Heat-treatment-free aluminum alloy as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of aluminum alloys, and particularly relates to a heat-treatment-free aluminum alloy and a preparation method and application thereof. Relative to the total weight of the heat-treatment-free aluminum alloy, the heat-treatment-free aluminum alloy comprises the following components in percentage by mass: 7-9% of Si, 0.2-0.7% of Mn, 0.08-0.3% of V, 0.08-0.3% of Ti, 0.015-0.03% of Sr, less than or equal to 0.5% of Fe, less than or equal to 0.3% of Mg, less than or equal to 0.3% of Cu, less than or equal to 0.3% of Zn, less than or equal to 0.1% of Cr and the balance of Al and inevitable impurities. According to the heat-treatment-free type aluminum alloy, on the basis of a conventional heat-treatment-free type structure Al-Si casting alloy, the compatible content interval of impurity elements is widened. By means of the strengthening effect of impurity elements, the tensile strength and the yield strength of the alloy are obviously higher than those of a conventional heat-treatment-free aluminum alloy, and meanwhile the alloy has high elongation at break.

Description

Technical Field

[0001] The present application belongs to the technical field of aluminum alloys, and in particular relates to a heat treatment-free aluminum alloy and a preparation method and application thereof. Background Art

[0002] Under the general trend of global energy conservation and emission reduction, automobile manufacturing and use are important areas of energy conservation and emission reduction. Electric vehicles have replaced traditional fuel vehicles and have become a globally recognized solution for energy conservation and emission reduction. As we all know, electric vehicles do not burn fossil fuels or produce tail gas emissions during use, which eliminates the contribution of tail gas to the greenhouse effect. However, so far, the manufacturing process of electric vehicles still relies heavily on fossil fuels or the electricity generated by them, which also produces more greenhouse gas emissions.

[0003] In order to improve the driving range and safety performance of electric vehicles, major automobile manufacturers are increasingly using light alloys. Among them, aluminum alloy has become the body material favored by mainstream electric vehicles due to its low density, high specific strength, good processing performance and abundant resources. Among them, aluminum alloy die-casting parts are often used in the joints of the car body due to their high production efficiency, excellent and stable performance, and the ability to be designed and processed into complex shapes, which reduces the connection and assembly required for traditional parts.

[0004] The processing technology of traditional die-cast aluminum alloy parts is usually high-pressure casting, trimming, heat treatment (solid solution + aging), shaping, surface treatment and final delivery. With the development of the industry, heat treatment-free has become an industry trend. The heat treatment process (solid solution + aging) not only consumes a lot of energy and produces a lot of greenhouse gas emissions, but also causes the parts to deform in size due to heating and cooling effects, affecting assembly accuracy and even causing scrapping. Eliminating the heat treatment process of die-cast parts (i.e., heat treatment-free) will result in an alloy with a lower elongation at break, usually less than 5%. Summary of the invention

[0005] The purpose of the present application is to provide a heat-treatment-free aluminum alloy and a preparation method and application thereof, aiming to solve the problem of low elongation at break of existing heat-treatment-free aluminum alloys to a certain extent.

[0006] In order to achieve the above application purpose, the technical solution adopted in this application is as follows:

[0007] In a first aspect, the present application provides a heat treatment-free aluminum alloy, comprising the following components in percentage by weight relative to the total weight of the heat treatment-free aluminum alloy:

[0008] Si is 7% to 9%, Mn is 0.2% to 0.7%, V is 0.08% to 0.3%, Ti is 0.08% to 0.3%, Sr is 0.015% to 0.03%, Fe≤0.5%, Mg≤0.3%, Cu≤0.3%, Zn≤0.3%, Cr≤0.1%, and the balance is Al and unavoidable impurities.

[0009] In some possible implementations, based on the total weight of the heat treatment-free aluminum alloy, the components include: Si 7% to 9%, Mn 0.2% to 0.7%, V 0.08% to 0.3%, Ti 0.08% to 0.3%, Sr 0.015% to 0.03%, Fe 0 to 0.5%, Mg 0 to 0.3%, Cu 0 to 0.3%, Zn 0 to 0.3%, Cr 0 to 0.1%, and Fe, Mg, Cu, Zn and Cr are not all 0 at the same time, and the remainder is Al and unavoidable impurities.

[0010] In some possible implementations, based on the total weight of the heat treatment-free aluminum alloy, the components include: Si 7% to 8.5%, Mn 0.2% to 0.6%, V 0.1% to 0.2%, Ti 0.08% to 0.2%, Sr 0.02% to 0.03%, Fe 0 to 0.5%, Mg 0 to 0.3%, Cu 0 to 0.3%, Zn 0 to 0.3%, Cr 0 to 0.1%, and Fe, Mg, Cu, Zn and Cr are not all 0 at the same time, and the remainder is Al and unavoidable impurities.

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

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

[0013] In some possible implementations, based on the total weight of the heat treatment-free aluminum alloy, the components include: 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, and the balance is Al and unavoidable impurities.

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

[0015] In some possible implementations, based on the total weight of the heat treatment-free aluminum alloy, the components include: 7.95% Si, 0.46% Mn, 0.15% V, 0.12% Ti, 0.0200% Sr, 0.39% Fe, 0.179% Mg, 0.184% Cu, 0.188% Zn, 0.003% Cr, and the balance is Al and unavoidable impurities.

[0016] In some possible implementations, based on the total weight of the heat treatment-free aluminum alloy, the components include: 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%, and the balance is Al and unavoidable impurities.

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

[0018] In a second aspect, the present application provides a method for preparing a heat treatment-free aluminum alloy, comprising the following steps:

[0019] Obtaining the metal raw material components in the formula amount according to the above-mentioned heat treatment-free aluminum alloy;

[0020] Smelting the metal raw material components into alloy liquid;

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

[0022] 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.

[0023] On the third aspect, the present application provides an application of a heat-treatment-free aluminum alloy, and applies the above-mentioned heat-treatment-free aluminum alloy or the heat-treatment-free aluminum alloy prepared by the above-mentioned method to at least one field of automobiles, electronics industry, communication equipment, aerospace, and shipbuilding.

