Heat-free aluminum alloys, their preparation methods and applications

Abstract

This application belongs to the field of aluminum alloy technology, and particularly relates to a heat-treatable aluminum alloy, its preparation method, and its application. The components, by weight percentage relative to the total weight of the heat-treatable aluminum alloy, are: Si 7%–9%, ​​Mn 0.2%–0.7%, V 0.08%–0.3%, Ti 0.08%–0.3%, Sr 0.015%–0.03%, Fe ≤0.5%, Mg ≤0.3%, Cu ≤0.3%, Zn ≤0.3%, Cr ≤0.1%, with the balance being Al and unavoidable impurities. This heat-treatable aluminum alloy, based on conventional heat-treatable structural Al-Si casting alloys, broadens the compatible content range of impurity elements. Utilizing the strengthening effect of impurity elements, the alloy exhibits significantly higher tensile strength and yield strength than conventional heat-treatable aluminum alloys, while also possessing high elongation at break.

Description

Technical Field

[0001] This application belongs to the field of aluminum alloy technology, and in particular relates to a heat-free aluminum alloy, its preparation method and application. Background Technology

[0002] Under the global trend of energy conservation and emission reduction, automobile manufacturing and use are important areas for energy conservation and emission reduction. Electric vehicles replacing traditional fuel vehicles have become a globally recognized solution for energy conservation and emission reduction. It is well known that electric vehicles do not burn fossil fuels or produce exhaust emissions during use, thus eliminating the contribution of exhaust gases to the greenhouse effect. However, to date, the manufacturing process of electric vehicles still largely relies on fossil fuels or the electricity generated from them, thereby producing significant greenhouse gas emissions.

[0003] To improve the driving range and safety performance of electric vehicles, major automakers are increasingly using lightweight alloys. Among them, aluminum alloys, due to their low density, high specific strength, good machinability, and abundant resources, have become the preferred body material for mainstream electric vehicles. Aluminum alloy die-cast parts, in particular, are frequently used in vehicle body joints because of their high production efficiency, excellent and stable performance, and ability to be designed and machined into complex shapes, reducing the need for traditional assembly connections.

[0004] Traditional die-cast aluminum alloy parts processing typically involves high-pressure casting, edge trimming, heat treatment (solution + aging), shaping, surface treatment, and final delivery. With industry development, heat treatment-free processes have become an industry trend. Heat treatment processes (solution + aging) not only consume significant amounts of energy and generate substantial greenhouse gas emissions, but also cause dimensional deformation of parts due to heating and cooling effects, affecting assembly accuracy and even leading to scrapping. Eliminating heat treatment processes for die-cast parts (i.e., heat treatment-free processing) results in alloys with lower elongation at break, typically below 5%. Summary of the Invention

[0005] The purpose of this application is to provide a heat-free aluminum alloy, its preparation method and application, which aims to solve the problem of low fracture elongation of existing heat-free aluminum alloys to a certain extent.

[0006] To achieve the above-mentioned objectives, the technical solution adopted in this application is as follows:

[0007] In a first aspect, this application provides a heat-treatable aluminum alloy, comprising the following components by mass percentage relative to the total weight of the heat-treatable aluminum alloy:

[0008] The composition is 7%–9% Si, 0.2%–0.7% Mn, 0.08%–0.3% V, 0.08%–0.3% Ti, 0.015%–0.03% Sr, ≤0.5% Fe, ≤0.3% Mg, ≤0.3% Cu, ≤0.3% Zn, ≤0.3% Cr, with the balance being Al and unavoidable impurities.

[0009] In some possible implementations, the components, relative to the total weight of the heat-free aluminum alloy, include the following by mass percentage: Si 7%–9%, ​​Mn 0.2%–0.7%, V 0.08%–0.3%, Ti 0.08%–0.3%, Sr 0.015%–0.03%, Fe 0–0.5%, Mg 0–0.3%, Cu 0–0.3%, Zn 0–0.3%, Cr 0–0.1%, where Fe, Mg, Cu, Zn, and Cr are not all zero, with the balance being Al and unavoidable impurities.

[0010] In some possible implementations, the components, relative to the total weight of the heat-free aluminum alloy, include the following components by mass percentage: Si 7%–8.5%, Mn 0.2%–0.6%, V 0.1%–0.2%, Ti 0.08%–0.2%, Sr 0.02%–0.03%, Fe 0–0.5%, Mg 0–0.3%, Cu 0–0.3%, Zn 0–0.3%, Cr 0–0.1%, wherein Fe, Mg, Cu, Zn, and Cr are not all zero, and the balance is Al and unavoidable impurities.

[0011] In some possible implementations, the components, relative to the total weight of the heat-free aluminum alloy, include the following components by mass percentage: Si 7%–8.3%, Mn 0.2%–0.6%, V 0.1%–0.2%, Ti 0.08%–0.2%, Sr 0.02%–0.03%, Fe 0.001%–0.5%, Mg 0.001%–0.3%, Cu 0.001%–0.3%, Zn 0.001%–0.3%, Cr 0.001%–0.1%, with the balance being Al and unavoidable impurities.

[0012] In some possible implementations, the components, relative to the total weight of the heat-free aluminum alloy, include the following by mass percentage: Si 7.5%–8.1%, Mn 0.3%–0.5%, V 0.1%–0.15%, Ti 0.1%–0.15%, Sr 0.02%–0.03%, Fe 0.2%–0.5%, Mg 0.1%–0.3%, Cu 0.1%–0.3%, Zn 0.1%–0.3%, Cr 0.001%–0.1%, with the balance being Al and unavoidable impurities.

[0013] In some possible implementations, the components, relative to the total weight of the heat-free aluminum alloy, include the following by mass percentage: Si 7.94%, Mn 0.45%, V 0.15%, Ti 0.12%, Sr 0.0294%, Fe 0.23%, Mg 0.186%, Cu 0.194%, Zn 0.194%, Cr 0.003%, with the balance being Al and unavoidable impurities.

[0014] In some possible implementations, the components, relative to the total weight of the heat-free aluminum alloy, include the following by mass percentage: Si 8.03%, Mn 0.45%, V 0.15%, Ti 0.12%, Sr 0.0238%, Fe 0.28%, Mg 0.177%, Cu 0.191%, Zn 0.192%, Cr 0.003%, with the balance being Al and unavoidable impurities.

[0015] In some possible implementations, the components, relative to the total weight of the heat-free aluminum alloy, include the following by mass percentage: Si 7.95%, Mn 0.46%, V 0.15%, Ti 0.12%, Sr 0.0200%, Fe 0.39%, Mg 0.179%, Cu 0.184%, Zn 0.188%, Cr 0.003%, with the balance being Al and unavoidable impurities.

[0016] In some possible implementations, the components, relative to the total weight of the heat-free aluminum alloy, include the following by mass percentage: Si 7.85%, Mn 0.44%, V 0.15%, Ti 0.12%, Sr 0.0298%, Fe 0.38%, Mg 0.195%, Cu 0.181%, Zn 0.183%, Cr 0.003%, with the balance being Al and unavoidable impurities.

