Al-Mg-Si series aluminum alloy, preparation method thereof and aluminum alloy structural member

Abstract

The invention provides an Al-Mg-Si series aluminum alloy, a preparation method thereof and an aluminum alloy structural part. The Al-Mg-Si series aluminum alloy contains the following components in percentage by mass: 0.7%-1.2% of Mg, 0.7%-1% of Si, 0%-0.4% of Fe, 0%-0.5% of Mn, 0%-0.8% of Cu, 0%-0.2% of Ti, 0%-0.3% of Zn, 0%-0.3% of Cr and the balance of Al and inevitable impurities. The aluminum alloy comprises the following components in percentage by mass: 0 to 0.6 percent of Zr, 0 to 0.2 percent of V, 0 to 0.1 percent of Be, 0 to 0.6 percent of RE, 0 to 0.1 percent of Sr, Al and inevitable impurities.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy technology, and more particularly to an Al-Mg-Si aluminum alloy, a method for preparing the Al-Mg-Si aluminum alloy, and aluminum alloy structural components. Background Technology

[0002] Al-Mg-Si aluminum alloys are widely used in building profiles, automobiles, bicycles, electric vehicles, and 3C product casings due to their low specific gravity, high strength, good machinability, and excellent corrosion resistance. However, coarse Mg2Si phases easily form in Al-Mg-Si aluminum alloys, which reduce the plasticity of the alloy and lead to cracking in aluminum alloy structural parts. Furthermore, Al-Mg-Si aluminum alloys have poor casting properties, generally requiring deformation processing to produce simple structural parts, and cannot be used to produce complex structures, severely limiting their applications. Summary of the Invention

[0003] In view of the above-mentioned deficiencies of the prior art, the present invention provides an Al-Mg-Si aluminum alloy, which aims to improve the elongation of the Al-Mg-Si aluminum alloy.

[0004] This invention provides an Al-Mg-Si aluminum alloy containing 0.7-1.2% Mg, 0.7-1% Si, 0-0.4% Fe, 0-0.5% Mn, 0-0.8% Cu, 0-0.2% Ti, 0-0.3% Zn, 0-0.3% Cr, 0-0.6% Zr, 0-0.2% V, 0-0.1% Be, 0-0.6% RE, 0-0.1% Sr, and Al, as well as unavoidable impurities.

[0005] Furthermore, the Al-Mg-Si aluminum alloy contains 0.8-1.2% Mg, 0.7-1% Si, 0.001-0.4% Fe, 0.001-0.5% Mn, 0.001-0.8% Cu, 0.001-0.2% Ti, 0.001-0.2% Zn, 0.001-0.3% Cr, 0.001-0.6% Zr, 0.001-0.2% V, 0.001-0.1% Be, 0.001-0.6% RE, and 0.001-0.05% Sr by mass.

[0006] Furthermore, at least one of the following conditions must be met: The mass ratio of the sum of the mass percentages of Mn, Cr, and Be to the mass percentage of Fe is 0.1-3; The mass ratio of Mn to Fe is greater than 0.2; The mass ratio of Cu to Mg is less than or equal to 2.6; The sum of the mass percentages of Si and Fe is less than 1.1%; The sum of the mass percentages of V and Ti is less than 0.4%; The atomic percentages of Zr and RE are 1-1.2:1.

[0007] Furthermore, the Al-Mg-Si aluminum alloy also contains at least one of In, Nb, Bi, Ge, Mo, Ni, Te, Co, Sn, Cd, Ag, and Ca, wherein the mass percentage content of In is 0-0.2%, the mass percentage content of Nb is 0-0.5%, the mass percentage content of Bi is 0-0.3%, the mass percentage content of Ge is 0-0.3%, the mass percentage content of Mo is 0-0.3%, the mass percentage content of Ni is 0-0.5%, the mass percentage content of Te is 0-0.3%, the mass percentage content of Co is 0-0.5%, the mass percentage content of Sn is 0-0.2%, the mass percentage content of Cd is 0-0.3%, the mass percentage content of Ag is 0-0.5%, and the mass percentage content of Ca is 0-0.1%.

[0008] This invention also provides a method for preparing Al-Mg-Si aluminum alloys, comprising the following steps: The Al source is subjected to a first heating treatment to obtain molten aluminum. Add Mg source, Si source, Fe source, Mn source, Cu source, Ti source, Zn source, Cr source, Zr source, V source, Be source, RE source and Sr source to the aluminum liquid, and perform a second heat treatment to obtain alloy liquid; The alloy liquid is refined, slag removed, and formed to obtain an Al-Mg-Si aluminum alloy. The Al-Mg-Si aluminum alloy contains 0.7-1.2% Mg, 0.7-1% Si, 0-0.4% Fe, 0-0.5% Mn, 0-0.8% Cu, 0-0.2% Ti, 0-0.3% Zn, 0-0.3% Cr, 0-0.6% Zr, 0-0.2% V, 0-0.1% Be, 0-0.6% RE, 0-0.1% Sr, and Al, as well as unavoidable impurities.

[0009] Further, the molten alloy is pushed into a mold and subjected to low-pressure filling casting. Once the molten alloy enters the semi-solid solidification zone to form semi-solid aluminum alloy parts, the semi-solid aluminum alloy parts are subjected to in-situ first-stage forging in the mold. The deformation of the semi-solid aluminum alloy parts during the in-situ first-stage forging is 5-70%.

[0010] Furthermore, the molding process also includes the following steps: After in-situ primary forging, in-situ secondary forging deformation is performed to obtain aluminum alloy parts.

[0011] Furthermore, the molding process also includes the following steps: Aluminum alloy parts that have undergone in-situ primary forging or in-situ secondary forging deformation are heat-treated to obtain Al-Mg-Si aluminum alloys.

[0012] Furthermore, the heat treatment includes direct aging treatment or offline solution aging treatment. In the direct aging treatment, the temperature is 160-200°C and the time is 0.2-20h; or the offline solution aging treatment includes solution treatment and aging treatment. In the solution treatment, the temperature is 500-560°C and the time is 0.1-20h, and in the aging treatment, the temperature is 160-200°C and the time is 0.2-20h.

[0013] The present invention also provides an aluminum alloy structural component, wherein at least a portion of the aluminum alloy structural component is made of the above-mentioned Al-Mg-Si aluminum alloy or an Al-Mg-Si aluminum alloy prepared by the preparation method described above.

[0014] In the technical solution of this invention, the Al-Mg-Si aluminum alloy contains 0.7-1.2% Mg, 0.7-1% Si, 0-0.4% Fe, 0-0.5% Mn, 0-0.8% Cu, 0-0.2% Ti, 0-0.3% Zn, 0-0.3% Cr, 0-0.6% Zr, 0-0.2% V, 0-0.1% Be, 0-0.6% RE, 0-0.1% Sr, and Al, as well as unavoidable impurities. The composite addition of Mg, Si, Fe, Mn, Cu, Ti, Zn, Cr, Zr, V, Be, RE, and Sr within the above content range interacts and influences each other, ensuring that Al-Mg-Si aluminum alloys have good formability and excellent mechanical properties. Detailed Implementation

[0015] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0016] One embodiment of the present invention provides an Al-Mg-Si aluminum alloy containing 0.7-1.2% Mg, 0.7-1% Si, 0-0.4% Fe, 0-0.5% Mn, 0-0.8% Cu, 0-0.2% Ti, 0-0.3% Zn, 0-0.3% Cr, 0-0.6% Zr, 0-0.2% V, 0-0.1% Be, 0-0.6% RE, 0-0.1% Sr, and Al and unavoidable impurities.

[0017] The specific percentage content of Mg by mass can be 0.7%, 0.75%, 0.8%, 0.85%, 0.9%, 0.95%, 1%, 1.05%, 1.1%, 1.15%, or 1.2%.

[0018] The specific percentage content of Si by mass can be 0.7%, 0.72%, 0.74%, 0.76%, 0.78%, 0.8%, 0.82%, 0.84%, 0.86%, 0.88%, 0.9%, 0.92%, 0.94%, 0.96%, 0.98%, or 1%.

[0019] The specific percentage of Fe by mass can be 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, or 0.4%.

[0020] The specific percentage content of Mn by mass can be 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, or 0.5%.

[0021] The specific percentage content of Cu by mass can be 0.001%, 0.005%, 0.01%, 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, 0.6%, 0.65%, 0.7%, 0.75%, or 0.8%.

[0022] The specific percentage content of Ti by mass can be 0.001%, 0.005%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.15%, or 0.2%.

[0023] The specific percentage content of Zn by mass can be 0.001%, 0.002%, 0.003%, 0.004%, 0.005%, 0.006%, 0.007%, 0.008%, 0.009%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.15%, 0.2%, 0.25%, or 0.3%.