[0024] In the heat-treatment-free aluminum alloy provided in the first aspect of the present application, the Si element content is 7wt.% to 9wt.%, which provides the fluidity of the aluminum alloy, ensures that the shrinkage during the solidification process of the alloy is controllable, and reduces the thermal cracking tendency of the casting. At the same time, the Si content is within this range, which not only ensures the tensile strength of the aluminum alloy, but also ensures that there is an α-aluminum phase with a volume fraction of more than 85% in the aluminum alloy casting, ensuring the plasticity and toughness of the casting. The addition of the Mn element has two purposes, one is to increase the demoulding property of the casting, and the other is to increase the strength of the casting. The Mn addition range is controlled at 0.2wt.% to 0.7wt.%. The addition of the V element can form Al-V intermetallic compounds, and the V addition range is 0.08wt.% to 0.3wt.%, providing the functions of grain refinement and dispersion strengthening. At the same time, the V element can also modify the type and morphology of the iron-rich phase together with Mn, ensure the elongation of the casting, and improve the compatibility of the alloy with the impurity Fe element. 0.08wt.% to 0.3wt.% of Ti element is also added to the alloy to refine the grain size of the α phase. The content of Sr is 0.015wt.% to 0.03wt.%. Under this content, the modification effect on the eutectic silicon phase is guaranteed, and the excessive hydrogen absorption of the aluminum liquid is not caused, and the cost of the alloy is controlled. In addition, the heat-treatment-free aluminum alloy of the present application also contains impurity elements such as Fe, Cu, Mg, Zn, and Cr, which can ensure the mechanical properties of aluminum alloy castings while being compatible with these impurity elements. Among them, the compatibility upper limit of the Fe element is increased to 0.5wt.%, but it does not significantly harm the mechanical properties of the castings, especially the elongation after fracture. At the same time, the compatibility upper limit of Mg, Cu and Zn is expanded to 0.3wt.%, and the compatibility upper limit of the Cr element is expanded to 0.1wt.%, which significantly broadens the upper limit of impurity elements. In the presence of these impurity elements, the alloy is not only compatible with high-proportion recycled aluminum scrap, but also has an elongation at break of no less than 8%, and the yield strength and tensile strength of the material are significantly improved.

[0025] The preparation method of the heat-treatment-free aluminum alloy provided in the present application is to obtain the metal raw material components of the formula according to the above-mentioned heat-treatment-free aluminum alloy, and after smelting into alloy liquid, perform refining, degassing and slag removal treatments in sequence to form the heat-treatment-free aluminum alloy. The preparation process is simple and suitable for industrial large-scale production and application. The prepared heat-treatment-free aluminum alloy, with the synergistic effect of various metal elements, not only ensures the compatibility of the alloy with a high proportion of recycled aluminum waste, so that the heat-treatment-free aluminum alloy has a higher yield strength and tensile strength than the conventional heat-treatment-free primary casting aluminum alloy, but also ensures that the alloy has a higher elongation at break, and the elongation at break is not less than 8%, and can meet the process requirements of vehicle body connection.

[0026] The heat-treatment-free aluminum alloy provided in the present application has a yield strength and tensile strength higher than those of conventional heat-treatment-free primary cast aluminum alloys, and ensures that the alloy has a higher elongation at break. It can be widely used in at least one of the fields of automobiles, electronics industry, communications equipment, aerospace, and shipbuilding, and has a wide range of applications and strong practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 1 is a schematic flow chart of a method for preparing a heat treatment-free aluminum alloy provided in Example 1 of the present application;

[0029] Figure 2 is a metallographic structure diagram of the heat treatment-free aluminum alloy provided in Example 1 of the present application;

[0030] Figure 3 is a metallographic structure diagram of the heat treatment-free aluminum alloy provided in Example 2 of the present application;

[0031] Figure 4 is a metallographic structure diagram of a heat treatment-free aluminum alloy provided in Example 3 of the present application;

[0032] Figure 5 This is the metallographic structure diagram of the heat treatment-free aluminum alloy provided in Example 4 of the present application. DETAILED DESCRIPTION

[0033] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0034] In this application, the term "and / or" describes the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural. The character " / " generally indicates that the associated objects are in an "or" relationship.

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

[0036] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution, some or all of the steps can be executed in parallel or sequentially, and 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 the present application.

[0037] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "an" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0038] The weight of the relevant components mentioned in the embodiments of the present specification can not only refer to the specific content of each component, but also represent the proportional relationship between the weights of the components. Therefore, as long as the content of the relevant components in the embodiments of the present specification is proportionally enlarged or reduced, it is within the scope disclosed in the embodiments of the present specification. Specifically, the mass described in the embodiments of the present specification can be μg, mg, g, kg and other mass units known in the chemical industry.

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

[0040] A first aspect of an embodiment of the present application provides a heat treatment-free aluminum alloy, which comprises the following components in percentage by weight relative to the total weight of the heat treatment-free aluminum alloy:

[0041] Si is 7% to 9%, Mn is 0.2% to 0.7%, V is 0.08% to 0.3%, Ti is 0.08% to 0.3%, Sr is 0.015% to 0.03%, Fe≤0.5%, Mg≤0.3%, Cu≤0.3%, Zn≤0.3%, Cr≤0.1%, and the balance is Al and unavoidable impurities.

[0042] It should be noted that, in the aluminum alloy formula of the embodiment of the present application, “~” includes endpoint values. For example, Si is 7%~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-treatment-free aluminum alloy provided in the first aspect of the embodiment of the present application, the Si element content is 7wt.% to 9wt.%, which provides the fluidity of the aluminum alloy, ensures that the shrinkage during the solidification process of the alloy is controllable, and reduces the thermal cracking tendency of the casting. At the same time, the Si content is within this range, which not only ensures the tensile strength of the aluminum alloy, but also ensures that there is an α-aluminum phase with a volume fraction of more than 85% in the aluminum alloy casting, ensuring the plasticity and toughness of the casting. The addition of the Mn element has two purposes, one is to increase the demoulding property of the casting, and the other is to increase the strength of the casting. The Mn addition range is controlled at 0.2wt.% to 0.7wt.%. The addition of the V element can form Al-V intermetallic compounds, and the V addition range is 0.08wt.% to 0.3wt.%, providing the functions of grain refinement and dispersion strengthening. At the same time, the V element can also modify the type and morphology of the iron-rich phase together with Mn, ensure the elongation of the casting, and improve the compatibility of the alloy with the impurity Fe element. 0.08wt.% to 0.3wt.% of Ti element is also added to the alloy to refine the grain size of the α phase. The content of Sr is 0.015wt.% to 0.03wt.%, which not only ensures the modification effect on the eutectic silicon phase, but also does not cause excessive hydrogen absorption of the aluminum liquid, and controls the cost of the alloy. In addition, the heat-treatment-free aluminum alloy of the embodiment of the present application also contains impurity elements such as Fe, Cu, Mg, Zn, and Cr, which can ensure the mechanical properties of the aluminum alloy castings while being compatible with these impurity elements. Among them, the compatibility upper limit of the Fe element is increased to 0.5wt.%, but it does not significantly harm the mechanical properties of the castings, especially the elongation after fracture. At the same time, the compatibility upper limit of Mg, Cu and Zn is extended to 0.3wt.%, and the compatibility upper limit of the Cr element is extended to 0.1wt.%, which significantly broadens the upper limit of impurity elements. In the presence of these impurity elements, the compatibility of the alloy with high-proportion recycled aluminum waste is guaranteed, and the elongation at fracture can be guaranteed to be not less than 8%, and the yield strength and tensile strength of the material are significantly improved.