[0017] In some possible implementations, the heat-free aluminum alloy has a tensile strength of not less than 280 MPa, a yield strength of not less than 130 MPa, and an elongation at break of not less than 8%.

[0018] Secondly, this application provides a method for preparing a heat-treatable aluminum alloy, comprising the following steps:

[0019] The metal raw material components of the formula are obtained based on the above-mentioned heat-free aluminum alloy;

[0020] The metal raw material components are melted into an alloy liquid;

[0021] The alloy liquid is subjected to refining and degassing treatment and slag removal treatment in sequence to form a heat-free aluminum alloy.

[0022] In some possible implementations, the metal raw material component is at least one recycled material selected from A356, AlSi10MnMg, C611, 6xxx series, 1xxx series, and AlSi9Cu3.

[0023] Thirdly, this application provides an application of a heat-free aluminum alloy, which is used in at least one of the fields of automobiles, electronics industry, communication equipment, aerospace, and shipbuilding.

[0024] The heat-treatable aluminum alloy provided in the first aspect of this application contains a Si content of 7 wt.% to 9 wt.%, which provides fluidity, ensures controllable shrinkage during solidification, and reduces the tendency for hot cracking in castings. Simultaneously, within this Si content range, both the tensile strength of the aluminum alloy and the presence of over 85% α-aluminum phase by volume in the casting ensures its plasticity and toughness. The addition of Mn serves two purposes: increasing the casting's release properties and increasing its strength. The Mn addition range is controlled between 0.2 wt.% and 0.7 wt.%. The addition of V can form Al-V intermetallic compounds. The V addition range is 0.08 wt.% to 0.3 wt.%, providing grain refinement and dispersion strengthening. Furthermore, V, together with Mn, can correct the type and morphology of iron-rich phases, ensuring the casting's elongation and improving the alloy's compatibility with Fe impurities. The alloy also contains 0.08 wt.% to 0.3 wt.% Ti to refine the grain size of the α phase. The Sr content is 0.015 wt.% to 0.03 wt.%, which ensures the modification effect on the eutectic silicon phase without causing excessive hydrogen absorption by the molten aluminum, and controls the cost of the alloy. Furthermore, the heat-treatable aluminum alloy of this application also contains impurity elements such as Fe, Cu, Mg, Zn, and Cr. The mechanical properties of the aluminum alloy casting are guaranteed while maintaining compatibility with these impurity elements. Specifically, the compatibility limit for Fe is increased to 0.5 wt.%, without significantly harming the mechanical properties of the casting, especially the elongation after fracture. Simultaneously, the compatibility limits for Mg, Cu, and Zn are extended to 0.3 wt.%, and the compatibility limit for Cr is extended to 0.1 wt.%, significantly broadening the upper limits of impurity elements. The presence of these impurity elements ensures the alloy's compatibility with high proportions of recycled aluminum waste, guarantees a fracture elongation of no less than 8%, and significantly improves the material's yield strength and tensile strength.

[0025] The method for preparing the heat-free aluminum alloy provided in this application involves obtaining the metal raw material components in the formula amount described above, melting them into an alloy liquid, and then sequentially performing refining, degassing, and slag removal treatments to form the heat-free aluminum alloy. The preparation process is simple and suitable for large-scale industrial production and application. The prepared heat-free aluminum alloy, through the synergistic effect of various metal elements, ensures compatibility with high-proportion recycled aluminum waste, resulting in a higher yield strength and tensile strength than conventional heat-free primary cast aluminum alloys. It also ensures a high elongation at break, not less than 8%, thus meeting the process requirements for vehicle body connections.

[0026] The heat-free aluminum alloy provided in this application has higher yield strength and tensile strength than conventional heat-free primary cast aluminum alloys, and also ensures that the alloy has a high fracture elongation. It can be widely used in at least one field of automobile, electronics industry, communication equipment, aerospace and shipbuilding, with a wide range of applications and strong practicality. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art 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.

[0028] Figure 1 This is a schematic flowchart of the preparation method of the heat-free aluminum alloy provided in Embodiment 1 of this application;

[0029] Figure 2 This is a metallographic diagram of the heat-free aluminum alloy provided in Embodiment 1 of this application;

[0030] Figure 3 This is a metallographic diagram of the heat-free aluminum alloy provided in Embodiment 2 of this application;

[0031] Figure 4 This is a metallographic diagram of the heat-free aluminum alloy provided in Embodiment 3 of this application;

[0032] Figure 5 This is a metallographic diagram of the heat-free aluminum alloy provided in Embodiment 4 of this application. Detailed Implementation

[0033] To make the technical problems, technical solutions, and beneficial effects of this application clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0034] In this application, the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0035] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b or c", or "at least one of a, b and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0036] It should be understood that in the various embodiments of this application, the order of the above processes does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0037] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms "a" and "the" as used in the embodiments of this application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0038] The weights of the relevant components mentioned in the embodiments of this application can refer not only to the specific content of each component, but also to the proportional relationship between the weights of the components. Therefore, any scaling up or down of the content of the relevant components according to the embodiments of this application is within the scope disclosed in the embodiments of this application. Specifically, the mass mentioned in the embodiments of this application can be a mass unit known in the chemical industry, such as μg, mg, g, or kg.

[0039] The terms "first" and "second" are used for descriptive purposes only, to distinguish objects, such as substances, from one another, and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. For example, without departing from the scope of the embodiments of this application, "first XX" may also be referred to as "second XX," and similarly, "second XX" may also be referred to as "first XX." Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of that feature.

[0040] The first aspect of this application provides a heat-treatable aluminum alloy, which, relative to the total weight of the heat-treatable aluminum alloy, comprises the following components by mass percentage:

[0041] The composition is 7%–9% Si, 0.2%–0.7% Mn, 0.08%–0.3% V, 0.08%–0.3% Ti, 0.015%–0.03% Sr, ≤0.5% Fe, ≤0.3% Mg, ≤0.3% Cu, ≤0.3% Zn, ≤0.3% Cr, with the balance being Al and unavoidable impurities.

[0042] It should be noted that in the aluminum alloy formulation of this application embodiment, "~" includes endpoint values. For example, Si is 7% to 9%, which means that the Si content is 7% to 9%, and can take two endpoint values ​​of 7% and 9%.

