Aluminum alloy, vehicle body member, vehicle, and casting method for vehicle body member

Abstract

This application relates to an aluminum alloy, a vehicle body component, a vehicle, and a casting method for the vehicle body component. The aluminum alloy comprises Al, Mn, and Fe, with Al accounting for 85% to 92% of the aluminum alloy by mass, providing a good foundation for tensile strength. Mn accounts for less than or equal to 0.3% of the aluminum alloy by mass, allowing manganese to enhance grain boundary strength and thus improve tensile strength. Furthermore, manganese can improve the yield strength and toughness of the aluminum alloy by refining recrystallized grains and inhibiting grain growth. Fe accounts for less than or equal to 0.3% of the aluminum alloy by mass. When the Mn / Fe ratio is controlled within the range of 1.0 to 1.2, it ensures that Mn can fully dissolve Fe, thereby reducing the adverse effects of Fe on the fluidity of the aluminum alloy and minimizing the damage to the toughness of the aluminum alloy caused by Fe-formed hard spots. This achieves the goal of improving the toughness of the aluminum alloy while optimizing its yield strength and tensile strength, ensuring that the reliability and safety of the vehicle body component made from this aluminum alloy meet the requirements.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and more particularly to a casting method for aluminum alloys, vehicle body components, vehicles, and vehicle body components. Background Technology

[0002] Taking the subframe as an example, as a key safety structural component of the chassis system, the subframe needs to provide mounting points for control arms, steering gear, stabilizer bars, and engine / motor mounts, and bear loads from the entire vehicle and powertrain. Its safety, durability, and reliability are of paramount importance. Subframes are typically cast from aluminum alloys; however, in related technologies, aluminum alloys suffer from insufficient strength and toughness, thus reducing the reliability and safety of subframes made from this alloy. Summary of the Invention

[0003] This application provides a casting method for aluminum alloy, vehicle body components, vehicles, and vehicle body components, aiming to solve the problem that the reliability and safety of vehicle body components made from aluminum alloys are reduced due to insufficient strength and toughness in related technologies.

[0004] To achieve the above objectives, according to a first aspect of this application, an aluminum alloy is provided, the aluminum alloy comprising Al, Mn and Fe, wherein Al accounts for 85% to 92% of the mass percentage of the aluminum alloy, Mn accounts for less than or equal to 0.3% of the mass percentage of the aluminum alloy, and Fe accounts for less than or equal to 0.3% of the mass percentage of the aluminum alloy, wherein 1.0 ≤ Mn / Fe ≤ 1.2.

[0005] Optionally, the sum of the mass percentage of Mn in the aluminum alloy and the mass percentage of Fe in the aluminum alloy is less than 0.5%.

[0006] Optionally, the aluminum alloy may also include at least one of Si, Zn, Mg, rare earth elements, Ti, Cu, Sr, and Ca.

[0007] Optionally, Si accounts for 6.0% to 8.0% of the mass percentage of the aluminum alloy; and / or,

[0008] Zn accounts for 1.0% to 2.0% of the mass of the aluminum alloy; and / or,

[0009] Mg accounts for 0.2% to 0.6% of the mass of the aluminum alloy; and / or,

[0010] Rare earth elements constitute 0.01% to 0.03% of the aluminum alloy by mass; and / or,

[0011] Ti constitutes less than or equal to 0.2% of the mass of the aluminum alloy; and / or,

[0012] The Cu content in the aluminum alloy is 0.1% to 0.5% by mass; and / or,

[0013] Sr accounts for 0.01% to 0.05% of the mass of the aluminum alloy; and / or,

[0014] The mass percentage of Ca in aluminum alloys is 0.002% to 0.006%.

[0015] Alternatively, rare earth elements include at least one of La, Ce, Y, and Sc.

[0016] According to a second aspect of this application, a vehicle body component is provided, the vehicle body component comprising the aluminum alloy as described above.

[0017] Optionally, the length of the vehicle body component is L, the width is K, and the height is H, wherein L≥1100mm, K≥800mm, and H≥250mm.

[0018] According to a third aspect of this application, a vehicle is provided, the vehicle including the vehicle body components as described above.

[0019] According to a fourth aspect of this application, a casting method for a vehicle body component as described above is provided, the casting method comprising the following steps:

[0020] Obtain the molten aluminum alloy as described above;

[0021] Vacuum extrusion casting of aluminum alloy molten metal.

[0022] Optionally, the steps for obtaining the aluminum alloy casting liquid as described above include:

[0023] A first material, including aluminum ingots, is added to a reverberatory furnace. After the first material melts, a first molten metal is obtained.

[0024] The temperature of the first molten metal is adjusted to 700℃~740℃, and the second material, including a manganese source, is added to the reverberatory furnace. The mixture is stirred for 3min~5min to obtain the second molten metal.

[0025] Optionally, the first material may further include crystalline silicon or aluminide; and / or

[0026] The second material also includes a zinc source; and / or,

[0027] Aluminum ingots account for 85% to 92% of the total mass of the aluminum alloy casting liquid.

[0028] Optionally, crystalline silicon accounts for 5% to 8% of the total mass of the aluminum alloy casting liquid.

[0029] Optionally, after adjusting the temperature of the first molten metal to 700℃~740℃, adding a second material, including a manganese source, to the reverberatory furnace, and stirring for 3min~5min to obtain the second molten metal, the process further includes:

[0030] The temperature of the second molten metal is raised to 740℃~780℃, and a third material, including an aluminum alloy containing rare earth elements, is added to the reverberatory furnace. The mixture is stirred for 3min~5min and then refined and slag is removed to obtain the third molten metal.

[0031] The temperature of the third molten metal is lowered to 680℃~740℃, and a fourth material, including magnesium, is added to the third molten metal. The mixture is stirred to obtain the fourth molten metal.

[0032] Optionally, the third material also includes at least one of aluminum copper and aluminum titanium boron; and / or,

[0033] The fourth material also includes aluminum and strontium.

[0034] Optionally, the step of vacuum extrusion casting the molten aluminum alloy includes:

[0035] The mold cavity is evacuated to a vacuum level of less than or equal to 80 mbar.

[0036] The temperature of the mold cavity should be controlled within the range of 150℃ to 200℃;

[0037] The molten aluminum alloy is poured into the mold cavity and subjected to multiple injection molding processes.

[0038] The pressure inside the mold cavity is increased to 100-120 bar within 1-3 seconds by a pressurization rate of 20-50 bar / s.

[0039] Dynamic pressure holding and local pressure increase are applied within the mold cavity;

[0040] The mold cavity is depressurized and the mold is opened to obtain the molded car body component.

[0041] Optionally, the process may include the following steps before pouring the molten aluminum alloy into the mold cavity and performing multiple injection molding processes:

[0042] The weight of the aluminum alloy molten casting is determined to be 140% to 160% of the weight of the car body component to be cast, and the pouring temperature is 690℃ to 710℃.

[0043] Optionally, in the step of pouring molten aluminum alloy into the mold cavity and performing multiple injection molding processes:

[0044] Two to eight different injection parameters were set to inject and fill the aluminum alloy casting into the mold cavity.

[0045] Optionally, the steps of dynamically maintaining pressure and locally increasing pressure within the mold cavity include:

[0046] Maintain the pressure inside the mold cavity at 150 bar to 210 bar, and hold the pressure for 25 to 40 seconds.

[0047] One to five seconds after the pressure holding begins, the engine mounting area of ​​the vehicle body component is locally pressurized. The local pressurization pressure is 160 bar to 210 bar, so that the aluminum alloy casting liquid locally generates a pressure of 120 MPa to 200 MPa.

[0048] Optionally, in the step of maintaining the pressure value in the mold cavity at 150 bar to 210 bar and holding the pressure for 25 seconds to 40 seconds,

[0049] The fluctuation of the holding pressure is Δp, where -0.5 bar < Δp < 0.5 bar.

[0050] Optionally, after the step of depressurizing the mold cavity and opening the mold to obtain the molded vehicle body component, the method further includes:

[0051] The molded car body components are placed in water at 55℃~65℃ for cooling.

[0052] Optionally, after the step of immersing the molded vehicle body components in water at 55°C to 65°C for cooling, the method further includes:

[0053] The vehicle body components are placed in a heating furnace, and the furnace is heated to 500-550°C and held for 3-10 hours.

[0054] Immerse the insulated vehicle body components in water at 20℃ to 60℃ for 5 to 10 seconds to cool them down, then remove them.

[0055] The cooled car body components are put back into the heating furnace, and the heating furnace is heated to 160-200°C within 2 hours and kept at that temperature for 3-10 hours.

[0056] The vehicle body components were removed from the heating furnace and then air-cooled to room temperature.

[0057] In this embodiment of the aluminum alloy, the tensile strength of the aluminum alloy is positively correlated with the aluminum content. Since the aluminum content in this alloy is as high as 85% to 92%, it provides a good foundation for tensile strength. Manganese can improve the tensile strength of the aluminum alloy, and the manganese content in this alloy is less than 0.3%, allowing manganese to enhance grain boundary strength and thus improve tensile strength. In addition, manganese can also improve the yield strength and toughness of the aluminum alloy by refining recrystallized grains and inhibiting grain growth. In this alloy, the iron content is also less than 0.3%, and the Mn / Fe ratio is controlled within the range of 1.0 to 1.2, which helps to reduce the adverse effects of iron on the tensile strength of the alloy. When the Mn / Fe ratio is controlled within the range of 1.0 to 1.2, it can be ensured that Mn can fully dissolve Fe, thereby reducing the adverse effects of Fe on the fluidity of the aluminum alloy and reducing the damage to the toughness of the aluminum alloy caused by Fe-formed hard spots. By limiting the Mn / Fe ratio to between 1.0 and 1.2, the synergistic effect between manganese and iron can be achieved, which can improve the toughness of aluminum alloys while optimizing their yield strength and tensile strength, so that the reliability and safety of vehicle body components made of this aluminum alloy meet the requirements.

[0058] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0059] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0060] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0061] Figure 1 This is a metallographic image of an aluminum alloy cast vehicle body component provided in an exemplary embodiment of this disclosure;

[0062] Figure 2 This is a schematic diagram of the structure of the vehicle body component provided in an exemplary embodiment of this disclosure;

[0063] Figure 3 This is a schematic diagram of the casting method for vehicle body components provided in an exemplary embodiment of this disclosure;

[0064] Figure 4 yes Figure 3 A flowchart illustrating an embodiment of step S100;

[0065] Figure 5 yesFigure 3 A flowchart illustrating another embodiment of the specific steps of step S100 shown.

[0066] Figure 6 yes Figure 3 A flowchart illustrating the specific steps of step S200 in the first embodiment.

[0067] Figure 7 yes Figure 3 A flowchart illustrating another embodiment of the specific steps of step S200 shown.

[0068] Figure 8 yes Figure 7 A flowchart illustrating two embodiments of the specific steps in step S260 shown.

[0069] Figure 9 yes Figure 3 A flowchart illustrating the specific steps of step S200 shown in three embodiments;

[0070] Figure 10 yes Figure 9 The flowchart of the steps following step S280 is shown.

[0071] Explanation of reference numerals in the attached figures:

[0072] 10. Vehicle body components. Detailed Implementation

[0073] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0074] This application provides an aluminum alloy comprising Al, Mn, and Fe.

[0075] Al accounts for 85% to 92% of the mass of aluminum alloys.

[0076] By maintaining an aluminum content between 85% and 92%, the basic properties of aluminum can be ensured in the alloy, resulting in a lightweight yet high-strength aluminum alloy. Achieving an aluminum content between 85% and 92% also allows for a dense oxide film on the alloy surface, improving its corrosion resistance.

[0077] Specifically, the mass percentage of Al in the aluminum alloy can be 85%, 86%, 88%, 89%, 90%, 91%, or 92%, etc. The mass percentage of Al in the aluminum alloy can be selected as needed, and this application does not limit the mass percentage of Al in the aluminum alloy.

[0078] Mn accounts for less than or equal to 0.3% of the mass of the aluminum alloy.

[0079] In some embodiments, the mass percentage of manganese (Mn) in the aluminum alloy is less than or equal to 0.3%. This allows Mn to react with Fe in the aluminum alloy to form new intermetallic compounds. These compounds typically have a more regular morphology, which helps improve the microstructure of the aluminum alloy, refining the grains and reducing the formation of harmful phases, thereby increasing the strength and toughness of the aluminum alloy. Because Mn enhances the solid solution strengthening effect of the alloy while reducing its deformation and fracture tendency under stress, maintaining a Mn mass percentage of less than or equal to 0.3% in the aluminum alloy can improve its mechanical properties such as tensile strength, hardness, and yield strength, making the aluminum alloy more stable and reliable under external forces. Maintaining a Mn mass percentage of less than or equal to 0.3% in the aluminum alloy can improve the alloy's fluidity and reduce defects during casting. Simultaneously, the addition of Mn can reduce the alloy's hot cracking tendency and improve the casting yield of the aluminum alloy. Controlling the Mn content within the range of less than or equal to 0.3% can balance the alloy's strength and corrosion resistance. Because a high Mn content not only increases the production difficulty and cost of the alloy, but may also have an adverse effect on the alloy's performance, the production cost and difficulty of aluminum alloy production can be reduced by making the mass percentage of Mn in the aluminum alloy less than or equal to 0.3%.

[0080] Specifically, the mass percentage of Mn in the aluminum alloy can be 0.3%, 0.25%, 0.2%, 0.13%, 0.1%, 0.06%, 0.05%, or 0.013%, etc. Specifically, the mass percentage of Mn in the aluminum alloy can be selected as needed, and this application does not limit the mass percentage of Mn in the aluminum alloy.

[0081] The percentage of Fe in the aluminum alloy is less than or equal to 0.3% by mass.

[0082] In some embodiments, Fe accounts for less than or equal to 0.3% of the mass of the aluminum alloy. Excessive Fe content can lead to the formation of intermetallic compounds, typically in needle-like or plate-like forms, which can interfere with the flow of the molten aluminum alloy and cause defects in the casting. Controlling the Fe content below 0.3% effectively reduces the formation of these harmful phases, thereby improving the fluidity of the aluminum alloy, making it easier for the casting to fill the mold, and reducing defects. Appropriate amounts of Fe can improve the strength and hardness of die-cast aluminum alloys, but excessive Fe can form hard spots, reducing the toughness and elongation of the aluminum alloy. Limiting the Fe content to below 0.3% ensures that the aluminum alloy maintains a certain strength while possessing good toughness and elongation, thus improving the mechanical properties of the aluminum alloy. Fe readily forms a cathodic phase in aluminum alloys, accelerating the corrosion rate. Controlling the Fe content below 0.3% can reduce the occurrence of electrochemical corrosion and improve the corrosion resistance of the aluminum alloy. When the Fe content is too high, iron-rich areas will form on the surface of the casting. These areas are prone to scratches and defects during machining and polishing. Limiting the Fe content to below 0.3% can reduce the formation of iron-rich areas, improve the surface quality of the casting, and make the casting more aesthetically pleasing and durable. Controlling the Fe content to below 0.3% can reduce production costs and resource consumption while ensuring the performance of the aluminum alloy.