[0044] The heat-treatment-free aluminum alloy of the present application embodiment has broadened the compatible content range of impurity elements such as Fe, Zn, Cu, and Mg on the basis of conventional heat-treatment-free structural Al-Si casting alloy. Under the configuration conditions of such alloy elements, by means of the strengthening effect of the above impurity elements, the content of the matrix α-Al phase and the precipitation phase is regulated, and the morphology of the intermetallic precipitation phase is controlled. The tensile strength and yield strength of the alloy are significantly higher than those of conventional heat-treatment-free aluminum alloys, and at the same time, it has a higher elongation at break, ensuring that the cast elongation of the high-pressure casting of the heat-treatment-free aluminum alloy is greater than 8%, so that it can be applied to body connection processes such as self-piercing riveting (SPR for short).

[0045] In some possible implementations, the metal elements in the heat-free aluminum alloy are derived from alloy recycling materials. In this case, various post-consumer recycled materials are used to manufacture the heat-free aluminum alloy of the embodiment of the present application, and the obtained die-cast aluminum alloy not only has a yield strength higher than that of the conventional heat-free primary aluminum alloy, but also the elongation can still meet the requirements of the body connection process. In some embodiments, the alloy recycling materials are widely sourced, such as: automotive structural parts dismantling materials, wheels, plates, and even 1xxx beverage cans and 6xxx aluminum alloy construction waste. The metal elements in the heat-free aluminum alloy of the embodiment of the present application are derived from alloy recycling materials. By using post-consumer waste (i.e., alloy recycling materials) to make recycled heat-free aluminum alloys, the heat-free aluminum alloys are manufactured into structural parts and applied to vehicles, and can be recycled again as raw materials for making heat-free aluminum alloys, so that aluminum alloy materials form a manufacturing-application-recycling closed loop. The dependence on primary electrolytic aluminum and natural mining is greatly reduced, and the carbon emission factor of aluminum alloys and parts is significantly reduced. For dismantled materials of automotive structural parts, this recycling is the same level recycling; while for other low-end sources of waste, this recycling is uphill recycling, creating higher value. Based on the composition design of the above-mentioned heat-treatment-free aluminum alloy, it can absorb up to 90% of post-consumer waste aluminum, effectively reducing the carbon emission factor of the alloy by more than 90%.

[0046] In some embodiments, the total weight of the heat-free aluminum alloy is 100%. In some possible implementations, relative to the total weight of the heat-free aluminum alloy, the components including the mass percentage content are: Si is 7% to 9%, Mn is 0.2% to 0.7%, V is 0.08% to 0.3%, Ti is 0.08% to 0.3%, Sr is 0.015% to 0.03%, Fe is 0 to 0.5%, Mg is 0 to 0.3%, Cu is 0 to 0.3%, Zn is 0 to 0.3%, Cr is 0 to 0.1%, and Fe, Mg, Cu, Zn and Cr are not 0 at the same time, and the remainder is Al and unavoidable impurities. In this case, the casting of the heat-free aluminum alloy not only has a yield strength higher than that of the conventional heat-free primary aluminum alloy, but also the elongation can still meet the process requirements such as body connection.

[0047] In some possible implementations, relative to the total weight of the heat-treatment-free aluminum alloy, the components include the following mass percentages: Si is 7% to 8.5%, Mn is 0.2% to 0.6%, V is 0.1% to 0.2%, Ti is 0.08% to 0.2%, Sr is 0.02% to 0.03%, Fe is 0 to 0.5%, Mg is 0 to 0.3%, Cu is 0 to 0.3%, Zn is 0 to 0.3%, Cr is 0 to 0.1%, and Fe, Mg, Cu, Zn and Cr are not all zero at the same time, and the remainder is Al and unavoidable impurities. In this case, the casting of the heat-treatment-free aluminum alloy not only has a higher yield strength than the conventional heat-treatment-free primary aluminum alloy, but also the elongation can still meet the process requirements such as body connection.

[0048] In some possible implementations, relative to the total weight of the heat-treatment-free aluminum alloy, the components include the following mass percentages: Si is 7% to 8.3%, Mn is 0.2% to 0.6%, V is 0.1% to 0.2%, Ti is 0.08% to 0.2%, Sr is 0.02% to 0.03%, Fe is 0.001% to 0.5%, Mg is 0.001% to 0.3%, Cu is 0.001% to 0.3%, Zn is 0.001% to 0.3%, Cr is 0.001% to 0.1%, and the balance is Al and unavoidable impurities. In this case, the casting of the heat-treatment-free aluminum alloy not only has a higher yield strength than the conventional heat-treatment-free primary aluminum alloy, but also the elongation can still meet the process requirements such as body connection.

[0049] In some possible implementations, relative to the total weight of the heat-treatment-free aluminum alloy, the components include the following mass percentages: Si is 7.5% to 8.1%, Mn is 0.3% to 0.5%, V is 0.1% to 0.15%, Ti is 0.1% to 0.15%, Sr is 0.02% to 0.03%, Fe is 0.2% to 0.5%, Mg is 0.1% to 0.3%, Cu is 0.1% to 0.3%, Zn is 0.1% to 0.3%, Cr is 0.001% to 0.1%, and the balance is Al and unavoidable impurities. In this case, the casting of the heat-treatment-free aluminum alloy not only has a higher yield strength than that of the conventional heat-treatment-free primary aluminum alloy, but also the elongation can still meet the process requirements such as body connection.