[0043] In the heat-treatable aluminum alloy provided by the first aspect of this application, the Si content is 7wt.% to 9wt.%, which provides fluidity to the aluminum alloy, ensures controllable shrinkage during solidification, and reduces the tendency of the casting to hot crack. Simultaneously, within this Si content range, both the tensile strength of the aluminum alloy and the presence of more than 85% α-aluminum phase by volume in the casting ensures the plasticity and toughness of the casting. The addition of Mn serves two purposes: firstly, to increase the mold release properties of the casting, and secondly, to increase the strength of the casting. The Mn addition range is controlled between 0.2wt.% and 0.7wt.%. The addition of V can form Al-V intermetallic compounds. The V addition range is 0.08wt.% to 0.3wt.%, providing grain refinement and dispersion strengthening functions. Simultaneously, V, together with Mn, can correct the type and morphology of the iron-rich phase, ensuring the elongation of the casting and improving the alloy's compatibility with the impurity Fe element. The alloy also contains 0.08 wt.% to 0.3 wt.% Ti to refine the grain size of the α phase. The Sr content is 0.015 wt.% to 0.03 wt.%, ensuring the modification effect on the eutectic silicon phase without causing excessive hydrogen absorption by the molten aluminum, and controlling the cost of the alloy. Furthermore, the heat-free aluminum alloy of this application embodiment also contains impurity elements such as Fe, Cu, Mg, Zn, and Cr. While maintaining compatibility with these impurity elements, the mechanical properties of the aluminum alloy castings can be guaranteed. Specifically, the compatibility limit for Fe is increased to 0.5 wt.%, without significantly harming the mechanical properties of the castings, especially the elongation after fracture. Simultaneously, the compatibility limits for Mg, Cu, and Zn are extended to 0.3 wt.%, and the compatibility limit for Cr is extended to 0.1 wt.%, significantly broadening the upper limits of impurity elements. The presence of these impurity elements ensures the alloy's compatibility with high proportions of recycled aluminum scrap, guarantees an elongation at fracture of no less than 8%, and significantly improves the yield strength and tensile strength of the material.

[0044] This application's embodiment of a heat-treatable aluminum alloy, based on conventional heat-treatable structural Al-Si casting alloys, broadens the compatible content range of impurity elements such as Fe, Zn, Cu, and Mg. Under this alloy element configuration, leveraging the strengthening effect of these impurity elements, and by controlling the content of the matrix α-Al phase and precipitated phases, as well as the morphology of the intermetallic precipitates, the alloy exhibits significantly higher tensile strength and yield strength than conventional heat-treatable aluminum alloys. Simultaneously, it possesses a high elongation at break, ensuring that the as-cast elongation of the high-pressure castings of the heat-treatable aluminum alloy exceeds 8%, making it suitable for body connection processes such as self-piercing riveting (SPR).

[0045] In some possible implementations, the metallic elements in the heat-free aluminum alloy are derived from recycled alloy materials. In this case, various post-consumer recycled materials are used to manufacture the heat-free aluminum alloy of this application embodiment. The resulting die-cast aluminum alloy not only has a higher yield strength than conventional heat-free primary aluminum alloys, but its elongation still meets the requirements of vehicle body connection processes. In some embodiments, the sources of recycled alloy materials are wide-ranging, such as: dismantled automotive structural components, wheel hubs, sheet metal, and even 1xxx beverage cans and 6xxx aluminum alloy construction waste. The metallic elements in the heat-free aluminum alloy of this application embodiment are derived from recycled alloy materials. By utilizing post-consumer waste (i.e., recycled alloy materials) to produce recycled heat-free aluminum alloys, and then manufacturing these heat-free aluminum alloys into structural parts for use in vehicles, they can be recycled again as raw materials for producing heat-free aluminum alloys, thus forming a closed loop of manufacturing-application-recycling for aluminum alloy materials. This significantly reduces dependence on primary electrolytic aluminum and natural mining, and significantly reduces the carbon emission factors of aluminum alloys and parts. For materials dismantled from automotive structural components, this recycling is at the same level; however, for other low-end waste sources, this recycling is an uphill climb, creating higher value. Based on the composition design of the aforementioned heat-free aluminum alloy, it can absorb up to 90% of post-consumer waste aluminum, effectively reducing the alloy's carbon emission factor by more than 90%.

[0046] In some embodiments, the total weight of the heat-free aluminum alloy is 100%. In some possible implementations, the components included by mass percentage relative to the total weight of the heat-free aluminum alloy are: Si 7%–9%, ​​Mn 0.2%–0.7%, V 0.08%–0.3%, Ti 0.08%–0.3%, Sr 0.015%–0.03%, Fe 0–0.5%, Mg 0–0.3%, Cu 0–0.3%, Zn 0–0.3%, Cr 0–0.1%, where Fe, Mg, Cu, Zn, and Cr are not all zero, with the balance being Al and unavoidable impurities. In this case, the castings of the heat-free aluminum alloy not only have a higher yield strength than conventional heat-free primary aluminum alloys, but also maintain an elongation that meets the process requirements such as body assembly.

[0047] In some possible implementations, the components, relative to the total weight of the heat-free aluminum alloy, include the following by mass percentage: Si 7%–8.5%, Mn 0.2%–0.6%, V 0.1%–0.2%, Ti 0.08%–0.2%, Sr 0.02%–0.03%, Fe 0–0.5%, Mg 0–0.3%, Cu 0–0.3%, Zn 0–0.3%, and Cr 0–0.1%, where Fe, Mg, Cu, Zn, and Cr are not all zero, with the balance being Al and unavoidable impurities. In this case, the castings of the heat-free aluminum alloy not only have a higher yield strength than conventional heat-free primary aluminum alloys, but also maintain an elongation that meets the process requirements for body assembly and other applications.

[0048] In some possible implementations, the components, relative to the total weight of the heat-treatable aluminum alloy, include the following composition by mass percentage: Si 7%–8.3%, Mn 0.2%–0.6%, V 0.1%–0.2%, Ti 0.08%–0.2%, Sr 0.02%–0.03%, Fe 0.001%–0.5%, Mg 0.001%–0.3%, Cu 0.001%–0.3%, Zn 0.001%–0.3%, Cr 0.001%–0.1%, with the balance being Al and unavoidable impurities. In this case, the castings of the heat-treatable aluminum alloy not only possess a higher yield strength than conventional heat-treatable primary aluminum alloys, but also maintain an elongation that meets the process requirements for body assembly and other applications.

[0049] In some possible implementations, the composition, relative to the total weight of the heat-free aluminum alloy, includes the following components by mass percentage: Si 7.5%–8.1%, Mn 0.3%–0.5%, V 0.1%–0.15%, Ti 0.1%–0.15%, Sr 0.02%–0.03%, Fe 0.2%–0.5%, Mg 0.1%–0.3%, Cu 0.1%–0.3%, Zn 0.1%–0.3%, Cr 0.001%–0.1%, with the balance being Al and unavoidable impurities. In this case, the castings of the heat-free aluminum alloy not only possess a higher yield strength than conventional heat-free primary aluminum alloys, but also maintain an elongation that meets the process requirements for body assembly and other applications.

[0050] In some specific embodiments, the components, relative to the total weight of the heat-free aluminum alloy, include the following components by mass percentage: Si 7.94%, Mn 0.45%, V 0.15%, Ti 0.12%, Sr 0.0294%, Fe 0.23%, Mg 0.186%, Cu 0.194%, Zn 0.194%, Cr 0.003%, with the balance being Al and unavoidable impurities.