[0024] The specific percentage content of Cr by mass can be 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.15%, 0.2%, 0.25%, or 0.3%.

[0025] The specific percentage content of Zr by mass can be 0.001%, 0.002%, 0.003%, 0.004%, 0.005%, 0.006%, 0.007%, 0.008%, 0.009%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, or 0.6%.

[0026] The specific percentage content of V by mass can be 0.001%, 0.005%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.15%, or 0.2%.

[0027] The specific percentage content of Be by mass can be 0.001%, 0.005%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, or 0.1%.

[0028] The specific percentage content of RE by mass can be 0.001%, 0.002%, 0.003%, 0.004%, 0.005%, 0.006%, 0.007%, 0.008%, 0.009%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, or 0.6%.

[0029] The specific percentage content of Sr by mass can be 0.001%, 0.005%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, or 0.1%.

[0030] In one embodiment, the Al-Mg-Si aluminum alloy contains 0.8-1.2% Mg, 0.7-1% Si, 0.001-0.4% Fe, 0.001-0.5% Mn, 0.001-0.8% Cu, 0.001-0.2% Ti, 0.001-0.2% Zn, 0.001-0.3% Cr, 0.001-0.6% Zr, 0.001-0.2% V, 0.001-0.1% Be, 0.001-0.6% RE, and 0.001-0.05% Sr by mass.

[0031] The mass ratio of the sum of the mass percentages of Mn, Cr, and Be to the mass percentage of Fe is 0.1-3, specifically 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.2, 1.4, 1.6, 1.8, 2, 2.2, 2.4, 2.6, 2.8, or 3. Within this range, the harmful effects of Fe are reduced, and the release properties and mechanical properties of aluminum alloys are improved through the addition of Mn, Cr, and Be.

[0032] The mass ratio of Mn to Fe is greater than 0.2, preferably 0.25-20, and can specifically be greater than 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20. Setting the mass ratio of Mn to Fe to greater than 0.4 reduces the harmful effects of Fe, and improves the demolding performance and mechanical properties of aluminum alloys through the addition of Mn, Cr, and Be.

[0033] When the mass ratio of Cu to Mg is less than or equal to 2.6, Cu reacts with Mg and Al to form the Al₂CuMg phase instead of the Al₂Cu phase, significantly improving the strength of the aluminum alloy. The strengthening effect of the Al₂CuMg phase is greater than that of the Al₂Cu phase. Specific mass ratios of Cu to Mg can be 2.6, 2.4, 2.2, 2, 1.8, 1.6, 1.4, 1.2, 1, 0.8, 0.6, 0.4, 0.2, 0.1, 0.01, or 0.001.

[0034] The sum of the mass percentages of Si and Fe is less than 1.1%, specifically 0.6%, 0.65%, 0.7%, 0.75%, 0.8%, 0.85%, 0.9%, 0.95%, 1%, or 1.05%. In the casting-forging integrated process, the alloy solution needs to be slowly and under high pressure to enter the mold cavity; fluidity of the alloy solution is not required. Therefore, the sum of the mass percentages of Si and Fe can be set to less than 1.1% to reduce the adverse effects of Si and Fe on the elongation of the aluminum alloy, thereby reducing the likelihood of cracks during deformation and resulting in thin-walled and medium-thick aluminum alloy structural parts.

[0035] The sum of the mass percentages of V and Ti is less than 0.4%, such as less than 0.3% or less than 0.2%, specifically 0.002%, 0.003%, 0.004%, 0.005%, 0.006%, 0.007%, 0.008%, 0.009%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, or 0.39%. When V and Ti are combined, their individual contents can be reduced; however, if the combined content exceeds 0.4%, a coarse second phase will form, leading to a decrease in the alloy's mechanical properties.

[0036] The sum of the mass percentages of RE and Zr shall not exceed 1.2%, specifically 0.002%, 0.003%, 0.004%, 0.005%, 0.006%, 0.007%, 0.008%, 0.009%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, 0.6%, 0.65%, 0.7%, 0.75%, 0.8%, 0.85%, 0.9%, 0.95%, 1%, 1.1%, or 1.2%. When RE and Zr are used together, they can effectively refine grains, second phases, and precipitates to improve the strength and elongation of aluminum alloys; the core-shell structure formed by the two, such as the L12 second phase, can significantly improve the thermal stability of aluminum alloys.

[0037] The atomic percentage of Zr and RE is 1-1.2:1, specifically 1:1, 1.1:1, or 1.2:1. At this atomic percentage, it is beneficial to form the Al3(ZrRE) phase to refine the grains, the second phase, and the precipitated phases, increasing the recrystallization temperature and further improving the tensile strength and elongation of the aluminum alloy. It also ensures sufficient Al3(ZrRE) phase to promote nucleation and increase the solid fraction during subsequent in-situ primary and secondary forging processes. Combined with the cooling steps, this increases the deformation amount in the in-situ primary and secondary forging processes, further enhancing the strength and elongation of the aluminum alloy.

[0038] The sum of the mass percentages of Mn, Cr, Zr, and RE is less than 1.5%, such as less than 1% or less than 0.5%, specifically less than 1.4%, 1.3%, 1.2%, 1.1%, 1%, 0.9%, 0.8%, 0.7%, 0.6%, 0.5%, 0.4%, 0.3%, 0.2%, or 0.1%. Mn, Cr, Zr, and RE react with each other to form Al. 12 The (Mn,Cr) and Al3(RE,Zr) second phases can significantly improve the strength of aluminum alloys.