[0050] In some specific embodiments, based on the total weight of the heat treatment-free aluminum alloy, the components include: Si is 7.94%, Mn is 0.45%, V is 0.15%, Ti is 0.12%, Sr is 0.0294%, Fe is 0.23%, Mg is 0.186%, Cu is 0.194%, Zn is 0.194%, Cr is 0.003%, and the balance is Al and unavoidable impurities.

[0051] In some specific embodiments, based on the total weight of the heat treatment-free aluminum alloy, the components include: Si is 8.03%, Mn is 0.45%, V is 0.15%, Ti is 0.12%, Sr is 0.0238%, Fe is 0.28%, Mg is 0.177%, Cu is 0.191%, Zn is 0.192%, Cr is 0.003%, and the balance is Al and unavoidable impurities.

[0052] In some specific embodiments, based on the total weight of the heat treatment-free aluminum alloy, the components include: 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.

[0053] In some specific embodiments, based on the total weight of the heat treatment-free aluminum alloy, the components include: Si is 7.85%, Mn is 0.44%, V is 0.15%, Ti is 0.12%, Sr is 0.0298%, Fe is 0.38%, Mg is 0.195%, Cu is 0.181%, Zn is 0.183%, Cr is 0.003%, and the balance is Al and unavoidable impurities.

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

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

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

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

[0058] In some possible implementations, the tensile strength of the heat-treatment-free aluminum alloy is not less than 280 MPa, the yield strength is not less than 130 MPa, and the elongation at break is not less than 8%. The heat-treatment-free aluminum alloy of the present application embodiment has a yield strength and tensile strength higher than that of the conventional heat-treatment-free primary casting aluminum alloy, and has a higher elongation at break, and the elongation can still meet the process requirements such as vehicle body connection.

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

[0060] In a second aspect, the present application provides a method for preparing a heat treatment-free aluminum alloy, as shown in the attached Figure 1 As shown, the following steps are included:

[0061] S10. Obtaining the metal raw material component according to the above-mentioned heat treatment-free aluminum alloy formula;

[0062] S20. melting the metal raw material components into a liquid alloy;

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

[0064] The method for preparing the heat-treatment-free aluminum alloy provided in the embodiment of the present application is to obtain the metal raw material components of the formula according to the above-mentioned heat-treatment-free aluminum alloy, and after smelting into alloy liquid, perform refining, degassing and slag removal treatments in sequence to form the heat-treatment-free aluminum alloy. The preparation process is simple and suitable for industrial large-scale production and application. The prepared heat-treatment-free aluminum alloy, with the synergistic effect of various metal elements, not only ensures the castability of the alloy, so that the heat-treatment-free aluminum alloy has a yield strength and tensile strength higher than that of conventional heat-treatment-free primary casting aluminum alloys, but also ensures that the alloy has a higher elongation at break, and the elongation at break is not less than 8%, and can meet the process requirements such as vehicle body connection.

[0065] In the above step S10:

[0066] In some possible implementations, the metal raw material component uses at least one recycled material from A356, AlSi10MnMg, C611, 6xxx series, 1xxx series, and AlSi9Cu3. Furthermore, a small amount of AI-Ti, AV, A00 pure aluminum and other materials are added to adjust the chemical composition of the aluminum alloy. In this case, the carbon emission factor of the original aluminum ingot is about 16.4Kg CO 2 / kg Al, while the carbon emission factor of recycled aluminum ingots made from post-consumer waste (i.e. recycled materials) is only 0.23Kg CO 2 / Kg Al (data from the International Aluminium Association). Therefore, the use of recycled materials as metal raw material components to prepare heat-treatment-free aluminum alloys, and further, the heat-treatment-free aluminum alloys are used to manufacture raw materials for automotive parts, achieving carbon reduction and emission reduction. The heat-treatment-free aluminum alloys made from post-consumer recycled materials can not only effectively reduce the emission factor of the material 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 problem of toxic and harmful red mud pollution.

[0067] The present application embodiment uses post-consumer recycled materials to prepare heat-treatment-free aluminum alloys. Further, the method for using heat-treatment-free aluminum alloys to manufacture structural aluminum alloy raw materials for automobiles is not simple and is not common at present. The main obstacle is the large amount of metal impurity elements and non-metallic pollutants contained in post-consumer recycled materials. These impurities and pollutants exist in aluminum alloys, which not only affect the smelting process of aluminum, such as promoting hydrogen absorption and slag formation. At the same time, they will also exist in the aluminum matrix in the form of non-metallic second phases, seriously deteriorating the forming properties of aluminum materials in stamping, rolling, extrusion and forging processes, causing pre-cracking of materials, reducing the qualified rate of parts forming, and increasing manufacturing costs. However, the heat-treatment-free aluminum alloy of the present application embodiment is based on the above-mentioned composition design, which significantly broadens the upper limit of impurity elements, and the upper limit of Fe reaches 0.5wt.%, the upper limit of Cu / Mg / Zn is widened to 0.3wt.%, and the upper limit of Cr is widened to 0.1wt.%. In this case, the heat-treatment-free aluminum alloy of the present application embodiment can accommodate higher impurity element components and contents, and can overcome the influence of metal impurity elements in the preparation of raw materials using recycled materials as alloys. The heat-treatment-free aluminum alloy in the embodiment of the present application, by virtue of the strengthening effect of the above-mentioned impurity elements, not only ensures the castability of the alloy, having a yield strength and tensile strength higher than those of conventional heat-treatment-free native cast aluminum alloys, but also ensures that the alloy's elongation at break is not less than 8%.

[0068] In some possible implementations, when the metal raw material component uses recycled materials, the recycled materials are also purified, including the following steps: after melting the recycled materials, remove the unmelted iron parts, exemplarily using a magnet; remove the unmelted impurities by melting point difference, remove the impurities by high and low temperature refining and degassing, and then filter. Specifically, the purification process can be: put the recycled raw materials into the melting furnace, set the temperature to about 610°C, wait for the raw materials to be fully melted, install the magnet with an iron rake, turn on the power, install it with a forklift and extend it into the aluminum water to stir continuously, so that the iron parts in the melting furnace are adsorbed on the magnet and removed. After the iron parts in the aluminum liquid are processed, the temperature remains unchanged, and the aluminum liquid is transferred to the lower furnace. Through the melting point difference, the foreign matter with a high melting point that has not been melted is left in the upper furnace to reduce the elemental pollution of the aluminum liquid. After the aluminum liquid is formulated, it needs to be degassed three times using high and low temperature refining to precipitate the impurities in the aluminum liquid. After completion, 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 channel when casting into aluminum ingots to improve the purity of the aluminum liquid.