[0051] In some specific embodiments, the components, relative to the total weight of the heat-free aluminum alloy, include the following components by mass percentage: 8.03% Si, 0.45% Mn, 0.15% V, 0.12% Ti, 0.0238% Sr, 0.28% Fe, 0.177% Mg, 0.191% Cu, 0.192% Zn, 0.003% Cr, with the balance being Al and unavoidable impurities.

[0052] In some specific embodiments, the components, relative to the total weight of the heat-free aluminum alloy, include the following components by mass percentage: Si 7.95%, Mn 0.46%, V 0.15%, Ti 0.12%, Sr 0.0200%, Fe 0.39%, Mg 0.179%, Cu 0.184%, Zn 0.188%, Cr 0.003%, with the balance being Al and unavoidable impurities.

[0053] In some specific embodiments, the components, relative to the total weight of the heat-free aluminum alloy, include the following components by mass percentage: 7.85% Si, 0.44% Mn, 0.15% V, 0.12% Ti, 0.0298% Sr, 0.38% Fe, 0.195% Mg, 0.181% Cu, 0.183% Zn, 0.003% Cr, with the balance being Al and unavoidable impurities.

[0054] The heat-free aluminum alloy provided in the above embodiments of this application has at least one of the following beneficial effects:

[0055] (1) The upper limit of impurity elements in heat-free aluminum alloys is significantly broadened. The upper limit of Fe is 0.5wt.%, the upper limit of Cu / Mg / Zn is broadened to 0.3wt.%, and the upper limit of Cr is broadened to 0.1wt., which not only ensures the castability of the alloy, but also ensures that the fracture elongation of the alloy is not less than 8%.

[0056] (2) By means of the strengthening effect of the above-mentioned impurity elements, the heat-free aluminum alloy of the present application embodiment has higher yield strength and tensile strength than conventional heat-free primary cast aluminum alloy.

[0057] (3) Based on the above composition design, the heat-free aluminum alloy of the application embodiment can absorb up to 90% of post-consumer waste aluminum, i.e. alloy recycling material (as raw material for preparing heat-free aluminum alloy), effectively reducing the carbon emission factor of the alloy by more than 90%.

[0058] In some possible implementations, the heat-free aluminum alloy has a tensile strength of not less than 280 MPa, a yield strength of not less than 130 MPa, and an elongation at break of not less than 8%. The heat-free aluminum alloy in this application embodiment has both higher yield strength and tensile strength than conventional heat-free native cast aluminum alloys, and a higher elongation at break, while still meeting the process requirements such as body connection.

[0059] For example, the tensile strength of the heat-free aluminum alloy can be any typical but non-limiting point value or a range between any two points, such as 280MPa, 283MPa, 285MPa, 288MPa, 290MPa, 293MPa, 295MPa, 298MPa, 300MPa, 305MPa, 310MPa, etc.; the yield strength can be any typical but non-limiting point value or a range between any two points, such as 130MPa, 131MPa, 132MPa, 135MPa, 138MPa, 140MPa, 145MPa, 150MPa, etc.; and the elongation at break can be any typical but non-limiting point value or a range between any two points, such as 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%.

[0060] Secondly, embodiments of this application provide a method for preparing a heat-treatment-free aluminum alloy, as shown in the attached figure. Figure 1 As shown, it includes the following steps:

[0061] S10. Obtain the metal raw material components in the formula amount according to the above-mentioned heat-free aluminum alloy;

[0062] S20. Melt the metal raw material components into an alloy liquid;

[0063] S30. The alloy liquid is subjected to refining, degassing and slag removal treatments in sequence to form a heat-free aluminum alloy.

[0064] The method for preparing heat-free aluminum alloy provided in this application involves obtaining the metal raw material components in the formula amount described above, melting them into an alloy liquid, and then sequentially performing refining, degassing, and slag removal treatments to form the heat-free aluminum alloy. The preparation process is simple and suitable for large-scale industrial production and application. The prepared heat-free aluminum alloy, through the synergistic effect of the various metal elements, ensures both the castability of the alloy, resulting in higher yield strength and tensile strength than conventional heat-free primary cast aluminum alloys, and a high elongation at break (not less than 8%), thus meeting the process requirements for vehicle body connections, etc.

[0065] In step S10 above:

[0066] In some possible implementations, the metal raw material component uses at least one recycled material selected from A356, AlSi10MnMg, C611, 6xxx series, 1xxx series, and AlSi9Cu3. Further, small amounts of materials such as Al-Ti, AV, and A00 pure aluminum are added to adjust the chemical composition of the aluminum alloy. In this case, the carbon emission factor of primary aluminum ingots is approximately 16.4 kg CO2 / kg Al, while the carbon emission factor of recycled aluminum ingots made from post-consumer waste (i.e., recycled materials) is only 0.23 kg CO2 / kg Al (data from the International Aluminium Association). Therefore, using recycled materials as the metal raw material component to prepare heat-treatable aluminum alloys, and further, using these heat-treatable aluminum alloys as raw materials for manufacturing automotive parts, achieves carbon reduction and emission reduction. The heat-free aluminum alloys made from post-consumer recycled materials can not only effectively reduce material emissions by more than 90%, but also reduce the dependence of industries such as automobiles on natural mines, protect the earth's resources, and reduce the damage of natural mining activities to the environment on which humans depend for survival. One of the most significant problems is the pollution of toxic and harmful red mud.

[0067] This application utilizes post-consumer recycled materials to prepare heat-treatable aluminum alloys. Furthermore, the method of using heat-treatable aluminum alloys to manufacture automotive structural aluminum alloy raw materials is not simple and is currently uncommon. The main obstacle is the large amount of metallic impurities and non-metallic contaminants contained in post-consumer recycled materials. These impurities and contaminants exist in the aluminum alloy, not only affecting the aluminum smelting process, such as promoting hydrogen absorption and slag formation, but also existing in the aluminum matrix as a non-metallic second phase, severely deteriorating the forming performance of aluminum materials in processes such as stamping, rolling, extrusion, and forging, causing pre-cracking of materials, reducing the yield of formed parts, and increasing manufacturing costs. However, the heat-treatable aluminum alloy of this application, based on the above-mentioned composition design, significantly broadens the upper limit of impurity elements: the upper limit of Fe reaches 0.5 wt.%, the upper limit of Cu / Mg / Zn is broadened to 0.3 wt.%, and the upper limit of Cr is broadened to 0.1 wt.%. Under these circumstances, the heat-treatable aluminum alloy of this application can accommodate higher impurity element compositions and contents, overcoming the influence of metallic impurities from using recycled materials as alloy preparation raw materials. The heat-free aluminum alloy of this application, by means of the strengthening effect of the above-mentioned impurity elements, not only ensures the castability of the alloy and has higher yield strength and tensile strength than conventional heat-free primary cast aluminum alloys, but also ensures that the elongation at break of the alloy is not less than 8%.

