic radiating rod at the center of the crystallizer after the casting speed has stabilized, with the bottom of the ultrasonic radiating rod immersed in the melt for ultrasonication.

[0031] Before semi-continuous casting, the casting speed of the casting machine is set to any value between 40 and 90 mm / min, for example, 50 mm / min, and then casting begins. During the casting process, starting from a standstill, the casting speed continuously increases from 0 mm / min until it reaches 50 mm / min, and then remains at 50 mm / min. Therefore, "stable casting speed" means that when the casting speed is 50 mm / min and the temperature remains constant, the casting speed is stable, and an ultrasonic field can be applied to the crystallizer.

[0032] By applying an ultrasonic field during the casting process, the as-cast microstructure and second phase can be significantly refined through cavitation and acoustic flow effects, and the network compounds at the grain boundaries can be effectively broken. On the other hand, the ultrasonic field can increase the solid solubility of solute atoms in the grains, reduce the enrichment of coarse second phases at the grain boundaries, and promote the precipitation of more strengthening phases in subsequent treatments, such as aging treatment.

[0033] Preferably, when the ultrasonic power is too low, the effect on refining and homogenizing the ingot structure is limited; when the ultrasonic power is too high, it easily leads to deeper cavitation and severe macroscopic segregation of the aluminum alloy. Therefore, the ultrasonic power is 80–1000W, for example, any value or a range between any two values ​​from 80W, 100W, 200W, 300W, 400W, 500W, 600W, 700W, 800W, 900W, or 1000W.

[0034] Preferably, the ultrasonic frequency of the ultrasonic field is 10–15 kHz.

[0035] S03, Multi-stage homogenization heat treatment: The ingot from step S02 is subjected to a first heating and holding process and a second heating and holding process.

[0036] The first heating and heat preservation temperature is 450-460℃, and the time is 2-5 hours.

[0037] The second heating and heat preservation temperature is 540-560℃, and the time is 2-5 hours.

[0038] The purpose of multi-stage homogenization heat treatment on ingots is to reduce the size and quantity of the second phase at grain boundaries, alleviate microsegregation of elements, spheroidize or passivate the morphology of coarse and sharp second phases, and further improve the extrusion performance of aluminum alloys.

[0039] S04, Extrusion molding: Extruding the material obtained in step S03.

[0040] Preferably, the extrusion molding process parameters include: extrusion temperature of 520-550℃, extrusion speed of 1-10m / min, and extrusion ratio of 20-80.

[0041] When the extrusion temperature is too low, the aluminum alloy may not be able to exert its plasticity, making it impossible to form. When the extrusion temperature is too high, the internal structure of the aluminum alloy may overheat and burn. When the extrusion speed is too low, cracks may easily form, and production efficiency may decrease. When the extrusion speed is too high, the aluminum alloy temperature may rise too quickly, resulting in overheating of the internal structure. When the extrusion ratio is too low, the aluminum alloy may not deform sufficiently, resulting in uneven structure and inadequate performance. When the extrusion ratio is too high, the aluminum alloy may not be able to form.

[0042] S05, Solution treatment: The material obtained in step S04 is subjected to solution treatment.

[0043] Preferably, solution treatment includes holding the material obtained by extrusion molding at 550–560°C for 5–30 minutes.

[0044] S06. Artificial aging treatment: The material obtained in step S05 is subjected to artificial aging treatment.

[0045] Preferably, the artificial aging treatment includes holding the solution-treated material at 175–190°C for 3–8 hours.

[0046] By performing solid solution treatment and artificial aging on the alloy, finer, more uniformly dispersed, and narrower-sized precipitated strengthening phases are formed within the alloy grains, thereby improving the mechanical properties of the aluminum alloy.

[0047] Thirdly, the present invention provides the application of a high-strength and high-toughness Al-Mg-Si aluminum alloy as described in the foregoing embodiments or a high-strength and high-toughness Al-Mg-Si aluminum alloy prepared by any of the foregoing embodiments in any of the fields of automobiles, electronics or building materials.