[0069] In some embodiments, when preparing the alloy liquid, various waste materials of different proportions are prepared and crushed according to the proportion of the alloy components. As needed, other alloy elements that need to be supplemented are added in the form of pure alloy or master alloy, for example, Si element is added in the form of elemental silicon, Cr element is added in the form of Al-Cr master alloy, V element is added in the form of Al-V master alloy, Ti element is added in the form of Al-Ti master alloy, Mn element (if present) is added in the form of Al-Mn master alloy, Fe element (if present) is added in the form of Al-Fe master alloy, and Sr element is added in the form of Al-Sr master alloy.

[0070] In the above step S20:

[0071] In some embodiments, the metal raw material components are smelted into a molten alloy, and the preparation of the molten alloy includes the steps of:

[0072] ① Melting aluminum ingots: baking the recycled materials after crushing, placing the crushed materials and silicon into a resistance crucible for heating and smelting, and controlling the temperature of the aluminum liquid between 720°C and 740°C; ② Adding intermediate alloys: when the temperature of the aluminum liquid reaches 730°C to 740°C, detecting the components in the furnace, adding the components that need to be supplemented, weighing the required intermediate alloys and baking, adding the dried Al-Mn intermediate alloys, Al-Cr intermediate alloys, Al-V intermediate alloys, Al-Ti and other intermediate alloys into the aluminum liquid, heating the aluminum liquid to 740°C to 760°C, and keeping the temperature for 10 to 30 minutes to ensure that all the added intermediate alloys are melted; obtaining alloy liquid.

[0073] In another embodiment, the preparation of alloy liquid includes the following steps: ① Melting aluminum ingots: baking the recycled materials after crushing, placing the crushed materials and silicon in a large furnace for heating and smelting, and controlling the temperature of aluminum liquid between 590℃ and 620℃; after the raw materials are fully melted, first use a large rake to rake the unmelted iron and other high-melting-point items at the bottom of the furnace; after the rake is completed, the iron-absorbing device is further inserted into the aluminum liquid, powered on, and small iron nail-like items that cannot be picked up by the large rake in the furnace are absorbed until they cannot be absorbed; then the temperature is raised to 730℃ to 740℃. ② Adding intermediate alloys: when the temperature of aluminum liquid reaches 730℃ to 740℃, the components in the furnace are detected, the components that need to be supplemented are added, the required intermediate alloys are weighed and baked, and the remaining intermediate alloys such as Al-Mn intermediate alloys, Al-V intermediate alloys, Al-Ti, etc. after drying are added to the aluminum liquid, and the aluminum liquid is heated to 740℃ to 760℃, and kept warm for 10 to 30 minutes to ensure that all the added intermediate alloys are melted to obtain alloy liquid.

[0074] In the above step S30: the alloy liquid is subjected to refining, degassing and slag removal treatments in sequence, in order to remove hydrogen and slag in the aluminum liquid.

[0075] In some possible implementations, the speed of the refining and degassing treatment is 150 rpm to 300 rpm, the gas introduced is argon and / or nitrogen with a purity of not less than 99.99%, and the gas flow rate is 0.3 liters / minute to 0.8 liters / minute. The hydrogen and other gases in the aluminum liquid are fully removed, and then the liquid surface is skimmed to remove the scum on the liquid surface to obtain the die-casting aluminum liquid.

[0076] Exemplarily, the speed of the degasser can be 150 rpm, 160 rpm, 180 rpm, 200 rpm, 250 rpm, 300 rpm, etc., typical but non-limiting arbitrary point values ​​or interval values ​​between any two points. The inert atmosphere can be nitrogen, argon, helium, etc. The gas flow rate can be 0.3 liters / minute, 0.4 liters / minute, 0.5 liters / minute, 0.6 liters / minute, 0.7 liters / minute, 0.8 liters / minute, etc., typical but non-limiting arbitrary point values ​​or interval values ​​between any two points. The degassing time can be 50 minutes, 52 minutes, 55 minutes, 58 minutes, 60 minutes, etc., typical but non-limiting arbitrary point values ​​or interval values ​​between any two points.

[0077] In some embodiments, the refining and degassing steps include: first pressing the Al-Sr master alloy into the aluminum liquid, and then degassing the aluminum liquid to remove hydrogen in 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 of >99.99%, and the gas flow rate is 0.3 to 0.8 liters / minute.

[0078] In other embodiments, the refining and degassing steps include: first pressing the Al-Sr master alloy into the aluminum liquid, and then degassing the aluminum liquid to remove hydrogen in the aluminum liquid. The control parameters are: connecting the equipment with a seamless steel pipe, and introducing high-purity argon or nitrogen with a purity of >99.99%. The bubble height cannot exceed 20 mm, and the refining and degassing time is 15 minutes to 25 minutes each time, and it is repeated twice.

[0079] In some embodiments, after refining and degassing, the scum on the surface of the aluminum liquid is removed, and after standing for 15 to 25 minutes, a spectrum sample is taken to detect the composition. When the composition meets the requirements, the temperature of the aluminum liquid is lowered and set aside.

[0080] In some possible implementations, the molding process includes a die-casting process and a casting process.

[0081] The heat-treatment-free aluminum alloy of the embodiment of the present application can be cast by 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 liquid temperature of 680°C to 700°C, a mold temperature machine temperature of 150°C to 170°C, an injection speed of 2.0m / s to 3.0m / s, and a boost pressure of 60Mpa to 70Mpa to obtain a casting of a heat-treatment-free aluminum alloy.

[0082] Exemplarily, in the die-casting process, the temperature of the aluminum liquid can be 680°C, 685°C, 690°C, 695°C, 700°C, etc., any typical but non-limiting point value or an interval value between any two point values; the temperature of the mold temperature controller can be 150°C, 155°C, 160°C, 165°C, 170°C, etc., any typical but non-limiting point value or an interval value between any two point values; the injection speed is 2.0m / s, 2.2m / s, 2.5m / s, 2.8m / s, 3.0m / s, etc., any typical but non-limiting point value or an interval value between any two point values; the boost pressure is 60Mpa, 61Mpa, 62Mpa, 63Mpa, 64Mpa, 65Mpa, 68Mpa, 69Mpa, 70Mpa, etc., any typical but non-limiting point value or an interval value between any two point values.