[0068] In some possible implementations, when recycled materials are used as the metal raw material components, the process also includes purification treatment of the recycled materials, including the following steps: after melting the recycled materials, removing unmelted iron parts, for example using a magnet; removing unmelted impurities by utilizing melting point differences; removing impurities by high and low temperature refining and degassing; and finally, filtering. Specifically, the purification treatment steps can be: putting the recycled raw materials into a melting furnace, setting the temperature to approximately 610°C, and after the raw materials are fully melted, using an iron rake loaded with a magnet, energizing it, and then using a forklift to continuously stir it into the molten aluminum, adsorbing the iron parts in the melting furnace onto the magnet and removing them. After the iron parts in the molten aluminum are removed, while maintaining the temperature, the molten aluminum is transferred to a lower furnace. By utilizing the melting point difference, high-melting-point unmelted foreign matter remains in the upper furnace, reducing elemental contamination of the molten aluminum. After the aluminum liquid composition is adjusted to meet the requirements, it needs to be refined and degassed three times at high and low temperatures to remove impurities from the aluminum liquid. When casting the aluminum ingots, an online degassing box and a 30-50 mesh filter plate (exemplary filter plates are 30 mesh, 40 mesh, 50 mesh, etc.) are added to the flow tank to improve the purity of the aluminum liquid.

[0069] In some embodiments, during the preparation of the alloy liquid, various waste materials in different proportions are prepared and crushed according to the alloy composition ratio. Other alloying elements that need to be added are added as needed, either as pure alloys or master alloys. For example, Si is added as elemental silicon, Cr as an Al-Cr master alloy, V as an Al-V master alloy, Ti as an Al-Ti master alloy, Mn (if present) as an Al-Mn master alloy, Fe (if present) as an Al-Fe master alloy, and Sr as an Al-Sr master alloy.

[0070] In step S20 above:

[0071] In some embodiments, the metal raw material components are melted into an alloy liquid, and the preparation of the alloy liquid includes the following steps:

[0072] ① Melting aluminum ingots: The crushed recycled material is baked, and the crushed material and silicon are placed in a resistance crucible for heating and melting. The temperature of the aluminum liquid is controlled between 720℃ and 740℃. ② Adding master alloys: When the temperature of the aluminum liquid reaches 730℃ to 740℃, the composition in the furnace is tested, and the required components are added. The required master alloys are weighed and baked. The dried Al-Mn master alloy, Al-Cr master alloy, Al-V master alloy, Al-Ti and other master alloys are added to the aluminum liquid. The aluminum liquid is heated to 740℃ to 760℃ and held for 10 to 30 minutes to ensure that all the added master alloys are melted. The alloy liquid is obtained.

[0073] In another embodiment, the preparation of the alloy liquid includes the following steps: ① Melting aluminum ingots: The crushed recycled material is baked, and the crushed material and silicon are placed in a large furnace for heating and melting. The temperature of the aluminum liquid is controlled between 590℃ and 620℃. After the raw materials are fully melted, the unmelted iron and other high-melting-point items at the bottom of the furnace are first removed with a large rake. After the rake is removed, the magnet is inserted into the aluminum liquid and powered on to remove small iron nail-like items that cannot be removed by the large rake until they can no longer be attracted. Then the temperature is raised to 730℃ to 740℃. ② Adding intermediate alloys: When the temperature of the aluminum liquid reaches 730℃ to 740℃, the composition in the furnace is tested, and the required components are added. The required intermediate alloys are weighed and baked. The dried Al-Mn intermediate alloy, Al-V intermediate alloy, Al-Ti and other intermediate alloys are added to the aluminum liquid. The aluminum liquid is heated to 740℃ to 760℃ and held for 10 to 30 minutes to ensure that all the added intermediate alloys are melted, thus obtaining the alloy liquid.

[0074] In step S30 above, the alloy liquid is subjected to refining and degassing treatment and slag removal treatment in sequence, with the aim of removing hydrogen and slag from the aluminum liquid.

[0075] In some possible implementations, the refining and degassing process involves a rotation speed of 150 rpm to 300 rpm, with the introduced gas being argon and / or nitrogen with a purity of not less than 99.99%, and a gas flow rate of 0.3 L / min to 0.8 L / min. This process thoroughly removes gases such as hydrogen from the molten aluminum, followed by skimming off slag from the surface to obtain the final die-casting aluminum liquid.

[0076] For example, the degassing machine speed can be any typical but non-limiting value or a range between any two values, such as 150 rpm, 160 rpm, 180 rpm, 200 rpm, 250 rpm, or 300 rpm. The inert atmosphere can be nitrogen, argon, helium, etc. The gas flow rate can be any typical but non-limiting value or a range between any two values, such as 0.3 L / min, 0.4 L / min, 0.5 L / min, 0.6 L / min, 0.7 L / min, or 0.8 L / min. The degassing duration can be any typical but non-limiting value or a range between any two values, such as 50 min, 52 min, 55 min, 58 min, or 60 min.

[0077] In some embodiments, the refining and degassing process includes: first pressing the Al-Sr master alloy into the molten aluminum, and then degassing the molten aluminum to remove hydrogen from it. The control parameters are: the degasser speed is 150 rpm to 300 rpm, the gas introduced is high-purity argon or nitrogen with a purity > 99.99%, and the gas flow rate is 0.3 to 0.8 liters per minute.

[0078] In other embodiments, the refining and degassing process includes: first pressing the Al-Sr master alloy into the molten aluminum, and then degassing the molten aluminum to remove hydrogen from it. The control parameters are: connecting the equipment with a seamless steel pipe, introducing high-purity argon or nitrogen with a purity > 99.99%, bubble height not exceeding 20 mm, and each refining and degassing process lasting 15-25 minutes, twice.

[0079] In some embodiments, after refining and degassing are completed, the slag on the surface of the molten aluminum is removed, and after standing for 15 to 25 minutes, a spectral sample is taken to detect the composition. Once the composition meets the requirements, the temperature of the molten aluminum is lowered for later use.

[0080] Among some possible implementations, the forming process includes die casting and casting.

[0081] The heat-treatable aluminum alloy of this application embodiment can be cast using conventional methods in the art. For example, it can be cast under high pressure. In some possible implementations, the die-casting process includes the steps of: hydraulically casting the aluminum alloy into specific parts under the conditions of an aluminum alloy melt temperature of 680℃~700℃, a mold temperature controller temperature of 150℃~170℃, an injection speed of 2.0m / s~3.0m / s, and a pressurization pressure of 60MPa~70MPa, thereby obtaining a heat-treatable aluminum alloy casting.

[0082] For example, in the die-casting process, the temperature of the molten aluminum can be any typical but non-limiting point value or a range between any two points, such as 680℃, 685℃, 690℃, 695℃, 700℃; the temperature of the mold temperature controller can be any typical but non-limiting point value or a range between any two points, such as 150℃, 155℃, 160℃, 165℃, 170℃; the injection speed can be any typical but non-limiting point value or a range between any two points, such as 2.0m / s, 2.2m / s, 2.5m / s, 2.8m / s, 3.0m / s; and the pressurization pressure can be any typical but non-limiting point value or a range between any two points, such as 60Mpa, 61Mpa, 62Mpa, 63Mpa, 64Mpa, 65Mpa, 68Mpa, 69Mpa, 70Mpa.