[0083] Specifically, the mass percentage of Fe in the aluminum alloy can be 0.3%, 0.25%, 0.2%, 0.13%, 0.1%, 0.06%, 0.05%, or 0.013%, etc. Specifically, the mass percentage of Fe in the aluminum alloy can be selected as needed, and this application does not limit the mass percentage of Fe in the aluminum alloy.

[0084] In this embodiment of the aluminum alloy, the tensile strength of the aluminum alloy is positively correlated with the aluminum content. Since the aluminum content in this alloy is as high as 85% to 92%, it provides a good foundation for tensile strength. Manganese can improve the tensile strength of the aluminum alloy, and the manganese content in this alloy is less than 0.3%, allowing manganese to enhance grain boundary strength and thus improve tensile strength. In addition, manganese can also improve the yield strength and toughness of the aluminum alloy by refining recrystallized grains and inhibiting grain growth. In this alloy, the iron content is also less than 0.3%, and the Mn / Fe ratio is controlled within the range of 1.0 to 1.2, which helps to reduce the adverse effects of iron on the tensile strength of the alloy. When the Mn / Fe ratio is controlled within the range of 1.0 to 1.2, it can be ensured that Mn can fully dissolve Fe, thereby reducing the adverse effects of Fe on the fluidity of the aluminum alloy and reducing the damage to the toughness of the aluminum alloy caused by Fe-formed hard spots. By limiting the Mn / Fe ratio to between 1.0 and 1.2, the synergistic effect between manganese and iron can be achieved, which can improve the toughness of aluminum alloys while optimizing their yield strength and tensile strength, so that the reliability and safety of vehicle body components made of this aluminum alloy meet the requirements.

[0085] Specifically, the Mn / Fe value can be 1, 1.05, 1.1, 1.15 or 1.2, etc. In particular, the Mn / Fe value can be selected as needed, and this application does not limit the Mn / Fe value.

[0086] In some embodiments, the sum of the mass percentage of Mn in the aluminum alloy and the mass percentage of Fe in the aluminum alloy is less than 0.5%. By controlling the sum of the percentages of Mn and Fe to be less than 0.5%, the balance between strength and toughness of the aluminum alloy can be optimized to a certain extent, so that the aluminum alloy has sufficient strength while maintaining good toughness.

[0087] Controlling the sum of Mn and Fe percentages to less than 0.5% helps reduce the brittleness of aluminum alloys and improve their impact resistance and low-temperature performance.

[0088] Specifically, the sum of the mass percentages of Mn and Fe in the aluminum alloy can be 0.45%, 0.4%, 0.3%, 0.25%, 0.2%, 0.13%, 0.1%, 0.06%, 0.05%, or 0.013%, etc. Specifically, the sum of the mass percentages of Mn and Fe in the aluminum alloy can be selected as needed, and this application does not limit the sum of the mass percentages of Mn and Fe in the aluminum alloy.

[0089] In some embodiments, the aluminum alloy further includes at least one of Si, Zn, Mg, rare earth elements, Ti, Cu, Sr, and Ca. When the aluminum alloy includes Si, Si enhances the liquid fluidity of the aluminum alloy, facilitating the filling of the molten aluminum alloy in the mold and improving the mold-filling performance of the casting. Si can form a silicon solid solution in the aluminum matrix, increasing the strength and hardness of the aluminum alloy. Si can stabilize the phase structure of the aluminum alloy, improving its heat resistance. Under high-temperature conditions, silicon can prevent phase transformation in the aluminum alloy, maintaining its stable properties. When the die-cast aluminum alloy also includes Zn, the addition of Zn can improve the hardness and corrosion resistance of the die-cast aluminum, making it more durable. The addition of Zn can improve the fluidity of the die-cast aluminum, making the aluminum alloy easier to form. When the die-cast aluminum alloy also includes Mg, Mg can form a solid solution with Al, increasing the strength and hardness of the aluminum alloy. Mg can stabilize the phase structure of the aluminum alloy, improving its heat resistance. Mg can improve the corrosion resistance of the aluminum alloy, giving it better corrosion resistance in harsh environments. When die-cast aluminum alloys include rare earth elements, these elements can remove gases and impurities, improving the purity of the alloy. Rare earth elements can refine the grain structure of the aluminum alloy, thereby increasing its strength and toughness. The addition of rare earth elements can improve the alloy's cold and hot working properties, making it easier to process and shape. Rare earth elements can also improve the alloy's corrosion resistance, extending its service life.

[0090] Ti can form compounds with other elements in aluminum alloys, and these compounds can act as nucleation sites for heterogeneous formation during solidification, thereby refining the grain size and improving the alloy's mechanical properties and corrosion resistance. The addition of Ti can enhance the strength of aluminum alloys, enabling them to withstand higher mechanical stresses. The addition of Ti can improve the casting performance of aluminum alloys and reduce casting defects such as porosity and inclusions. Cu's solid solution strengthening effect can significantly improve the mechanical properties of aluminum alloys, such as strength, hardness, and wear resistance. Adding Cu can improve the machinability of aluminum alloys, making them easier to process. Cu can form a protective film with other elements, thereby improving the alloy's corrosion resistance. Sr can refine the grain size of aluminum alloys, improving their mechanical properties and corrosion resistance. The addition of Sr can reduce defects such as hot cracking and porosity during the casting process, improving casting quality. Sr can form a stable oxide film with other elements in aluminum alloys, enhancing the alloy's corrosion resistance. Ca can refine the silicon and α-Al phases in aluminum alloys, thereby improving the alloy's mechanical properties and corrosion resistance. The addition of calcium (Ca) can improve the machinability of aluminum alloys, making them easier to process. Ca can also reduce defects such as shrinkage cavities and hot cracks in aluminum alloys during the casting process, thereby improving casting quality.

[0091] It should be noted that aluminum alloys may include at least one element selected from Si, Zn, Mg, rare earth elements, Ti, Cu, Sr, and Ca, or all of them. When all of them are included, the overall performance of the aluminum alloy can be significantly improved, including strength, hardness, wear resistance, corrosion resistance, casting performance, and machinability.

[0092] Specifically, rare earth elements include at least one of La, Ce, Y, and Sc. The addition of La can improve the alloy's oxidation resistance and reduce oxide shedding during oxidation, thereby increasing the alloy's service life in high-temperature environments. The addition of lanthanum may increase the alloy's strength and hardness, helping it maintain structural integrity and performance stability under high stress and high temperature conditions. Lanthanum can refine grains, making the alloy's microstructure more uniform, thus improving its mechanical and processing properties. The addition of Ce can optimize the alloy's casting properties, reducing defects such as porosity and inclusions, and improving the quality and reliability of castings. Y can improve its mechanical properties and corrosion resistance. Sc can significantly increase the alloy's strength. The addition of rare earth elements such as La, Ce, Y, and Sc can significantly improve the comprehensive properties of alloys or materials, including strength, hardness, wear resistance, casting performance, and corrosion resistance.

[0093] In some embodiments, Si accounts for 6.0% to 8.0% of the mass percentage of the aluminum alloy. When the Si content is between 6.0% and 8.0%, Si can form a silicon solid solution in the aluminum matrix. The presence of this solid solution significantly improves the strength and hardness of the aluminum alloy. When the Si content is between 6.0% and 8.0%, Si can lower the melting point and viscosity of the aluminum alloy, improve the fluidity of the liquid metal, making it easier for the aluminum alloy to fill the mold and reducing casting defects. Simultaneously, Si can refine the grain structure of the aluminum alloy, improving its density and mechanical properties. Although Si itself does not significantly affect corrosion resistance, when used in combination with other alloying elements, it can form a denser oxide film, thereby improving the corrosion resistance of the aluminum alloy.

[0094] Furthermore, a Si mass percentage less than 6.0% may reduce the strength and hardness of the aluminum alloy, making it unsuitable for certain applications requiring high strength and hardness. A Si mass percentage less than 6.0% may also decrease the alloy's wear resistance, making it more susceptible to damage during friction and wear. A Si mass percentage less than 6.0% may affect the heat treatment strengthening effect, preventing the alloy from achieving the expected mechanical properties through heat treatment. A Si mass percentage greater than 8.0% can lead to cracking and deformation during processing, increasing processing difficulty and cost. A Si mass percentage greater than 8.0% can increase porosity during die casting, reducing the alloy's density and mechanical properties, affecting the quality and service life of the casting. A Si mass percentage greater than 8.0% increases the number of Si phases in the aluminum alloy microstructure, resulting in an uneven microstructure and affecting the alloy's mechanical properties and corrosion resistance. A Si mass percentage greater than 8.0% can also cause overheating and burning during heat treatment, leading to a decline in the alloy's mechanical properties. In addition, an Si mass percentage greater than 8.0% can cause annealing softening in aluminum alloys, which can lead to a gradual decrease in the alloy's performance over long-term use.

[0095] Specifically, the mass percentage of Si in the aluminum alloy can be 6%, 6.4%, 6.8%, 7%, 7.2%, 7.63%, or 8%, etc. Specifically, the mass percentage of Si in the aluminum alloy can be selected as needed, and this application does not limit the mass percentage of Si in the aluminum alloy.

[0096] In one embodiment, Zn accounts for 1.0% to 2.0% of the mass percentage of the aluminum alloy. This Zn content significantly improves the strength and hardness of the aluminum alloy, resulting in better mechanical properties. A Zn content of 1.0% to 2.0% of the mass percentage of the aluminum alloy enhances its wear resistance and extends its service life. A Zn content of 1.0% to 2.0% of the mass percentage of the aluminum alloy accelerates the age hardening process, increasing the hardening rate and enabling the alloy to achieve higher hardness in a shorter time. A Zn content of 1.0% to 2.0% of the mass percentage of the aluminum alloy promotes the fine dispersion of precipitated phases in the aluminum alloy, thereby improving its performance.

[0097] Furthermore, when the Zn mass percentage is greater than 2.0%, the elongation of the aluminum alloy may decrease, leading to poorer plasticity. A Zn mass percentage greater than 2.0% may increase the risk of stress corrosion cracking, especially under certain environments such as humidity and high temperatures. A Zn mass percentage greater than 2.0% may affect the weldability of the aluminum alloy, leading to defects such as cracks and porosity in the weld joint. When the Zn mass percentage is less than 1.0%, its strengthening effect on the aluminum alloy may be insufficient to meet the performance requirements of certain applications. A Zn mass percentage less than 1.0% may reduce the age hardening rate of the aluminum alloy, causing it to reach the required hardness over a longer period. A Zn mass percentage less than 1.0% may result in uneven distribution of precipitated phases in the aluminum alloy, thus affecting the alloy's properties and uniformity.

[0098] Specifically, the mass percentage of Zn in the aluminum alloy can be 1%, 1.4%, 1.6%, 1.8%, or 2%, etc. The mass percentage of Zn in the aluminum alloy can be selected as needed, and this application does not limit the mass percentage of Zn in the aluminum alloy.

[0099] In some embodiments, Mg accounts for 0.2% to 0.6% of the mass percentage of the aluminum alloy. Thus, the addition of Mg within this range can significantly improve the physical and chemical properties of the aluminum alloy, such as strength, hardness, corrosion resistance, and biocompatibility. A Mg content of 0.2% to 0.6% by mass can reduce raw material costs while maintaining performance.

[0100] Furthermore, a Mg content of less than 0.2% by mass in aluminum alloys may lead to a decrease in the overall properties of the alloy, such as reduced strength and hardness, making it unsuitable for specific applications. A Mg content of less than 0.2% by mass may make the aluminum alloy production process more complex and unstable, as it requires more precise control of the content of other elements to maintain overall performance. A Mg content of more than 0.6% by mass in aluminum alloys will lead to a corresponding increase in raw material costs, thereby reducing the product's competitiveness. A Mg content of more than 0.6% by mass in aluminum alloys may increase the brittleness of the aluminum alloy, reducing its impact resistance and fatigue resistance. A Mg content of more than 0.6% by mass in aluminum alloys may increase the difficulty of process control, such as increasing the difficulty of smelting and casting, and increasing the cost of subsequent processing and treatment. A Mg content of more than 0.6% by mass in aluminum alloys may also cause adverse reactions with other elements, thereby affecting the overall properties of the aluminum alloy, such as corrosion resistance and heat resistance.

[0101] Specifically, the mass percentage of Mg in the aluminum alloy can be 0.2%, 0.21%, 0.24%, 0.26%, 0.28%, 0.3%, 0.34%, 0.38%, 0.4%, 0.45%, 0.5%, or 0.6%, etc. Specifically, the mass percentage of Mg in the aluminum alloy can be selected as needed, and this application does not limit the mass percentage of Mg in the aluminum alloy.

[0102] In some embodiments, rare earth elements constitute 0.01% to 0.03% of the aluminum alloy by mass. This range of rare earth content allows for effective interaction with other elements in the aluminum alloy, forming stable compounds that improve the alloy's strength, hardness, and fracture toughness. This range of rare earth content also improves the casting and processing properties of the aluminum alloy, reduces porosity and inclusion formation, and enhances the alloy's density and uniformity. Furthermore, this range of rare earth content can reduce raw material costs while maintaining performance.

[0103] Furthermore, a rare earth content of less than 0.01% may not fully utilize the superior properties of rare earth elements, resulting in limited improvement in the overall performance of the aluminum alloy. When the rare earth content is too low, the corrosion resistance of the aluminum alloy may decrease, making it more susceptible to damage in humid or corrosive environments. A rare earth content greater than 0.03% will significantly increase production costs. A rare earth content greater than 0.03% may also increase the brittleness of the aluminum alloy, reducing its impact resistance and fatigue resistance, thereby affecting the alloy's service life and safety.

[0104] Specifically, the mass percentage of rare earth elements in the aluminum alloy can be 0.01%, 0.012%, 0.014%, 0.016%, 0.018%, 0.02%, 0.024%, 0.028%, or 0.03%, etc. In particular, the mass percentage of rare earth elements in the aluminum alloy can be selected as needed, and this application does not limit the mass percentage of rare earth elements in the aluminum alloy.

