LIGHTWEIGHT, HIGH-STRENGTH, CORROSION-RESISTANT ALUMINUM ALLOY MATERIAL AND PREPARATION METHOD THEREOF

Abstract

 Disclosed is a lightweight, high-strength, corrosion-resistant aluminum alloy material, comprising: Mg 6.0-10.0 wt%, Zn 1.0-3.5 wt%, Si 0.1-1.3 wt%, and at least one of Mn, Cu, Zr, Sc, and Ti elements with a total content not exceeding 0.8 wt%, and the rest being Al and unavoidable impurities. Further disclosed are a method of producing a deformed aluminum alloy material, a method of producing a casting aluminum alloy material, a product and a final construct. The aluminum alloy material exhibits excellent low density, high strength, corrosion resistance, and damage resistance.

Description

[0001] The present application claims priority of the Chinese Patent Application No. 202310201048.8 filed on March 6, 2023, the disclosure of which is hereby incorporated by reference in its entirety as part of the present application.

TECHNICAL FIELD

[0002] The present disclosure belongs to the technical field of aluminum alloys and the preparation and processing thereof, especially to Al-Mg-Zn-Si-based aluminum alloys. More specifically, the present disclosure relates to light-weight, high-strength, corrosion-resistant Al-Mg-Zn-Si-based aluminum alloy materials and methods for producing the same.

BACKGROUND

[0003] Aluminum alloys have characteristics of light specific weight, high specific strength, easy processing and low cost, etc., which are widely used in the fields of aerospace, transportation, and other fields. To better support the lightweighting design of aluminum alloy structural parts, there is a need of to further develop novel aluminum alloys with low density, high strength, corrosion resistance and damage resistance.

[0004] Existing commercial deformed aluminum alloys mainly include 2xxx series (Al-Cu-Mg), 3xxx series (Al-Mn), 4xxx series (Al-Si), 5xxx series (Al-Mg), 6xxx series (Al-Mg-Si), and 7xxx series (Al-Zn-Mg-Cu) aluminum alloys. Among them, 5xxx series aluminum alloys (Al-Mg-based aluminum alloys) taking Mg as the main alloying element have medium strength, excellent corrosion resistance, and welding performance, which are the second largest aluminum alloy variety after the 6xxx series in terms of usage. Commonly used Al-Mg-based aluminum alloys at home and abroad include mainly 5052, 5056, 5083, 5182, 5A02, and 5A06 in which the Mg content is generally between 2.5-5.5 wt.%. Those alloys have the highest Mg content and the lowest density among all the commercial deformed aluminum alloys, and the density decreases by nearly 0.4% with an increase of 1 wt% in the content of Mg.

[0005] The difference in atomic radius between Mg and Al is 13%. Within the normal Mg content range (2.5-5.5 wt.%), it is the main strengthening mechanisms of Al-Mg-based aluminum alloys to cause a lattice distortion by the solid solution of Mg atoms in the Al matrix to achieve a solid solution strengthening of alloys, and to achieve a work hardening of the alloys during deformation. When the Mg content further increases beyond the normal range, a large number of β-Al₃Mg₂ phase distributed in a network will be precipitated along the grain boundary in the alloy matrix, which is not coherent with the matrix and cannot produce a dispersion strengthening effect. Moreover, the β-phase has a more negative self-corrosion potential of -1.085V than the self-corrosion potential of the α-Al matrix of -0.812V, and may be corroded before the matrix, causing serious peeling corrosion and intergranular corrosion. Therefore, with regard to the Al-Mg-based aluminum alloys, simply increasing the Mg content to improve the alloy strength will generally lead to serious deterioration in the overall performance of the alloy. If the Mg content in the Al-Mg-based aluminum alloys increases and appropriate alloying element(s) are simultaneously added to form a precipitation strengthening phase together with excess of Mg element which effectively inhibits the formation of network-distributed β phase along the grain boundaries, it is likely to significantly improve the strength of the Al-Mg-based aluminum alloys and avoid serious deterioration in corrosion resistance while maintaining their low-density characteristic.