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

[0084] For example, in the casting process, the temperature of the aluminum liquid can be 700°C, 702°C, 704°C, 705°C, 707°C, 708°C, 709°C, 710°C, etc., typical but non-limiting arbitrary point values ​​or interval values ​​between any two point values; the distribution hub temperature can be 630°C, 635°C, 640°C, 645°C, 650°C, etc., typical but non-limiting arbitrary point values ​​or interval values ​​between any two point values; the casting speed can be 6 Hz / min, 7 Hz / min, 8 Hz / min, etc., typical but non-limiting arbitrary point values ​​or interval values ​​between any two point values; the nitrogen pressure can be 0.8 kgf / cm 2、0.9kgf / cm 2 、1.0kgf / cm 2 、1.1kgf / cm 2 , 1.2kgf / cm 2 Typical but non-limiting values ​​at any point or between any two points, such as 1.0m 3 / h、1.2m 3 / h、1.4m 3 / h、1.6m 3 / h、1.8m 3 / h and other typical but non-restrictive arbitrary point values ​​or interval values ​​between any two point values; the rotor speed can be 350r / min, 360r / min, 380r / min, 400r / min, 420r / min, 440r / min, 450r / min and other typical but non-restrictive arbitrary point values ​​or interval values ​​between any two point values; the mesh number of the filter plate can be 30 mesh, 40 mesh, 5 mesh and other typical but non-restrictive arbitrary point values ​​or interval values ​​between any two point values.

[0085] On the third aspect, an embodiment of the present application provides an application of a heat-treatment-free aluminum alloy, and the above-mentioned heat-treatment-free aluminum alloy or the heat-treatment-free aluminum alloy prepared by the above-mentioned method is applied to at least one field of automobiles, electronics industry, communication equipment, aerospace, and shipbuilding.

[0086] The heat-treatment-free aluminum alloy provided in the embodiment of the present application has a yield strength and tensile strength higher than those of conventional heat-treatment-free native cast aluminum alloys, and ensures that the alloy has a higher elongation at break. It can be widely used in at least one of the fields of automobiles, electronics industry, communications equipment, aerospace, and shipbuilding, and has a wide range of applications and strong practicality.

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

[0088] In order to enable the above-mentioned implementation details and operations of the present application to be clearly understood by those skilled in the art, as well as to demonstrate the significant improvement in performance of the heat-treatment-free aluminum alloy and its preparation method and application in the embodiments of the present application, the above-mentioned technical scheme is illustrated by means of multiple embodiments below.

[0089] Example 1

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

[0091] 1. Raw material components: 24wt.% of A356 scrap, 15wt.% of AlSi10MnMg scrap, 35wt.% of C611 scrap, 18wt.% of 6xxx scrap, 1wt.% of AlSi9Cu3 scrap, plus 1wt.% of electrolytic pure aluminum A00, and intermediate alloys of Si single substance, Al-Ti alloy and Al-V alloy, totaling 6wt.%, are used as raw material components.

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

[0093] ① Melting aluminum ingots: bake the recycled materials after crushing, put the crushed materials and silicon into the resistance crucible for heating and smelting. After the raw materials are fully melted, use an iron rake to install the magnet, turn on the power, install it with a forklift and extend it into the aluminum liquid to stir continuously, so that the iron parts in the melting furnace are adsorbed to the magnet and removed; after the iron parts in the aluminum liquid are processed, the temperature remains unchanged, and the aluminum liquid is transferred to the lower furnace. Through the melting point difference, the foreign matter with high melting point that has not been melted is left in the upper furnace to reduce the elemental pollution of the aluminum liquid; after the aluminum liquid composition is adjusted and qualified, it needs to be degassed by high and low temperature refining for 3 times to precipitate the impurities in the aluminum liquid. After completion, when casting into aluminum ingots, an online degassing box and a 40-mesh filter plate are added to the launder to improve the purity of the aluminum liquid; the aluminum liquid temperature is controlled between 720℃ and 740℃;

[0094] ② Adding master alloy: When the temperature of aluminum liquid reaches 730℃-735℃, detect the composition in the furnace, add the required supplementary components, weigh the required master alloy and bake it, add the dried Al-Cr master alloy, Al-V master alloy, Al-Ti and other master alloys into the aluminum liquid, heat the aluminum liquid to 740℃-760℃, keep it warm for 10-30 minutes, and ensure that all the added master alloys are melted;

[0095] 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 in the aluminum liquid. The control parameters are: the speed of the degasser is 150 rpm to 300 rpm, the gas introduced is high-purity argon or nitrogen with a purity of >99.99%, and the gas flow rate is 0.3 liters / minute to 0.8 liters / minute;

[0096] ④ Composition detection and cooling: After refining and degassing, remove the scum on the surface of the aluminum liquid. After standing for 15-25 minutes, take the spectrum sample to detect the composition. When the composition meets the requirements, lower the temperature of the aluminum liquid.

[0097] ⑤ Casting by die-casting process: The temperature of die-casting aluminum liquid is controlled at 680℃~700℃, the temperature of the mold temperature machine is controlled at 150℃~170℃, the high speed is controlled at 2.0m / s~3.0m / s, and the boost pressure is 65Mpa. When processed into specific parts, trimming, dimensional inspection and optional appropriate shaping are also carried out after casting to obtain aluminum alloy test pieces.

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

[0099] ① Melting aluminum ingots: bake the recycled materials after crushing, put the crushed materials and silicon into a large furnace for heating and smelting, and control the temperature of aluminum liquid between 590℃ and 620℃; after all the raw materials are melted, use a large rake to rake the unmelted iron and other high-melting-point items at the bottom of the furnace; after the rake is completed, put the iron-absorbing device deep into the aluminum liquid, power it on, and absorb small iron nails in the furnace that cannot be picked up by the large rake until they can no longer be adsorbed; then raise the temperature to 730℃~740℃;

[0100] ② Adding master alloy: When the temperature of aluminum liquid reaches 730℃~740℃, detect the composition in the furnace, add the required supplementary components, weigh the required master alloy and bake it, add the dried Al-Mn master alloy, Al-V master alloy, Al-Ti and other master alloys into the aluminum liquid, heat the aluminum liquid to 740℃~760℃, keep it warm for 10 minutes to 30 minutes, and ensure that all the added master 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 in the aluminum liquid. The control parameters are: connect the equipment with a seamless steel pipe, and the gas introduced is high-purity argon or nitrogen with a purity of >99.99%. The bubble height cannot exceed 20mm. The refining and degassing time is 15 minutes to 25 minutes each time, and it is repeated twice.