[0039] In the technical solution of this invention, the Al-Mg-Si aluminum alloy contains 0.7-1.2% Mg, 0.7-1% Si, 0-0.4% Fe, 0-0.5% Mn, 0-0.8% Cu, 0-0.2% Ti, 0-0.3% Zn, 0-0.3% Cr, 0-0.6% Zr, 0-0.2% V, 0-0.1% Be, 0-0.6% RE, 0-0.1% Sr, and Al, as well as unavoidable impurities. The addition of Mg, Si, Fe, Mn, Cu, Ti, Zn, Cr, Zr, V, Be, RE, and Sr within the above content ranges interacts and influences each other, ensuring that Al-Mg-Si aluminum alloys not only have good formability but also excellent mechanical properties (such as strength and elongation). Specifically: Setting the Mg mass percentage content to 0.7-1.2% and the Si mass percentage content to 0.7-1%, Mg can react with Si to form the Mg2Si strengthening phase, thereby improving the strength of the aluminum alloy. Mg and Si can also react with Al, Fe, Cu, Zn, etc., to form second phases such as AlFeMgSi, Al2CuMg, AlCuMgSi, Mg2Zn, Mg2SiZn, and Mg2Si, thereby improving the tensile strength of the aluminum alloy. Setting the Cu mass percentage content to 0-0.8%, Cu can react with Al, Fe, Si, Mg, Zn, Mn, etc., to form Al2CuMg, AlFeSiCu, Al2CuZn, and Al... 12 CuMn2、τ(Cu2Mn3Al 20 Cu, along with other minerals such as Al, Si, Cu, Ni, Mg, and Mn, forms second phases to improve the tensile strength of aluminum alloys. Cu can also promote the formation of GP zones, Mg2Si, and MgZn2, further enhancing the strength of aluminum alloys. Setting the Fe mass percentage content to 0-0.4% improves mold release properties and allows Fe to react with Al, Si, Cu, Ni, Mg, and Mn to form second phases such as Al3Fe, AlFeSi, AlFeSiCu, AlFeMgSiNi, AlFeSiNi, FeNiAl9, AlFeMgSi, Al6(Fe,Mn), and α-Al(FeMn)Si, thus increasing the tensile strength of aluminum alloys. Setting the Mn mass percentage content to 0-0.5% allows Mn to react with Al, Fe, Si, and Cu to form MnAl2, MnAl6, and Al... 12 CuMn2, Al3(Fe,Mn), Al6(Fe,Mn), Al 12 (Fe,Mn)3Si, α-Al(FeMn)Si, τ(Cu2Mn3Al 20 The formation of α-Al(FeMn)Si and other second phases can improve the tensile strength of aluminum alloys. The formation of α-Al(FeMn)Si inhibits the coarsening of grain boundary precipitates such as Mg2Si and Al2CuMg, and also reduces the content of impurity Fe. Mn can significantly refine grain size and improve elongation through lattice distortion caused by solid solution in the matrix and the dispersed particles of MnAl6 produced by reaction with Al. Setting the mass percentage content of Ti to 0-0.2% allows Ti to react with Al to form the TiAl3 phase, which acts as a non-spontaneous nucleus during crystallization, refining grains, second phases, and precipitates, thereby improving the tensile strength and elongation of aluminum alloys. Mg can also destroy the original oxide film between Ti and the aluminum matrix, promoting the formation of Al from Ti and the aluminum alloy. 18The Ti₂Mg₃ ternary phase is used to improve the strength of aluminum alloys. Setting the Zn mass percentage content to 0-0.3% allows Zn to react with Mg, Si, and Al to form highly soluble strengthening phases such as Mg₂Zn, Al₂Mg₃Zn₃, and Mg₂SiZn. Zn also promotes the precipitation of second phases such as Mg₂Si, Al₃Fe, AlFeSi, AlFeSiCu, Al₂CuMg, Mg₂Zn, and Mg₂SiZn, thereby improving the tensile strength of aluminum alloys. Zn can also eliminate elemental Si and Mg, reducing their influence on aluminum alloy properties, such as reducing the elongation of aluminum alloys with high Si and Mg content. Setting the Cr mass percentage content to 0-0.3% allows Cr to transform the acicular β-Fe phase into the α-Fe phase, improving Fe morphology and eliminating its harmful effects. Cr also readily forms dispersed phases with Fe, reducing... The Fe content is reduced to mitigate the harmful effects of Fe. Cr can also hinder the nucleation and growth process of recrystallization, thus improving the tensile strength and elongation of aluminum alloys. Various chromium-containing fine compounds formed by Cr in aluminum alloys can redissolve in the α phase during the solid solution stage, and various Cr-containing phases, such as α-AlCrSi dispersed phase, precipitate diffusely during the natural aging stage. These Cr-containing phases can improve the tensile strength of aluminum alloys. Setting the Zr mass percentage content to 0-0.6% can improve the tensile strength of aluminum alloys. Zr can also promote the precipitation of second phases such as Mg2Si, Mg2Zn, Al2CuZn, AlCuMgSi, and Al2CuMg, thereby reducing the solid solubility of these elements in the aluminum matrix. Zr can also refine the grains, second phases, and precipitated phases, further improving the elongation of aluminum alloys. Setting the V mass percentage content to 0-0.2% can allow V to react with Al to form VAl. 11 Refractory compounds such as vanadium (Be) play a role in refining grains during the casting process. Benzene (V) can also refine the recrystallization structure and increase the recrystallization temperature, thereby improving the tensile strength and elongation of aluminum alloys. Setting the mass percentage content of Be to 0-0.1% can increase the tensile strength of aluminum alloys. Benzene can also transform the plate-like β-mezzanine phase into the relatively harmless α-Fe (Al₈Fe₂SiBe) phase and prevent the formation of acicular β-Fe phase, thus reducing or eliminating the adverse effects of Fe on the properties of aluminum alloys. Furthermore, Benzene can promote the formation of Mg₂Si, Mg₂Zn, Mg₂SiZn, and Al₂Fe. l2The formation and precipitation of CuMg and other phases reduce the solid solubility of these elements in the aluminum matrix. Be can also form an active film on the surface of impurity element phases such as Fe, preventing the growth of impurity elements. It can also agglomerate on grain boundaries or adsorb on the solid-liquid interface, forming supercooling and increasing the chance of dendrite melting, thereby refining the grains. Setting the mass percentage content of RE to 0-0.6% can refine the alloy structure to improve the mechanical properties of aluminum alloys. It can also form a rare earth active film on the surface of Fe-containing phases or combine with Al, Fe, Ti and other atoms to form rare earth compounds, effectively reducing the solid solubility of harmful elements in the aluminum matrix. RE can also transform the long strip β-Fe phase into a spherical α-Fe phase and modify elemental Si. RE can also promote the dispersion of phases such as Mg2Si, Al2CuMg, and Al The precipitation of Fe, Mg2Zn, Mg2SiZn, etc., improves the tensile strength and elongation of aluminum alloys. RE can also combine with Zr to form Al3 (ZrRE) phase, which refines grains, second phases, and precipitated phases (e.g., it can refine Al2CuMg, Mg2Si, Al3Fe phases, etc.), increases recrystallization temperature, and further improves the tensile strength and elongation of aluminum alloys. Setting the mass percentage content of Sr to 0-0.1% allows Sr to refine grains and inhibit recrystallization growth, thus improving the strength and elongation of aluminum alloys. Sr can also hinder the diffusion of Fe atoms, causing compositional supercooling, which transforms the morphology of the Al3Fe phase from needle-like to flower-like, thereby eliminating the influence of impurity Fe on the alloy.

[0040] In summary, the tensile strength of aluminum alloys can be significantly improved by adjusting the content of Mg, Si, Zn, Cu, Fe, and Mn as described above. Mg₂Si is the main strengthening phase, and Al₂CuMg can also significantly improve the strength. The Si content ensures the fluidity and die-casting performance of the aluminum alloy; the Fe content improves the tensile strength and mold release properties; and the Cr, Sr, RE, Ti, V, Mn, B, and Be content refines the grains, second phases (especially the Mg₂Si phase), and precipitated phases, thereby improving the tensile strength and elongation. Zr, Zn, RE, and Be can also promote the precipitation of second phases (such as Al₂CuMg, Mg₂Zn, Mg₂SiZn, and Mg₂Si phases), further improving the tensile strength and elongation. This results in Al-Mg-Si aluminum alloys with excellent mechanical and formability properties.

[0041] The Al-Mg-Si aluminum alloy also contains 0-0.2% In by mass, specifically 0.001%, 0.005%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.15%, or 0.2%. In can improve the mechanical properties of aluminum alloys. In can react with other elements to form second phases, thereby improving the mechanical properties of aluminum alloys. Specifically, In can react with Al and Cu to form second phases such as AlIn and CuIn. In addition, In can refine the grains, thereby improving the elongation of aluminum alloys.

[0042] The Al-Mg-Si aluminum alloy also contains 0-0.5% Nb by mass, specifically 0.001%, 0.005%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, or 0.5%. Nb can improve the mechanical properties of aluminum alloys. Nb can react with other elements to form a second phase, thereby improving the mechanical properties of aluminum alloys. Specifically, Nb can react with Ti and Al to form the TiAl-Nb phase. In addition, Nb can refine the grain size, thereby increasing the elongation of the aluminum alloy.

[0043] The Al-Mg-Si aluminum alloy also contains Bi at a mass percentage of 0-0.3%, specifically 0.001%, 0.005%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.15%, 0.2%, 0.25%, or 0.3%. Bi can improve the mechanical properties of aluminum alloys. Bi can react with other elements to form a second phase, thereby improving the mechanical properties of aluminum alloys. Specifically, Bi can react with Mg and Cd to form second phases such as Mg3Bi2 and Mg3(BiCd)2.

[0044] The Al-Mg-Si aluminum alloy also contains 0-0.3% Ge by mass, specifically 0.001%, 0.005%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.15%, 0.2%, 0.25%, or 0.3%. Ge can improve the mechanical properties of aluminum alloys. Ge can react with other elements to improve the mechanical properties of aluminum alloys. Specifically, Ge can react with Al and Si to form second phases such as Al9Ge7, Al6Ge5, Al5Ge2, Al3Ge4, and SiGe. Ge can also promote the precipitation of second phases such as Al2Cu, Mg2Zn, Mg2SiZn, and Mg2Si, refine the precipitated phases, and reduce the solid solubility of the above elements in the aluminum matrix. Ge can also replace some Si atoms in the metastable precipitated phases. The precipitated Si-Ge and Cu-Ge phases provide nucleation sites for the β'', β', S'', S' phases, increasing the density of the β'', β', S'', S' phases, thereby further improving the mechanical properties of aluminum alloys.

[0045] The Al-Mg-Si aluminum alloy also contains 0-0.3% Mo by mass, specifically 0.001%, 0.005%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.15%, 0.2%, 0.25%, or 0.3%. Mo can improve the mechanical properties of aluminum alloys. Mo can react with other elements to improve the mechanical properties of aluminum alloys. Specifically, Mo can react with Al, Si, Fe, etc., to form second phases such as AlMo, AlSiMo, and AlSiFeMo, which are dispersed phases distributed at the grain boundaries of the aluminum matrix. In addition, Mo can refine the grains and improve the morphology of Fe-containing intermetallic compounds, further improving the mechanical properties of aluminum alloys.

[0046] The Al-Mg-Si aluminum alloy also contains 0-0.5% Ni by mass, specifically 0.001%, 0.005%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, or 0.5%. Ni can refine the grains, improve the tensile strength of the aluminum alloy, and promote the precipitation of second phases such as Al2Cu, Mg2Zn, Mg2SiZn, and Mg2Si, thereby increasing the volume fraction and dispersion of the precipitated phases.