[0006] In order to enable the Al-Mg aluminum alloys to achieve an aging precipitation strengthening, current researches show that adding two alloying elements, Ag and Zn, can lead to the formation of T-Mg₃₂(Al,Ag)₄₉ and T-Mg₃₂(Al,Zn)₄₉ precipitation strengthening phase, respectively. Since the 1960s, it has been discovered and confirmed that adding trace amount of Ag element to the Al-Mg alloys will result in the precipitation of T-Mg₃₂(Al,Ag)₄₉ precipitation strengthening phase, wherein the T phase and the α-Al matrix are in an orientation relationship of (010)_T//(112)_α and (001)_T//(11 0)_α, and the lattice parameter a=1.41 nm. Although adding Ag can effectively improve the precipitation strengthening reaction of the Al-Mg alloys, and a reasonable combination of pretreatment and aging treatment enables the Al-Mg-Ag alloys to obtain good strength and plasticity matching, Ag elements cannot be used in industrial production on large scale due to their expensiveness. Since the beginning of this century, it has been found that if Zn elements are added into conventional Al-Mg-based aluminum alloys, a T-Mg₃₂(Al,Zn)₄₉ precipitation phase can be formed in the grains and at the grain boundaries by toughening heat treatment to inhibit the formation of β phase so as to effectively improve the strength of Al-Mg-based aluminum alloys and avoid serious deterioration of its corrosion resistance performance, showing an important application value. For example, Patent document CN104694800A discloses a high-strength, light-weight Al-Mg-Zn alloy with a basic composition of Mg: 6.0-10.0 wt%, Zn: 3.0-5.0 wt%, Cu < 2.0 wt%, Mn < 1.2 wt%, Fe < 0.3 wt%, Si < 0.3 wt%, and at least one element selected from Cr, Ti, Zr, Sc, Hf, La, Ce, Pr and Nd in an amount of less than 0.5 wt% of each element, wherein the alloy has a tensile strength of more than 530 MPa in the T6 state. Patent document CN104862551A discloses Al-Mg-Cu-Zn-based aluminum alloys and methods for preparing aluminum alloy sheets, wherein the alloy has a basic composition of: Mg: 4.0-6.0 wt%, Cu: 0.30-1.0 wt%, Zn: 1.0-3.5 wt%, Mn ≤ 0.4 wt%, Fe ≤ 0.4 wt%, Si ≤ 0.4 wt%, Cr ≤ 0.2 wt%, Ti ≤ 0.1 wt%, and the balance of Al and inevitable impurities. This alloy has increased Cu content on the basis of AA5182 and AA5023 alloys, and further has Zn added. It fully utilizes the precipitation strengthening of the transition phase of the S phase in the Al-Mg-Cu-based alloys and the transition phase of the T phase in the Al-Mg-Zn-based alloy, and can be used to achieve significant improvement of the strength of automobile inner panels during at 180°C for30 min baking process. Patent document CN110541096A discloses an easily weldable Al-Mg-Zn-Cu alloy with high strength and a method for preparing the same, wherein the alloy has a basic composition of Mg: 4.3-7.0 wt%, Zn: 2.5-5.0 wt%, Cu: 0.4-1.2 wt%, Mn ≤ 0.3 wt%, Cr ≤ 0.1 wt%, Ti ≤ 0.2 wt%, Zr ≤ 0.3 wt%, and the balance of Al and inevitable impurities, wherein a mass ratio of Zn/Mg is ≤ 1.0, and the strength of the alloy is substantially comparable to that of conventional 7xxx series aluminum alloys. Patent document CN103866167A discloses an aluminum alloy and alloy sheets thereof, and a method for preparing the alloy sheets, wherein the alloy has a basic composition of Mg: 5.5-6.0 wt%, Zn: 0.6-1.2 wt%, Cu: 0.1-0.2 wt%, Mn: 0.6-1.0 wt%, Zr: 0.05-0.25 wt%, Cr ≤ 0.1 wt%, Ti ≤ 0.15 wt%, Fe ≤ 0.25 wt%, Si ≤ 0.2 wt%, and the balance of Al. By adding Zn, the ability of Al₃Mg₂ to continuously precipitate at grain boundaries is greatly reduced, and the alloy exhibits relatively high strength and corrosion resistance performance compared with conventional AA5059-H321 and AA5059-H131 sheets. Patent document CN104152759A discloses a high-strength, corrosion-resistant Al-Mg alloy and its preparation process, wherein the alloy has a basic composition of Mg: 5.0-6.5 wt%, Zn: 1.2-2.5 wt%, Mn: 0.4-1.2 wt%, Zr: 0.05-0.25 wt%, Cu ≤ 0.4 wt%, Cr ≤ 0.1 wt%, Ti ≤ 0.15 wt%, Fe ≤ 0.4 wt%, Si ≤ 0.4 wt%, and the balance of Al and inevitable impurities. This alloy has a significantly improved intergranular corrosion resistance on the premise of maintaining certain mechanical properties and spalling corrosion properties unchanged, as compared with conventional AA5083, AA5059 alloys for marine, etc. Patent document CN114438356A discloses a high-strength, corrosion-resistant, high-toughness Al-Mg-Zn-Ag(-Cu) aluminum alloy with a basic composition of Mg: 4.0-6.5 wt%, Zn: 3.0-5.5 wt%, Ag: 0.05-0.8 wt%, Cu ≤ 1.0 wt%, Mn ≤ 0.15 wt%, Ti ≤ 0.15 wt%, Zr ≤ 0.20 wt%, and the balance of Al and inevitable impurities. This alloy has an improved strength and an intergranular corrosion level of 3.

[0007] Although the research and development of Al-Mg-Zn-based alloys has achieved some achievements in recent years, there is still a large improvement space in the excellent match of the key alloy properties such as low density, high strength, corrosion resistance, and damage resistance. For example, most of the research work is still focused on adding Zn elements to the Al-Mg-based aluminum alloys with normal (or slightly higher) Mg content range, resulting in that while the Al-Mg-based aluminum alloys have an improved (strength) performance, the alloys loss their inherent low-density advantage due to the addition of high-density Zn elements and other elements, and the specific strength performances of such alloys is not as competitive as that of conventional 2xxx and 7xxx-based aluminum alloys. In some research work on high-Mg content Al-Mg-based aluminum alloys, due to unreasonable types and amounts of added alloying elements, a relatively high amount of β-Al₃Mg₂ phase is still precipitated in the alloy, which is distributed in a network along the grain boundaries, thus deteriorating the corrosion resistance properties of the alloy.