[0102] ④ Composition detection and cooling: After refining and degassing, remove the scum on the surface of the aluminum liquid. After standing for 15min to 25min, take the spectrum sample to detect the composition. When the composition meets the requirements, lower the temperature of the aluminum liquid.

[0103] ⑤ Casting aluminum ingots: scoop aluminum liquid from the flow channel behind the filter box to test the composition in the early, middle and late stages of casting; the aluminum liquid temperature in the furnace 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 / cm 2 ~1.2kgf / cm 2, nitrogen flow rate 1.0m 3 / h~1.8m 3 / h, the rotor speed is 350r / min~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 treatment-free aluminum alloy comprises the following components in percentage by mass, relative to the total weight of the heat treatment-free aluminum alloy: 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, and the remainder being Al and unavoidable impurities.

[0106] Raw material components: 47wt.% A356 scrap, 1wt.% AlSi10MnMg scrap, 13wt.% C611 scrap, 26wt.% 1xxx scrap, 1wt.% AlSi9Cu3 scrap, plus 6wt.% electrolytic pure aluminum A00, and intermediate alloys of Si single substance, Al-Ti alloy and Al-V alloy, totaling 6wt.%, are used as raw material components.

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

[0108] Example 3

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

[0110] Raw material components: 36% A356 scrap, 2wt.% AlSi10MnMg scrap, 6% C611 scrap, 1wt.% 6xxx extrusion profile scrap, 1wt.% 1xxx extrusion profile scrap, 1wt.% AlSi9Cu3 scrap, plus 46wt.% electrolytic pure aluminum A00, and intermediate alloys of Si single substance, Al-Ti alloy and Al-V alloy, totaling 6wt.%, are used as raw material components.

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

[0112] Example 4

[0113] A heat treatment-free aluminum alloy comprises the following components in percentage by mass, relative to the total weight of the heat treatment-free aluminum alloy: 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, and the balance being Al and unavoidable impurities.

[0114] Raw material components: 34wt.% A356 scrap, 1wt.% AlSi10MnMg scrap, 7% C611 scrap, 1wt.% 6xxx extrusion profile scrap, 2wt.% 1xxx scrap, 1wt.% AlSi9Cu3 scrap, plus 46wt.% electrolytic pure aluminum A00, and intermediate alloys of Si single substance, Al-Ti alloy and Al-V alloy, totaling 6wt.%, are used as raw material components.

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

[0116] Comparative Example 1

[0117] A heat treatment-free aluminum alloy, the metal element composition and content of which are shown in Table 1 below.

[0118] Raw material components: 55wt.% A356 scrap, 2wt.% AlSi10MnMg scrap, 10% C611 scrap, 16wt.% 6xxx extrusion profile scrap, 5wt.% 1xxx scrap, 1wt.% AlSi9Cu3 scrap, plus 4wt.% electrolytic pure aluminum A00, and intermediate alloys of Si single substance, Al-Ti alloy and Al-V alloy, totaling 6wt.%, are used as raw material components.

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

[0120] Comparative Example 2

[0121] A heat treatment-free aluminum alloy, the metal element composition and content of which are shown in Table 1 below.

[0122] Raw material components: 14wt.% A356 scrap, 23wt.% AlSi10MnMg scrap, 10% C611 scrap, 14wt.% 6xxx extrusion profile scrap, 28wt.% 1xxx scrap, 2wt.% AlSi9Cu3 scrap, plus 3wt.% electrolytic pure aluminum A00, and intermediate alloys of Si single substance, Al-Ti alloy and Al-V alloy, totaling 6wt.%, are used as raw material components.

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

[0124] Comparative Example 3

[0125] A heat treatment-free aluminum alloy, the metal element composition and content of which are shown in Table 1 below.

[0126] Raw material components: 25wt.% A356 scrap, 22wt.% AlSi10MnMg scrap, 10% C611 scrap, 12wt.% 6xxx extrusion profile scrap, 12wt.% 1xxx scrap, 3wt.% AlSi9Cu3 scrap, plus 12wt.% electrolytic pure aluminum A00, and intermediate alloys of Si single substance, Al-Ti alloy and Al-V alloy, totaling 6wt.%, are used as raw material components.

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

[0128] Comparative Example 4

[0129] A heat treatment-free aluminum alloy, the metal element composition and content of which are shown in Table 1 below.

[0130] Raw material components: 32wt.% A356 scrap, 13wt.% AlSi10MnMg scrap, 10wt.% C611 scrap, 12wt.% 6xxx extrusion profile scrap, 12wt.% 1xxx scrap, 3wt.% AlSi9Cu3 scrap, plus 14wt.% electrolytic pure aluminum A00, and intermediate alloys of Si single substance, Al-Ti alloy and Al-V alloy, totaling 6wt.%, are used as raw material components.

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

[0132] Comparative Example 5 to Comparative Example 17

[0133] Comparative Examples 5 to 17 provide a heat treatment-free aluminum alloy, respectively, and the metal element composition and content thereof are shown in Table 1. Aluminum alloy test pieces and aluminum alloy ingots were prepared respectively according to the method of Example 1.

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

[0135] Table 1

[0136]

[0137]

[0138] In order to verify the progress of the embodiments of the present 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-treatment-free aluminum alloys prepared in Examples 1 to 4 were observed. The metallographic structure diagram of the heat-treatment-free aluminum alloy in Example 1 is shown in the attached figure. Figure 2 As shown, the metallographic structure diagram of the heat-treatment-free aluminum alloy of Example 2 is shown in the attached Figure 3 As shown, the metallographic structure diagram of the heat treatment-free aluminum alloy of Example 3 is shown in the attached Figure 4 As shown, the metallographic structure diagram of the heat-treatment-free aluminum alloy of Example 4 is shown in the attached Figure 5 It can be seen that the microstructure of the heat treatment-free aluminum alloy prepared in the embodiment of the present application is normal.

