A lightweight aluminum alloy material, its preparation method and application in new energy vehicles

Abstract

The present invention discloses a lightweight aluminum alloy material, its preparation method and application in new energy vehicles, belonging to a new type of aviation aluminum alloy material. The aluminum alloy comprises the following components: magnesium, manganese, copper, zinc, a combination of transition elements, chromium, strontium, titanium, nano silicon carbide, as well as the main material aluminum and other inevitable impurities. By optimizing the element composition and adding inorganic nanoparticles, the present invention effectively refines the grains, improves the density of the system, and supplemented by an efficient surface treatment method, the obtained aluminum alloy material has good comprehensive mechanical properties and corrosion resistance, is suitable for use in parts such as the battery case and battery guard plate of new energy vehicles to effectively protect the battery, and is also suitable for use in parts such as the vehicle frame, being lightweight and durable.

Description

Technical Field

[0001] The present invention belongs to the technical field of new aviation aluminum alloy materials, and particularly relates to a lightweight aluminum alloy material, a preparation method thereof, and an application thereof in new energy vehicles. Background Art

[0002] With the gradual aggravation of global climate change and environmental pollution problems, new energy vehicles have become an energy-saving and environmentally friendly travel mode at present. The emergence of new energy vehicle types such as electric vehicles, hybrid vehicles, and fuel cell vehicles marks that the automotive industry is moving towards a cleaner and more sustainable direction. However, the weight of the battery in new energy vehicles has always been the main condition restricting its performance and cruising range. The weight of the battery system not only affects the power performance of the vehicle but also causes a decrease in energy efficiency, restricting the popularization of new energy vehicles.

[0003] With the increasing global attention to environmental protection and energy sustainability, the lightweight design of new energy vehicles has become a hot topic in the automotive industry. The lightweight design aims to reduce the overall weight of the vehicle to improve the cruising range, increase energy efficiency, and reduce the dependence on limited resources.

[0004] At present, the lightweight design of new energy vehicles mainly focuses on two aspects: material innovation design and structural optimization. Materials such as carbon fiber composites, aluminum alloys, magnesium alloys, and high-strength steels are used. These materials have low density and excellent strength, which helps to reduce the weight of the vehicle. In the lightweight design of new energy vehicles, aluminum alloys are widely used to manufacture key components of the engine and transmission system, such as engine blocks, crankcases, and transmission housings. Compared with traditional iron materials, aluminum alloys have a lower density, which can effectively reduce the burden on the power system and improve fuel efficiency. In addition, aluminum alloys have excellent thermal conductivity, which helps to dissipate heat and improve the performance and reliability of the engine.

[0005] Existing materials such as battery trays and battery cases are mainly prepared from aluminum alloy materials. However, the hardness and fatigue resistance of the current materials are relatively insufficient. When used as battery case materials, they are easily pierced by sharp objects, resulting in damage to the internal battery cell structure, leakage or short circuit, etc., and even causing the vehicle to catch fire and burn. At the same time, the overall corrosion resistance of the material is poor. After long-term use, structural defects are likely to appear, significantly reducing the protection of the internal battery cells, thus affecting the safety of electric vehicles.

[0006] Therefore, how to develop a lightweight aluminum alloy material with excellent mechanical properties and high corrosion resistance has positive significance for accelerating the high-quality development of new energy vehicles and is also a technical problem that needs to be solved urgently at present. Summary of the Invention

[0007] In view of the problems existing in the prior art, the present invention optimizes the element composition. By adding a small amount of transition elements and nano silicon carbide, the grain size is effectively refined, the density of the system is improved, and the mechanical properties and erosion resistance of the material are significantly improved, meeting the usage requirements in the field of new energy vehicles.