[0047] The Al-Mg-Si aluminum alloy also contains 0-0.3% Te by mass, specifically 0.001%, 0.005%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.15%, 0.2%, 0.25%, or 0.3%. Te can improve the mechanical properties of aluminum alloys. Te can narrow the solidification temperature range of aluminum alloys, form fine petal-like rather than dendritic primary crystals, reduce or eliminate micro-shrinkage porosity, thereby improving the mechanical properties of aluminum alloys.

[0048] The Al-Mg-Si aluminum alloy also contains 0-0.5% Co by mass, specifically 0.001%, 0.005%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, or 0.5%. Co can refine the grains to improve the mechanical properties of the aluminum alloy, and can also react with other elements to form a second phase, further improving the mechanical properties of the aluminum alloy. Specifically, Co can react with Al, Fe, Si, etc., to form Al 15 Secondary phases include (Fe,Co)3Si2 and Al3(Fe,Co). Furthermore, Co has a refining effect on the Al3Fe phase, transforming coarse needle-like and plate-like β-Al3Fe phases into small flower-like and fine strip-like α-Al3Fe phases. 15 The (Fe,Co)3Si2 phase can also promote α-Al 15 The precipitation of the (Fe,Co)3Si2 phase further improves the mechanical properties of aluminum alloys. The combined addition of Ni and Co can effectively modify Fe and transform free Fe into the second phase. The combined addition of Co, Ni and Be can rapidly reduce their solid solubility in the alloy and increase the volume fraction of the second phase, thereby improving the mechanical properties of aluminum alloys.

[0049] The Al-Mg-Si aluminum alloy also contains 0-0.5% Ag by mass, specifically 0.001%, 0.005%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, or 0.5%. Adding a small amount of Ag will form dispersed precipitates such as Al2CuMgAg and Mg2SiAg in the alloy. The formation of these phases inhibits the coarsening of the original Mg2Si and Al2CuMg precipitates, increases their volume fraction, and alters the aging precipitation process of Mg2Si and Al2CuMg. It also refines the Ag-containing transition phases β'', β' phase and S'', S' phase, significantly improving plasticity and strength.

[0050] The Al-Mg-Si aluminum alloy also contains 0-0.2% Sn by mass, specifically 0.001%, 0.005%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.15%, or 0.2%. Sn can refine grains, the second phase, and precipitated phases, thereby improving the tensile strength and elongation of the aluminum alloy. Sn can also react with Mg to form the Mg3Sn2 phase, further enhancing the strength of the aluminum alloy.

[0051] The Al-Mg-Si aluminum alloy also contains 0-0.3% Cd by mass, specifically 0.001%, 0.005%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.15%, 0.2%, 0.25%, or 0.3%. Cd can refine α-Al, and Cd will form a large number of Cd- vacancy clusters, promoting and accelerating the precipitation of phases such as Al2Cu, Mg2Zn, Mg2SiZn, and Mg2Si, thereby reducing the impact of high Cu content on the elongation of the aluminum alloy.

[0052] The Al-Mg-Si aluminum alloy also contains 0-0.1% Ca by mass, specifically 0.001%, 0.005%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, or 0.1%. Ca can improve the β-Fe phase to reduce the harmful effects of Fe. It can also react with Al, Cu, Zn, and Si to form second phases such as Al4Ca, Al2Ca3, AlCa2, AlCaCu, CaZn, CaAlZn, and Al2CaSi2, thereby improving the tensile strength of aluminum alloys. Ca can also refine the eutectic structure and improve the β-Fe phase. It also has a modifying effect on Al-Mg-Si alloys, refining the Si phase. Sn can react with Al, Mg, and Sc to form second phases such as Al9Sn7, Al6Sn5, Al5Sn2, Al3Sn4, Mg2Sn, and Mg2ScSn, thereby improving the tensile strength of aluminum alloys. Sn can promote the precipitation of second phases such as Mg2Si, Mg2Zn, Mg2SiZn, and Al2Cu, thereby reducing the solid solubility of these elements in the aluminum matrix. Ca and Sn can also significantly reduce the surface tension of molten aluminum alloys, reducing or even eliminating the influence of the surface tension of the oxide film on the aluminum alloy surface, thereby improving the fluidity of aluminum alloys. The combination of Ca and RE can significantly refine the grains and the second phase, thereby improving tensile strength, fluidity, and elongation.

[0053] This invention also provides a method for preparing Al-Mg-Si aluminum alloys, comprising the following steps: Aluminum liquid is obtained by heating an Al source at a temperature of 750-830°C; At a temperature of 720-780°C, Mg source, Si source, Fe source, Mn source, Cu source, Ti source, Zn source, Cr source, Zr source, V source, Be source, RE source and Sr source are added to the aluminum liquid to obtain an alloy liquid; The alloy liquid is refined, slag removed, and formed to obtain an Al-Mg-Si aluminum alloy. The Al-Mg-Si aluminum alloy contains 0.7-1.2% Mg, 0.7-1% Si, 0-0.4% Fe, 0-0.5% Mn, 0-0.8% Cu, 0-0.2% Ti, 0-0.3% Zn, 0-0.3% Cr, 0-0.6% Zr, 0-0.2% V, 0-0.1% Be, 0-0.6% RE, 0-0.1% Sr, and Al, as well as unavoidable impurities.

[0054] Mg source, Si source, Fe source, Mn source, Cu source, Ti source, Zn source, Cr source, Zr source, V source, Be source, RE source, and Sr source can be added in the form of elements or alloys.

[0055] At least one of the following sources can be added to the molten aluminum: In, Nb, Bi, Ge, Mo, Ni, Te, Co, Sn, Cd, Ag, and Ca. These raw materials can also be added in elemental form or as intermediate alloys.

[0056] The degassing process involves adjusting the temperature of the molten alloy to 650-780℃ and introducing an inert gas such as argon into the molten alloy using a degassing machine. Specific degassing temperatures can be 650℃, 660℃, 670℃, 680℃, 690℃, 700℃, 710℃, 720℃, 730℃, 740℃, 750℃, 760℃, 770℃, or 780℃. The degassing time is 10-30 minutes, specifically 10 minutes, 15 minutes, 20 minutes, 25 minutes, or 30 minutes.

[0057] The refining process involves introducing inert gases such as argon into the molten alloy using a degasser. A refining agent can be added simultaneously. The vortex formed by the degasser's rotating disc in the molten alloy allows the refining agent to be evenly mixed into the alloy. The refining agent refines the alloy microstructure, thereby improving the tensile strength and elongation of the aluminum alloy. It has the advantages of good dispersibility and low cost. The refining time is 10-30 minutes, specifically 10, 15, 20, 25, or 30 minutes. The refining temperature is 650-780℃, specifically 650℃, 660℃, 670℃, 680℃, 690℃, 700℃, 710℃, 720℃, 730℃, 740℃, 750℃, 760℃, 770℃, or 780℃. The refining agent contains: 5-10 parts potassium fluoroaluminate, 6-20 parts AlTi5B1 metal powder, 8-25 parts potassium titanate whisker powder, 20-40 parts sodium chloride + potassium chloride, 5-10 parts potassium nitrate, 5-10 parts potassium carbonate, and 0.5-3 parts potassium silicate.

[0058] The parting surface of the mold can undergo surface treatment to form a boron carbide layer. This layer not only improves demolding performance but also enhances the mold's wear resistance and protects against corrosion from acids, alkalis, salts, and other chemicals, as well as thermal erosion of the aluminum alloy, thus extending the mold's service life. The thickness of the boron carbide layer can range from 1 to 10 mm, specifically 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, or 10 mm. The surface treatment can involve mixing a boron-containing gas (such as BCl3) with a carbon-containing gas (such as CH4) to obtain a mixed gas. This mixed gas is then introduced into the cavity, and through chemical vapor deposition (CVD), the boron-containing and carbon-containing gases react chemically and deposit onto the parting surface to form the boron carbide layer. The CVD temperature is 900-1200°C, the deposition pressure is 200-500 Pa, and the carrier gas flow rate is 100-200 sccm. The boron carbide layer can increase the hardness of mold steel to 3000-4000 Hv; the boron carbide layer can reduce the affinity of the mixed melt to the mold surface, improve the demolding performance of aluminum alloy, and greatly increase the elongation of aluminum alloy; the boron carbide layer can resist the corrosion of chemicals such as acids, alkalis, and salts, and can improve the corrosion resistance of aluminum alloy; the boron carbide layer can maintain good physical and chemical properties at high temperature, and can improve the thermal stability of aluminum alloy; the boron carbide layer has an extremely low coefficient of friction, which can improve the surface smoothness of aluminum alloy and significantly reduce the wear and energy consumption of aluminum alloy products caused by mechanical friction; the boron carbide layer also has high heat transfer properties. During the instant of aluminum alloy forming, the boron carbide layer can quickly conduct away heat, increasing the heat transfer rate of the mold by 2-4 times that of ordinary molds, allowing the aluminum alloy to cool down faster.