[0105] In some embodiments, Ti accounts for less than or equal to 0.2% of the mass of the aluminum alloy. This allows Ti to form stable compounds with other elements in the aluminum alloy, thereby improving the overall performance of the material. Controlling the Ti content to less than or equal to 0.2% helps reduce raw material costs while maintaining acceptable material performance. When the Ti content is controlled to less than or equal to 0.2%, the addition of Ti does not significantly affect the alloy's casting, machining, and heat treatment processes, thus improving process adaptability and stability. Controlling the Ti content to less than or equal to 0.2% can reduce defects such as hot cracking and porosity during solidification, improving the quality and reliability of castings.

[0106] Furthermore, when Ti accounts for more than 0.2% of the mass of an aluminum alloy, the cost of raw materials increases significantly. A Ti percentage greater than 0.2% may lead to performance overkill in the alloy, meaning the alloy's properties exceed actual requirements. This not only wastes Ti resources but may also increase the difficulty of subsequent processing and handling. A Ti percentage greater than 0.2% may increase the alloy's brittleness, reducing its impact and fatigue resistance, affecting its service life and safety. A Ti percentage greater than 0.2% may increase the difficulty of the alloy's manufacturing process. For example, during smelting and casting, more precise control of the alloy composition and temperature is required to avoid problems such as compositional segregation and coarse grains. A Ti percentage greater than 0.2% may lead to the formation of excessive Ti compounds, resulting in an inhomogeneous alloy microstructure. This will affect the alloy's mechanical properties and corrosion resistance.

[0107] Specifically, the mass percentage of Ti in the aluminum alloy can be 0.2%, 0.18%, 0.15%, 0.13%, 0.1%, 0.06%, 0.05%, or 0.013%, etc. Specifically, the mass percentage of Ti in the aluminum alloy can be selected as needed, and this application does not limit the mass percentage of Fe in the aluminum alloy.

[0108] In some embodiments, Cu accounts for 0.1% to 0.5% of the mass of the aluminum alloy. This Cu content range enhances the alloy's strength and toughness, enabling it to withstand higher mechanical stresses and impact loads. This Cu content range also improves the alloy's corrosion resistance; particularly in certain corrosive environments, Cu can form a protective film with other elements in the alloy, thereby extending the alloy's service life. Furthermore, this Cu content range improves the alloy's machinability, such as cutting, casting, and welding, thus increasing production efficiency.

[0109] Furthermore, a Cu percentage of less than 0.1% in an aluminum alloy may result in insufficient strength and toughness, failing to meet the mechanical performance requirements of certain applications. A Cu percentage less than 0.1% may reduce the alloy's corrosion resistance, especially in corrosive environments, potentially shortening its service life. A Cu percentage greater than 0.5% significantly increases raw material costs. Cu is a relatively expensive metallic element, and excessive use increases production costs. A Cu percentage greater than 0.5% may lead to overperformance, meaning the alloy's properties exceed actual requirements, wasting Cu resources and potentially increasing the difficulty of subsequent processing and handling. A Cu percentage greater than 0.5% may cause hot brittleness during hot working, making hot forging and rolling difficult, affecting the alloy's machinability and service life. A Cu percentage greater than 0.5% may lead to the formation of excessive Cu compounds or enriched regions, resulting in an uneven alloy microstructure. This affects the alloy's mechanical properties and corrosion resistance.

[0110] Specifically, the mass percentage of Cu in the aluminum alloy can be 0.1%, 0.18%, 0.2%, 0.23%, 0.28%, 0.3%, 0.35%, 0.4%, 0.45%, or 0.5%, etc. Specifically, the mass percentage of Cu in the aluminum alloy can be selected as needed, and this application does not limit the mass percentage of Cu in the aluminum alloy.

[0111] In some embodiments, Sr accounts for 0.01% to 0.05% of the aluminum alloy by mass. This Sr content range effectively refines the alloy's grains, resulting in a more uniform microstructure. Grain refinement contributes to improved strength and toughness while reducing casting defects such as hot cracks and porosity. This Sr content range also improves the alloy's casting properties, increasing the density and surface quality of the castings. This helps reduce scrap rates during casting and improves production efficiency. Furthermore, this Sr content range may also improve the alloy's wear resistance and corrosion resistance, extending its service life.

[0112] Furthermore, when the Sr percentage in an aluminum alloy is less than 0.01% by mass, its grain-refining effect may be insignificant, potentially hindering a substantial improvement in the alloy's strength and toughness, while also increasing the likelihood of defects during casting. A Sr percentage less than 0.01% by mass may decrease the alloy's casting performance, affecting the density and surface quality of the castings. A Sr percentage greater than 0.05% by mass will significantly increase raw material costs. A Sr percentage greater than 0.05% by mass may lead to inhomogeneous microstructures within the alloy, such as the formation of Sr-rich or Sr-depleted phases. This will affect the alloy's mechanical properties and corrosion resistance. A Sr percentage greater than 0.05% by mass may result in more defects during casting, such as porosity and inclusions, which reduce the quality and reliability of the castings. A Sr percentage greater than 0.05% by mass may lead to an overabundance of Sr in the alloy. This not only wastes Sr resources but may also increase the difficulty of subsequent processing and treatment.

[0113] Specifically, the mass percentage of Sr in the aluminum alloy can be 0.01%, 0.015%, 0.02%, 0.026%, 0.03%, 0.036%, 0.04%, 0.048%, or 0.05%, etc. In particular, the mass percentage of Sr in the aluminum alloy can be selected as needed, and this application does not limit the mass percentage of Sr in the aluminum alloy.

[0114] In some embodiments, the Ca content in the aluminum alloy is 0.002% to 0.006% by mass. This Ca content range effectively refines the alloy's grains, resulting in a more uniform microstructure and thus improving the alloy's strength and toughness. This Ca content range also enhances the alloy's corrosion resistance, particularly in corrosive environments where Ca can form a protective layer, reducing the corrosion rate. Furthermore, this Ca content range improves the alloy's machinability, such as cutting, casting, and welding, thereby increasing production efficiency. Finally, this Ca content range optimizes the alloy's composition, improving its overall properties, such as hardness and wear resistance.

[0115] Furthermore, a Ca content of less than 0.002% by mass in aluminum alloys may result in a negligible effect on grain refinement, leading to a lack of significant improvement in the alloy's strength and toughness. A Ca content of less than 0.002% by mass may decrease the alloy's corrosion resistance, particularly in corrosive environments, potentially shortening its service life. A Ca content of less than 0.002% by mass may affect the alloy's machinability, potentially causing more problems during cutting, casting, and welding. A Ca content of greater than 0.006% by mass will significantly increase raw material costs. A Ca content of greater than 0.006% by mass may lead to microstructural inhomogeneity within the alloy, such as the formation of Ca-rich or Ca-poor phases. This will affect the alloy's mechanical properties and corrosion resistance. A Ca content of greater than 0.006% by mass may increase the alloy's brittleness, reducing its impact and fatigue resistance. A Ca content of greater than 0.006% by mass may result in an alloy with excessive performance, meaning the alloy's properties exceed actual requirements. This not only wastes Ca resources but may also increase the difficulty of subsequent processing and treatment.

[0116] Specifically, the mass percentage of Ca in the aluminum alloy can be 0.002%, 0.0025%, 0.003%, 0.0035%, 0.004%, 0.0046%, 0.005%, 0.0058%, or 0.006%, etc. Specifically, the mass percentage of Ca in the aluminum alloy can be selected as needed, and this application does not limit the mass percentage of Ca in the aluminum alloy.

[0117] It should be noted that the elemental contents of the aluminum alloy in this application are as follows: Al: 85%–92%, Si: 6.0%–8.0%, Zn: 1.0%–2.0%, Mg: 0.2%–0.6%, Cu: 0.1%–0.5%, Re: 0.01%–0.03%, Sr: 0.01%–0.05%, Fe≤0.3%, Ti≤0.2%, Mn≤0.3%, Ca: 0.002%–0.006%, Mn+Fe<0.5%, 1.0≤Mn / Fe≤1.2. The other contents are unavoidable trace impurities, making the total elemental content and the total amount of unavoidable impurities 100%. The content of a single trace impurity element is ≤0.05%, and the total amount of trace impurities is ≤0.15%.

[0118] According to a second aspect of this disclosure, a vehicle body component 10 is provided, with reference to... Figure 1 and Figure 2 The vehicle body component 10 comprises the aforementioned aluminum alloy. The vehicle body component 10 possesses all the beneficial effects of the aforementioned aluminum alloy, which will not be elaborated further in this disclosure.

[0119] It should be noted that, due to the significantly improved toughness of the aluminum alloy provided in this application, its resistance to deformation and fracture is enhanced. This means that, while maintaining the same strength level, the wall thickness can be reduced without worrying about material fracture under stress. Lightweighting is a crucial objective in the design of the vehicle body component 10. By reducing the wall thickness of the vehicle body component 10, its weight can be significantly reduced, thereby lowering the overall vehicle's energy consumption and improving fuel economy (for traditional gasoline vehicles) or driving range (for electric vehicles).

[0120] In addition, the vehicle body component 10 made of the aforementioned aluminum alloy possesses sufficient strength and rigidity to withstand various loads and vibrations during vehicle operation. The aluminum alloy also exhibits excellent corrosion resistance, giving the vehicle body component 10 superior corrosion resistance and extending its service life.

[0121] In some embodiments, the vehicle body component 10 is illustrated using a subframe as an example. The subframe has a length of L, a width of K, and a height of H, where L ≥ 1100 mm, K ≥ 800 mm, and H ≥ 250 mm. This allows the subframe to have a larger size, enabling it to more effectively disperse and absorb impacts and vibrations from the road surface, thereby improving the overall rigidity and stability of the vehicle. Sufficient length and width provide more space for the suspension system layout, helping to optimize suspension geometry and improve vehicle handling and ride comfort. A large-size subframe can provide more robust suspension connection points, reducing suspension system vibration and noise, and improving ride quality. A large-size subframe can accommodate larger and heavier powertrains, including engines and transmissions, meeting the needs of high-performance vehicles.

[0122] In some embodiments, the wall thickness of the body component 10 is T, the tensile strength is TS, and the yield strength is YS, wherein T ≥ 3mm. Thus, a wall thickness T ≥ 3mm significantly enhances the deformation resistance of the body component 10, enabling it to better withstand impacts and vibrations from the road surface, thereby improving the overall rigidity and stability of the vehicle. A wall thickness T ≥ 3mm means that the body component 10 can withstand greater loads and longer service life, reducing deformation and damage caused by long-term use and extending its service life. In the event of a vehicle collision, a wall thickness T ≥ 3mm can more effectively absorb and disperse impact forces, protecting the integrity of the passenger compartment and reducing the risk of occupant injury. Furthermore, the minimum wall thickness of the body component 10 can be 3mm. Combining the aforementioned characteristics of aluminum alloys, the weight of the body component 10 can be reduced while meeting its strength requirements.

[0123] Furthermore, a wall thickness of less than 3mm for the body component 10 may cause it to deform easily under impact and vibration, affecting the vehicle's stability and handling. A wall thickness of less than 3mm also means that the body component 10 has limited load-bearing capacity, making it prone to damage over long-term use and requiring more frequent maintenance and replacement, thus increasing operating costs. In the event of a collision, a wall thickness of less than 3mm for the body component 10 may not be able to effectively absorb and disperse impact forces, increasing the risk of injury to occupants.

[0124] It should be noted that the vehicle body component 10 has a hollow cavity, so that the vehicle body component 10 has an inner side and an outer side that are arranged opposite to each other. The wall thickness of the vehicle body component 10 refers to the distance between the inner side and the outer side.

[0125] When the tensile strength TS ≥ 350 MPa, since tensile strength measures a material's maximum ability to resist tensile failure, a tensile strength of 10 equal to or exceeding 350 MPa means it can withstand greater tensile forces without breaking, thus enhancing its load-bearing capacity. Higher tensile strength helps reduce deformation and damage to the body component 10 during long-term use, extending its service life. In a vehicle collision, the body component 10, as a crucial part connecting the vehicle body and suspension system, must withstand enormous impact forces. Higher tensile strength ensures the body component 10 remains intact during a collision, effectively absorbing and dispersing impact forces, protecting the integrity of the passenger compartment, and reducing the risk of occupant injury. The tensile strength of the body component 10 has a significant impact on the stability of the suspension system. Higher tensile strength ensures the suspension system maintains a stable posture during vehicle operation, reducing body roll and pitch, and improving driving safety. Higher tensile strength means that the body components 10 can better withstand impacts and vibrations from the road surface and transmit them to the suspension system and body, minimizing vibrations and thus improving ride comfort.

[0126] When the yield strength YS ≥ 260 MPa, since yield strength measures the maximum stress a material can withstand before plastic deformation, a yield strength of 10 in the vehicle body component 10 that reaches or exceeds 260 MPa means it can more effectively resist impacts and vibrations from the road surface, reducing plastic deformation caused by external forces and thus maintaining vehicle stability and safety. In a collision, the vehicle body component 10 needs to withstand enormous impact forces. A higher yield strength ensures that the vehicle body component 10 is less prone to plastic deformation or fracture during a collision, thus more effectively protecting the integrity of the passenger compartment and reducing the risk of occupant injury. The yield strength of the vehicle body component 10 has a significant impact on the response speed and accuracy of the suspension system. A higher yield strength reduces the deformation of the suspension system during stress, improving its response speed and stability, thereby enhancing vehicle handling performance. A higher yield strength means that the vehicle body component 10 can better absorb and disperse vibrations and noise from the road surface, reducing the impact of these adverse factors on vehicle handling performance and ride comfort. A higher yield strength reduces fatigue damage to the body components 10 caused by stress during long-term use, thus extending their service life. Because of the high yield strength, the body components 10 are less prone to plastic deformation or damage during use, reducing the frequency of maintenance and replacement, and lowering vehicle operating costs. The higher yield strength also allows the body components 10 to better adapt to various harsh road conditions, such as rugged mountain roads and bumpy country lanes, ensuring that the vehicle maintains stable handling performance and ride comfort under these conditions.

[0127] It should be noted that the wall thickness, tensile strength and yield strength of the above-mentioned vehicle body component 10 can be satisfied individually or simultaneously. When all three are satisfied, the performance of the vehicle body component 10 is the best.

[0128] According to a third aspect of this disclosure, a vehicle is provided that includes the body components as described above, and the vehicle has all the beneficial effects of the aforementioned body components, which will not be repeated here.

[0129] Reference Figure 3 According to a fourth aspect of this disclosure, a method for casting a vehicle body component 10 as described above is provided, the method comprising the following steps:

[0130] S100. Obtain the aluminum alloy casting liquid as described above;

[0131] S200, vacuum extrusion casting of aluminum alloy molten metal.