[0008] To achieve the above technical objectives, the technical solution adopted by the present invention is as follows:

[0009] A lightweight aluminum alloy material, by mass percentage, comprises the following components: magnesium 0.6 - 1.8%, manganese 0.3 - 0.5%, copper 0.2 - 0.5%, zinc 0.1 - 0.3%, transition element combination 0.1 - 0.5%, chromium 0.04 - 0.06%, strontium 0.01 - 0.05%, titanium 0.01 - 0.02%, nano silicon carbide 0.1 - 0.3%, and the balance is aluminum and impurities, where the total amount of impurities is not more than 0.1% and the total is 100%.

[0010] Preferably, the transition element combination includes scandium, molybdenum, and niobium, and the mass ratio of the three is 1:1:1.

[0011] Preferably, the preparation method of the nano silicon carbide is as follows: Put starch, nano silica sol, and water in a container, heat and stir at 80 - 90 °C until it becomes gel-like, then naturally cool and freeze-dry, ball-mill to obtain solid powder. Then, calcine the solid powder at 1200 - 1300 °C for 3 - 6 h under nitrogen protection, then place it in a muffle furnace and calcine at 500 - 600 °C for 3 - 4 h and then naturally cool. Then, soak the calcined solid powder in 1M hydrofluoric acid for treatment, let it stand for 5 - 10 h, and then repeatedly rinse with deionized water until neutral, and dry and grind.

[0012] More preferably, the mass ratio of the starch, nano silica sol, and water is 3:10:40; the average particle size of the silica sol is 20 - 50 nm.

[0013] More preferably, the solid-liquid ratio of the calcined solid powder to hydrofluoric acid is 1 g:10 mL.

[0014] A preparation method of a lightweight aluminum alloy material, comprising the following preparation steps:

[0015] (1) Prepare materials: Prepare magnesium, manganese, copper, zinc, transition element combination, chromium, strontium, titanium, and aluminum metal raw materials according to the ratio, and prepare materials.

[0016] (2) Prepare nano silicon carbide;

[0017] (3) After cleaning the main material aluminum, put the aluminum ingots into a melting furnace or an intermediate frequency furnace for melting. Heat until completely melted and then keep warm for 20 - 30 minutes. Then add raw materials of magnesium, manganese, copper, zinc, transition element combination, chromium, strontium, and titanium elements. Finally, add nano silicon carbide. Control the melting temperature between 750 - 760 °C. The melting process is protected by argon. After all the metal is melted, successively carry out refining, slag removal, and casting to obtain an aluminum alloy casting;

[0018] (4) Surface treatment: After treating the aluminum alloy casting in boiling water for 20 - 30 min, immerse it in an octadecyltrimethoxysilane toluene solution for 10 - 20 min, and then dry after the treatment is completed.

[0019] Preferably, after the casting preparation in step (3), quenching and tempering treatments are also included: The temperature of the quenching treatment is 700 - 800 °C. After the quenching treatment, cool down and then carry out the tempering treatment. The temperature of the tempering treatment is 200 - 220 °C.

[0020] Preferably, the mass concentration of the octadecyltrimethoxysilane toluene solution in step (4) is 5 - 10%.

[0021] An application of a lightweight aluminum alloy material. The obtained aluminum alloy material can be used to manufacture motor housings, battery housings, and battery tray components of new energy vehicles, and can also be used in parts such as vehicle frames. It can not only reduce the vehicle body weight, but also has excellent mechanical properties and corrosion resistance, effectively protecting the battery.

[0022] Beneficial effects:

[0023] (1) In the present invention, trace amounts of transition metals scandium, molybdenum, and niobium are added to the aluminum matrix. Among them, scandium is the most effective grain refiner for aluminum and its alloys. By adding a small amount of scandium, the grain size of the as-cast alloy can be significantly reduced, thereby enhancing the strength and toughness of the aluminum alloy. At the same time, scandium can inhibit the recrystallization process, so the corrosion resistance of the aluminum alloy can be significantly improved. Molybdenum can significantly improve the strength and hardness of the aluminum alloy, and also enhance its heat resistance and corrosion resistance. Niobium can increase the ductility, abrasion resistance, and impact resistance in the aluminum alloy. When used in combination with scandium, molybdenum, etc. in a certain proportion, a synergistic effect is produced, and the grain refinement is more significant, which can further improve the comprehensive performance of the aluminum alloy;