[0083] In some possible implementations, the casting process includes the following steps: a molten aluminum alloy temperature of 700℃~710℃, a distribution hub temperature of 630℃~650℃, a casting speed of 6 Hz / min~8 Hz / min, and a nitrogen pressure of 0.8 kgf / cm³. 2 ~1.2 kgf / cm 2 Nitrogen flow rate 1.0 m³ / h 3 / h~1.8m 3 At a rotor speed of 350 r / min to 450 r / min and a filter plate mesh of 30 to 50 mesh, molten aluminum alloy is cast to obtain heat-treatable aluminum ingots. The surface of the aluminum ingots must be free of oil, corrosion spots, slag, and non-metallic inclusions.

[0084] For example, in the casting process, the temperature of the molten aluminum can be any typical but non-limiting point value or a range between any two points, such as 700℃, 702℃, 704℃, 705℃, 707℃, 708℃, 709℃, and 710℃; the distribution hub temperature can be any typical but non-limiting point value or a range between any two points, such as 630℃, 635℃, 640℃, 645℃, and 650℃; the casting speed can be any typical but non-limiting point value or a range between any two points, such as 6 Hz / min, 7 Hz / min, and 8 Hz / min; and the nitrogen pressure can be 0.8 kgf / cm³. 20.9 kgf / cm 2 1.0 kgf / cm 2 1.1 kgf / cm 2 1.2 kgf / cm 2 For any typical but non-restrictive point value or interval between any two point values, the nitrogen flow rate can be 1.0 m³. 3 / h, 1.2m 3 / h, 1.4m 3 / h, 1.6m 3 / h, 1.8m 3 / h is a typical but non-limiting point value or an interval between any two points, and the rotor speed can be any typical but non-limiting point value or an interval between any two points, such as 350r / min, 360r / min, 380r / min, 400r / min, 420r / min, 440r / min, 450r / min; the mesh size of the filter plate can be any typical but non-limiting point value or an interval between any two points, such as 30 mesh, 40 mesh, 5 mesh.

[0085] Thirdly, this application provides an application of a heat-free aluminum alloy, which is applied to at least one field of automobiles, electronics industry, communication equipment, aerospace, and shipbuilding.

[0086] The heat-free aluminum alloy provided in the embodiments of this application has higher yield strength and tensile strength than conventional heat-free primary cast aluminum alloys, and also ensures that the alloy has a high fracture elongation. It can be widely used in at least one field of automobile, electronics industry, communication equipment, aerospace and shipbuilding, with a wide range of applications and strong practicality.

[0087] The heat-free aluminum alloy described in this application can be used to manufacture structural parts, including but not limited to body, chassis, and battery pack frame parts, and can meet the process requirements such as body connection.

[0088] To enable those skilled in the art to clearly understand the above-described implementation details and operations, and to highlight the significant advancements in the heat-free aluminum alloys, their preparation methods, and applications of the embodiments of this application, the following examples illustrate the above technical solutions.

[0089] Example 1

[0090] A heat-treatable aluminum alloy, relative to the total weight of the heat-treatable aluminum alloy, comprises the following components by mass percentage: 7.94% Si, 0.45% Mn, 0.15% V, 0.12% Ti, 0.0294% Sr, 0.23% Fe, 0.186% Mg, 0.194% Cu, 0.194% Zn, 0.003% Cr, with the balance being Al and unavoidable impurities.

[0091] 1. Raw material composition: 24 wt.% A356 waste, 15 wt.% AlSi10MnMg waste, 35 wt.% C611 waste, 18 wt.% 6xxx waste, 1 wt.% AlSi9Cu3 waste, plus 1 wt.% electrolytic pure aluminum A00, and 6 wt.% elemental Si, Al-Ti alloy and Al-V alloy intermediate alloy, totaling 6 wt.% as raw material composition.

[0092] 2. The preparation steps of the aluminum alloy test piece include:

[0093] ① Melting Aluminum Ingots: After the crushed recycled material is baked, the crushed material and silicon are placed in a resistance crucible for heating and melting. After the raw materials are fully melted, a magnet is attached to an iron rake, electricity is turned on, and a forklift is used to load it into the molten aluminum and continuously stir it to attract and remove iron parts in the melting furnace onto the magnet. After the iron parts in the molten aluminum are removed, the temperature is kept constant, and the molten aluminum is transferred to the lower furnace. By using the melting point difference, the high-melting-point foreign matter that has not melted is left in the upper furnace, reducing elemental contamination of the molten aluminum. After the composition of the molten aluminum is adjusted and qualified, it needs to be refined and degassed three times at high and low temperatures to precipitate the impurities in the molten aluminum. After completion, when casting into aluminum ingots, an online degassing box and a 40-mesh filter plate are added to the casting trough to improve the purity of the molten aluminum. The temperature of the molten aluminum is controlled between 720℃ and 740℃.

[0094] ② Add intermediate alloy: When the temperature of the aluminum liquid reaches 730℃-735℃, check the composition in the furnace, weigh the required intermediate alloy and bake it. Add the dried Al-Cr intermediate alloy, Al-V intermediate alloy, Al-Ti and other intermediate alloys to the aluminum liquid. Raise the temperature of the aluminum liquid to 740℃-760℃ and hold it for 10-30 minutes to ensure that all the added intermediate alloys are melted.

[0095] ③ Refining, modification, and degassing: First, the Al-Sr master alloy is pressed into the aluminum liquid, and then the aluminum liquid is degassed to remove hydrogen from the aluminum liquid. The control parameters are: the degasser speed is 150 rpm to 300 rpm, the gas introduced is high-purity argon or nitrogen with a purity > 99.99%, and the gas flow rate is 0.3 L / min to 0.8 L / min;

[0096] ④ Composition detection and cooling: After refining and degassing, remove the slag from the surface of the molten aluminum, let it stand for 15-25 minutes, then take a spectral sample to detect the composition. Once the composition meets the requirements, lower the temperature of the molten aluminum.

[0097] ⑤ Die casting process: The temperature of the die casting aluminum liquid is controlled at 680℃~700℃, the temperature of the mold temperature controller is controlled at 150℃~170℃, the high speed is controlled at 2.0m / s~3.0m / s, and the pressure is 65Mpa. After being processed into specific parts, the casting process includes trimming, dimensional inspection, and optional shaping to obtain aluminum alloy test pieces.