[0059] The forming process includes the following steps: Molten alloy is poured into a mold and subjected to low-pressure filling casting. Once the molten alloy enters the semi-solid solidification zone, semi-solid aluminum alloy parts are formed. These semi-solid aluminum alloy parts are then subjected to in-situ primary forging within the mold to obtain the aluminum alloy parts. The deformation amount of the semi-solid aluminum alloy parts during the in-situ primary forging process is 5-70%. Further in-situ secondary forging deformation of the aluminum alloy parts after primary forging can be performed to obtain the aluminum alloy parts. The deformation amount of the semi-solid aluminum alloy parts during the in-situ secondary forging process is 5-80%. The aluminum alloy parts after either primary or secondary forging can then be heat-treated to obtain an Al-Mg-Si aluminum alloy.

[0060] It is understandable that the above forming process steps can be selected according to needs, and this application does not impose any restrictions on this. For example, aluminum alloy parts can be obtained after only performing in-situ primary forging. The aluminum alloy parts after in-situ primary forging can also be heat-treated. Alternatively, in-situ primary forging and in-situ secondary forging deformation can be performed sequentially. Furthermore, heat treatment can be performed after in-situ primary forging and in-situ secondary forging deformation.

[0061] In low-pressure filling casting, the filling speed (i.e., the moving speed of the punch) is 0.1-1.2 m / s, the filling time (i.e., the time required for the molten alloy to completely fill the mold) is 2-20 s, the casting pressure is 0.1-40 MPa, the holding time is 2-10 s (i.e., the time to maintain the molten alloy under a certain pressure after it has completely filled the mold), the mold temperature is 180-300℃, and the alloy casting temperature (i.e., the temperature when the molten alloy is filled into the mold) is 660-720℃.

[0062] A filling speed of 0.1-1.2 m / s increases the fluidity of the molten alloy, facilitating its full filling of the cavity. At this speed, the pressure applied by the punch to the molten alloy is also relatively low (specific pressure approximately 50-200 MPa), preventing casting defects such as porosity, shrinkage cavities, and looseness in the aluminum alloy product. It also avoids splashing and turbulence caused by excessively fast filling speeds, which can lead to casting defects such as oxide inclusions and air entrapment. Specific filling speeds can be 0.1 m / s, 0.2 m / s, 0.3 m / s, 0.4 m / s, 0.5 m / s, 0.6 m / s, 0.7 m / s, 0.8 m / s, 0.9 m / s, 1 m / s, 1.05 m / s, 1.1 m / s, 1.15 m / s, or 1.2 m / s. Specific filling times can be 2 s, 5 s, 10 s, 15 s, or 20 s.

[0063] Under casting pressures ranging from 0.1 to 40 MPa, the molten alloy is relatively stable and can solidify in a directional sequence. The precipitated phases within the semi-solid aluminum alloy parts are perpendicular to the basal surface of the aluminum alloy matrix. When the molten alloy solidifies stably, there are fewer pores, looseness, and cracks in the semi-solid aluminum alloy parts. Specific casting pressures can be 0.1 MPa, 0.5 MPa, 1 MPa, 5 MPa, 10 MPa, 15 MPa, 20 MPa, 25 MPa, 30 MPa, 35 MPa, or 40 MPa.

[0064] Semi-solid aluminum alloy parts can be formed within a holding time of 2-10 seconds and a casting pressure of 0.1-40 MPa. Moreover, the solidification range of Al-Mg-Si aluminum alloys is very large, which easily leads to casting defects such as low density and a large number of inclusions, as well as hot and cold cracking problems. Within the low casting pressure range of 0.1-40 MPa, the above-mentioned casting defects can be solved, as well as the porosity problem of high pressure casting.

[0065] As the holding time and casting pressure increase, the casting structure inside the semi-solid aluminum alloy parts gradually becomes uniform and dense. If the holding time exceeds 10 seconds or the casting pressure is too high, the liquid phase inside the mold will completely solidify, and the semi-solid aluminum alloy parts cannot be formed. The holding time can be 2s, 3s, 4s, 5s, 6s, 7s, 8s, 9s, or 10s.

[0066] The low-pressure filling casting process of this invention requires lower casting and mold preheating temperatures, which not only reduces thermal shock corrosion to the mold but also saves energy. The mold temperature can specifically be 180°C, 200°C, 250°C, or 300°C. The alloy casting temperature can specifically be 660°C, 670°C, 680°C, 690°C, 700°C, 710°C, or 720°C.

[0067] In semi-solid aluminum alloy parts, the solid-liquid ratio, or solid phase fraction, is 20-90%, specifically 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, or 90%. At this solid-liquid ratio, there are fewer casting defects in semi-solid aluminum alloy parts, and the precipitated phases within them solidify almost entirely vertically.

[0068] In the in-situ primary forging process, the forging temperature (i.e., the temperature of the semi-solid aluminum alloy parts in the mold) is 580-650℃, the forging specific pressure is 30-300MPa, the forging start time (i.e., the time interval between the formation of the semi-solid aluminum alloy parts and the in-situ primary forging process) is 2-20s, the holding time is 2-20s, and the deformation is 5-70%. After this in-situ primary forging process, the semi-solid aluminum alloy parts are transformed into solid parts.

[0069] Setting the forging temperature to 580-650℃ ensures the alloy remains in a semi-solid state. Specific forging temperatures can be 580℃, 590℃, 600℃, 610℃, 620℃, 630℃, 640℃, or 650℃. Specific forging pressures can be 30MPa, 40MPa, 50MPa, 60MPa, 70MPa, 80MPa, 90MPa, 100MPa, 120MPa, 140MPa, 160MPa, 180MPa, 200MPa, 220MPa, 240MPa, 260MPa, 280MPa, or 300MPa. The specific forging start time can be 2s, 3s, 4s, 5s, 6s, 7s, 8s, 9s, 10s, 11s, 12s, 13s, 14s, 15s, 16s, 17s, 18s, 19s, or 20s. The specific pressure holding time can be 2s, 3s, 4s, 5s, 6s, 7s, 8s, 9s, 10s, 11s, 12s, 13s, 14s, 15s, 16s, 17s, 18s, 19s, or 20s.

[0070] With a deformation amount of 5-70%, semi-solid aluminum alloy parts can be transformed into solid aluminum alloy parts after in-situ primary forging. As the deformation amount increases, the volume fraction and size of precipitates such as Mg2Si, Al2CuMg, and Al2Cu in the solid aluminum alloy parts gradually increase, thereby improving the mechanical properties of the aluminum alloy (including tensile strength and elongation). The preferred deformation amount is 20-60%, with the precipitates being essentially perpendicular to the basal plane, significantly improving the alloy's mechanical properties (including tensile strength and elongation). Specific deformation amounts can be 5%, 6%, 7%, 8%, 9%, 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, 38%, 40%, 42%, 44%, 46%, 48%, 50%, 52%, 54%, 56%, 58%, 60%, 62%, 64%, 66%, 68%, or 70%.

[0071] In this in-situ primary forging process, the semi-solid aluminum alloy parts are not cooled, removed from the mold, and then placed in the forging device for reheating to the forging temperature. Instead, the semi-solid aluminum alloy parts are directly subjected to in-situ primary forging in the original mold without the need for cooling and reheating. This allows the solid-liquid mixed phases present in the semi-solid aluminum alloy parts to deform and solidify uniformly in the in-situ primary forging process on the basis of low-pressure filling casting (without cooling to room temperature before reheating and forging, the deformation during cooling and heating is uncontrollable and it is difficult to maintain the semi-solid state). This further eliminates casting defects in the semi-solid aluminum alloy parts, significantly refines the coarse grains and the second-phase as-cast structure, refines the size of the precipitates, and introduces a large number of nano-sized precipitates inside the grains. The volume fraction of the precipitates gradually increases, thereby improving the mechanical properties of the alloy.

[0072] To improve the smooth transition between low-pressure filling casting and in-situ primary forging, a first cooling process is performed during low-pressure filling casting. This ensures that semi-solid aluminum alloy parts with a temperature of 580-650℃ are obtained immediately after pressure holding, allowing for faster entry into the in-situ primary forging process. Alternatively, if the first cooling process during low-pressure filling casting does not result in a semi-solid aluminum alloy part with a solid content of 20-90% after pressure holding (e.g., the solid content is below 20%), a semi-solid aluminum alloy part with a temperature of 580-650℃ (solid content of 20-90%) can be obtained by undergoing a forging start-up time. Or, a second cooling process during the forging start-up time and in-situ primary forging can achieve a semi-solid aluminum alloy part with a temperature of 580-650℃ (solid content of 20-90%). A circulating oil circuit, such as a 3D contour cooling circuit, can be configured for cooling and temperature control.