[0132] The casting method for the vehicle body component 10 according to this application embodiment obtains the aluminum alloy molten casting as described above, and performs vacuum extrusion casting on the molten aluminum alloy. Since aluminum alloy has good toughness and mechanical properties, the vacuum extrusion casting process, by removing gas from the die-casting mold cavity, can significantly reduce porosity and dissolved gases in the die-casting, thereby reducing the defect rate inside the cast vehicle body component 10. The vacuum environment helps the molten aluminum alloy to better fill the mold cavity, preventing gas from forming bubbles or depressions on the surface of the vehicle body component 10, thus improving the surface quality of the vehicle body component 10. Vacuum extrusion casting can refine the microstructure of the vehicle body component 10, improve its hardness and strength, and reduce internal stress concentration, thereby improving the mechanical properties of the vehicle body component 10. Through vacuum extrusion casting, the elongation of the vehicle body component 10 can be significantly improved, which helps to enhance the toughness and deformation resistance of the vehicle body component 10. During the vacuum extrusion casting process, since the gas in the cavity is removed, the back pressure during die casting is greatly reduced, so a lower specific pressure can be used for casting, reducing the requirements on the die-casting machine. Vacuum extrusion casting has a relatively simple process and is easy to operate. It can reduce internal defects and scrap rates in vehicle body components 10, thereby lowering production costs. Furthermore, the use of lower specific pressures during casting also reduces investment and maintenance costs for die-casting equipment.

[0133] Reference Figure 4 Specifically, the steps for obtaining the aluminum alloy casting liquid as described above include:

[0134] S110. Add a first material, including aluminum ingots, to the reverberatory furnace. After the first material melts, a first molten metal is obtained.

[0135] In this step, aluminum ingots, as the main component of the aluminum alloy casting liquid, possess high purity and stable composition, helping to ensure that the composition of the casting liquid meets design requirements. Aluminum ingots have high thermal conductivity and good melting properties, enabling rapid melting in a reverberatory furnace, shortening smelting time and improving production efficiency. As a primary casting raw material, aluminum ingots are relatively stable in price and readily available, helping to reduce production costs. The smelting process of aluminum ingots is relatively simple and easy to control, contributing to reduced energy consumption and pollutant emissions.

[0136] In addition, aluminum ingots account for 85% to 92% of the total mass of the aluminum alloy casting. Thus, by precisely controlling the amount of aluminum ingots added, the alloy composition can be optimized, and the mechanical properties, corrosion resistance, and heat resistance of the castings can be improved.

[0137] In one embodiment, the first material further includes crystalline silicon or silicon aluminide. Of course, in other embodiments, the first material can be selected as needed, and this application does not limit it.

[0138] Crystalline silicon comprises 5% to 8% of the total mass of the molten aluminum alloy. This range of silicon addition can significantly improve the tensile strength and hardness of the aluminum alloy, resulting in better mechanical properties. This range of silicon addition can also improve the fluidity of the aluminum alloy, reducing defects during casting, such as porosity and shrinkage cavities, thereby improving the quality of the castings. Furthermore, this range of silicon addition can enhance the high-temperature resistance and corrosion resistance of the aluminum alloy, allowing it to maintain good performance even in harsh environments. Finally, this range of silicon addition can optimize the composition of the aluminum alloy, resulting in better overall performance.

[0139] Furthermore, when the amount of crystalline silicon added is less than 5%, the strength and hardness of the aluminum alloy may decrease due to insufficient silicon content, failing to meet certain high-performance requirements. When the amount of crystalline silicon added is less than 5%, the fluidity of the aluminum alloy may be affected, leading to increased defects during casting and a decline in casting quality. When the amount of crystalline silicon added is greater than 8%, the plasticity of the aluminum alloy decreases, while its brittleness increases, making it prone to cracking and fracture. When the amount added is greater than 8%, the aluminum alloy may encounter difficulties in machining, and its weldability will also be affected. When the amount of crystalline silicon added is greater than 8%, it increases the hot cracking susceptibility of the aluminum alloy, making it more prone to cracking during processing and welding.

[0140] S120. Adjust the temperature of the first molten metal to 700℃~740℃, add the second material to the reverberatory furnace, the second material includes a manganese source, and stir for 3min~5min to obtain the second molten metal.

[0141] In this step, the manganese source may include electrolytic manganese blocks. Adjusting the temperature of the first molten metal to 700℃~740℃ ensures that the alloying elements are fully melted, reduces the presence of gases and inclusions, and avoids problems such as segregation, cold shuts, and undercasting. When the temperature of the first molten metal exceeds 740℃, it leads to energy waste, increased hydrogen absorption, coarse grains, and severe oxidation, thus affecting the mechanical and casting properties of the alloy. When the temperature of the first molten metal is below 700℃, the alloying elements may not melt sufficiently, thus affecting the mechanical and casting properties of the alloy.

[0142] In this step, the stirring time of 3 to 5 minutes is designed based on the optimal stirring time designed for the melting of the second material in this step. If the stirring time is less than 3 minutes, insufficient stirring may lead to component segregation. If the stirring time is more than 5 minutes, excessive stirring time may lead to severe oxidation of the melt and an increase in slag inclusions.

[0143] It should be noted that although no iron was added during the process of obtaining the first and second molten metals, the second molten metal obtained at the end contains iron because the first and second materials may contain iron impurities.

[0144] In one embodiment, the second material further includes a zinc source. Specifically, the zinc source may include electrolytic zinc ingots. As a high-purity zinc source, the addition of electrolytic zinc ingots can significantly increase the zinc content of the aluminum alloy, thereby optimizing the alloy composition. The addition of zinc can improve the hardness, strength, and corrosion resistance of the alloy, while also improving its fluidity and formability, resulting in better overall performance. The addition of zinc can improve the fluidity of the aluminum alloy, making it easier to fill the mold cavity during casting, reducing defects, and improving the density and surface quality of the casting. The addition of zinc can reduce the hot cracking tendency of the aluminum alloy and improve the crack resistance of the vehicle body component 10. As a high-purity zinc source, the addition of electrolytic zinc ingots can accelerate the dissolution and uniform distribution of zinc in the alloy, thereby shortening the smelting time and improving production efficiency. The price of electrolytic zinc ingots is relatively stable and readily available, and their addition can reduce the production cost of the alloy.

[0145] Reference Figure 5 In some embodiments, after step S120, which adjusts the temperature of the first molten metal to 700°C–740°C, adds a second material, including a manganese source, to the reverberatory furnace and stirs for 3–5 minutes to obtain the second molten metal, the process further includes:

[0146] Step S130: Heat the second molten metal to 740℃~780℃, add a third material to the reverberatory furnace, the third material includes an aluminum alloy containing rare earth elements, stir for 3min~5min, and refine and remove slag to obtain the third molten metal.

[0147] In this step, raising the temperature of the second molten metal to 740℃~780℃ ensures complete melting of alloying elements, reduces the presence of gases and inclusions, and avoids problems such as segregation, cold shuts, and undercasting. Temperatures above 780℃ can lead to energy waste, increased hydrogen absorption, coarse grains, and severe oxidation, thus affecting the mechanical and casting properties of the alloy. Temperatures below 740℃ may result in incomplete melting of alloying elements, also affecting the mechanical and casting properties of the alloy.

[0148] In this step, the stirring time of 3 to 5 minutes is designed based on the optimal stirring time designed for the melting of the third material in this step. If the stirring time is less than 3 minutes, insufficient stirring may lead to component segregation. If the stirring time is more than 5 minutes, excessive stirring time may lead to severe oxidation of the melt and an increase in slag inclusions.

[0149] It should be noted that aluminum alloys containing rare earth elements may include at least one of aluminum lanthanum and aluminum cerium. Of course, in other embodiments, aluminum alloys containing rare earth elements may also include aluminum praseodymium, aluminum neodymium, and aluminum promethium, etc. The selection of aluminum alloys containing rare earth elements can be made as needed, and this application does not limit this selection.

[0150] In some embodiments, the third material further includes at least one of aluminum copper and aluminum titanium boron, thus achieving the addition of at least one of Ti and Cu. When copper is added, the strength and hardness of the aluminum alloy can be significantly improved, making it more suitable for components subjected to heavy loads. When aluminum titanium boron is added, it can act as a grain refiner, reducing impurities and defects in the alloy and improving the toughness and strength of the metal. Aluminum titanium boron can significantly improve the hardness and wear resistance of the alloy, making it more suitable for components that need to withstand wear. During the smelting process, aluminum titanium boron can react with gases to form oxides or nitrides, thereby inhibiting the reaction between the gas and the metal and improving the purity of the alloy. In addition, the addition of aluminum copper and aluminum titanium boron can improve the fluidity of the alloy, making it easier to fill the mold cavity during casting and reducing the generation of defects. The addition of aluminum copper and aluminum titanium boron can reduce the alloy's tendency to hot crack and improve the crack resistance of the casting. The addition of aluminum copper and aluminum titanium boron can accelerate the alloy smelting process, reduce energy consumption, and improve production efficiency. The addition of aluminum-copper and aluminum-titanium-boron can reduce pollutant emissions during the smelting process, which is conducive to achieving green casting and sustainable development.

[0151] Step S140: Reduce the temperature of the third molten metal to 680℃~740℃, add the fourth material, which includes magnesium, to the third molten metal, and stir to obtain the fourth molten metal.

[0152] In this step, the temperature of the third molten metal is reduced to 680℃~740℃ to prepare for the subsequent casting of the car body component 10. If the temperature of the third molten metal exceeds 740℃, it will overheat, causing slag inclusions in the car body component 10. Slow cooling of the car body component 10 will also lead to defects such as shrinkage cavities, thus affecting its performance. Conversely, if the temperature of the third molten metal is reduced to below 680℃, the casting temperature will be too low, resulting in defects such as pre-crystallization and cold shuts in the car body component 10, further impacting its performance.

[0153] In some embodiments, the fourth material further includes aluminum strontium. Thus, the aluminum strontium alloy, acting as a modifier, can effectively refine the eutectic silicon and primary silicon in the alloy, resulting in finer, more uniform grains and thus improving the mechanical properties of the alloy. The addition of strontium can significantly improve the strength and hardness of the aluminum alloy, making it more suitable for components subjected to larger loads and higher stresses. The addition of aluminum strontium alloy can improve the fluidity of the alloy, making it easier to fill the mold cavity during casting, reducing defects, and improving the density and surface quality of the casting. The addition of aluminum strontium can reduce the alloy's tendency to hot crack, improving the crack resistance of the vehicle body component 10, making the vehicle body component 10 more complete and reliable. The addition of aluminum strontium alloy can accelerate the alloy smelting process, reduce energy consumption, and improve production efficiency. The modifying effect of aluminum strontium alloy can reduce impurities and defects in the alloy, thereby reducing the scrap rate and improving product quality. The preparation and addition of aluminum strontium alloy generate fewer pollutants, which is conducive to achieving green casting and sustainable development.

[0154] It should be noted that although no iron was added during the process of obtaining the third and fourth molten metals, the fourth molten metal obtained at the end contains iron because the third and fourth materials may contain iron impurities.

[0155] Reference Figure 6 Step S200, which involves vacuum extrusion casting of the aluminum alloy molten metal, includes:

[0156] Step S210: Evacuate the mold cavity to make the vacuum level of the mold cavity less than or equal to 80 mbar.

[0157] In this step, the vacuum level of the mold cavity is less than or equal to 80 mbar. When the vacuum level reaches 80 mbar or below, the amount of residual gas in the mold cavity is significantly reduced. This low-gas environment helps reduce the amount of gas entrained by the molten metal during filling the mold cavity, thereby reducing the risk of gas entrapment defects. During the process of metal melting and filling the mold cavity, due to the increase in temperature and decrease in pressure, the dissolved gases gradually precipitate out, reducing gas retention in the molten metal and further reducing the possibility of gas entrapment defects. Within this vacuum range, the fluidity of the molten metal is improved, which helps to increase filling efficiency and allows the molten metal to fill the mold cavity more uniformly. When the filling efficiency is improved, the flow path of the molten metal in the mold cavity becomes smoother, thereby reducing the chance of gas entrainment.

[0158] Step S220: Control the temperature of the mold cavity within the range of 150℃~200℃.

[0159] In this step, controlling the mold cavity temperature within the range of 150℃ to 200℃ effectively prevents a significant decrease in the fluidity of the molten metal when the mold cavity temperature is too low. This can lead to insufficient fusion during filling, especially in areas far from the gate, where cold shuts can easily occur. Cold shuts manifest as one or more incompletely fused seams or cracks on the casting surface. This defect not only affects the aesthetics of the casting but also negatively impacts its mechanical properties. Maintaining the mold cavity temperature within the 150℃ to 200℃ range ensures sufficient fluidity of the molten metal during filling, effectively preventing cold shuts. Too low a mold cavity temperature can also cause significant resistance to the molten metal during filling, slowing down the filling speed and potentially leading to incomplete filling. This can result in defects such as missing material or incompleteness in the casting. Increasing the mold cavity temperature to 150℃ to 200℃ reduces the resistance of the molten metal during filling, improves filling efficiency, and thus avoids incomplete filling. When the mold cavity temperature is too high, the heat exchange between the molten metal and the mold intensifies, causing the mold surface temperature to rise rapidly. This renders the release agent on the mold ineffective, allowing the molten metal to directly contact and adhere to the mold surface, resulting in mold sticking. Mold sticking not only leads to defects such as surface scratches and internal looseness in the casting, but also severely damages the mold and increases the consumption of die-casting consumables. Controlling the mold cavity temperature within the range of 150℃ to 200℃ ensures that the mold surface temperature remains within a reasonable range, avoiding mold sticking and scratches. Excessively high mold cavity temperatures also cause significant shrinkage of the molten metal during solidification, increasing the probability of shrinkage cavities. Shrinkage cavities are a type of internal cavity defect in castings that severely affects their mechanical properties and reliability. By controlling the mold cavity temperature within the range of 150℃ to 200℃, the solidification rate of the molten metal can be slowed down, allowing for more uniform cooling and solidification, thereby reducing the probability of shrinkage cavity formation.

[0160] Step S240: Pour the molten aluminum alloy into the mold cavity and perform multiple injection molding processes.

[0161] It should be noted that in this step, 2 to 8 different injection parameters are set to inject the aluminum alloy molten casting into the mold cavity. In this way, due to the large size of the die-cast parts and the long distance of the molten metal filling, the injection speed of the melt will be divided into several stages, including the initial slow speed, the subsequent rapid filling, and the final slow holding pressure stage. Each stage will be graded and adjusted according to the characteristics of the material, the die-casting process parameters, and the performance of the equipment to minimize the generation of internal defects in the parts and ensure the performance of the parts.