[0008] Therefore, there is a need to further research and develop novel Al-Mg-based aluminum alloy materials with excellent match of key properties such as low density, high strength, corrosion resistance, and damage resistance.

SUMMARY OF THE INVENTION

[0009] The present inventor conducted a lot of research and industrial practice, and found that existing Al-Mg-Zn-based aluminum alloys mainly take Mg and Zn as the main strengthening components and Mg₃₂(Al,Zn)₄₉ as the main strengthening phase; the precipitation sequence and main strengthening phases thereof are relatively single in type, and difficult to give a desirable comprehensive property match of light weight, high strength, corrosion resistance, and damage resistance. If the Mg content is significantly increased and appropriate amount of Si is added as main alloying element based on the existing Al-Mg-Zn-based aluminum alloys, then a new aging precipitation sequence is added while the alloys can be further lightweight, which can remarkably enhance the aging strengthening response ability of the alloys, and at the same time further inhibit the generation of β-Al₃Mg₂ upon when the Mg content is greatly increased, thereby effectively avoiding the deterioration of the corrosion resistance of alloys; further auxiliarily utilizing Zr, Mn, Sc, Cu, and other elements for microalloying is beneficial to the refinement of the material tissues, strengthening of precipitated phase, and improvement of material properties. The premise optimization and design of the component ranges and ratios of various elements of the alloys is an important safeguard to ensure the superior property matching of the alloys. By reasonable designs, the alloys can maintain the light weight, while synergistically precipitating strengthening phase with Mg₃₂(Al,Zn)₄₉ and Mg₂Si during the aging process, and reducing the precipitation of β-Al₃Mg₂ phase in the case of high Mg content, so that the Al-Mg-Zn-Si-based alloys of the present invention can maintaining good corrosion property while obtaining a high strength and toughness.

[0010] The present invention overcomes the shortcomings of the comprehensive property matching of existing Al-Mg-Zn-based aluminum alloy materials, and further improve the comprehensive performance matching by optimizing the design of composition and preparation and processing technology on the basis of existing alloys, so that a desirable light-weight Al-Mg-Zn-Si-based aluminum alloy materials with strength and toughness and corrosion resistance can be provided for the advanced manufacturing industry.

[0011] A first technical problem to be solved by the present invention is to provide a light-weight, high-strength, corrosion-resistant, and damage-resistant aluminum alloy material; a second technical problem to be solved by the present invention is to provide a method for preparing the aluminum alloy materials; a third technical problem to be solved by the present invention is to provide a new product formed by welding the aluminum alloy material with the same alloy or another alloy; a fourth technical problem to be solved by the present invention is to provide a final component produced by processing the aluminum alloy material via various surface treatments, stamping and forming, and machining methods; and a fifth technical problem to be solved by the present invention is to provide use of the final components.

[0012] The present invention relates to a light-weight, high-strength, corrosion-resistant aluminum alloy material including: Mg 6.0-10.0 wt%, Zn 1.0-3.5 wt%, Si 0.1-1.3 wt%, at least one of Mn, Cu, Zr, Sc and Ti elements with a total content of less than 0.8 wt%, and the balance of Al and inevitable impurities.

[0013] In a first preferred embodiment of the present invention, the aluminum alloy includes: Mg 6.3-9.9 wt%, Zn 1.1-2.9 wt%, Si 0.15-1.0 wt%, at least one of Mn, Cu, Zr, Sc, and Ti elements with a total content of less than 0.6 wt%, and the balance of Al and inevitable impurities.

[0014] In a second preferred embodiment of the present invention, the aluminum alloy includes: Mg 6.6-9.0 wt%, Zn 1.3-2.9 wt%, and Si 0.15-0.8 wt%.

[0015] In a third preferred embodiment of the present invention, the aluminum alloy includes: Mg 7.1-8.8 wt%, Zn 1.5-2.8 wt%, and Si 0.25-0.7 wt%.

[0016] In a fourth preferred embodiment of the present invention, the aluminum alloy includes: Mg 7.3-8.5 wt%, Zn 1.5-2.7 wt%, and Si 0.4-0.6 wt%.

[0017] In a fifth preferred embodiment of the present invention, the contents of Mg, Zn and Si in the aluminum alloy satisfy a relationship of: 2.5 ≤ (9 × Mg) / [(1 × Si) + (8 × Zn)] ≤ 6.

[0018] In a sixth preferred embodiment of the present invention, the aluminum alloy comprises: Mn 0.10 ~ 0.50 wt%.

[0019] In a seventh preferred embodiment of the present invention, the aluminum alloy includes: Cu 0.10-0.50 wt%.

[0020] In an eighth preferred embodiment of the present invention, the aluminum alloy includes: Ti 0.01-0.15 wt%.