[0073] In low-pressure filling casting, the cooling rate for the first cooling process is 1-50℃ / s, specifically 1℃ / s, 5℃ / s, 10℃ / s, 15℃ / s, 20℃ / s, 25℃ / s, 30℃ / s, 35℃ / s, 40℃ / s, 45℃ / s, or 50℃ / s. In in-situ primary forging, the cooling rate for the second cooling process is 5-60℃ / s, specifically 5℃ / s, 10℃ / s, 15℃ / s, 20℃ / s, 25℃ / s, 30℃ / s, 35℃ / s, 40℃ / s, 45℃ / s, 50℃ / s, 55℃ / s, or 60℃ / s.

[0074] In the in-situ secondary forging deformation treatment, the forging temperature is 150-350℃, the forging pressure is 30-500MPa, the holding time is 0-10s, and the deformation is 5-80%.

[0075] The forging temperature can be 150℃, 200℃, 250℃, 300℃, or 350℃. Temperatures below 150℃ can cause aluminum alloy parts to break easily, while temperatures above 350℃ can easily lead to complete recrystallization, resulting in excessively large grain size and precipitated phase size, which is also not conducive to the formation of twins and causes a reduction in mechanical properties.

[0076] The forging specific pressure can be 30 MPa, 40 MPa, 50 MPa, 60 MPa, 70 MPa, 80 MPa, 90 MPa, 100 MPa, 120 MPa, 140 MPa, 160 MPa, 180 MPa, 200 MPa, 220 MPa, 240 MPa, 260 MPa, 280 MPa, 300 MPa, 320 MPa, 340 MPa, 360 MPa, 380 MPa, 400 MPa, 420 MPa, 440 MPa, 460 MPa, 480 MPa, or 500 MPa. The forging specific pressure in the in-situ secondary forging deformation treatment is preferably greater than that in the in-situ primary forging treatment to further promote the refinement of the precipitated phase size. In one embodiment, the forging specific pressure of the in-situ secondary forging deformation treatment is 0.1-20 times that of the in-situ primary forging treatment, specifically 0.1 times, 0.5 times, 1 times, 5 times, 10 times, 15 times, or 20 times. This can effectively eliminate casting defects in semi-solid aluminum alloy parts and initially refine the grains and second-phase as-cast structure during the in-situ primary forging treatment, resulting in a large number of nanoscale precipitates within the grains. The in-situ secondary forging deformation treatment further refines these precipitates, thereby obtaining an aluminum alloy with excellent mechanical properties.

[0077] The holding time can be 0s, 1s, 2s, 3s, 4s, 5s, 6s, 7s, 8s, 9s, or 10s. For example, after in-situ primary forging, when the parameter requirements of in-situ secondary forging deformation are met, the pressure can be held for a certain period of time (e.g., 2s). For example, when the parameters reach the in-situ secondary forging deformation, the in-situ secondary forging deformation can be stopped immediately, and subsequent heat treatment can be carried out; this holding time can be 0s. For example, when the parameters reach the in-situ secondary forging deformation, the pressure can be held for 5s before subsequent heat treatment.

[0078] The deformation amount can be 5%, 6%, 7%, 8%, 9%, 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, 38%, 40%, 42%, 44%, 46%, 48%, 50%, 52%, 54%, 56%, 58%, 60%, 62%, 64%, 66%, 68%, 70%, 72%, 74%, 76%, 78%, or 80%.

[0079] In in-situ primary forging and in-situ secondary forging deformation processes, when the deformation amount is large, Ag can be dissolved in strengthening phases (such as AlFeMgSi, Al2CuMg, AlCuMgSi, Mg2Zn, Mg2SiZn, Mg2Si phase, etc.) to significantly improve the strength of aluminum alloys, which allows the Ag content of this application to reach 0.5%.

[0080] In the in-situ primary forging process, the molten aluminum alloy gradually transforms into a semi-solid state, and the nucleus content increases accordingly. A higher nucleus content results in a higher solid fraction. The Al3(RE,Zr) phase formed by Zr reacting with Al and RE is conducive to nucleus formation. In this application, the Zr and RE content can reach 0.6% to ensure sufficient Al3(RE,Zr) phase presence, thereby increasing the solid fraction. The relatively high cooling rates of the in-situ primary forging and secondary forging deformation processes prevent Al3(RE,Zr) phase coarsening, avoiding adverse effects on the strength and elongation of the aluminum alloy when the Zr and RE content is high. Moreover, the in-situ primary forging process and the in-situ secondary forging deformation process of this application are performed in "in-situ" (which can be understood as the two forging processes being carried out in the same location without being moved to other locations). Compared with the non-"in-situ" forming technology in the prior art (which requires reheating and homogenization after casting), the grains are less likely to grow. Combined with a larger cooling rate and a higher solid fraction, the in-situ primary forging process and the in-situ secondary forging deformation process of this application can have a larger deformation amount.

[0081] Preferably, the content of Zr and RE is 0.1-0.6%.

[0082] Understandably, the mold is an integrated casting and forging mold. The punch, driven by a feed rod, pushes the mixture into the mold cavity for casting and forging. During low-pressure filling casting, the filling speed and time can be adjusted by regulating the punch speed. The downward pressure of the punch during filling generates filling injection force, and the stroke of the punch after filling generates boosting pressure. These filling injection force and boosting pressure can be used to regulate the casting pressure during the casting process. In subsequent in-situ primary forging and in-situ secondary forging deformation processes, the forging pressure can also be adjusted by regulating the punch stroke.

[0083] To improve the smoothness of the connection between the in-situ primary forging process and the in-situ secondary forging deformation process, a second cooling process was carried out during the in-situ primary forging process. This allows solid aluminum alloy parts with a temperature of 150-350℃ to be obtained as soon as possible after the pressure holding is completed, so that they can enter the in-situ secondary forging deformation process as soon as possible.

[0084] The high dislocation density generated by the pre-formed twins through in-situ secondary forging pre-deformation treatment provides more diffusion pathways for the dissolution of Mg, Cu, Zn, Si, Fe, Ag, and Mn solute atoms in the aluminum matrix, promotes the nucleation of precipitates, accelerates the formation of precipitates, enhances the hardening response of the alloy, and further refines the grain size.

[0085] A third cooling process was performed during the in-situ secondary forging deformation to facilitate the formation of twins. The cooling rate for this third cooling process in the in-situ secondary forging deformation was 20-60℃ / s, specifically 20℃ / s, 25℃ / s, 30℃ / s, 35℃ / s, 40℃ / s, 45℃ / s, 50℃ / s, 55℃ / s, or 60℃ / s. Cooling treatment was performed during the low-pressure filled casting, in-situ primary forging, and in-situ secondary forging deformation processes. After these processes, the precipitation of Mg2Zn, Mg2Si, Mg2SiZn, AlCuMgSi, and Al2CuMg phases was promoted, while the coarsening of Mg2Si and Al2CuMg precipitates was inhibited. Furthermore, the formation of β-AlFeSi phase was suppressed, thereby improving the tensile strength of the aluminum alloy and preventing the coarsening of Mg2Si and Al2CuMg precipitates and the formation of β-AlFeSi phase, which would reduce the elongation of the aluminum alloy.

[0086] In one embodiment, the heat treatment is a direct aging treatment, with a temperature of 160-200°C, specifically 160°C, 170°C, 180°C, 190°C, or 200°C, and a time of 0.2-20h, specifically 0.2h, 0.5h, 1h, 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h, 15h, or 20h.

[0087] In one embodiment, the heat treatment is an offline solution aging treatment, which includes solution treatment and aging treatment. In the solution treatment, the temperature is 500-560°C, specifically 500°C, 510°C, 520°C, 530°C, 540°C, 550°C, or 560°C, and the time is 0.1-20 hours, specifically 0.1 hours, 0.5 hours, 1 hour, 2 hours, 3 hours, or 4 hours. 5h, 6h, 7h, 8h, 9h, 10h, 15h or 20h; during aging treatment, the temperature is 160-200°C, specifically 160℃, 170℃, 180℃, 190℃ or 200℃, and the time is 0.2-20h, specifically 0.2h, 0.5h, 1h, 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h, 15h or 20h.

[0088] In this invention, an alloy liquid containing Mg, Si, Fe, Mn, Cu, Ti, Zn, Cr, Zr, V, Be, RE, and Sr elements is refined, degassed, and formed to obtain an Al-Mg-Si aluminum alloy. The composite addition of Mg, Si, Fe, Mn, Cu, Ti, Zn, Cr, Zr, V, Be, RE, and Sr within the aforementioned content range interacts and influences each other, resulting in superior mechanical properties for the Al-Mg-Si aluminum alloy. The alloy liquid may further contain at least one source selected from In, Nb, Bi, Ge, Mo, Ni, Te, Co, Sn, Cd, Ag, and Ca.