[0162] Furthermore, by setting different injection parameters, the filling speed and pressure of the aluminum alloy molten metal in the mold cavity can be precisely controlled, ensuring that the molten metal can uniformly and fully fill the mold cavity, avoiding defects such as poor filling and cold shuts. Reasonable injection parameter settings help reduce porosity and inclusions in the casting, improving its density and purity. This is because appropriate filling speed and pressure promote the expulsion of gases and impurities from the molten metal, reducing their residue in the casting. Optimizing injection parameters can also improve the strength and toughness of the casting, better meeting application requirements. This is because reasonable filling speed and pressure contribute to grain refinement and microstructural densification within the casting, thereby improving its mechanical properties. By setting appropriate injection parameters, the forming cycle of aluminum alloys can be shortened, improving production efficiency. Reasonable injection parameter settings can also reduce energy consumption during production. Setting 2 to 8 different injection parameter levels can adapt to the production requirements of different castings. For castings with complex shapes and uneven wall thicknesses, the filling effect and mechanical properties can be optimized by adjusting the injection parameters.

[0163] Reference Figure 7 Specifically, before step S240, which involves pouring the molten aluminum alloy into the mold cavity and performing multiple injection molding processes, the following steps are also included:

[0164] Step S230: Determine that the weight of the aluminum alloy casting liquid is 140% to 160% of the weight of the car body component 10 to be cast, and the pouring temperature is 690℃ to 710℃.

[0165] In this step, setting the weight of the molten aluminum alloy to 140%–160% of the weight of the car body component 10 to be cast ensures sufficient fluidity of the molten aluminum alloy when filling the mold cavity, allowing it to fully fill all corners and details of the mold. This helps avoid defects such as incomplete filling and shrinkage cavities in the casting, ensuring the integrity and structural strength of the casting. Setting the weight of the molten aluminum alloy to 140%–160% of the weight of the car body component 10 to be cast also ensures sufficient pressure is generated during the die casting process, helping to compact the melt and reduce internal porosity and looseness. This helps reduce casting defects and improve the quality and reliability of the casting. In addition, controlling the pouring temperature within the range of 690℃–710℃ ensures that the molten aluminum alloy has appropriate fluidity, which helps the melt flow smoothly when filling the mold cavity, avoiding defects such as cold shuts and flow lines. Controlling the pouring temperature within the range of 690℃ to 710℃ can reduce the thermal stress generated during the cooling process of the casting. This helps to prevent the casting from cracking or deforming due to excessive thermal stress, and improves the dimensional stability and shape accuracy of the casting. Controlling the pouring temperature within the range of 690℃ to 710℃ also results in a more uniform and dense microstructure in the casting, thereby improving its mechanical properties and fatigue resistance.

[0166] Step S250: Increase the pressure inside the mold cavity to 100 bar to 120 bar within 1 to 3 seconds by increasing the pressure at a rate of 20 bar / s to 50 bar / s.

[0167] It should be noted that a pressurization rate of 20 bar / s to 50 bar / s can significantly shorten the switching time between multiple pressure levels. This is because a faster pressurization rate means that the pressure can quickly reach the required level, reducing waiting time and thus improving production efficiency and reducing energy consumption. Controlling the pressurization rate within the range of 20 bar / s to 50 bar / s can effectively prevent turbulent air entrapment during metal filling of the mold cavity. This is because a faster pressurization rate can quickly balance the pressure distribution within the mold cavity, reducing turbulence caused by uneven pressure. A pressurization rate of 20 bar / s to 50 bar / s can reduce defects such as porosity and inclusions caused by uneven pressure; at the same time, it also helps to reduce defects such as cracks and deformation caused by turbulence.

[0168] Furthermore, during die casting, the molten metal requires sufficient pressure to overcome flow resistance and ensure complete filling of the mold cavity. Insufficient pressure may prevent the molten metal from reaching certain areas of the cavity, resulting in incomplete filling. A rapid increase in pressure within the mold cavity to 100-120 bar within 1-3 seconds ensures the molten metal receives sufficient pressure in a short time, thus fully filling the cavity and avoiding incomplete filling. Before the mold cavity is completely filled, some metal may begin to solidify, leading to an uneven microstructure within the casting and reducing its mechanical properties and reliability. A rapid increase in pressure to 100-120 bar within 1-3 seconds accelerates the flow rate of the molten metal, allowing it to fill the cavity more quickly and reducing pre-crystallization. This rapid increase in pressure also promotes the expulsion of gases and impurities from the molten metal, further reducing the likelihood of pre-crystallization. If the flow rate of the molten metal is too slow or the temperature is too low, cold shuts are likely to occur. Increasing the pressure inside the mold cavity to 100-120 bar within 1-3 seconds can significantly improve the flow rate and temperature of the molten metal, making the molten metal fill the mold cavity more evenly and stably, thereby avoiding the occurrence of cold shuts.

[0169] Step S260: Perform dynamic pressure holding and local pressure increase within the mold cavity.

[0170] Reference Figure 8 Specifically, this step includes;

[0171] S261. Maintain the pressure value in the mold cavity at 150 bar to 210 bar, and hold the pressure for 25 to 40 seconds.

[0172] During the casting process, the molten metal undergoes volume shrinkage as it cools and solidifies within the mold cavity. If the pressure within the mold cavity is insufficient or the holding time is inadequate, the molten metal will not be effectively compensated for, leading to voids or shrinkage cavities inside the part. Maintaining the pressure within the mold cavity at 150-210 bar and holding it for 25-40 seconds ensures that the molten metal receives sufficient pressure during solidification, effectively compensating for the volume reduction caused by cooling shrinkage. This compensating effect reduces voids and shrinkage cavities inside the part, improving its integrity. Furthermore, maintaining the pressure within the mold cavity at 150-210 bar and holding it for 25-40 seconds compresses the molecular chains in the molten metal more tightly, reducing the gaps between molecules and thus improving the density of the part's microstructure. Additionally, maintaining the pressure within the mold cavity at 150-210 bar and holding it for 25-40 seconds also helps to fully compact the molten metal within the mold cavity, reducing internal porosity and defects.

[0173] In addition, porosity and shrinkage cavities are common defects in the casting process. They are usually caused by insufficient filling of the mold cavity by the melt or insufficient feeding during solidification. Maintaining the pressure in the mold cavity at 150 bar to 210 bar and holding it for 25 to 40 seconds can ensure that the melt is fully filled and compacted in the mold cavity. At the same time, the higher pressure can also promote the expulsion of gases and impurities in the melt, further reducing the formation of porosity.

[0174] In the casting process, the stability of the holding pressure is crucial to the quality of the parts. In this step, the fluctuation of the holding pressure is Δp, where -0.5 bar < Δp < 0.5 bar. Therefore, controlling the holding pressure fluctuation within -0.5 bar to 0.5 bar ensures that the melt receives uniform and stable pressure within the mold cavity, thereby improving part quality. When the holding pressure fluctuation Δp is controlled between -0.5 bar and 0.5 bar, the pressure change of the melt within the mold cavity is relatively stable, helping to reduce dimensional changes in the parts caused by pressure fluctuations. Controlling the holding pressure fluctuation within -0.5 bar to 0.5 bar can reduce problems such as uneven melt flow and insufficient feeding within the mold cavity, thereby reducing defects such as porosity and shrinkage cavities inside the parts. This contributes to improving the internal quality and overall performance of the parts. By controlling the holding pressure fluctuation within the range of -0.5 bar to 0.5 bar, the melt flow within the mold cavity becomes smoother, reducing surface ripples and unevenness caused by pressure fluctuations. This results in a smoother, flatter surface for the parts, improving their aesthetics and performance. Maintaining the holding pressure fluctuation within this range also helps reduce scrap and rework rates during production, thereby increasing production efficiency.

[0175] S262. After 1 to 5 seconds of holding pressure, the engine mounting area of ​​the vehicle body component 10 is locally pressurized. The local pressurization pressure is 160 bar to 210 bar, so that the aluminum alloy casting liquid locally generates a pressure of 120 MPa to 200 MPa.

[0176] In this step, the localized pressurization pressure of 160 bar to 210 bar pushes and compresses the molten aluminum alloy, further densifying it under high pressure. This helps reduce porosity and looseness within the casting, especially in critical areas such as the engine mounting region. Higher density translates to stronger mechanical properties and better durability, thereby improving the overall quality of the vehicle body component 10. The localized pressurization pressure of 160 bar to 210 bar effectively reduces defects such as porosity, shrinkage cavities, and looseness during the casting process. Particularly in locally thick-walled areas of the casting, such as the engine mounting region, the localized pressurization pressure of 160 bar to 210 bar ensures that the molten metal fully fills the mold, preventing shrinkage cavities and looseness. The localized pressurization pressure of 160 bar to 210 bar compresses the molecular chains in the molten metal more tightly, reducing the gaps between molecules, resulting in a more uniform and fine microstructure. This helps improve the mechanical properties and fatigue resistance of the casting. Local pressurization in the engine mounting area, with a pressure ranging from 160 bar to 210 bar, can significantly improve the local strength of that area. Higher local strength translates to better load-bearing capacity and resistance to deformation, thereby enhancing the safety and reliability of the vehicle body component 10.

[0177] Step S270: Depressurize the mold cavity and open the mold to obtain the molded vehicle body component 10.

[0178] In this step, during the casting process, the molten metal gradually solidifies under high temperature and pressure within the mold cavity. Once the melt fills the mold cavity and reaches the desired forming state, a pressure relief operation is required, gradually reducing the pressure within the mold cavity to facilitate subsequent mold opening. Pressure relief can be achieved by adjusting the casting machine's pressure control system, ensuring that the pressure within the mold cavity gradually decreases within a safe range.

[0179] After depressurization, the pressure inside the mold cavity has decreased to a sufficiently low level, at which point the mold opening operation can be performed. Mold opening refers to separating the upper and lower parts of the mold to remove the molded vehicle body component 10. The mold opening operation is usually performed by the mold opening mechanism of the casting machine, which uses hydraulic or mechanical means to push the upper and lower parts of the mold apart.

[0180] Depressurization gradually reduces the pressure within the mold cavity, preventing damage to the mold or casting due to excessive pressure differentials during sudden mold opening. This helps extend the mold's lifespan and reduces production interruptions and increased costs caused by mold damage. Depressurization and mold opening ensure that the casting is removed from the mold only after it has fully formed and cooled, preventing deformation or damage caused by premature removal. This contributes to improved dimensional stability and surface quality of the casting, meeting the manufacturing requirements of the vehicle body component 10.

[0181] Reference Figure 9 In one embodiment, after step S270, which involves depressurizing the mold cavity and opening the mold to obtain the molded vehicle body component 10, the method further includes:

[0182] Step S280: Place the molded vehicle body component 10 into water at 55℃~65℃ for cooling.

[0183] In this step, the vehicle body component 10 is cooled in water at 55℃~65℃. This ensures a more uniform heat transfer from the casting surface to the interior, effectively reducing internal stress caused by rapid cooling. Reduced internal stress helps prevent cracking or deformation during subsequent processing or use. Uniform cooling helps maintain the dimensional stability of the casting, preventing dimensional changes caused by uneven cooling. Cooling in warm water at 55℃~65℃ allows the vehicle body component 10 to form a more uniform and dense microstructure, thereby improving its strength and toughness.

[0184] Reference Figure 10 In one embodiment, after step S280, which involves immersing the molded vehicle body component 10 in water at 55°C to 65°C for cooling, the method further includes:

[0185] Step S290: Place the vehicle body component 10 into the heating furnace and heat the furnace to 500-550°C for 3-10 hours.

[0186] In this step, the vehicle body component 10 is heated to 500–550°C and held at that temperature for 3–10 hours. This ensures the reinforcing phase is fully dissolved. The temperature range of 500–550°C is designed to allow the second phase in the alloy to fully dissolve into the solid solution. Solution treatment is a heat treatment process that uses heating to dissolve alloying elements into the base metal, forming a solid solution, thereby altering the material's microstructure and properties. Holding the temperature for 3–10 hours ensures the complete dissolution of the reinforcing phase, forming a uniform solid solution structure. The reinforcing phase gradually dissolves into the base metal during heating, forming a solid solution. This process is the core of solution treatment and a key step in improving material properties. The dissolved reinforcing phase will recrystallize in a finer and more uniform manner during subsequent cooling, forming a dispersed reinforcing body, thereby increasing the material's strength and hardness. After the reinforcing phase is fully dissolved, the lattice distortion caused by the solute atoms in the base metal increases the resistance to dislocation movement, thus improving the yield strength and tensile strength of the vehicle body component 10. Solution treatment can optimize the toughness of materials. After solution treatment, the presence of solute atoms can affect the electrochemical behavior and surface chemical properties of the material, thereby slowing down the corrosion and oxidation rates. Solution treatment can adjust the microstructure of the material, making it more uniform and finer, which helps reduce internal defects and stress concentration, improving the material's reliability and service life. Solution-treated materials have better plasticity and toughness, and can withstand greater deformation without cracking or fracture. This makes the vehicle body component 10 easier to process and form in subsequent operations.

[0187] Furthermore, during the cooling process, certain stresses may be generated inside the vehicle body component 10. Eliminating these stresses can improve the overall strength and durability of the vehicle body component 10. Heating to 500–550℃ and holding for 3–10 hours helps the atoms inside the vehicle body component 10 rearrange, thereby releasing and reducing these stresses. This avoids problems such as cracking and deformation caused by stress concentration in the vehicle body component 10, improving its reliability and service life. Heating the vehicle body component 10 to 500–550℃ and holding for 3–10 hours improves its microstructure, enhancing the material's strength, hardness, toughness, and other mechanical properties, thus strengthening its load-bearing capacity and durability. Heating to 500–550℃ and holding for 3–10 hours allows for sufficient diffusion and rearrangement of the metal atoms inside the vehicle body component 10, reducing dimensional changes caused by uneven internal material structure. Heating to 500–550°C and holding for 3–10 hours may form a dense oxide film on the surface of the vehicle body component 10 or change the chemical properties of the metal surface, thereby improving the corrosion resistance of the vehicle body component 10.

[0188] It should be noted that when the heat preservation time is less than 3 hours, the reinforcing phase may not be completely dissolved into the solid solution, resulting in insufficient solid solubility. This will affect the mechanical properties of the vehicle body component 10, preventing it from achieving the expected strengthening effect.

[0189] If the heat treatment time exceeds 10 hours, the grains in the alloy may grow, leading to a decrease in the mechanical properties of the vehicle body component 10. In addition, grain growth will reduce the strength and toughness of the material, while increasing its brittleness.