[0021] In a ninth preferred embodiment of the present invention, the aluminum alloy includes: Zr 0.05-0.25 wt%.

[0022] In a tenth preferred embodiment of the present invention, the aluminum alloy includes: Sc 0.05-0.30 wt%; preferably, it further includes Zr 0.05-0.20 wt%; and further preferably, the contents of Sc and Zr satisfy: 0.15 wt% ≤ (Sc + Zr) wt% ≤ 0.35 wt%.

[0023] In an eleventh preferred embodiment of the present invention, the inevitable impurities contained in the aluminum alloy include elements unintentionally introduced as impurities during the process of manufacturing the alloy ingots. The impurities meet: Fe ≤ 0.40 wt%, each of other impurity elements ≤ 0.20 wt%, and the total ≤ 0.50 wt%; preferably, Fe ≤ 0.20 wt%, each of other impurity elements ≤ 0.10 wt%, and the total ≤ 0.25 wt%; and further preferably, Fe ≤ 0.10 wt%.

[0024] The present invention also relates to a process for producing the aluminum alloy material. The process of producing the aluminum alloy deformed material can be described as "alloy formulation and melting - semi-continuous casting for preparing ingots - homogenizing heat treatment of ingots - hot deformation - (intermediate annealing) - (cold deformation) - solid solution treatment - (pre-deforming or straightening) - aging treatment - product supply"; and the basic manufacturing process of the aluminum alloy casting can be described as "alloy formulation and melting - casting molding of castings - solid solution treatment - aging treatment - product supply".

[0025] Among them, the method for producing the aluminum alloy deformed material includes the steps of:

(1) producing the semi-continuous casting ingot according to the present disclosure;

(2) homogenizing and/or pre-heating the produced ingot;

(3) thermally deforming the ingot to a desired processed material or a pre-processed material by one or more thermal deformation process selected from the group consisting of extrusion, rolling and forging;

(4) optionally processing the pre-processed material to the desired processed material by reheating and cold deformation;

(5) solution heat treating the processed material;

(6) rapidly cooling the treated processed material to room temperature; and

(7) naturally or artificially aging the cooled processed materials to give an aged processed alloy material.

[0026] Among them, in step (1), the ingots are produced by the steps of smelting, degasification, removal of inclusion, and semi-continuous casting; during the smelting process, the concentrations of elements are accurately controlled by taking Mg and Cu as core elements; and the ratios among alloying elements are rapidly supplemented and adjusted by on-line detection and analysis of components so as to complete the production of casting ingots. In a preferred aspect, 0.0002-0.005 wt% of Be is added in the form of Al-Be intermediate during the smelting process to change the properties of the oxide film and reduce oxidation burning loss and inclusions. In another preferred aspect, step (1) further includes applying electromagnetic field, ultrasonic field or mechanical stirring at or near the crystallizer site.

[0027] In step (2), the homogenization treatment is carried out by means selected from the group consisting of: (i)a single-stage homogenization treatment in a temperature range of from 360-490°C for 12 to 60 h; and (ii) a two- or multi-stage homogenization treatment in a temperature range of from 360-500°C for total 12 to 60 h.

[0028] In steps (3) and (4), the pre-heating temperature and reheating temperature before each thermal deformation process are 370-460°C, and the processing time is 1-8 h. In a preferred aspect, an intermediate annealing treatment at 350-450°C/0.5-6 h is further comprised between the cold deformation passes.

[0029] In step (5), the solid solution treatment requires to further adjust the sub-grain size and the recrystallized structure ratio in the material according to the performance requirements, and is carried out by means selecting from the group consisting of: (i) a single-, two-, or multi-stage solid solution treatment in a range of 440-500°C for total 0.5-8 h; and (ii) a progressive heating solid solution treatment in a range of 440-500°C for total 0.5-5 h. In a preferred aspect, a progressive heating solid solution treatment is used with a heating rate of ≤ 60°C/min.

[0030] In step (6), the processed material is rapidly cooled to room temperature using a method selected from the group consisting of cooling medium spray quenching, immersion quenching, strong air cooling and combinations thereof.

[0031] In step (7), the artificially aging treatment is carried out by means selected from the group consisting of: (i) after completion of quenching and cooling, natural aging treatment at room temperature for ≥ 48 h; (ii) within 2 h after completion of quenching and cooling, artificial aging treatment in a range of 70-240°C for total 6-60 h; and ) (iii) after completing of quenching and cooling, a combination of natural aging treatment and artificial aging treatment, wherein the artificial aging temperature is carried out at 70-240°C for 6-60 h.

[0032] Between steps (6) and (7), the method can further include a step of straightening and/or pre-deforming the cooled processed material, wherein the straightening can be carried out by means of roller straightening, stretch straightening, stretch bending straightening and any combination thereof to improve the straightness of the processed materials, and the pre-deformation can be carried out by means of stretching, compression and any combination thereof to reduce the residual stress formed by quenching and cooling, so as to facilitate subsequent processing and application.

[0033] According to the method of the present disclosure, the processed material may be wires, rods, pipes, sheets, plates, or forging products.