[0024] (2) On the other hand, in the present invention, metal elements such as strontium, titanium, copper, and magnesium are added. The solid solution strengthening brought by Cu and Mg elements endows the alloy with excellent mechanical properties. In addition, the addition of elements such as strontium and titanium endows the alloy with good corrosion resistance and thermal conductivity;

[0025] (3) The present invention uses starch and nano-silica sol to prepare inorganic nanomaterials, which are finally added to the aluminum melt. They have a high melting point and elastic modulus, which enables them to maintain high thermal stability and deformation stability at high temperatures. Introducing these inorganic nanoparticles into aluminum alloys can effectively refine the grains, enhance the microstructure of the material, increase the density of the system, and thus significantly improve its stiffness and strength;

[0026] (4) On the basis of effectively improving the grain refinement of the system, the present invention uses octadecyl trimethoxysilane toluene for surface treatment. Under the impact of bubbles of high-temperature boiling water, the surface structure of the aluminum profile is further refined to form a finer and rougher micro-nano villi structure. Such a structure can stably store a large amount of air, forming an air cushion between the sample surface and the corrosive medium to slow down corrosion. At the same time, it is also more conducive to the subsequent modification of octadecyl trimethoxysilane toluene to form a super-hydrophobic surface, reduce the attachment of moisture and various corrosive matrices, and further improve the material's corrosion resistance;

[0027] (5) In summary, the present invention optimizes the elemental composition and adds inorganic nanoparticles to effectively refine the grains and improve the density of the system. Assisted by efficient surface treatment methods, the obtained aluminum alloy material has good comprehensive mechanical properties and corrosion resistance. It is suitable for use in new energy vehicle battery shells, battery guards and other parts to effectively protect the battery. It is also suitable for use in parts such as vehicle frames and is lightweight and durable. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the tensile test specimen;

[0029] Figure 2 This is an electron microscope image of the fracture morphology of the tensile specimen in the test of Example 3 of the present invention;

[0030] Figure 3 This is an electron microscope image of the fracture morphology of the tensile test specimens of Comparative Examples 1-9 of the present invention;

[0031] Figure 4 This is an electron microscope image of the fracture morphology of the tensile test specimen of Comparative Example 10 of the present invention. DETAILED DESCRIPTION

[0032] The technical solution of the present invention is further described below in conjunction with specific embodiments, but is not limited thereto.

[0033] Example 1

[0034] A lightweight aluminum alloy material, by mass percentage, includes the following components: magnesium 0.6%, manganese 0.3%, copper 0.5%, zinc 0.3%, transition element combination 0.1%, chromium 0.04%, strontium 0.01%, titanium 0.01%, nano silicon carbide 0.1%, and the balance is aluminum and impurities, where the total amount of impurities is not more than 0.1% and the total is 100%.

[0035] The transition element combination includes scandium, molybdenum, and niobium, and the mass ratio of the three is 1:1:1.

[0036] The preparation method of the nano silicon carbide is as follows: Put starch, nano silicon sol, and water in a container, heat and stir at 80 - 90 °C until it becomes gel-like, then naturally cool and freeze-dry, ball-mill to obtain solid powder, then calcine the solid powder at 1200 °C for 3 h under nitrogen protection, then place it in a muffle furnace and calcine at 500 °C for 3 h and then naturally cool, and then soak the calcined solid powder in 1M hydrofluoric acid for treatment, let it stand for 5 h, and then repeatedly rinse with deionized water until neutral, and dry and grind.

[0037] The mass ratio of the starch, nano silicon sol, and water is 3:10:40; the average particle size of the silicon sol is 20 - 50 nm.

[0038] The solid-liquid ratio of the calcined solid powder to hydrofluoric acid is 1 g:10 mL.