[0190] Step S2100: Immerse the insulated vehicle body component 10 in water at 20℃ to 60℃ for 5s to 10s to cool it down, and then remove it.

[0191] In this step, the insulated car body component 10 is immersed in water at 20℃ to 60℃ for cooling within 5 to 10 seconds and then removed, achieving rapid cooling of the car body component 10. This suppresses the re-precipitation of the second phase in the alloy, thereby achieving maximum supersaturation of solute atoms and vacancies. The supersaturated solid solution can precipitate finer and more uniform dispersed strengthening bodies during subsequent aging treatment, thus improving the strength and hardness of the car body component 10. After aging, the strength and hardness of the car body component 10 will be significantly improved due to the solid solution strengthening effect of solute atoms. Simultaneously, the precipitation of fine and uniform dispersed strengthening bodies will further enhance the mechanical properties of the car body component 10. Rapid cooling can improve the wear resistance and corrosion resistance of the car body component 10, enabling it to better resist wear and corrosion during use. Immersing the insulated car body component 10 in water at 20℃ to 60℃ for cooling within 5 to 10 seconds and then removing it allows the car body component 10 to achieve good comprehensive properties such as strength, toughness, wear resistance, and corrosion resistance. Rapidly cooling the car body component 10 within 5 to 10 seconds can suppress the re-precipitation of the second phase.

[0192] It should be noted that the cooling water temperature setting is related to the cooling rate, mainly to ensure the preservation of the solid solution structure. If the cooling water temperature is below 45℃, it will cause deformation of the vehicle body component 10. If the cooling water temperature is above 60℃, there may be precipitation of strengthening phase, which will affect the performance of the vehicle body component 10.

[0193] Step S2110: Put the cooled car body component 10 back into the heating furnace, and heat the heating furnace to 160-200°C within 2 hours and keep it at that temperature for 3-10 hours.

[0194] In this step, reheating the vehicle body component 10 to 160–200°C within 2 hours and holding it at that temperature for 3–10 hours can eliminate these stresses through atomic diffusion and rearrangement, thereby improving the stability and toughness of the vehicle body component 10. Reheating the vehicle body component 10 to 160–200°C within 2 hours and holding it at that temperature for 3–10 hours can further adjust the microstructure of the auxiliary materials, giving them better comprehensive properties such as strength, toughness, wear resistance, and corrosion resistance. Reheating the vehicle body component 10 to 160–200°C within 2 hours and holding it at that temperature for 3–10 hours allows the dispersion strengthening phase to precipitate, further improving the strength and hardness of the vehicle body component 10. Reheating the vehicle body component 10 to 160–200°C within 2 hours and holding it at that temperature for 3–10 hours can eliminate the internal stress generated in step S2100, thereby improving the toughness of the vehicle body component 10 and helping it to better resist damage when subjected to impact or vibration. Fine, uniform, dispersed reinforcing phases can effectively hinder dislocation movement, thereby improving the fatigue resistance of materials.

[0195] It should be noted that in step S2110, excessively low or high heating temperatures may result in unsatisfactory quantity, size, and distribution of the precipitated strengthening phase. Furthermore, excessively rapid heating may induce new stresses within the material. Additionally, holding time and temperature are critical factors affecting the aging treatment effect. Holding time that is too short (less than 3 hours) or temperature that is too low (below 160℃) may lead to insufficient precipitation of the strengthening phase, while holding time that is too long (more than 10 hours) or temperature that is too high (above 200℃) may result in grain growth and performance degradation.

[0196] Step 2120: Remove the vehicle body component 10 from the heating furnace and air-cool it to room temperature.

[0197] During the heating and heat preservation process, certain thermal stresses are generated within the material of the vehicle body component 10. If the cooling rate is too rapid, these thermal stresses may not be fully released, leading to their accumulation within the material, resulting in a decline in material properties and even cracking. In this step, air cooling allows the vehicle body component 10 to gradually release its internal stresses during the cooling process, thereby avoiding the accumulation and destructive effects of these stresses. Air cooling typically does not cause drastic changes in the material structure, thus better preserving the material properties acquired by the vehicle body component 10 during heating and heat preservation, such as hardness, strength, and toughness. This is crucial for ensuring the reliability and durability of the vehicle body component 10 in actual use.

[0198] The following is an embodiment of the casting method for the vehicle body components of the present invention:

[0199] A first material, comprising aluminum ingots and crystalline silicon, is added to the reverberatory furnace. The aluminum ingots comprise 85%–92% of the total mass of the aluminum alloy casting liquid, and the crystalline silicon comprises 5%–8% of the total mass of the aluminum alloy casting liquid. After the first material melts, a first molten metal is obtained. The temperature of the first molten metal is adjusted to 700℃–740℃. A second material, comprising a manganese source and a zinc source, is added to the reverberatory furnace. The mixture is stirred for 3–5 minutes to obtain a second molten metal. The temperature of the second molten metal is raised to 740℃–780℃. A third material, comprising aluminum-copper, aluminum-titanium-boron, aluminum-lanthanum, and aluminum-cerium, is added to the reverberatory furnace. The mixture is stirred for 3–5 minutes, and then refined and slag removed to obtain the first molten metal. The process involves merging three metal solutions, cooling the third metal solution to 680℃~740℃, adding a fourth material (including magnesium, aluminum, and strontium), and stirring to obtain a fourth metal solution. The elemental composition of the fourth solution is as follows: Si: 6.0%~8.0%, Zn: 1.0%~2.0%, Mg: 0.2%~0.6%, Cu: 0.1%~0.5%, Re: 0.01~0.03%, Sr: 0.01%~0.05%, Fe≤0.3%, Ti≤0.2%, Mn≤0.3%, Ca: 0.002%~0.006%, Mn+Fe<0.5%, 1.0≤Mn / Fe≤1.2.

[0200] The mold cavity is evacuated to a vacuum level of less than or equal to 80 mbar. The temperature of the mold cavity is controlled within the range of 150℃ to 200℃. The weight of the molten aluminum alloy is determined to be 140% to 160% of the weight of the vehicle body component 10 to be cast, and the pouring temperature is set to 690℃ to 710℃. Two to eight different injection parameters are set to inject the molten aluminum alloy into the mold cavity. The pressure inside the mold cavity is increased to 100 to 120 bar within 1 to 3 seconds at a pressurization rate of 20 bar / s to 50 bar / s. The pressure inside the mold cavity is then maintained at 150 to 210 bar for a holding time of 25 to 40 seconds. One to five seconds after the start of the holding period, local pressure is applied to the engine mounting area of ​​the vehicle body component 10, with a local pressure of 16 mbar. The pressure is set from 0 bar to 210 bar to locally generate a pressure of 120 MPa to 200 MPa in the aluminum alloy casting liquid, where the fluctuation of the holding pressure is Δp, and -0.5 bar < Δp < 0.5 bar. The mold cavity is depressurized and the mold is opened to obtain the formed car body component 10. The formed car body component 10 is placed in water at 55℃ to 65℃ for cooling. The car body component 10 is placed in a heating furnace and heated to 500℃ to 550℃ and held for 3h to 10h. Within 5s to 10s, the heated car body component 10 is immersed in water at 20℃ to 60℃ for cooling and then removed. Within 2h, the car body component 10 is reheated to 160℃ to 200℃ and held for 3h to 10h. The car body component 10 after the holding period is completed is removed from the heating furnace and air-cooled to room temperature.

[0201] It should be noted that the internal structure of the car body components produced by vacuum extrusion casting is dense and free from defects such as porosity, shrinkage cavities, and inclusions. Figure 1 Localized pressurization technology is used to apply high-pressure compensation to the motor mounting area, eliminating shrinkage defects in the thick-walled area and specifically improving the performance of this area. Simultaneously, precise mold temperature control technology ensures the fluidity of the molten metal for rapid filling while preventing rapid cooling and defects such as cold shuts.

[0202] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are only used to explain the present invention and are not intended to limit the present invention.

[0203] Example 1

[0204] Specifically, Embodiment 1 provides an integral vehicle body component 10 prepared using the above-described casting method. The integral vehicle body component 10 has dimensions of 1100*870*260mm, a single weight of 23kg, a minimum wall thickness of 3mm, and is made of the aforementioned aluminum alloy. The preparation method of the integral vehicle body component 10 is as follows:

[0205] A first material, comprising aluminum ingots and crystalline silicon, is added to the reverberatory furnace. The aluminum ingots comprise 85%–92% of the total mass of the aluminum alloy casting liquid, and the crystalline silicon comprises 5%–8% of the total mass of the aluminum alloy casting liquid. After the first material melts, a first molten metal is obtained. The temperature of the first molten metal is adjusted to 720°C. A second material, comprising a manganese source and a zinc source, is added to the reverberatory furnace and stirred for 5 minutes to obtain a second molten metal. The temperature of the second molten metal is raised to 760°C. A third material, comprising aluminum-copper and aluminum-titanium-boron alloys, is added to the reverberatory furnace. Aluminum, lanthanum, and aluminum, cerium, are stirred for 5 minutes and refined to remove slag to obtain a third metal liquid. The temperature of the third metal liquid is reduced to 730°C, and a fourth material, including magnesium and aluminum, strontium, is added to the third metal liquid. The mixture is stirred to obtain a fourth metal liquid. The elemental composition of the fourth solution is: Si: 6.5%, Zn: 1.2%, Mg: 0.5%, Cu: 0.2%, Re: 0.02%, Sr: 0.02%, Fe: 0.18%, Ti: 0.18%, Mn: 0.18%, Mn / Fe = 1.0.

[0206] The mold cavity was evacuated to a vacuum level of 50 mbar, and the temperature was controlled at 180°C. The weight of the molten aluminum alloy was determined to be 150% of the weight of the vehicle body component 10 to be cast, and the pouring temperature was set to 710°C. Three different injection parameters were set to inject the molten aluminum alloy into the mold cavity. The pressure inside the mold cavity was increased to 110 bar within 3 seconds at a pressurization rate of 35 bar / s. The pressure inside the mold cavity was then maintained at 200 bar for 30 seconds. After 3 seconds of holding pressure, the engine mounting area of ​​the vehicle body component 10 was locally pressurized at a pressure of 200 bar to allow the aluminum alloy to... The gold casting liquid locally generates a pressure of 200 MPa, where the fluctuation of the holding pressure is Δp, where -0.5 bar < Δp < 0.5 bar. The mold cavity is depressurized and the mold is opened to obtain the molded car body component 10. The molded car body component 10 is placed in water at 60°C for cooling. The car body component 10 is placed in a heating furnace and heated to 520°C and held for 6 hours. Within 10 seconds, the heated car body component 10 is immersed in water at 20°C to 60°C for cooling and then removed. Within 2 hours, the car body component 10 is reheated to 160°C and held for 8 hours. The car body component 10 after the holding period is completed is removed from the heating furnace and air-cooled to room temperature.

[0207] Example 2

[0208] Specifically, Embodiment 2 provides an integral vehicle body component 10 prepared using the above-described casting method. The integral vehicle body component 10 has dimensions of 1100*870*260mm, a single weight of 23kg, a minimum wall thickness of 3mm, and is made of the aforementioned aluminum alloy. The preparation method of the integral vehicle body component 10 is as follows:

[0209] A first material, comprising aluminum ingots and crystalline silicon, is added to the reverberatory furnace. The aluminum ingots comprise 85%–92% of the total mass of the aluminum alloy casting liquid, and the crystalline silicon comprises 5%–8% of the total mass of the aluminum alloy casting liquid. After the first material melts, a first molten metal is obtained. The temperature of the first molten metal is adjusted to 720°C. A second material, comprising a manganese source and a zinc source, is added to the reverberatory furnace and stirred for 5 minutes to obtain a second molten metal. The temperature of the second molten metal is raised to 760°C. A third material, comprising aluminum-copper and aluminum-titanium-boron alloys, is added to the reverberatory furnace. Aluminum, lanthanum, and aluminum, cerium, are stirred for 5 minutes and refined to remove slag to obtain a third metal liquid. The temperature of the third metal liquid is reduced to 730°C, and a fourth material, including magnesium and aluminum, strontium, is added to the third metal liquid. The mixture is stirred to obtain a fourth metal liquid. The elemental composition of the fourth solution is: Si: 7.5%, Zn: 1.5%, Mg: 0.5%, Cu: 0.3%, Re: 0.02%, Sr: 0.02%, Fe: 0.18%, Ti: 0.18%, Mn: 0.18%, Mn / Fe = 1.0.

[0210] The mold cavity was evacuated to a vacuum level of 50 mbar, and the temperature was controlled at 180°C. The weight of the molten aluminum alloy was determined to be 150% of the weight of the vehicle body component 10 to be cast, and the pouring temperature was set to 710°C. Three different injection parameters were set to inject the molten aluminum alloy into the mold cavity. The pressure inside the mold cavity was increased to 110 bar within 3 seconds at a pressurization rate of 35 bar / s. The pressure inside the mold cavity was then maintained at 200 bar for 30 seconds. After 3 seconds of holding pressure, the engine mounting area of ​​the vehicle body component 10 was locally pressurized at a pressure of 200 bar to allow the aluminum alloy to... The gold casting liquid locally generates a pressure of 200 MPa, where the fluctuation of the holding pressure is Δp, where -0.5 bar < Δp < 0.5 bar. The mold cavity is depressurized and the mold is opened to obtain the molded car body component 10. The molded car body component 10 is placed in water at 60°C for cooling. The car body component 10 is placed in a heating furnace and heated to 520°C and held for 6 hours. Within 10 seconds, the heated car body component 10 is immersed in water at 20°C to 60°C for cooling and then removed. Within 2 hours, the car body component 10 is reheated to 160°C and held for 8 hours. The car body component 10 after the holding period is completed is removed from the heating furnace and air-cooled to room temperature.