[0034] Among them, the lightweight, high-strength, corrosion-resistant aluminum alloy material of the present disclosure may have a density of ≤ 2.68 g/cm³, a tensile strength of ≥ 400MPa, and an exfoliation corrosion performance of not lower than EA level. Preferably, the aluminum alloy material may have a density of ≤ 2.66g/cm³, a tensile strength of ≥ 410MPa, and the exfoliation corrosion performance of not lower than EA level. Further preferably, the aluminum alloy material may have a density of ≤ 2.64g/cm³, a tensile strength of ≥ 420MPa, and the exfoliation corrosion performance of not lower than PC level.

[0035] The invention further relates to a method for producing the aluminum alloy casting including the steps of:

(1) preparing an aluminum alloy ingot using smelting, degasification, removal of inclusion, sand- or metal-mold casting, or die casting, wherein during the smelting process, the concentrations of elements are accurately controlled by taking Mg and Cu as core elements; and the ratios among alloying elements are rapidly supplemented and adjusted by on-line detection and analysis of components so as to complete the casting production;

(2) solid solution heat treating the produced aluminum casting, comprising: allowing the aluminum alloy casting to undergo a single-, two-, or multi-stage solid solution treatment in a range of 440-500°C for total 0.5-8h, or a progressive heating solid solution treatment in a range of 440-500°C for total 0.5-5 h.

(3) naturally or artificially aging the aluminum alloy casting; wherein the natural aging treatment is carried out at room temperature for ≥ 48 h; the artificial aging treatment is carried out in a range of 70-240°C for total 6-60 h; and a combination of natural aging treatment and artificial aging treatment is carried out with the artificial aging temperature of 70-240°C and the artificial aging time of 6-60 h.

[0036] The aluminum alloy material of the present disclosure may be welded with the same alloy or another alloy to form a new product with welding methods of friction stir welding, fusion welding, brazing, electron beam welding, or laser welding. It can also be processed into a final component through various surface treatments, stamping forming, or machining; and the final component may be load-bearing structural components.

[0037] The beneficial effects of the present disclosure comprise:

(1) By optimizing the composition of the Al-Mg-Zn-Si aluminum alloy together, and provide a matching preparation method as supplement, the present disclosure achieves a high Mg content, and the synergistic strengthening of dual-aging precipitation sequences of Mg₃₂(Al,Zn)₄₉ and Mg₂Si, which greatly improves the strengthening response ability of the alloy, so that the material obtains high strength and toughness while ensuring the lightweight property, and has good corrosion resistance. The material shows excellent comprehensive properties, which is an ideal material for various load-bearing structural parts, and can meet the stringent requirements of various advanced manufacturing for lightweight and high-performance aluminum alloy materials.

(2) By adding the alloying element Si, the present disclosure not only introduces a new aging sequence of Mg₂Si precipitate, but also provides a basis for further increasing the Mg content in the Al-Mg-based aluminum alloy so that the aging strengthening potential of the alloy is further explored, which is conducive to promoting the development of lightweighting in aerospace, transportation, automobiles and ships, and has important social and economic benefits.

(3) The material of the present disclosure has superior performance, moderate cost, simple and practical preparation method, strong operability, easy industrial promotion, and promising market prospects.

BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to clearly illustrate the technical solution of the embodiments of the invention, the drawings of the embodiments will be briefly described in the following; it is obvious that the described drawings are only related to some embodiments of the invention and thus are not limitative of the invention.

FIG. 1 shows a TEM morphology image of the intra-granular precipitates in the aged state of Alloy 22# in Example 2 of the present disclosure.

FIG. 2 shows a TEM morphology image of the grain boundary precipitates in the aged state of Alloy 22# in Example 2 of the present disclosure.

FIG. 3 shows a comparison of the specific strength and fracture toughness of the alloy of the present disclosure and existing typical alloys.

FIG. 4 is a comparison of the specific strength and corrosion resistance of the alloy of the present disclosure and existing typical alloys.

DETAILED DISCRIPTION

[0039] Hereinafter the present embodiments of the disclosure will be further illustrated by reference to the examples.

EXAMPLE 1

[0040] Alloy extruded strips were prepared at laboratory scale to demonstrate the principles of the disclosure. The compositions of the experimental alloys are shown in Table 1.

[0041] Round ingots with Φ210 mm were prepared by alloy smelting, degassing, removal of inclusion, and simulated the semi-continuous casting conditions well known in the art, and the conditions for the homogenization treatment of the ingots were selected as:(400±5°C/12h) + (475±5°C/24h) and air cooling. After peeling, milling and sawing, an extrusion billet with size of Φ180 mm was obtained. The billet was pre-heated at 440±10°C for 4h, and extruded for deformation to give a 25 x 100 mm strip with the extrusion temperature controlled at approximately 400°C. The extruded strip was placed into an air furnace at 450°C to undergo a progressive heating solid solution treatment at a temperature of 450-480°C for total 90 min, quenched in water immediately before a 1.5-2% tensile straightening treatment, followed by a two-stage aging treatment at 90±5°C/24h + 140±5°C/22-26h according to the characteristics of the alloy.