[0039] A preparation method of a lightweight aluminum alloy material includes the following preparation steps:

[0040] (1) Material preparation: Prepare magnesium, manganese, copper, zinc, transition element combination, chromium, strontium, titanium, and aluminum metal raw materials according to the ratio, and prepare the materials;

[0041] (2) Prepare nano silicon carbide;

[0042] (3) After cleaning the main material aluminum, put the aluminum ingot into a melting furnace or intermediate frequency furnace for melting, heat to complete melting and keep warm for 20 minutes; then add magnesium, manganese, copper, zinc, transition element combination, chromium, strontium, and titanium element raw materials, and finally add nano silicon carbide. The melting temperature is controlled between 750 - 760 °C, and the melting process is protected by argon. After all the metals are melted, successively carry out refining, slag removal, and casting to obtain an aluminum alloy casting;

[0043] (4) Surface treatment: Place the aluminum alloy casting in boiling water for 20 min, then immerse it in an octadecyltrimethoxysilane toluene solution for 10 min, and dry after the treatment is completed.

[0044] After the casting in step (3) is prepared, it also includes quenching and tempering treatments: The temperature of the quenching treatment is 700 °C, cool down after the quenching treatment, and then carry out the tempering treatment. The temperature of the tempering treatment is 200 °C.

[0045] In step (4), the mass concentration of the octadecyltrimethoxysilane toluene solution is 5%.

[0046] Example 2

[0047] A lightweight aluminum alloy material, by mass percentage, comprises the following components: 1% of magnesium, 0.4% of manganese, 0.3% of copper, 0.2% of zinc, 0.3% of a transition element combination, 0.04% of chromium, 0.03% of strontium, 0.02% of titanium, 0.2% of nano silicon carbide, the balance being aluminum and impurities, wherein the total amount of impurities is not more than 0.1% and the total is 100%.

[0048] The transition element combination includes scandium, molybdenum and niobium, and the mass ratio of the three is 1:1:1.

[0049] The preparation method of the nano silicon carbide is as follows: put starch, nano silica sol and water into a container, heat and stir at 80 - 90 °C until it becomes gel-like, then naturally cool and freeze-dry, ball-mill to obtain solid powder, then calcine the solid powder at 1200 °C for 4 h under nitrogen protection, then place it in a muffle furnace and calcine at 600 °C for 4 h and then naturally cool, then soak and treat the calcined solid powder in 1M hydrofluoric acid, let it stand for 6 h, then repeatedly rinse with deionized water until neutral, and dry and grind.

[0050] The mass ratio of the starch, nano silica sol and water is 3:10:40; the average particle size of the silica sol is 20 - 50 nm.

[0051] The solid-liquid ratio of the calcined solid powder and hydrofluoric acid is 1 g:10 mL.

[0052] A preparation method of a lightweight aluminum alloy material, comprising the following preparation steps:

[0053] (1) Prepare materials: Prepare magnesium, manganese, copper, zinc, transition element combination, chromium, strontium, titanium and aluminum metal raw materials according to the ratio, and prepare materials;

[0054] (2) Prepare nano silicon carbide;

[0055] (3) After cleaning the main material aluminum, put the aluminum ingot into a melting furnace or an intermediate frequency furnace for melting, heat to complete melting and keep warm for 30 minutes; then add magnesium, manganese, copper, zinc, transition element combination, chromium, strontium, titanium element raw materials, and finally add nano silicon carbide, control the melting temperature between 750 - 760 °C, use argon protection during the melting process, after all the metals are melted, successively carry out refining, slag removal and casting to obtain an aluminum alloy casting;

[0056] (4) Surface treatment: After placing the aluminum alloy casting in boiling water for 20 minutes, immerse it in an octadecyltrimethoxysilane toluene solution for 20 minutes, and then dry it after the treatment is completed.