[0211] Example 3

[0212] Specifically, Embodiment 3 provides an integral vehicle body component 10 prepared using the above-described casting method. The integral vehicle body component 10 has dimensions of 1100*870*260mm, a single weight of 23kg, a minimum wall thickness of 3mm, and is made of the aforementioned aluminum alloy. The preparation method of the integral vehicle body component 10 is as follows:

[0213] A first material, comprising aluminum ingots and crystalline silicon, is added to the reverberatory furnace. The aluminum ingots comprise 85%–92% of the total mass of the aluminum alloy casting liquid, and the crystalline silicon comprises 5%–8% of the total mass of the aluminum alloy casting liquid. After the first material melts, a first molten metal is obtained. The temperature of the first molten metal is adjusted to 720°C. A second material, comprising a manganese source and a zinc source, is added to the reverberatory furnace and stirred for 5 minutes to obtain a second molten metal. The temperature of the second molten metal is raised to 760°C. A third material, comprising aluminum-copper and aluminum-titanium-boron alloys, is added to the reverberatory furnace. Aluminum, lanthanum, and aluminum, cerium, are stirred for 5 minutes and refined to remove slag to obtain a third metal liquid. The temperature of the third metal liquid is reduced to 730°C, and a fourth material, including magnesium and aluminum, strontium, is added to the third metal liquid. The mixture is stirred to obtain a fourth metal liquid. The elemental composition of the fourth solution is: Si: 7.5%, Zn: 1.5%, Mg: 0.5%, Cu: 0.3%, Re: 0.02%, Sr: 0.02%, Fe: 0.2%, Ti: 0.18%, Mn: 0.22%, Mn / Fe = 1.1.

[0214] The mold cavity was evacuated to a vacuum level of 50 mbar, and the temperature was controlled at 180°C. The weight of the molten aluminum alloy was determined to be 150% of the weight of the vehicle body component 10 to be cast, and the pouring temperature was set to 720°C. Three different injection parameters were set to inject the molten aluminum alloy into the mold cavity. The pressure inside the mold cavity was increased to 110 bar within 3 seconds at a pressurization rate of 35 bar / s. The pressure inside the mold cavity was then maintained at 200 bar for 30 seconds. After 3 seconds of holding pressure, the engine mounting area of ​​the vehicle body component 10 was locally pressurized at a pressure of 200 bar to allow the aluminum alloy to... The gold casting liquid locally generates a pressure of 200 MPa, where the pressure fluctuation is Δp, where -0.5 bar < Δp < 0.5 bar. The mold cavity is depressurized and the mold is opened to obtain the molded car body component 10. The molded car body component 10 is placed in water at 60°C for cooling. The car body component 10 is placed in a heating furnace and heated to 530°C and held for 8 hours. Within 10 seconds, the heated car body component 10 is immersed in water at 20°C to 60°C for cooling and then removed. Within 2 hours, the car body component 10 is reheated to 170°C and held for 8 hours. The car body component 10 after the holding period is completed is removed from the heating furnace and air-cooled to room temperature.

[0215] Example 4

[0216] Specifically, Example 4 provides a one-piece vehicle body component 10 prepared using the above-described casting method. The one-piece vehicle body component 10 has outline dimensions of 1100*870*260mm, a single weight of 23kg, a minimum wall thickness of 3mm, and is made of the aforementioned aluminum alloy. The preparation method of the one-piece vehicle body component 10 is as follows:

[0217] A first material, comprising aluminum ingots and crystalline silicon, is added to the reverberatory furnace. The aluminum ingots comprise 85%–92% of the total mass of the aluminum alloy casting liquid, and the crystalline silicon comprises 5%–8% of the total mass of the aluminum alloy casting liquid. After the first material melts, a first molten metal is obtained. The temperature of the first molten metal is adjusted to 720°C. A second material, comprising a manganese source and a zinc source, is added to the reverberatory furnace and stirred for 5 minutes to obtain a second molten metal. The temperature of the second molten metal is raised to 760°C. A third material, comprising aluminum-copper alloy and aluminum alloy, is then added to the reverberatory furnace. Titanium boron, aluminum lanthanum, and aluminum cerium are stirred for 5 minutes and refined to remove slag to obtain a third metal liquid. The temperature of the third metal liquid is reduced to 730°C, and a fourth material, including magnesium and aluminum strontium, is added to the third metal liquid. The mixture is stirred to obtain a fourth metal liquid. The elemental composition of the fourth solution is as follows: Si: 8%, Zn: 2%, Mg: 0.6%, Cu: 0.5%, Re: 0.02%, Sr: 0.02%, Fe: 0.2%, Ti: 0.18%, Mn: 0.24%, Mn / Fe = 1.2.

[0218] The mold cavity was evacuated to a vacuum level of 50 mbar, and the temperature was controlled at 180°C. The weight of the molten aluminum alloy was determined to be 150% of the weight of the vehicle body component 10 to be cast, and the pouring temperature was set to 720°C. Three different injection parameters were set to inject the molten aluminum alloy into the mold cavity. The pressure inside the mold cavity was increased to 110 bar within 3 seconds at a pressurization rate of 35 bar / s. The pressure inside the mold cavity was then maintained at 200 bar for 30 seconds. After 3 seconds of holding pressure, the engine mounting area of ​​the vehicle body component 10 was locally pressurized at a pressure of 200 bar to allow the aluminum alloy to... The gold casting liquid locally generates a pressure of 200 MPa, where the fluctuation of the holding pressure is Δp, where -0.5 bar < Δp < 0.5 bar. The mold cavity is depressurized and the mold is opened to obtain the molded car body component 10. The molded car body component 10 is placed in water at 60°C for cooling. The car body component 10 is placed in a heating furnace and heated to 520°C and held for 6 hours. Within 10 seconds, the heated car body component 10 is immersed in water at 20°C to 60°C for cooling and then removed. Within 2 hours, the car body component 10 is reheated to 160°C and held for 8 hours. The car body component 10 after the holding period is completed is removed from the heating furnace and air-cooled to room temperature.

[0219] Example 5

[0220] Specifically, Example 5 provides a one-piece vehicle body component 10 prepared using the above-described casting method. The one-piece vehicle body component 10 has outline dimensions of 1100*870*260mm, a single weight of 23kg, a minimum wall thickness of 3mm, and is made of the aforementioned aluminum alloy. The preparation method of the one-piece vehicle body component 10 is as follows:

[0221] A first material, comprising aluminum ingots and crystalline silicon, is added to the reverberatory furnace. The aluminum ingots comprise 85%–92% of the total mass of the aluminum alloy casting liquid, and the crystalline silicon comprises 5%–8% of the total mass of the aluminum alloy casting liquid. After the first material melts, a first molten metal is obtained. The temperature of the first molten metal is adjusted to 720°C. A second material, comprising a manganese source and a zinc source, is added to the reverberatory furnace and stirred for 5 minutes to obtain a second molten metal. The temperature of the second molten metal is raised to 760°C. A third material, comprising aluminum-copper alloy and aluminum alloy, is then added to the reverberatory furnace. Titanium boron, aluminum lanthanum, and aluminum cerium are stirred for 5 minutes and refined to remove slag to obtain a third metal liquid. The temperature of the third metal liquid is reduced to 730°C, and a fourth material, including magnesium and aluminum strontium, is added to the third metal liquid. The mixture is stirred to obtain a fourth metal liquid. The elemental composition of the fourth solution is as follows: Si: 8%, Zn: 2%, Mg: 0.6%, Cu: 0.5%, Re: 0.02%, Sr: 0.02%, Fe: 0.16%, Ti: 0.18%, Mn: 0.18%, Mn / Fe = 1.1.

[0222] The mold cavity was evacuated to a vacuum level of 50 mbar, and the temperature was controlled at 180°C. The weight of the molten aluminum alloy was determined to be 150% of the weight of the vehicle body component 10 to be cast, and the pouring temperature was set to 720°C. Three different injection parameters were set to inject the molten aluminum alloy into the mold cavity. The pressure inside the mold cavity was increased to 110 bar within 3 seconds at a pressurization rate of 35 bar / s. The pressure inside the mold cavity was then maintained at 200 bar for 30 seconds. After 3 seconds of holding pressure, the engine mounting area of ​​the vehicle body component 10 was locally pressurized at a pressure of 200 bar to allow the aluminum alloy to... The gold casting liquid locally generates a pressure of 200 MPa, where the fluctuation of the holding pressure is Δp, where -0.5 bar < Δp < 0.5 bar. The mold cavity is depressurized and the mold is opened to obtain the molded car body component 10. The molded car body component 10 is placed in water at 60°C for cooling. The car body component 10 is placed in a heating furnace and heated to 530°C and held for 8 hours. Within 10 seconds, the heated car body component 10 is immersed in water at 20°C to 60°C for cooling and then removed. Within 2 hours, the car body component 10 is reheated to 180°C and held for 8 hours. The car body component 10 after the holding period is completed is removed from the heating furnace and air-cooled to room temperature.

[0223] Comparative Example 1

[0224] Comparative Example 1 uses a low-pressure sand core casting method to prepare a one-piece hollow car body component. The component has dimensions of 1100*870*260mm, a weight of 28.8kg, a minimum wall thickness of 4mm, and is made of A356.2 material. The manufacturing process is as follows:

[0225] The A356.2 alloy ingot was placed into a flame reverberatory furnace. After all the material was melted, the temperature of the molten aluminum was adjusted to 720℃ and held at that temperature.

[0226] The casting weight and pouring temperature were determined. The mass of the raw material injected into the mold cavity was 150% of the weight of the vehicle body component part. The casting temperature was 720℃, the mold cavity temperature was 180℃, the filling speed was 0.09m / s, and the holding time was 30s. After molding, the part was removed from the metal mold and sand was removed. The workpiece was placed in a heating furnace and heated to 525℃. After holding at that temperature for 10 hours, it was immersed in water at 20℃~60℃ for 10 seconds to cool. After being removed, it was reheated to 170℃ and held for 8 hours within 2 hours before being removed from the furnace and cooled to room temperature.

[0227] Comparative Example 2

[0228] Comparative Example 2 uses a low-pressure sand core casting method to prepare a one-piece hollow car body component. This one-piece car body component has dimensions of 1100*870*260mm, a single weight of 28.8kg, a minimum wall thickness of 4mm, and is made of A356.2 material. Its preparation method is as follows:

[0229] The A356.2 alloy ingot was placed into a flame reverberatory furnace. After all the material was melted, the temperature of the molten aluminum was adjusted to 720℃ and held at that temperature.

[0230] Low-pressure casting. The casting weight and pouring temperature are determined. The mass of raw material injected into the mold cavity is 150% of the weight of the vehicle body component part. The casting temperature is 720℃, the mold cavity temperature is 180℃, the filling speed is 0.12m / s, and the holding time is 30s. After molding, the part is removed from the metal mold and sand is removed. The workpiece is placed in a heating furnace and heated to 535℃. After holding at that temperature for 8 hours, it is immersed in water at 20℃~60℃ for 10 seconds to cool, then removed. It is then reheated to 160℃ and held for 8 hours within 2 hours before being removed from the furnace and cooled to room temperature.

[0231] Comparative Example 3

[0232] Comparative Example 3 uses a low-pressure sand core casting method to prepare a one-piece hollow car body component. This one-piece car body component has dimensions of 1100*870*260mm, a single weight of 28.8kg, a minimum wall thickness of 4mm, and is made of A356.2 material. Its preparation method is as follows:

[0233] The A356.2 alloy ingot was placed into a flame reverberatory furnace. After all the material was melted, the temperature of the molten aluminum was adjusted to 720℃ and held at that temperature.

[0234] The casting weight and pouring temperature were determined. The mass of the raw material injected into the mold cavity was 150% of the weight of the vehicle body component part. The casting temperature was 720℃, the mold cavity temperature was 180℃, the filling speed was 0.1m / s, and the holding time was 30s. After molding, the part was removed from the metal mold and sand was removed. The workpiece was placed in a heating furnace and heated to 520℃. After holding at that temperature for 10 hours, it was immersed in water at 20℃~60℃ for 10 seconds to cool. After being removed, it was reheated to 180℃ and held for 8 hours within 2 hours before being removed from the furnace and cooled to room temperature.

[0235] Comparative Example 4

[0236] Specifically, Comparative Example 4 shows a one-piece vehicle body component prepared using the aforementioned casting method. This one-piece vehicle body component has dimensions of 1100*870*260mm, a single weight of 23kg, a minimum wall thickness of 3mm, and is made of the aforementioned aluminum alloy. The preparation method of the one-piece vehicle body component is as follows:

[0237] A first material, comprising aluminum ingots and crystalline silicon, is added to the reverberatory furnace. The aluminum ingots comprise 85%–92% of the total mass of the aluminum alloy casting liquid, and the crystalline silicon comprises 5%–8% of the total mass of the aluminum alloy casting liquid. After the first material melts, a first molten metal is obtained. The temperature of the first molten metal is adjusted to 720°C. A second material, comprising a manganese source and a zinc source, is added to the reverberatory furnace and stirred for 5 minutes to obtain a second molten metal. The temperature of the second molten metal is raised to 760°C. A third material, comprising aluminum-copper alloy and aluminum alloy, is then added to the reverberatory furnace. Titanium boron, aluminum lanthanum, and aluminum cerium are stirred for 5 minutes and refined to remove slag to obtain a third metal liquid. The temperature of the third metal liquid is reduced to 730°C, and a fourth material, including magnesium and aluminum strontium, is added to the third metal liquid. The mixture is stirred to obtain a fourth metal liquid. The elemental composition of the fourth solution is as follows: Si: 8%, Zn: 2%, Mg: 0.6%, Cu: 0.5%, Re: 0.02%, Sr: 0.02%, Fe: 0.2%, Ti: 0.18%, Mn: 0.18%, Mn / Fe = 0.9.

[0238] The mold cavity was evacuated to a vacuum level of 50 mbar, and the temperature was controlled at 180°C. The weight of the molten aluminum alloy was determined to be 150% of the weight of the vehicle body component to be cast, and the pouring temperature was set at 720°C. Three different injection parameters were set to inject the molten aluminum alloy into the mold cavity. The pressure inside the mold cavity was increased to 110 bar within 3 seconds at a pressurization rate of 35 bar / s. The pressure inside the mold cavity was then maintained at 200 bar for 30 seconds. After 3 seconds of holding pressure, the engine mounting area of ​​the vehicle body component was locally pressurized to a pressure of 200 bar. To generate a local pressure of 200 MPa in the aluminum alloy casting liquid, the pressure fluctuation is Δp, where -0.5 bar < Δp < 0.5 bar. The mold cavity is depressurized and the mold is opened to obtain the formed car body component. The formed car body component is placed in 60°C water for cooling. The car body component is placed in a heating furnace and heated to 530°C and held for 8 hours. Within 10 seconds, the heated car body component is immersed in water at 20°C to 60°C for cooling and then removed. Within 2 hours, the car body component is reheated to 180°C and held for 8 hours. The car body component after the holding period is completed is removed from the heating furnace and air-cooled to room temperature.