[0042] The samples were cut according to the relevant methods, and tested in accordance with the relevant test standards for density (GB/T 1423), tensile properties (GB/T 16865), fracture toughness (GB/T 4161), fatigue properties (GB/T 3075), exfoliation corrosion (GB/T 22639) and intergranular corrosion of the alloy in accordance with the relevant testing standards, which were taken as common performance indicators of alloys for evaluation. The results are shown in Table 2.

Table 1. Compositions of Experimental Alloys

Alloy No.	Alloy of the present disclosure	Mg (wt%)	Zn (wt%)	Si (wt%)	Cu (wt%)	Mn (wt%)	Zr (wt%)	Sc (wt%)	Content of main impurities (wt%)
	(Y/N)
1#	Y	8.53	3.01	0.49	/	/	0.11	/	Fe=0.14, Ti=0.02
2#	Y	8.62	2.61	0.47	/	/	0.13	/	Fe=0.12, Ti=0.02
3#	Y	8.82	2.27	0.51	/	/	0.11	/	Fe=0.13, Ti=0.02
4#	Y	8.59	2.02	0.41	/	/	0.12	/	Fe=0.09, Ti=0.02
5#	Y	8.63	1.61	0.54	/	/	0.13	/	Fe=0.11, Ti=0.02
6#	Y	8.04	2.94	0.50	/	/	0.12	/	Fe=0.13, Ti=0.02
7#	Y	7.95	2.14	0.44	/	/	0.13	/	Fe=0.12, Ti=0.02
8#	Y	8.12	1.63	0.49	/	/	0.11	/	Fe=0.09, Ti=0.02
9#	Y	7.22	2.97	0.47	/	/	0.11	/	Fe=0.13, Ti=0.02
10#	Y	7.15	2.29	0.19	/	/	0.11	0.17	Fe=0.12, Ti=0.02
11#	Y	7.03	1.53	0.25	/	/	0.10	/	Fe=0.09, Ti=0.02
12#	Y	8.21	2.86	0.48	/	0.45	/	/	Fe=0.12, Ti=0.02
13#	Y	7.87	2.72	0.33	0.3	/	0.12	/	Fe=0.13, Ti=0.02
14#	Y	9.18	2.97	0.61	/	/	0.15	/	Fe=0.09, Ti=0.02
15#	N	5.81	3.52	0.5	/	/	0.11	/	Fe=0.10, Ti=0.02
16#	N	5.79	1.05	0.5	/	/	0.11	/	Fe=0.14, Ti=0.02
17#	N	8.63	0.92	0.47	/	/	0.12	/	Fe=0.11, Ti=0.02
18#	N	5.77	7.51	0.50	/	/	0.11	/	Fe=0.09, Ti=0.02
19#	N	8.47	7.36	0.50	/	/	0.13	/	Fe=0.12, Ti=0.02
20#	N	8.73	3.05	1.49	/	/	0.13	/	Fe=0.09, Ti=0.02

Table 2. Performance Test Results of Experimental Alloys

Experimental Alloy		Tensile Property			Fracture Toughness	Fatigue Properties	Corrosion Property		Density
Alloy No.	State	Rm (MPa)	Rp0.2 (MPa)	A (%)	KIC (MPa·m1/2)	Under conditions of 241 MPa, R=0.1, 120,000 cycles	Exfoliation Corrosion	Intergranular Corrosion	g/cm3
1#	TX	602	507	11.8	32.9	Pass	N	Level 2	2.64
2#	TX	579	467	11.7	33.1	Pass	N	Level 2	2.63
3#	TX	561	458	12.5	34.4	Pass	N	Level 3	2.62
4#	TX	535	439	13.9	36.3	Pass	N	Level 3	2.62
5#	TX	512	417	14.2	36.4	Pass	N	Level 3	2.61
6#	TX	584	489	13.7	34.7	Pass	N	Level 2	2.64
7#	TX	554	437	12.9	35.8	Pass	N	Level 2	2.63
8#	TX	521	433	12.5	34.3	Pass	N	Level 3	2.62
9#	TX	549	437	11.5	36.2	Pass	N	Level 2	2.66
10#	TX	492	357	19.0	37.5	Pass	N	Pitting corrosion	2.65
11#	TX	436	301	25.8	40.7	Pass	N	Pitting corrosion	2.64
12#	TX	582	490	11.9	32.6	Pass	N	Level 2	2.64
13#	TX	578	491	12.7	35.4	Pass	N	Level 2	2.65
14#	TX	617	528	11.0	31.2	Pass	N	Level 3	2.63
15#	TX	428	353	14.8	33.4	Pass	EB	Level 4	2.68
16#	TX	394	276	21.4	36.2	Pass	N	Level 2	2.64
17#	TX	411	286	19.8	38.6	Pass	EB	Level 4	2.60
18#	TX	599	526	7.2	27.1	Pass	EB	Level 3	2.75
19#	TX	612	531	6.3	22.5	Pass	EC	Level 4	2.71
20#	TX	594	489	8.8	34.3	Failed	PB	Level 3	2.64