[0057] After the casting preparation in step (3), quenching and tempering treatments are also included: the temperature of the quenching treatment is 800 °C, cool down after the quenching treatment, and then carry out the tempering treatment, and the temperature of the tempering treatment is 200 °C.

[0058] In step (4), the mass concentration of the octadecyltrimethoxysilane toluene solution is 7%.

[0059] Example 3

[0060] A lightweight aluminum alloy material, by mass percentage, includes the following components: 1.8% magnesium, 0.5% manganese, 0.2% copper, 0.3% zinc, 0.5% transition element combination, 0.06% chromium, 0.05% strontium, 0.02% titanium, 0.3% nano silicon carbide, and the balance is aluminum and impurities, where the total amount of impurities is not more than 0.1% and the total amount is 100%.

[0061] The transition element combination includes scandium, molybdenum, and niobium, and the mass ratio of the three is 1:1:1.

[0062] The preparation method of the nano silicon carbide is as follows: Place starch, nano silica sol, and water in a container, heat and stir at 80 - 90 °C until it becomes gel-like, then naturally cool and freeze-dry, ball-mill to obtain a solid powder, then calcine the solid powder at 1300 °C for 6 hours under nitrogen protection, then place it in a muffle furnace and calcine at 600 °C for 4 hours and then naturally cool, and then soak and treat the calcined solid powder in 1M hydrofluoric acid, let it stand for 10 hours, then repeatedly rinse with deionized water until neutral, and dry and grind.

[0063] The mass ratio of the starch, nano silica sol, and water is 3:10:40; the average particle size of the silica sol is 20 - 50 nm.

[0064] The solid-liquid ratio of the calcined solid powder and hydrofluoric acid is 1 g:10 mL.

[0065] A preparation method of a lightweight aluminum alloy material includes the following preparation steps:

[0066] (1) Material preparation: Prepare magnesium, manganese, copper, zinc, transition element combination, chromium, strontium, titanium, and aluminum metal raw materials according to the ratio, and carry out material preparation;

[0067] (2) Prepare nano silicon carbide;

[0068] (3) After cleaning the main material aluminum, put the aluminum ingots into a melting furnace or an intermediate frequency furnace for melting. Heat it until it is completely melted and then keep it warm for 30 minutes. Then add the raw materials of magnesium, manganese, copper, zinc, transition element combination, chromium, strontium, and titanium. Finally, add nano silicon carbide. Control the melting temperature between 750 - 760 °C. The melting process is protected by argon. After all the metal is melted, successively carry out refining, slag removal, and casting to obtain an aluminum alloy casting.

[0069] (4) Surface treatment: Place the aluminum alloy casting in boiling water for 30 minutes, then immerse it in an octadecyltrimethoxysilane toluene solution for 20 minutes. After the treatment is completed, dry it.

[0070] After the casting preparation in step (3), it also includes quenching and tempering treatments: The temperature of the quenching treatment is 800 °C. After the quenching treatment, cool down and then carry out the tempering treatment. The temperature of the tempering treatment is 220 °C.

[0071] In step (4), the mass concentration of the octadecyltrimethoxysilane toluene solution is 10%.

[0072] Comparative Examples 1 - 9

[0073] Change the dosage ratio of the transition element combination and set comparative examples. The other raw materials and preparation methods are the same as those in Example 3. Specifically:

[0074] Table 1 Dosage relationship of the transition element combination in comparative examples

[0075]

[0076] Comparative Example 10

[0077] A lightweight aluminum alloy material, by mass percentage, includes the following components: magnesium 1.8%, manganese 0.5%, copper 0.2%, zinc 0.3%, transition element combination 0.5%, chromium 0.06%, strontium 0.05%, titanium 0.02%, and the balance is aluminum and impurities, where the total amount of impurities does not exceed 0.1% and the total is 100%.

[0078] The transition element combination includes scandium, molybdenum, and niobium, and the mass ratio of the three is 1:1:1.