[0140] 2. Ultra tensile strength (UTS) test: GB / T 228.1-2010 "Tensile test of metallic materials Part 1: Room temperature test method";

[0141] 3. Yield strength (YS) test: GB / T 228.1-2010 "Tensile test of metallic materials Part 1: Room temperature test method";

[0142] 4. Elongation at break (EL) test: GB / T 228.1 "Metal Tensile Test Method";

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

[0144] Table 2

[0145]

[0146]

[0147] It can be seen from the above test results that the heat-free aluminum alloy of the present application embodiment has been significantly widened by the reasonable configuration of alloying elements, and the upper limit of impurity elements has been widened to 0.5wt.%, the upper limit of Cu / Mg / Zn has been widened to 0.3wt.%, and the upper limit of Cr has been widened to 0.1wt.%. With the strengthening effect of each impurity element, the heat-free aluminum alloy of the present application embodiment has a yield strength and tensile strength higher than that of the conventional heat-free primary casting aluminum alloy, and its tensile strength is not less than 280MPa, the yield strength is not less than 130MPa, and the elongation at break is not less than 10%, wherein the elongation at break of embodiment 1 is as high as 13.7%, which not only ensures the castability of the aluminum alloy, but also ensures the elongation at break of the alloy. In addition, the heat-free aluminum alloy of the present application embodiment can absorb up to 90% of post-consumer waste aluminum (i.e., recycled materials), effectively reducing the carbon emission factor of the alloy by more than 90%.

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

Claims

1. A heat treatment-free aluminum alloy, characterized in that: Relative to the total weight of the heat-treatment-free aluminum alloy, the following components are included in percentage by mass: Si is 7% to 9%, Mn is 0.2% to 0.7%, V is 0.08% to 0.3%, Ti is 0.08% to 0.3%, Sr is 0.015% to 0.03%, Fe≤0.5%, Mg≤0.3%, Cu≤0.3%, Zn≤0.3%, Cr≤0.1%, and the balance is Al and unavoidable impurities.

2. The heat treatment-free aluminum alloy according to claim 1, characterized in that: Relative to the total weight of the heat treatment-free aluminum alloy, the components include: Si 7% to 9%, Mn 0.2% to 0.7%, V 0.08% to 0.3%, Ti 0.08% to 0.3%, Sr 0.015% to 0.03%, Fe 0 to 0.5%, Mg 0 to 0.3%, Cu 0 to 0.3%, Zn 0 to 0.3%, Cr 0 to 0.1%, and Fe, Mg, Cu, Zn and Cr are not 0 at the same time, and the balance is Al and unavoidable impurities.

3. The heat treatment-free aluminum alloy according to claim 2, characterized in that: Relative to the total weight of the heat treatment-free aluminum alloy, the components include: Si is 7% to 8.5%, Mn is 0.2% to 0.6%, V is 0.1% to 0.2%, Ti is 0.08% to 0.2%, Sr is 0.02% to 0.03%, Fe is 0 to 0.5%, Mg is 0 to 0.3%, Cu is 0 to 0.3%, Zn is 0 to 0.3%, Cr is 0 to 0.1%, and Fe, Mg, Cu, Zn and Cr are not 0 at the same time, and the balance is Al and unavoidable impurities.

4. The heat treatment-free aluminum alloy according to claim 3, characterized in that: Measured relative to the total weight of the heat treatment-free aluminum alloy, the components include: Si 7% to 8.3%, Mn 0.2% to 0.6%, V 0.1% to 0.2%, Ti 0.08% to 0.2%, Sr 0.02% to 0.03%, Fe 0.001% to 0.5%, Mg 0.001% to 0.3%, Cu 0.001% to 0.3%, Zn 0.001% to 0.3%, Cr 0.001% to 0.1%, and the balance is Al and unavoidable impurities.

5. The heat treatment-free aluminum alloy according to claim 4, characterized in that: Measured relative to the total weight of the heat treatment-free aluminum alloy, the components include: Si 7.5% to 8.1%, Mn 0.3% to 0.5%, V 0.1% to 0.15%, Ti 0.1% to 0.15%, Sr 0.02% to 0.03%, Fe 0.2% to 0.5%, Mg 0.1% to 0.3%, Cu 0.1% to 0.3%, Zn 0.1% to 0.3%, Cr 0.001% to 0.1%, and the balance is Al and unavoidable impurities.

6. The heat treatment-free aluminum alloy according to claim 5, characterized in that: The heat-treatment-free aluminum alloy includes the following components in percentage by mass: Si is 7.94%, Mn is 0.45%, V is 0.15%, Ti is 0.12%, Sr is 0.0294%, Fe is 0.23%, Mg is 0.186%, Cu is 0.194%, Zn is 0.194%, Cr is 0.003%, and the balance is Al and unavoidable impurities; Alternatively, Si is 8.03%, Mn is 0.45%, V is 0.15%, Ti is 0.12%, Sr is 0.0238%, Fe is 0.28%, Mg is 0.177%, Cu is 0.191%, Zn is 0.192%, Cr is 0.003%, and the balance is 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, Si is 7.85%, Mn is 0.44%, V is 0.15%, Ti is 0.12%, Sr is 0.0298%, Fe is 0.38%, Mg is 0.195%, Cu is 0.181%, Zn is 0.183%, Cr is 0.003%, and the balance is Al and unavoidable impurities.

7. The heat treatment-free aluminum alloy according to any one of claims 1 to 6, characterized in that: The tensile strength of the heat treatment-free aluminum alloy is not less than 280 MPa, the yield strength is not less than 130 MPa, and the elongation at break is not less than 8%.

8. A method for preparing a heat-treatment-free aluminum alloy, characterized in that: The following steps are involved: Obtaining a formula amount of metal raw material components according to the heat treatment-free aluminum alloy according to any one of claims 1 to 7; Smelting the metal raw material components into alloy liquid; The alloy liquid is subjected to refining, degassing and slag removal treatments in sequence, and is formed into a heat-treatment-free aluminum alloy.

9. The method for preparing the heat treatment-free aluminum alloy according to claim 8, characterized in that: The metal raw material component adopts at least one recycled material selected from A356, AlSi10MnMg, C611, 6xxx series, 1xxx series, and AlSi9Cu3.

10. An application of a heat-treatment-free aluminum alloy, characterized in that: The heat-treatment-free aluminum alloy as described in any one of claims 1 to 7 or the heat-treatment-free aluminum alloy prepared by the method as described in any one of claims 8 to 9 is applied to at least one field of automobiles, electronics industry, communication equipment, aerospace, and shipbuilding.

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