[0043] As seen from the tables, Alloys 1#, 2#, 3#, 4#, 5#, 6#, 7#, 8#, 9#, 10#, 11#, 12#, 13# and 14# have good match of density-strength-plasticity-fracture toughness-fatigue performance-corrosion resistance: density does not exceed 2.66 g/cm³, the tensile strength remains above 430MPa, the percentage elongation after fracture is higher than 11.0%, the fracture toughness is higher than 31.0MPa·m^1/2level, and the fatigue test of 120,000 cycles passes under the conditions of a constant stress of 241MPa and a strain ratio of 0.1, the exfoliation corrosion level of the alloy is N, and the intergranular corrosion level is no less than 3. However, Alloys 15#, 16#, 17#, 18#, 19#, and 20# do not have good match of density-strength-plasticity-fracture toughness-fatigue performance-corrosion resistance, wherein, Alloy 15# has low Mg content, relatively low strength, and deteriorated corrosion resistance; Alloy 16# has low Mg and Zn contents, and relatively lowest strength; Alloy 17# has high Mg content and low Zn content, and seriously deteriorated corrosion resistance; in contrast, Alloy 18# has low Mg content and high Zn content, relatively low percentage elongation after fracture, decreased plasticity, and deteriorated corrosion resistance and increased density; while Alloy 19# has high Mg and high Zn contents, relatively high strength, but has seriously deteriorated plasticity and corrosion resistance; and Alloy 20# has high Si content, decreased plasticity and fatigue property, and slightly decreased corrosion resistance.

EXAMPLE 2

[0044] Aluminum alloy rolled plates were prepared in the laboratory, and the experimental alloy compositions are shown in Table 3.

[0045] Slab ingots with 100-mm thickness were prepared by alloy smelting, degassing, removal of inclusion, and simulated semi-continuous casting conditions well known in the industry, wherein the ingots underwent a three-stage homogenization treatment of (400±5°C/12h) + (475±5°C/24h) + (500±5°C/12h) homogenization heat treatment, followed by air cooling. After peeling, milling and sawing, a rolled billet with thickness of 80 mm was obtained. The billet was pre-heated at 450±10°C for 2h, first rolled for 3-4 passes along the width direction of the slab ingot at a blooming temperature of 440°C, inter-annealed at 400±5°C for 2h, and then rolled by reverse rolling along the length direction of the flat ingot to a 20-mm thickness. The plate was placed into an air furnace at 450°C to undergo a solid solution treatment of 450°C/30min + 480°C/60min, quenched in water immediately before a 2% tensile straightening treatment, followed by a two-stage aging treatment at 90±5°C/24h + 140±5°C/24h according to the characteristics of the alloy.

[0046] The samples were cut according to the relevant methods, and tested in accordance with the relevant test standards for density (GB/T 1423), tensile properties (GB/T 16865), fracture toughness (GB/T 4161), fatigue properties (GB/T 3075), exfoliation corrosion (GB/T 22639) and intergranular corrosion of the alloy in accordance with the relevant testing standards, which were taken as common performance indexes of alloys for evaluation. The results are shown in Table 4.

Table 3. Compositions of Experimental Alloys

Alloy No.	Alloy of the present disclosure (Y/N)	Mg (wt%)	Zn (wt%)	Si (wt%)	Cu (wt%)	Mn (wt%)	Zr (wt%)	Sc (wt%)	Content of main impurities (wt%)
21#	Y	7.19	2.26	0.28	0.13	/	0.12	/	Fe=0.11, Ti=0.02
22#	Y	8.02	2.71	0.43	/	/	0.12	/	Fe=0.10, Ti=0.02
23#	N	7.97	2.74	0.05*	/	/	0.12	/	Fe=0.10, Ti=0.02

*Note: Indicates that the element is an impurity element and is not added as an alloying element.

Table 4. Performance Test Results of Experimental Alloys

Experiment al alloy		Tensile property			Fracture toughne ss	Fatigue performan ce	Corrosion properties		Densit y
Alloy No.	State	Rm(MP a)	Rp0.2(MP a)	A (%)	KIC (MPa·m1/ 2)	Under 241MPa, R = 0.1, 120,000 cycles	Exfoliatio n Corrosion	Intergranul ar	g/cm3
21#	TX	491	353	17. 4	37.5	Pass	N	Pitting corrosion	2.64
22#	TX	566	468	12. 9	35.6	Pass	N	Level 2	2.64
23#	TX	484	387	12. 3	32.0	Pass	PC	Level 3	2.64

[0047] As seen from Table 4, both Alloys 21# and 22# of the present disclosure show good match of strength, toughness and corrosion resistance, and are significantly better than Alloy 23# without added Si. FIGs. 1 and 2 show the TEM morphology images of the intragranular and grain boundary precipitates of Alloy 22# respectively. It can be clearly seen that T-Mg₃₂(Al, Zn)₄₉ and β'-Mg₂Si phase precipitated in the alloy at the same time, the grain boundary precipitates distribute discontinuously , which is conducive to the alloy obtaining high strength, toughness and good corrosion resistance.

EXAMPLE 3

[0048] Small-size aluminum alloy forgings were prepared on a pilot platform, and the alloy composition is shown in Table 5.