[0048] Example 1

[0049] This embodiment provides a high-strength and high-toughness Al-Mg-Si aluminum alloy, comprising, by mass percentage: Mg: 1.1%, Si: 1.3%, Cu: 0.8%, Zn: 1.0%, Mn: 0.1%, Cr: 0.07%, Ce: 0.07%, Nd: 0.07%, Fe: 0.08%, with each other impurity element having a single content ≤0.05%, the total amount of other impurity elements ≤0.12%, and the balance being Al.

[0050] This embodiment also provides a method for preparing the above-mentioned high-strength and high-toughness Al-Mg-Si aluminum alloy, including the following steps:

[0051] S01. Melting: Pure Al, pure Zn, AlCu master alloy, AlSi master alloy, AlCr master alloy, and AlMn master alloy are added to the melting furnace according to the element ratio and melted at a melting temperature of 800℃. After complete melting, AlCe master alloy and AlNd master alloy are added and stirred thoroughly. After complete melting, the mixture is allowed to stand for 25 minutes, cooled to 780℃, and then pure Mg is added and stirred thoroughly. After complete melting, the following operations are performed in sequence: adding refining agent, degassing for 10 minutes, removing slag, standing for 20 minutes, and adding AlTiB refining agent.

[0052] S02, Semi-continuous Casting: When the melt temperature in the furnace from step S01 is reduced to 720°C, semi-continuous casting is initiated, resulting in an ingot diameter of 127mm. The conditions for semi-continuous casting include: cooling water flow rate of 35L / min, and a casting speed reaching 60mm / min within 2 seconds. When the ingot length reaches 30cm, the casting speed is slowly increased to 70mm / min, and continuous casting enters a stable state. At this point, the ultrasonic radiation rod is placed in the center of the crystallizer, with its bottom submerged in the molten aluminum. The ultrasonic generator is turned on, with the ultrasonic power set to 800W and the frequency set to 12kHz.

[0053] S03, Multi-stage homogenization heat treatment: The ingot from step S02 is subjected to a first heating and holding process and a second heating and holding process.

[0054] The first heating and heat preservation temperature is 450℃, and the time is 2 hours.

[0055] The second heating and heat preservation temperature is 540℃, and the time is 5 hours.

[0056] S04, Extrusion molding: The material obtained in step S03 is extruded to obtain a rod with a diameter of 20mm.

[0057] The extrusion molding process parameters include: extrusion temperature 540℃, extrusion speed 5m / min, and extrusion ratio 40.3.

[0058] S05, Solution treatment: The material obtained in step S04 is kept at 550℃ for 15 minutes and then cooled with water to perform solution treatment.

[0059] S06. Artificial aging treatment: The material obtained in step S05 is kept at 80℃ for 6 hours for artificial aging treatment.

[0060] Comparative Example 1

[0061] This comparative example provides a high-strength and high-toughness Al-Mg-Si aluminum alloy with an elemental composition similar to that of Example 1, except that Ce and Nd are not added.

[0062] This comparative example provides a method for preparing the above-mentioned high-strength and high-toughness Al-Mg-Si aluminum alloy. The specific steps are similar to those in Example 1, except that an ultrasonic field is not applied in step S02.

[0063] Comparative Example 2

[0064] This comparative example provides a high-strength and high-toughness Al-Mg-Si aluminum alloy with an elemental composition similar to that of Example 1, the only difference being the absence of Ce. Furthermore, the preparation method of this high-strength and high-toughness Al-Mg-Si aluminum alloy is the same as that of Example 1.

[0065] Comparative Example 3

[0066] This comparative example provides a high-strength and high-toughness Al-Mg-Si aluminum alloy with an elemental composition similar to that of Example 1, the only difference being the absence of Nd. Furthermore, the preparation method of this high-strength and high-toughness Al-Mg-Si aluminum alloy is the same as that of Example 1.