[0098] 3. The preparation steps of aluminum alloy ingots include:

[0099] ① Melting aluminum ingots: The crushed recycled material is baked, and the crushed material and silicon are put into a large furnace for heating and smelting. The temperature of the aluminum liquid is controlled between 590℃ and 620℃. After all the raw materials have been melted, the unmelted iron and other high-melting-point items at the bottom of the furnace are first removed with a large rake. After the rake is removed, the iron magnet is inserted into the aluminum liquid, and electricity is turned on to remove small iron nail-like items that cannot be picked up by the large rake in the furnace until they can no longer be attracted. Then the temperature is raised to 730℃ to 740℃.

[0100] ② Add intermediate alloy: When the temperature of the aluminum liquid reaches 730℃~740℃, check the composition in the furnace, weigh the required intermediate alloy and bake it. Add the dried Al-Mn intermediate alloy, Al-V intermediate alloy, Al-Ti and other intermediate alloys to the aluminum liquid. Raise the temperature of the aluminum liquid to 740℃~760℃ and hold it for 10 minutes to 30 minutes to ensure that all the added intermediate alloys are melted.

[0101] ③ Refining, modification and degassing: First, press the Al-Sr master alloy into the aluminum liquid, and then degas the aluminum liquid to remove hydrogen from it. The control parameters are: connect the equipment with seamless steel pipe, the gas introduced is high-purity argon or nitrogen with a purity of >99.99%, the bubble height should not exceed 20mm, and the refining and degassing time is 15-25 minutes each time, twice.

[0102] ④ Composition detection and cooling: After refining and degassing, remove the slag from the surface of the molten aluminum. After standing for 15 to 25 minutes, take a spectral sample to detect the composition. Once the composition meets the requirements, lower the temperature of the molten aluminum.

[0103] ⑤ Casting aluminum ingots: During the early, middle, and late stages of casting, aluminum molten material is scooped from the flow channel after the filter box to test its composition; the furnace temperature of the aluminum molten material is 700℃~710℃, the distribution hub temperature is 630℃~650℃, the casting speed is 6Hz / min~8Hz / min, and the nitrogen pressure is 0.8kgf / cm³. 2 ~1.2 kgf / cm 2Nitrogen flow rate 1.0 m³ / h 3 / h~1.8m 3 The rotor speed is 350r / min to 450r / min, the filter plate is 40 mesh, and the surface of the aluminum ingot is required to be free of oil stains, corrosion spots, slag and non-metallic inclusions to obtain aluminum alloy ingots.

[0104] Example 2

[0105] A heat-treatable aluminum alloy, relative to the total weight of the heat-treatable aluminum alloy, comprises the following components by mass percentage: 8.03% Si, 0.45% Mn, 0.15% V, 0.12% Ti, 0.0238% Sr, 0.28% Fe, 0.177% Mg, 0.191% Cu, 0.192% Zn, 0.003% Cr, with the balance being Al and unavoidable impurities.

[0106] Raw material composition: 47 wt.% A356 waste, 1 wt.% AlSi10MnMg waste, 13 wt.% C611 waste, 26 wt.% 1xxx waste, 1 wt.% AlSi9Cu3 waste, plus 6 wt.% electrolytic pure aluminum A00, and 6 wt.% elemental Si, Al-Ti alloy and Al-V alloy intermediate alloy, totaling 6 wt.%, as raw material composition.

[0107] Aluminum alloy test pieces and aluminum alloy ingots were prepared according to the method in Example 1.

[0108] Example 3

[0109] A heat-treatable aluminum alloy, by weight of the heat-treatable aluminum alloy, comprises the following components in the following mass percentages: Si 7.95%, Mn 0.46%, V 0.15%, Ti 0.12%, Sr 0.0200%, Fe 0.39%, Mg 0.179%, Cu 0.184%, Zn 0.188%, Cr 0.003%, with the balance being Al and unavoidable impurities.

[0110] Raw material composition: 36% A356 waste, 2wt.% AlSi10MnMg waste, 6% C611 waste, 1wt.% 6xxx extruded profile waste, 1wt.% 1xxx extruded profile waste, 1wt.% AlSi9Cu3 waste, plus 46wt.% electrolytic pure aluminum A00, and 6wt.% elemental Si, Al-Ti alloy and Al-V alloy intermediate alloy, totaling 6wt.%, as raw material composition.

[0111] Aluminum alloy test pieces and aluminum alloy ingots were prepared according to the method in Example 1.

[0112] Example 4

[0113] A heat-treatable aluminum alloy, relative to the total weight of the heat-treatable aluminum alloy, comprises the following components by mass percentage: 7.85% Si, 0.44% Mn, 0.15% V, 0.12% Ti, 0.0298% Sr, 0.38% Fe, 0.195% Mg, 0.181% Cu, 0.183% Zn, 0.003% Cr, with the balance being Al and unavoidable impurities.

[0114] Raw material composition: 34 wt.% A356 waste, 1 wt.% AlSi10MnMg waste, 7% C611 waste, 1 wt.% 6xxx extruded profile waste, 2 wt.% 1xxx waste, 1 wt.% AlSi9Cu3 waste, plus 46 wt.% electrolytic pure aluminum A00, and 6 wt.% of elemental Si, Al-Ti alloy and Al-V alloy intermediate alloys, totaling 6 wt.% as raw material composition.

[0115] Aluminum alloy test pieces and aluminum alloy ingots were prepared according to the method in Example 1.

[0116] Comparative Example 1

[0117] A heat-free aluminum alloy, the composition and content of its metallic elements are shown in Table 1 below.

[0118] Raw material composition: 55 wt.% A356 waste, 2 wt.% AlSi10MnMg waste, 10% C611 waste, 16 wt.% 6xxx extruded profile waste, 5 wt.% 1xxx waste, 1 wt.% AlSi9Cu3 waste, plus 4 wt.% electrolytic pure aluminum A00, and 6 wt.% of elemental Si, Al-Ti alloy and Al-V alloy intermediate alloys, totaling 6 wt.% as raw material composition.

[0119] Aluminum alloy test pieces and aluminum alloy ingots were prepared according to the method in Example 1.

[0120] Comparative Example 2

[0121] A heat-free aluminum alloy, the composition and content of its metallic elements are shown in Table 1 below.

[0122] Raw material composition: 14 wt.% A356 waste, 23 wt.% AlSi10MnMg waste, 10% C611 waste, 14 wt.% 6xxx extruded profile waste, 28 wt.% 1xxx waste, 2 wt.% AlSi9Cu3 waste, plus 3 wt.% electrolytic pure aluminum A00, and 6 wt.% of elemental Si, Al-Ti alloy and Al-V alloy intermediate alloys, totaling 6 wt.% as raw material composition.

[0123] Aluminum alloy test pieces and aluminum alloy ingots were prepared according to the method in Example 1.

[0124] Comparative Example 3

[0125] A heat-free aluminum alloy, the composition and content of its metallic elements are shown in Table 1 below.

[0126] Raw material composition: 25 wt.% A356 waste, 22 wt.% AlSi10MnMg waste, 10% C611 waste, 12 wt.% 6xxx extruded profile waste, 12 wt.% 1xxx waste, 3 wt.% AlSi9Cu3 waste, plus 12 wt.% electrolytic pure aluminum A00, and 6 wt.% of elemental Si, Al-Ti alloy and Al-V alloy intermediate alloys, as raw material composition.