[0239] Comparative Example 5

[0240] Specifically, Comparative Example 5 shows a one-piece vehicle body component prepared using the aforementioned casting method. This one-piece vehicle body component has dimensions of 1100*870*260mm, a single weight of 23kg, a minimum wall thickness of 3mm, and is made of the aforementioned aluminum alloy. The preparation method of the one-piece vehicle body component is as follows:

[0241] A first material, comprising aluminum ingots and crystalline silicon, is added to the reverberatory furnace. The aluminum ingots comprise 85%–92% of the total mass of the aluminum alloy casting liquid, and the crystalline silicon comprises 5%–8% of the total mass of the aluminum alloy casting liquid. After the first material melts, a first molten metal is obtained. The temperature of the first molten metal is adjusted to 720°C. A second material, comprising a manganese source and a zinc source, is added to the reverberatory furnace and stirred for 5 minutes to obtain a second molten metal. The temperature of the second molten metal is raised to 760°C. A third material, comprising aluminum-copper alloy and aluminum alloy, is then added to the reverberatory furnace. Titanium boron, aluminum lanthanum, and aluminum cerium are stirred for 5 minutes and refined to remove slag to obtain a third metal liquid. The temperature of the third metal liquid is reduced to 730°C, and a fourth material, including magnesium and aluminum strontium, is added to the third metal liquid. The mixture is stirred to obtain a fourth metal liquid. The elemental composition of the fourth solution is as follows: Si: 8%, Zn: 2%, Mg: 0.6%, Cu: 0.5%, Re: 0.02%, Sr: 0.02%, Fe: 0.18%, Ti: 0.18%, Mn: 0.25%, Mn / Fe = 1.4.

[0242] The mold cavity was evacuated to a vacuum level of 50 mbar, and the temperature was controlled at 180°C. The weight of the molten aluminum alloy was determined to be 150% of the weight of the vehicle body component to be cast, and the pouring temperature was set at 720°C. Three different injection parameters were set to inject the molten aluminum alloy into the mold cavity. The pressure inside the mold cavity was increased to 110 bar within 3 seconds at a pressurization rate of 35 bar / s. The pressure inside the mold cavity was then maintained at 200 bar for 30 seconds. After 3 seconds of holding pressure, the engine mounting area of ​​the vehicle body component was locally pressurized to a pressure of 200 bar. To generate a local pressure of 200 MPa in the aluminum alloy casting liquid, the pressure fluctuation is Δp, where -0.5 bar < Δp < 0.5 bar. The mold cavity is depressurized and the mold is opened to obtain the formed car body component. The formed car body component is placed in 60°C water for cooling. The car body component is placed in a heating furnace and heated to 530°C and held for 8 hours. Within 10 seconds, the heated car body component is immersed in water at 20°C to 60°C for cooling and then removed. Within 2 hours, the car body component is reheated to 180°C and held for 8 hours. The car body component after the holding period is completed is removed from the heating furnace and air-cooled to room temperature.

[0243] Comparative Example 6

[0244] The difference between step (1) and that in Example 1 is the absence of RE, while step (2) is the same as that in Example 1.

[0245] Comparative Example 7

[0246] The difference between step (1) and that in Example 1 is the absence of Mn, while step (2) is the same as that in Example 1.

[0247] Comparative Example 8

[0248] The difference between step (1) and that in Example 1 is the absence of Zn, while step (2) is the same as that in Example 1.

[0249] Ten samples of the vehicle body components prepared in the above embodiments and comparative examples were taken by wire cutting, with consistent wire cutting locations for each component. Tensile samples were prepared according to GB / T 16865-2013, and mechanical property tests were conducted using an electronic universal testing machine at a strain rate of 0.00025 s⁻¹. -1 The average mechanical properties of each embodiment and comparative example are shown in Table 1 below.

[0250]

[0251]

[0252] Examples 1 to 5 and Comparative Examples 4 to 8 are vehicle body components prepared using the aluminum alloy and casting method provided in this application. Comparative Examples 1 to 3 are vehicle body components prepared using A356.2 and low-pressure hollow casting methods. Elongation and toughness are positively correlated; a higher elongation also means higher toughness. Therefore, this application aims to ensure that the vehicle body component has good tensile strength and yield strength while also possessing good toughness, and that the reliability and safety of the vehicle body component meet the requirements.

[0253] Comparing Example 1 with Comparative Examples 2 and 3, Example 1 uses the aluminum alloy and casting method provided in this application to prepare the vehicle body component, while Comparative Examples 2 and 3 use A356.2 and low-pressure hollow casting methods to prepare the vehicle body components. As shown in the figures, although the elongation of the vehicle body component 10 obtained in Example 1 is the same as that obtained in Comparative Examples 2 and 3, the tensile strength and yield strength of the vehicle body component 10 obtained in Example 1 are superior to those obtained in Comparative Examples 2 and 3. Furthermore, the vehicle body component prepared using the aluminum alloy and casting method provided in this application is lighter in weight. Therefore, the vehicle body component prepared using the aluminum alloy and casting method provided in this application can achieve lightweight design while possessing good tensile strength, yield strength, and toughness, and the reliability and safety of the manufactured vehicle body component 10 meet the requirements.

[0254] Examples 2 and 3 are compared with Comparative Example 1. Examples 2 and 3 use the aluminum alloy and casting method provided in this application to prepare the vehicle body components, while Comparative Example 1 uses A356.2 and a low-pressure hollow casting method to prepare the vehicle body components. As shown in the figures, the tensile strength, yield strength, and elongation of the vehicle body components 10 obtained in Examples 2 and 3 are all superior to those of the vehicle body components 10 obtained in Comparative Example 1. The vehicle body components prepared using the aluminum alloy and casting method provided in this application are lighter in weight. Therefore, the vehicle body components prepared using the aluminum alloy and casting method provided in this application have good tensile strength and yield strength, good toughness, and can achieve lightweight design, ensuring that the reliability and safety of the manufactured vehicle body components 10 meet the requirements.

[0255] Comparing Example 4 and Comparative Example 4, the Mn / Fe ratio in Example 4 is 1.2, while in Comparative Example 4 it is 0.9. As shown in the graph, the tensile strength, yield strength, and elongation of the vehicle body component 10 obtained in Example 4 are all superior to those of the vehicle body component 10 obtained in Comparative Example 4. Therefore, when 1.0 ≤ Mn / Fe ≤ 1.2, the vehicle body component 10 exhibits both good tensile strength and yield strength, as well as good toughness, ensuring that the reliability and safety of the manufactured vehicle body component 10 meet the requirements.

[0256] Comparing Example 5 and Comparative Example 5, the Mn / Fe ratio in Example 5 is 1.1, while that in Comparative Example 5 is 1.4. As shown in the graph, although the yield strength of the vehicle body component 10 prepared in Comparative Example 5 is greater than that in Example 5, the tensile strength and elongation of the vehicle body component 10 obtained in Example 5 are superior to those of the vehicle body component 10 obtained in Comparative Example 5. Therefore, when 1.0 ≤ Mn / Fe ≤ 1.2, the vehicle body component 10 exhibits both good tensile strength and good toughness, ensuring that the reliability and safety of the manufactured vehicle body component 10 meet the requirements.

[0257] Comparing Example 1 and Comparative Example 6, the difference between Example 1 and Comparative Example 6 is that Comparative Example 6 lacks RE. As shown in the figure, the tensile strength, yield strength and elongation of the vehicle body component 10 obtained in Example 1 are better than those of the vehicle body component 10 obtained in Comparative Example 6. It can be seen that the presence of RE can enable the vehicle body component 10 to have good tensile strength and yield strength while also having good toughness, and make the reliability and safety of the manufactured vehicle body component 10 meet the requirements.

[0258] Comparing Example 1 and Comparative Example 7, the difference between Example 1 and Comparative Example 7 is that Comparative Example 6 lacks Mn. As shown in the figure, the tensile strength, yield strength and elongation of the vehicle body component 10 obtained in Example 1 are all better than those of the vehicle body component 10 obtained in Comparative Example 7. It can be seen that the presence of Mn can enable the vehicle body component 10 to have good tensile strength and yield strength while also having good toughness, and make the reliability and safety of the manufactured vehicle body component 10 meet the requirements.

[0259] Comparing Example 1 and Comparative Example 8, the difference between Example 1 and Comparative Example 8 is that Comparative Example 6 lacks Zn. As shown in the graph, although the elongation of the vehicle body component 10 obtained in Comparative Example 8 is better than that of the vehicle body component 10 obtained in Example 1, the tensile strength and yield strength of the vehicle body component 10 obtained in Comparative Example 8 are both worse than those of the vehicle body component 10 obtained in Example 1. Therefore, the presence of Zn can enable the vehicle body component 10 to have good tensile strength and yield strength while also having a certain degree of toughness, and make the reliability and safety of the manufactured vehicle body component 10 meet the requirements.

[0260] In summary, based on Examples 1 to 5 and Comparative Examples 1 to 8, the vehicle body components prepared using the aluminum alloy and casting method provided in this application not only have good tensile strength and yield strength but also good toughness, ensuring that the reliability and safety of the manufactured vehicle body components 10 meet the requirements.

[0261] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0262] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0263] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0264] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. An aluminum alloy, characterized in that, The aluminum alloy comprises Al, Mn and Fe, wherein Al accounts for 85% to 92% of the mass percentage of the aluminum alloy, Mn accounts for less than or equal to 0.3% of the mass percentage of the aluminum alloy, and Fe accounts for less than or equal to 0.3% of the mass percentage of the aluminum alloy, wherein 1.0 ≤ Mn / Fe ≤ 1.

2.

2. The aluminum alloy according to claim 1, characterized in that, The sum of the mass percentage of Mn in the aluminum alloy and the mass percentage of Fe in the aluminum alloy is less than 0.5%.

3. The aluminum alloy according to claim 1 or 2, characterized in that, The aluminum alloy also includes at least one of Si, Zn, Mg, rare earth elements, Ti, Cu, Sr, and Ca.

4. The aluminum alloy according to claim 3, characterized in that, The Si content in the aluminum alloy is 6.0% to 8.0% by mass; and / or, The Zn content in the aluminum alloy is 1.0% to 2.0% by mass; and / or, The Mg content in the aluminum alloy is 0.2% to 0.6% by mass; and / or, The rare earth element constitutes 0.01% to 0.03% of the aluminum alloy by mass; and / or, The Ti content in the aluminum alloy is less than or equal to 0.2% by mass; and / or, The Cu content in the aluminum alloy is 0.1% to 0.5% by mass; and / or, The Sr content in the aluminum alloy is 0.01% to 0.05% by mass; and / or, The Ca content in the aluminum alloy is 0.002% to 0.006% by mass.

5. The aluminum alloy according to claim 3, characterized in that, The rare earth elements include at least one of La, Ce, Y, and Sc.

6. A vehicle body component, characterized in that, The vehicle body components include the aluminum alloy as described in any one of claims 1 to 5.

7. A vehicle, characterized in that, Includes the vehicle body components as described in claim 6.

8. A casting method for a vehicle body component as described in claim 6, characterized in that, Includes the following steps: Obtain the molten aluminum alloy as described in any one of claims 1 to 5; The molten aluminum alloy is subjected to vacuum extrusion casting.

9. The casting method for a vehicle body component according to claim 8, characterized in that, The step of obtaining the molten aluminum alloy as described in any one of claims 1 to 5 includes: A first material, including aluminum ingots, is added to a reverberatory furnace, and a first molten metal is obtained after the first material melts. The temperature of the first molten metal is adjusted to 700℃~740℃, and a second material, including a manganese source, is added to the reverberatory furnace. The mixture is stirred for 3min~5min to obtain a second molten metal.

10. The casting method for a vehicle body component according to claim 9, characterized in that, After adjusting the temperature of the first molten metal to 700℃~740℃, adding the second material, which includes a manganese source, to the reverberatory furnace, and stirring for 3min~5min to obtain the second molten metal, the process further includes: The temperature of the second molten metal is raised to 740℃~780℃, and a third material is added to the reverberatory furnace. The third material includes an aluminum alloy containing rare earth elements. The mixture is stirred for 3min~5min and then refined and slag is removed to obtain the third molten metal. The temperature of the third molten metal is reduced to 680°C to 740°C, and a fourth material, including magnesium, is added to the third molten metal. The mixture is then stirred to obtain a fourth molten metal.

11. The casting method for a vehicle body component according to any one of claims 8 to 10, characterized in that, The step of vacuum extrusion casting the aluminum alloy includes: The cavity is evacuated to a vacuum level of less than or equal to 80 mbar. The temperature of the mold cavity is controlled within the range of 150℃ to 200℃; The molten aluminum alloy is poured into the mold cavity and subjected to multiple injection molding processes. The pressure inside the mold cavity is increased to 100-120 bar within 1-3 seconds by a pressurization rate of 20-50 bar / s. Dynamic pressure holding and local pressure increase are performed within the mold cavity; The mold cavity is depressurized and the mold is opened to obtain the molded vehicle body component.

12. The casting method for a vehicle body component according to claim 11, characterized in that, Before the step of pouring the molten aluminum alloy into the mold cavity and performing multiple injection molding processes, the method further includes: The weight of the aluminum alloy casting liquid is determined to be 140% to 160% of the weight of the vehicle body component to be cast, and the pouring temperature is 690℃ to 710℃.

13. The casting method for a vehicle body component according to claim 11, characterized in that, The steps of dynamically maintaining pressure and locally increasing pressure within the mold cavity include: The pressure inside the mold cavity is maintained at 150 bar to 210 bar, and the pressure holding time is 25 s to 40 s; One to five seconds after the pressure holding begins, the engine mounting area of ​​the vehicle body component is locally pressurized. The local pressurization pressure is 160 bar to 210 bar, so that the aluminum alloy casting liquid locally generates a pressure of 120 MPa to 200 MPa.

14. The casting method for a vehicle body component according to claim 13, characterized in that, In the step of maintaining the pressure value in the mold cavity at 150 bar to 210 bar for a holding time of 25 s to 40 s, The fluctuation of the holding pressure is Δp, where -0.5 bar < Δp < 0.5 bar.

15. The casting method for a vehicle body component according to claim 11, characterized in that, The step of depressurizing and opening the mold cavity to obtain the molded vehicle body component further includes: The formed vehicle body components are placed in water at 55℃~65℃ for cooling.

16. The casting method for a vehicle body component according to claim 15, characterized in that, Following the step of immersing the molded vehicle body component in water at 55°C to 65°C for cooling, the method further includes: The vehicle body components are placed in a heating furnace, and the heating furnace is heated to 500-550°C and held for 3-10 hours. The insulated vehicle body components are immersed in water at 20°C to 60°C for 5 to 10 seconds to cool and then removed. The cooled vehicle body components are placed back into the heating furnace, and the heating furnace is heated to 160-200°C within 2 hours and held at that temperature for 3-10 hours. The vehicle body component is removed from the heating furnace and then air-cooled to room temperature.

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