[0067] Comparative Example 4

[0068] This comparative example provides a high-strength and high-toughness Al-Mg-Si aluminum alloy with an elemental composition similar to that of Example 1, the only difference being the absence of Ce and Nd. Furthermore, the preparation method of this high-strength and high-toughness Al-Mg-Si aluminum alloy is the same as that of Example 1.

[0069] Comparative Example 5

[0070] This comparative example provides a high-strength and high-toughness Al-Mg-Si aluminum alloy with the same elemental composition and preparation method as Example 1, except that an ultrasonic field was not applied in the S02 step.

[0071] Comparative Example 6

[0072] This comparative example provides a high-strength and high-toughness Al-Mg-Si aluminum alloy, whose elemental composition is similar to that of Example 1, except that Ce: 0.02% and Nd: 0.02%. Furthermore, the preparation method of this high-strength and high-toughness Al-Mg-Si aluminum alloy is the same as that of Example 1.

[0073] Comparative Example 7

[0074] This comparative example provides a high-strength and high-toughness Al-Mg-Si aluminum alloy, whose elemental composition is similar to that of Example 1, except that Ce: 0.2% and Nd: 0.2%. Furthermore, the preparation method of this high-strength and high-toughness Al-Mg-Si aluminum alloy is the same as that of Example 1.

[0075] Comparative Example 8

[0076] This comparative example provides a high-strength and high-toughness Al-Mg-Si aluminum alloy with the same elemental composition as Example 1, the only difference being the location where the ultrasonic field is applied. In this comparative example, the ultrasonic field is added in step S01. After all alloying elements have melted, the bottom of the ultrasonic radiation rod is immersed in the melt and ultrasonic field treatment is applied before semi-continuous casting. The ultrasonic power is 800W and the frequency is set to 12KHz.

[0077] Experimental Example 1

[0078] The high-strength and high-toughness Al-Mg-Si aluminum alloys provided in Example 1 and Comparative Examples 1 to 8 were subjected to tensile strength testing (testing method: GB / T 16865), yield strength testing (testing method: GB / T 16865), and elongation testing (testing method: GB / T 16865), and the results are shown in Table 1.

[0079] Table 1 Properties of high-strength and high-toughness Al-Mg-Si aluminum alloys

[0080]

[0081]

[0082] As shown in Table 1, the Al-Mg-Si aluminum alloy provided in this embodiment of the invention has higher strength and elongation, achieving a simultaneous improvement in both strength and elongation, resulting in superior overall performance. A series of experiments in Example 1 and Comparative Examples 1-5 demonstrate that adding Ce and Nd elements to the Al-Mg-Si aluminum alloy, combined with the incorporation of an ultrasonic field during the semi-continuous casting process, can significantly improve the overall performance of the aluminum alloy. A series of experiments in Example 1 and Comparative Examples 6 and 7 demonstrate the influence of Ce and Nd element content on the overall performance of the aluminum alloy; specifically, the aluminum alloys in Comparative Examples 6 and 7 show significantly lower strength and poorer overall performance compared to Example 1. A series of experiments in Example 1 and Comparative Example 8 demonstrate that the placement of the ultrasonic field during the aluminum alloy production process also significantly affects the alloy's performance. In Comparative Example 8, ultrasonic treatment of the melt during smelting resulted in a significantly reduced strength and poorer overall performance of the obtained aluminum alloy.

[0083] The above are merely preferred embodiments of the present invention and are not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A high-strength and high-toughness Al-Mg-Si aluminum alloy, characterized in that, The content, by mass percentage, includes: 1.1%≤Mg≤1.4%, 1.3%≤Si≤1.8%, 0.5%≤Cu≤1.5%, 0.5%≤Zn≤1.5%, 0.05%≤Mn≤0.25%, 0.05%≤Cr≤0.25%, 0.02%≤Ce≤0.2%, 0.02%≤Nd≤0.2%, Fe≤0.2%, with each other impurity element having a single content ≤0.05% and the total amount of other impurity elements ≤0.12%, with the balance being Al; among which, the content of Ce and Nd satisfies 0.05%≤Ce+Nd≤0.25%.