[0079] A preparation method of a lightweight aluminum alloy material includes the following preparation steps:

[0080] (1) Material preparation: Prepare the raw materials of magnesium, manganese, copper, zinc, transition element combination, chromium, strontium, titanium, and aluminum metal according to the ratio, and carry out material preparation.

[0081] (2) After cleaning the main material aluminum, put the aluminum ingots into a melting furnace or an intermediate frequency furnace for melting. Heat until completely melted and then hold for 30 minutes. Then add raw materials of magnesium, manganese, copper, zinc, transition element combination, chromium, strontium, and titanium. Control the melting temperature between 750 - 760 °C. Use argon protection during the melting process. After all the metal is melted, successively carry out refining, slag removal, and casting to obtain aluminum alloy castings;

[0082] (3) Surface treatment: Place the aluminum alloy castings in boiling water for 30 minutes, then immerse them in an octadecyltrimethoxysilane toluene solution for 20 minutes, and dry after the treatment is completed.

[0083] After the casting in step (3) is completed, it also includes quenching and tempering treatments: The temperature of the quenching treatment is 800 °C. After the quenching treatment, cool down and then carry out the tempering treatment. The temperature of the tempering treatment is 220 °C.

[0084] In step (4), the mass concentration of the octadecyltrimethoxysilane toluene solution is 10%.

[0085] This comparative example is the same as Example 3 in terms of the remaining raw materials and preparation methods except that the raw materials do not contain nano - silicon carbide.

[0086] Performance testing

[0087] Test the aluminum alloy materials obtained in Examples 1 - 3 and Comparative Examples 1 - 10 of the present invention. Cast dumbbell - shaped tensile specimens, which meet the requirements of GB / T228.1 - 2021, as Figure 1 shown. Use a tensile testing machine (Intsron3369) and a hardness tester (220HBS - 3000) to test the tensile properties and Brinell hardness of the aluminum alloy respectively.

[0088] Contact angle measurement: Use a Chinese Chengde JY - 82 video contact angle measuring instrument to measure the contact angle between the sample and water.

[0089] Observation of fracture morphology: Use an S - 3400N type scanning electron microscope to observe the fracture morphology of the tensile fracture specimens to determine the fracture mode of the alloy under the test conditions.

[0090] Electrochemical testing: Use a CHI600E type electrochemical workstation produced by Shanghai Chenhua Company to test the specimens. In the experiment, a standard three - electrode system is used. The working electrode is the specimen to be tested, the reference electrode is a calomel electrode, and the auxiliary electrode is a platinum sheet electrode. Prepare an aqueous NaCl solution with a mass fraction of 3.5% as the corrosion medium (the aqueous NaCl solution with a mass fraction of 3.5% simulates the seawater state). The area of the working electrode is 3.14 cm 2 , and the voltage test range is - 2 - 0 V, and the potential scanning rate is 3 mV / s.

[0091] All test results were repeated 5 times, and the average value was taken as the result.

[0092] Test result table

[0093] Table 2 Mechanical property test results

[0094]

[0095] Table 3 Self-corrosion current density and corrosion potential of the specimens

[0096]

[0097] From the data in Tables 2-3, we can see that the specimens of the embodiments of the present invention exhibit good mechanical properties and corrosion resistance. The higher the corrosion potential, the lower the tendency of corrosion; and the current density reflects the corrosion rate, the smaller the current density, the slower the corrosion rate. For Comparative Examples 1-10 with changed element composition and raw material composition, their mechanical properties and corrosion resistance are weakened to varying degrees. This is because in Comparative Examples 1-9 with changed transition element composition and Comparative Example 10 without the addition of nano-silicon carbide, the refining effect on the matrix is weakened and the synergistic balance effect is broken, thus leading to the decline of mechanical properties and erosion resistance. It can be seen from this that the addition of the transition element composition and nano-silicon carbide in the present invention is crucial for the improvement of the comprehensive properties of aluminum alloy materials, and the lack of either will result in weakened effects. From the fracture morphology of the specimens, it can be seen that the specimen of Embodiment 3 of the present invention shows a tensile fracture with a large number of small dimples, and no obvious cleavage plane is found, and the fracture mode is a typical ductile fracture. The morphology of the comparative examples is relatively poor.