[0127] Aluminum alloy test pieces and aluminum alloy ingots were prepared according to the method in Example 1.

[0128] Comparative Example 4

[0129] A heat-free aluminum alloy, the composition and content of its metallic elements are shown in Table 1 below.

[0130] Raw material composition: 32 wt.% A356 waste, 13 wt.% AlSi10MnMg waste, 10% C611 waste, 12 wt.% 6xxx extruded profile waste, 12 wt.% 1xxx waste, 3 wt.% AlSi9Cu3 waste, plus 14 wt.% electrolytic pure aluminum A00, and 6 wt.% of elemental Si, Al-Ti alloy and Al-V alloy intermediate alloys, as raw material composition.

[0131] Aluminum alloy test pieces and aluminum alloy ingots were prepared according to the method in Example 1.

[0132] Comparative Examples 5 to 17

[0133] Comparative Examples 5 through 17 each provide a heat-treatable aluminum alloy, the composition and content of which are shown in Table 1 below. Aluminum alloy specimens and ingots were prepared according to the method of Example 1.

[0134] The types and compositions of metallic elements in the aluminum alloys of the above embodiments and comparative examples are shown in Table 1 below.

[0135] Table 1

[0136]

[0137]

[0138] To verify the progressiveness of the embodiments of this application, the aluminum alloys provided in the above embodiments and comparative examples were subjected to the following performance tests:

[0139] 1. The metallographic structures of the heat-free aluminum alloys prepared in Examples 1 to 4 were observed. The metallographic structure diagram of the heat-free aluminum alloy in Example 1 is shown in the attached figure. Figure 2 As shown in the attached figure, the metallographic structure of the heat-free aluminum alloy of Example 2 is as follows. Figure 3 As shown in the attached figure, the metallographic structure of the heat-free aluminum alloy of Example 3 is as follows. Figure 4 As shown in the attached figure, the metallographic structure of the heat-free aluminum alloy of Example 4 is as follows. Figure 5 As shown, the microstructure of the heat-free aluminum alloy obtained in this embodiment is normal.

[0140] 2. Testing of tensile strength (UTS): GB / T 228.1-2010 "Metallic materials, tensile testing - Part 1: Test method at room temperature";

[0141] 3. Yield strength (YS) test: GB / T 228.1-2010 "Metallic materials, tensile testing - Part 1: Test method at room temperature";

[0142] 4. Test for elongation at break (EL): GB / T 228.1 "Metallic materials - Tensile testing method";

[0143] The test results are shown in Table 2 below:

[0144] Table 2

[0145]

[0146]

[0147] As can be seen from the above test results, the heat-free aluminum alloy of this application significantly broadens the upper limit of impurity elements through the reasonable configuration of alloying elements. The upper limit of Fe is broadened to 0.5 wt.%, the upper limit of Cu / Mg / Zn is broadened to 0.3 wt.%, and the upper limit of Cr is broadened to 0.1 wt.%. Utilizing the strengthening effect of each impurity element, the heat-free aluminum alloy of this application exhibits higher yield strength and tensile strength than conventional heat-free primary cast aluminum alloys. Its tensile strength is not less than 280 MPa, its yield strength is not less than 130 MPa, and its elongation at break is not less than 10%. In particular, the elongation at break of Example 1 is as high as 13.7%, ensuring both the castability of the aluminum alloy and its elongation at break. Furthermore, the heat-free aluminum alloy of this application can absorb up to 90% of post-consumer waste aluminum (i.e., recycled material), effectively reducing the carbon emission factor of the alloy by more than 90%.

[0148] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A heat-treatable aluminum alloy, characterized in that, The total weight of the aluminum alloy, relative to the heat-free type, includes the following components by mass percentage: The alloy composition is as follows: Si 7.5%~8.1%, Mn 0.3%~0.5%, V 0.1%~0.15%, Ti 0.1%~0.15%, Sr 0.02%~0.03%, Fe 0.2%~0.5%, Mg 0.1%~0.3%, Cu 0.1%~0.3%, Zn 0.1%~0.3%, Cr 0.001%~0.1%, with the balance being Al and unavoidable impurities. The heat-free aluminum alloy can absorb up to 90% of post-consumer waste aluminum, reducing the alloy's carbon emission factor by over 90%. The post-consumer waste aluminum includes at least one of A356, AlSi10MnMg, C611, 6xxx series, 1xxx series, and AlSi9Cu3. The heat-free aluminum alloy has a tensile strength of not less than 280 MPa, a yield strength of not less than 130 MPa, and an elongation at break of not less than 8%.

2. The heat-free aluminum alloy as described in claim 1, characterized in that, The total weight of the heat-free aluminum alloy, including components by mass percentage, is as follows: Si 7.94%, Mn 0.45%, V 0.15%, Ti 0.12%, Sr 0.0294%, Fe 0.23%, Mg 0.186%, Cu 0.194%, Zn 0.194%, Cr 0.003%, with the balance being Al and unavoidable impurities. Alternatively, the composition is 8.03% Si, 0.45% Mn, 0.15% V, 0.12% Ti, 0.0238% Sr, 0.28% Fe, 0.177% Mg, 0.191% Cu, 0.192% Zn, 0.003% Cr, with the balance being Al and unavoidable impurities. Alternatively, Si is 7.95%, Mn is 0.46%, V is 0.15%, Ti is 0.12%, Sr is 0.0200%, Fe is 0.39%, Mg is 0.179%, Cu is 0.184%, Zn is 0.188%, Cr is 0.003%, and the balance is Al and unavoidable impurities; Alternatively, the composition is 7.85% Si, 0.44% Mn, 0.15% V, 0.12% Ti, 0.0298% Sr, 0.38% Fe, 0.195% Mg, 0.181% Cu, 0.183% Zn, 0.003% Cr, with the balance being Al and unavoidable impurities.

3. A method for preparing a heat-treatable aluminum alloy, characterized in that, Includes the following steps: The metal raw material components of the formula are obtained according to any one of claims 1 to 2 for the heat-free aluminum alloy; The metal raw material components are melted into an alloy liquid; The alloy liquid is subjected to refining and degassing treatment and slag removal treatment in sequence to form a heat-free aluminum alloy.

4. The method for preparing the heat-free aluminum alloy as described in claim 3, characterized in that, The metal raw material composition adopts at least one recycled material selected from A356, AlSi10MnMg, C611, 6xxx series, 1xxx series, and AlSi9Cu3.

5. An application of a heat-treatable aluminum alloy, characterized in that, The heat-free aluminum alloy as described in any one of claims 1 to 2 or the heat-free aluminum alloy prepared by the method described in any one of claims 3 to 4 shall be applied to at least one of the fields of automobile, electronics industry, communication equipment, aerospace, and shipbuilding.

Images