2. The high-strength and high-toughness Al-Mg-Si aluminum alloy according to claim 1, characterized in that, The content, by mass percentage, includes: 1.2%≤Mg≤1.3%, 1.5%≤Si≤1.6%, 1.0%≤Cu≤1.2%, 1.0%≤Zn≤1.2%, 0.12%≤Mn≤0.15%, 0.12%≤Cr≤0.15%, 0.05%≤Ce≤0.08%, 0.05%≤Nd≤0.08%, 0.10%≤Ce+Nd≤0.14%, Fe≤0.15%, with each other impurity element having a single content ≤0.03% and the total amount of other impurity elements ≤0.11%, with the balance being Al.

3. A method for preparing a high-strength and high-toughness Al-Mg-Si aluminum alloy as described in claim 1 or 2, characterized in that, The process includes melting raw materials of various elements in proportion to obtain a melt, and then semi-continuously casting the melt through a crystallizer to obtain an ingot. The semi-continuous casting process also includes applying an ultrasonic field to the melt in the crystallizer.

4. The preparation method according to claim 3, characterized in that, The process of applying an ultrasonic field includes placing an ultrasonic radiation rod at the center of the crystallizer after the casting speed has stabilized, with the bottom of the ultrasonic radiation rod immersed in the melt for ultrasonic treatment.

5. The preparation method according to claim 4, characterized in that, The process parameters of the ultrasonic field include: ultrasonic power of 80~1000W and ultrasonic frequency of 10~15kHz.

6. The preparation method according to any one of claims 3 to 5, characterized in that, The process parameters for the semi-continuous casting include: casting speed of 40~90mm / min, cooling water flow rate of 25~70L / min, and casting temperature of 680~740℃.

7. The preparation method according to claim 3, characterized in that, It also includes subjecting the ingot to multi-stage homogenization heat treatment, extrusion molding, solution treatment and artificial aging treatment in sequence.

8. The preparation method according to claim 7, characterized in that, The multi-stage homogenization heat treatment includes a first heating and holding process and a second heating and holding process for the ingot. The temperature for the first heating and heat preservation is 450~460℃, and the time is 2~5 hours; The second heating and heat preservation temperature is 540~560℃, and the time is 2~5h.

9. The preparation method according to claim 7, characterized in that, The extrusion molding process parameters include: extrusion temperature of 520~550℃, extrusion speed of 1~10m / min, and extrusion ratio of 20~80.

10. The preparation method according to claim 7, characterized in that, The solution treatment includes holding the material obtained by extrusion molding at 550~560℃ for 5~30 minutes.

11. The preparation method according to claim 7, characterized in that, The artificial aging treatment includes holding the solution-treated material at 175-190°C for 3-8 hours.

12. The preparation method according to claim 3, characterized in that, The raw materials for the melt include pure Al, pure Mg, pure Zn, AlCu master alloy, AlSi master alloy, AlCr master alloy, AlMn master alloy, AlCe master alloy, and AlNd master alloy.

13. The preparation method according to claim 12, characterized in that, The smelting process includes adding pure Al, pure Zn, AlCu master alloy, AlSi master alloy, AlCr master alloy, and AlMn master alloy into a smelting furnace for smelting at a temperature of 750~800℃; after complete melting, adding AlCe master alloy and AlNd master alloy and stirring thoroughly; after complete melting, letting stand for 20~25 minutes, then adding pure Mg and stirring thoroughly; after complete melting, performing the following operations in sequence: adding refining agent, degassing for 10~20 minutes, removing slag, letting stand for 20~30 minutes, and adding refining agent.

14. The application of a high-strength and high-toughness Al-Mg-Si aluminum alloy as described in claim 1 or 2, or a high-strength and high-toughness Al-Mg-Si aluminum alloy prepared by any of the preparation methods described in any one of claims 3 to 13, in any field of automobiles, electronics, or building materials.

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