[0098] It should be noted that the above-mentioned embodiments are only some of the preferred embodiments for implementing the present invention, rather than all embodiments. Obviously, based on the above-mentioned embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Claims

1. A lightweight aluminum alloy material, characterized in that, By mass percentage, it has the following components: magnesium 0.6 - 1.8%, manganese 0.3 - 0.5%, copper 0.2 - 0.5%, zinc 0.1 - 0.3%, transition element combination 0.1 - 0.5%, chromium 0.04 - 0.06%, strontium 0.01 - 0.05%, titanium 0.01 - 0.02%, nano silicon carbide 0.1 - 0.3%, and the balance is aluminum and impurities, where the total amount of impurities is not more than 0.1%; the transition element combination is scandium, molybdenum, and niobium, and the mass ratio of the three is 1:1:

1.

2. The light aluminum alloy material according to claim 1, characterized in that, The preparation method of the nano silicon carbide is as follows: Put starch, nano silica sol, and water in a container, heat and stir at 80 - 90 °C until it becomes gel-like, then naturally cool and freeze-dry, ball-mill to obtain a solid powder. Then, calcine the solid powder at 1200 - 1300 °C for 3 - 6 h under nitrogen protection, and then place it in a muffle furnace and calcine at 500 - 600 °C for 3 - 4 h and then naturally cool. Then, soak the calcined solid powder in 1 M hydrofluoric acid for treatment, let it stand for 5 - 10 h, and then repeatedly rinse with deionized water until it is neutral, and dry and grind it.

3. The light aluminum alloy material according to claim 2, characterized in that The mass ratio of the starch, nano silica sol, and water is 3:10:40; the average particle size of the silica sol is 20 - 50 nm.

4. The lightweight aluminum alloy material according to claim 2, characterized in that, The solid-liquid ratio of the calcined solid powder and hydrofluoric acid is 1 g:10 mL.

5. A preparation method of the light aluminum alloy material according to any one of claims 1-4, characterized in that, It includes the following preparation steps: (1) Material preparation: Prepare magnesium, manganese, copper, zinc, transition element combination, chromium, strontium, titanium, and aluminum metal raw materials according to the ratio, and prepare the materials. (2) Prepare nano silicon carbide. (3) After cleaning the main material aluminum ingot, put the aluminum ingot into an intermediate frequency furnace for melting, heat it until it is completely melted and keep it warm for 20 - 30 minutes; then add magnesium, manganese, copper, zinc, transition element combination, chromium, strontium, and titanium element raw materials, and finally add nano silicon carbide. The melting temperature is controlled between 750 - 760 °C. The melting process is protected by argon. After all the metals are melted, successively carry out refining, slag skimming, and casting to form an aluminum alloy casting. (4) Surface treatment: Immerse the aluminum alloy casting in boiling water for 20 - 30 min, and then immerse it in an octadecyltrimethoxysilane toluene solution for 10 - 20 min. After the treatment is completed, dry it.

6. The preparation method of the lightweight aluminum alloy material according to claim 5, characterized in that, After the casting in step (3) is prepared, it also includes quenching and tempering treatments: the temperature of the quenching treatment is 700 - 800 °C, cool down after the quenching treatment, and then carry out the tempering treatment. The temperature of the tempering treatment is 200 - 220 °C.

7. The preparation method of the lightweight aluminum alloy material according to claim 5, wherein, In step (4), the mass concentration of the octadecyltrimethoxysilane toluene solution is 5 - 10%.

8. Use of the light aluminum alloy material according to any one of claims 1-4, characterized in that, The aluminum alloy material is used to manufacture the battery case and battery tray components of new energy vehicles.

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