[0089] During the forming process, the molten alloy is pushed into the mold by a punch for low-pressure filling casting. Once the molten alloy enters the semi-solid solidification zone, the semi-solid aluminum alloy part undergoes in-situ first-stage forging and second-stage forging deformation processes with large deformation amounts within the mold, resulting in the aluminum alloy part. The part is then heat-treated to obtain the final aluminum alloy product. This aluminum alloy product possesses not only the structural complexity of cast products but also the high strength and toughness of deformed products. By eliminating the need to remove the semi-solid aluminum alloy part from the low-pressure filling casting mold and place it into the subsequent multi-stage forging mold, the aluminum alloy preparation method of this invention offers advantages such as fewer process steps, shorter production cycle, higher production efficiency, and lower cost. During the low-pressure filling casting process, casting defects within the aluminum alloy part are minimal. During the in-situ primary forging process with large deformation, casting defects inside the semi-solid aluminum alloy parts are further eliminated, and the coarse grains and second-phase as-cast structure are significantly refined. A large number of nanoscale precipitates appear within the grains, their size is refined, and their volume fraction is increased, thus improving the mechanical properties of the alloy (including tensile strength and elongation). During the in-situ secondary forging pre-deformation process, the grain size can be further refined. Furthermore, the high dislocation density generated by pre-formed twins provides more diffusion pathways for the dissolution of Mg, Cu, Zn, Si, Fe, Ag, and Mn solute atoms in the aluminum matrix during subsequent heat treatment. This promotes the nucleation of precipitates, enhances the alloy's hardening response, accelerates precipitate formation, and further increases the volume fraction of precipitates, thereby improving the alloy's mechanical properties.

[0090] This invention also provides an aluminum alloy structural component, at least a portion of which is made of the aforementioned Al-Mg-Si aluminum alloy or an Al-Mg-Si aluminum alloy prepared by the same method. The aluminum alloy structural component possesses excellent mechanical properties and elongation, and can be applied in aerospace, automotive and transportation, military and weaponry, mold and machinery manufacturing, and special high-temperature structural components. Since this aluminum alloy structural component adopts all the technical solutions of all the embodiments of the aforementioned Al-Mg-Si aluminum alloy, it possesses at least all the beneficial effects brought about by the technical solutions of the aforementioned embodiments, which will not be elaborated further here.

[0091] For aluminum alloy structural components, the mechanical properties decrease sharply with increasing thickness. However, the aluminum alloy of this invention, when using an integrated casting and forging process, maintains good mechanical properties even when its thickness is greater than 3mm and further greater than 5mm. Furthermore, when using die casting and vacuum die casting processes, the aluminum alloy of this invention maintains good mechanical properties even when its thickness is greater than 2mm.

[0092] Example Please refer to Table 1 for the composition and content of the aluminum alloys in Examples 1 to 9, and Table 2 for the performance test results.

[0093] Table 1. Composition and content of aluminum alloys in Examples 1 to 9 For the sake of simplicity, the content of trace elements such as impurities in the examples is not shown.

[0094] When preparing the aluminum alloys of Examples 1 to 9, the preparation methods of these aluminum alloys differ in the types and contents of elements, as well as in the forming process. Other steps, such as Al source heating temperature, refining process, and degassing process, can be the same.

[0095] In preparing the Al-Mg-Si integrated cast-forged aluminum alloy of Example 1, the forming process included low-pressure filling casting, in-situ primary forging, in-situ secondary forging deformation, and direct aging. In the low-pressure filling casting, the filling speed was 0.1 m / s, the filling time was 20 s, the casting pressure was 0.2 MPa, the holding time was 2 s, the mold temperature was 200℃, the alloy casting temperature was 660℃, and the cooling rate was 5℃ / s. In the in-situ primary forging, the forging temperature was 600℃, the forging specific pressure was 60 MPa, the forging start time was 2 s, the holding time was 10 s, the cooling rate was 25℃ / s, and the deformation was 10%. In the in-situ secondary forging deformation, the forging temperature was 250℃, the forging specific pressure was 110 MPa, the holding time was 2 s, the cooling rate was 50℃ / s, and the deformation was 40%. In the direct aging process, the temperature is 200℃ and the time is 3 hours.

[0096] In preparing the Al-Mg-Si integrated cast-forged aluminum alloy of Example 2, the forming process included low-pressure filling casting, in-situ primary forging, in-situ secondary forging deformation, and offline solution treatment and aging. In the low-pressure filling casting, the filling speed was 0.2 m / s, the filling time was 15 s, the casting pressure was 0.5 MPa, the holding time was 2 s, the mold temperature was 200℃, the alloy casting temperature was 660℃, and the cooling rate was 5℃ / s. In the in-situ primary forging, the forging temperature was 610℃, the forging specific pressure was 300 MPa, the forging start time was 2 s, the holding time was 10 s, the cooling rate was 20℃ / s, and the deformation was 60%. In the in-situ secondary forging deformation, the forging temperature was 210℃, the forging specific pressure was 120 MPa, the holding time was 5 s, the cooling rate was 30℃ / s, and the deformation was 30%. In the solution treatment, the temperature was 500℃ and the time was 2 hours. In the aging treatment, the temperature was 160℃ and the time was 2 hours.

[0097] In preparing the Al-Mg-Si integrated cast-forged aluminum alloy of Example 3, the forming process included low-pressure filling casting, in-situ primary forging, in-situ secondary forging deformation, and direct aging. In the low-pressure filling casting, the filling speed was 0.6 m / s, the filling time was 10 s, the casting pressure was 40 MPa, the holding time was 2 s, the mold temperature was 250 °C, the alloy casting temperature was 720 °C, and the cooling rate was 10 °C / s. In the in-situ primary forging, the forging temperature was 600 °C, the forging specific pressure was 300 MPa, the forging start time was 2 s, the holding time was 4 s, the cooling rate was 50 °C / s, and the deformation was 40%. In the in-situ secondary forging deformation, the forging temperature was 200 °C, the forging specific pressure was 80 MPa, the holding time was 1 s, the cooling rate was 20 °C / s, and the deformation was 50%. During the aging process, the temperature was 200℃ and the time was 1 hour.

[0098] In preparing the Al-Mg-Si integrated cast-forged aluminum alloy of Example 4, the forming process included low-pressure filling casting, in-situ primary forging, in-situ secondary forging deformation, and offline solution treatment and aging. In the low-pressure filling casting, the filling speed was 0.5 m / s, the filling time was 12 s, the casting pressure was 35 MPa, the holding time was 3 s, the mold temperature was 210℃, the alloy casting temperature was 660℃, and the cooling rate was 10℃ / s. In the in-situ primary forging, the forging temperature was 590℃, the forging specific pressure was 280 MPa, the forging start time was 2 s, the holding time was 6 s, the cooling rate was 40℃ / s, and the deformation was 30%. In the in-situ secondary forging deformation, the forging temperature was 250℃, the forging specific pressure was 120 MPa, the holding time was 1 s, the cooling rate was 30℃ / s, and the deformation was 10%. In the solution treatment, the temperature was 500℃ and the time was 13 hours. In the aging treatment, the temperature was 160℃ and the time was 14 hours.

[0099] In preparing the Al-Mg-Si integrated cast-forged aluminum alloy of Example 5, the forming process included low-pressure filling casting, in-situ primary forging, in-situ secondary forging deformation, and offline solution aging. In the low-pressure filling casting, the filling speed was 1.1 m / s, the filling time was 3 s, the casting pressure was 3 MPa, the holding time was 2 s, the mold temperature was 250℃, the alloy casting temperature was 720℃, and the cooling rate was 40℃ / s. In the in-situ primary forging, the forging temperature was 580℃, the forging specific pressure was 120 MPa, the forging start time was 2 s, the holding time was 5 s, the cooling rate was 40℃ / s, and the deformation was 30%. In the in-situ secondary forging deformation, the forging temperature was 280℃, the forging specific pressure was 150 MPa, the holding time was 1 s, the cooling rate was 20℃ / s, and the deformation was 30%. In the solution treatment, the temperature was 550℃ and the time was 1 hour. In the aging treatment, the temperature was 160℃ and the time was 15 hours.

[0100] In preparing the Al-Mg-Si integrated cast-forged aluminum alloy of Example 6, the forming process included low-pressure filling casting, in-situ primary forging, in-situ secondary forging deformation, and offline solution treatment and aging. In the low-pressure filling casting, the filling speed was 1.1 m / s, the filling time was 3 s, the casting pressure was 5 MPa, the holding time was 2 s, the mold temperature was 180℃, the alloy casting temperature was 710℃, and the cooling rate was 30℃ / s. In the in-situ primary forging, the forging temperature was 610℃, the forging specific pressure was 140 MPa, the forging start time was 2 s, the holding time was 18 s, the cooling rate was 20℃ / s, and the deformation was 25%. In the in-situ secondary forging deformation, the forging temperature was 150℃, the forging specific pressure was 160 MPa, the holding time was 1 s, the cooling rate was 20℃ / s, and the deformation was 60%. In the solution treatment, the temperature was 530℃ and the time was 1 hour. In the aging treatment, the temperature was 160℃ and the time was 5 hours.

[0101] In preparing the Al-Mg-Si integrated cast-forged aluminum alloy of Example 7, the forming process included low-pressure filling casting, in-situ primary forging, in-situ secondary forging deformation, and offline solution treatment and aging. In the low-pressure filling casting, the filling speed was 1 m / s, the filling time was 5 s, the casting pressure was 15 MPa, the holding time was 2 s, the mold temperature was 200℃, the alloy casting temperature was 710℃, and the cooling rate was 5℃ / s. In the in-situ primary forging, the forging temperature was 600℃, the forging specific pressure was 80 MPa, the forging start time was 2 s, the holding time was 4 s, the cooling rate was 50℃ / s, and the deformation was 10%. In the in-situ secondary forging deformation, the forging temperature was 200℃, the forging specific pressure was 500 MPa, the holding time was 5 s, the cooling rate was 60℃ / s, and the deformation was 70%. In the solution treatment, the temperature was 560℃, and the time was 1 h. During the aging process, the temperature was 180℃ and the time was 2 hours.

[0102] In preparing the Al-Mg-Si integrated cast-forged aluminum alloy of Example 8, the forming process included low-pressure filling casting, in-situ primary forging, in-situ secondary forging pre-deformation, and offline solution treatment and aging. In the low-pressure filling casting, the filling speed was 0.8 m / s, the filling time was 10 s, the casting pressure was 20 MPa, the holding time was 5 s, the mold temperature was 200 °C, the alloy casting temperature was 700 °C, and the cooling rate was 10 °C / s. In the in-situ primary forging, the forging temperature was 650 °C, the forging specific pressure was 60 MPa, the forging start time was 2 s, the holding time was 9 s, the cooling rate was 50 °C / s, and the deformation was 10%. In the in-situ secondary forging pre-deformation, the forging temperature was 200 °C, the forging specific pressure was 120 MPa, the holding time was 10 s, the cooling rate was 30 °C / s, and the deformation was 20%. In the solution treatment, the temperature was 520℃ and the time was 2 hours. In the aging treatment, the temperature was 180℃ and the time was 1 hour.

[0103] In preparing the Al-Mg-Si integrated cast-forged aluminum alloy of Example 9, the forming process included low-pressure filling casting, in-situ primary forging, and offline solution treatment and aging. In the low-pressure filling casting, the filling speed was 1 m / s, the filling time was 5 s, the casting pressure was 10 MPa, the holding time was 2 s, the mold temperature was 210℃, the alloy casting temperature was 700℃, and the cooling rate was 10℃ / s. In the in-situ primary forging, the forging temperature was 600℃, the forging specific pressure was 60 MPa, the forging start time was 2 s, the holding time was 10 s, the cooling rate was 40℃ / s, and the deformation was 10%. In the solution treatment, the temperature was 520℃ and the time was 3 h. In the aging treatment, the temperature was 170℃ and the time was 1 h.

[0104] Table 2 Performance test results of aluminum alloys in Examples 1 to 9 Referring to Table 2, the Al-Mg-Si aluminum alloys of Examples 1 to 9 exhibit excellent tensile strength and elongation. Specifically, the Al-Mg-Si cast-forged aluminum alloys of Examples 1 to 9 possess a tensile strength of not less than 275 MPa and an elongation of not less than 7.2%. In summary, the Al-Mg-Si cast-forged aluminum alloys of the present invention possess a tensile strength of not less than 275 MPa and an elongation of not less than 7.2%.

[0105] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the content of the present invention under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. An Al-Mg-Si aluminum alloy, characterized in that, The Al-Mg-Si aluminum alloy contains 0.7-1.2% Mg, 0.7-1% Si, 0-0.4% Fe, 0-0.5% Mn, 0-0.8% Cu, 0-0.2% Ti, 0-0.3% Zn, 0-0.3% Cr, 0-0.6% Zr, 0-0.2% V, 0-0.1% Be, 0-0.6% RE, 0-0.1% Sr, and Al, as well as unavoidable impurities.

2. The Al-Mg-Si aluminum alloy according to claim 1, characterized in that, The Al-Mg-Si aluminum alloy contains 0.8-1.2% Mg, 0.7-1% Si, 0.001-0.4% Fe, 0.001-0.5% Mn, 0.001-0.8% Cu, 0.001-0.2% Ti, 0.001-0.2% Zn, 0.001-0.3% Cr, 0.001-0.6% Zr, 0.001-0.2% V, 0.001-0.1% Be, 0.001-0.6% RE, and 0.001-0.05% Sr by mass.

3. The Al-Mg-Si aluminum alloy according to claim 1, characterized in that, At least one of the following conditions must be met: The mass ratio of the sum of the mass percentages of Mn, Cr, and Be to the mass percentage of Fe is 0.1-3; The mass ratio of Mn to Fe is greater than 0.2; The mass ratio of Cu to Mg is less than or equal to 2.6; The sum of the mass percentages of Si and Fe is less than 1.1%; The sum of the mass percentages of V and Ti is less than 0.4%; The atomic percentages of Zr and RE are 1-1.2:

1.

4. The Al-Mg-Si aluminum alloy according to claim 1, characterized in that, The Al-Mg-Si aluminum alloy further contains at least one of In, Nb, Bi, Ge, Mo, Ni, Te, Co, Sn, Cd, Ag, and Ca, with In having a mass percentage content of 0-0.2%, Nb 0-0.5%, Bi 0-0.3%, Ge 0-0.3%, Mo 0-0.3%, Ni 0-0.5%, Te 0-0.3%, Co 0-0.5%, Sn 0-0.2%, Cd 0-0.3%, Ag 0-0.5%, and Ca 0-0.1%.

5. A method for preparing an Al-Mg-Si aluminum alloy, comprising the following steps: The Al source is subjected to a first heating treatment to obtain molten aluminum. Add Mg source, Si source, Fe source, Mn source, Cu source, Ti source, Zn source, Cr source, Zr source, V source, Be source, RE source and Sr source to the aluminum liquid, and perform a second heat treatment to obtain alloy liquid; The alloy liquid is refined, slag removed, and formed to obtain an Al-Mg-Si aluminum alloy. The Al-Mg-Si aluminum alloy contains 0.7-1.2% Mg, 0.7-1% Si, 0-0.4% Fe, 0-0.5% Mn, 0-0.8% Cu, 0-0.2% Ti, 0-0.3% Zn, 0-0.3% Cr, 0-0.6% Zr, 0-0.2% V, 0-0.1% Be, 0-0.6% RE, 0-0.1% Sr, and Al, as well as unavoidable impurities.

6. The method for preparing Al-Mg-Si aluminum alloy according to claim 5, characterized in that, The molding process includes the following steps: The molten alloy is pushed into a mold and subjected to low-pressure filling casting. Once the molten alloy enters the semi-solid solidification zone, it forms a semi-solid aluminum alloy part. The semi-solid aluminum alloy part is then subjected to in-situ first-stage forging in the mold. The deformation of the semi-solid aluminum alloy part during the in-situ first-stage forging process is 5-70%.

7. The method for preparing Al-Mg-Si aluminum alloy according to claim 6, characterized in that, The molding process also includes the following steps: After in-situ primary forging, in-situ secondary forging deformation is performed to obtain aluminum alloy parts.

8. The method for preparing Al-Mg-Si aluminum alloy according to claim 6 or 7, characterized in that, The molding process also includes the following steps: Aluminum alloy parts that have undergone in-situ primary forging or in-situ secondary forging deformation are heat-treated to obtain Al-Mg-Si aluminum alloys.

9. The method for preparing Al-Mg-Si aluminum alloy according to claim 8, characterized in that, The heat treatment includes direct aging or offline solution aging. In the direct aging, the temperature is 160-200°C and the time is 0.2-20h. Alternatively, the offline solution aging includes solution treatment and aging. In the solution treatment, the temperature is 500-560°C and the time is 0.1-20h. In the aging treatment, the temperature is 160-200°C and the time is 0.2-20h.

10. An aluminum alloy structural component, characterized in that, At least a portion of the aluminum alloy structural component is made of an Al-Mg-Si aluminum alloy as described in any one of claims 1 to 4 or an Al-Mg-Si aluminum alloy prepared by the preparation method as described in any one of claims 5 to 9.

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