[0049] Round ingots with Φ530mm were prepared by alloy smelting, degassing, removal of inclusion, and semi-continuous casting conditions well known in the industry, wherein the conditions for the homogenization treatment of the ingots were selected as: (400±5°C/12h) + (475±5°C/30h) and air cooling. After peeling, milling and sawing, an extrusion billet with size of Φ490 mm was obtained. The billet was pre-heated at 440±10°C for 6 h to give a Φ240-mm extruded bar, and then subject to a multi-direction forging to give a 60 x 500 x 900mm small-sized forging, wherein the extrusion and forging deformation temperatures were controlled at 400-420°C. The forging was placed into an air furnace at 450°C to undergo a solid solution treatment of 450°C/30min + 480°C/90min, quenched in water immediately before a 1.5-2.5% pre-compression deformation treatment, followed by a two-stage aging treatment at 90±5°C/24h + 140±5°C/28h according to the characteristics of the alloy.

[0050] The samples were cut according to the relevant methods, and tested in accordance with the relevant test standards for density (GB/T 1423), tensile properties (GB/T 16865), fracture toughness (GB/T 4161), fatigue properties (GB/T 3075), exfoliation corrosion (GB/T 22639) and intergranular corrosion of the alloy in accordance with the relevant testing standards, which were taken as common performance indicators of alloys for evaluation. The results are shown in Table 6.

Table 5. Compositions of Experimental Alloys

Alloy No.	Alloy of the present disclosure	Mg (wt%)	Zn (wt%)	Si (wt%)	Cu (wt%)	Mn (wt%)	Zr (wt%)	Sc (wt%)	Content of main impurities (wt%)
	(Y/N)
24#	Y	8.72	2.56	0.75	/	/	0.11	/	Fe=0.09, Ti=0.02

Table 6. Performance Test Results of Experimental Alloys

Experiment al alloy		Tensile property			Fracture toughnes s	Fatigue performan ce	Corrosion properties		Densit y
No.	State	Rm(MP a)	Rp0.2(MP a)	A (%)	KIC (MPa·m1/ 2)	Under 241MPa, R = 0.1, 120,000 cycles	Exfoliatio n Corrosion	Intergranul ar	g/cm3
24#	TX	574	453	11. 2	33.4	Pass	N	Level 2	2.62

[0051] As seen from Table 6, Alloy 24# of the present disclosure show good match of strength, toughness and corrosion resistance.

EXAMPLE 4

[0052] Aluminum alloy castings were prepared in the laboratory, and the compositions of alloys were shown in Table 7.

[0053] Raw materials (high-purity aluminum, pure magnesium, pure zinc, Al-Si intermediate alloy, Al-Zr intermediate alloy, Al-Ti-B intermediate alloy refiner were prepared, and tools and molds were baked. High-purity aluminum was melted at 730°C, and pure zinc, Al-Si master alloy and Al-Zr master alloy were added in conventional order. The material was stirred to fully melt, and cooled to 720°C. Al-Ti-B intermediate alloy was added, stirred and left to stand for 4-6 minutes. The material continued to cool to 710°C, and aluminum foiled-coated pure magnesium was pressed into the aluminum alloy liquor, and stirred to fully melt. The material was heated to 720°C, and subject to degassing and slagging refining and pre-furnace inspection. After standing at a casting temperature of 690°C for 30 minutes, the aluminum alloy melt was poured into the baked metal mold at a temperature of about 180-200°C. The produced aluminum alloy casting was placed into an air furnace at 470°C, and subject to a solid solution treatment of 470±5°C/12h + 485±5°C/12h, cooled by water, naturally aged for 48h, and then underwent a two-stage aging treatment of 95±5°C/12h + 150±5°C/24h.

[0054] The samples were cut according to the relevant methods, and tested in accordance with the relevant test standards for density (GB/T 1423), tensile properties (GB/T 16865), exfoliation corrosion (GB/T 22639) and intergranular corrosion of the alloy in accordance with the relevant testing standards, which were taken as common performance indexes of alloys for evaluation. The results are shown in Table 8.

Table 7. Compositions of Experimental Alloys

Alloy No.	Alloy of the present disclosure	Mg (wt%)	Zn (wt%)	Si (wt%)	Cu (wt%)	Mn (wt%)	Zr (wt%)	Sc (wt%)	Content of main impurities (wt%)
	(Y/N)
25#	Y	8.93	2.67	1.15	0.19	0.29	0.11	/	Fe=0.16, Ti=0.02
26#	N	5.34	/	2.09	0.26	0.32	/	/	Fe=0.13, Ti=0.02

Table 8. Performance Test Results of Experimental Alloys

Experimental alloy		Tensile property			Corrosion properties		Density
Alloy No.	State	Rm(MPa)	Rp0.2(MPa)	A(%)	Exfoliation Corrosion	Intergranular	g/cm3
25#	TX	467	396	7.1	N	Level 2	2.65
26#	TX	306	192	9.8	N	Level 2	2.60

[0055] As seen from Table 8, Alloy 25# of the present disclosure exhibits high strength level and good match of high plasticity and corrosion resistance, as compared with Alloy 26# (Al-Mg-Si casting aluminum alloy) castings.

EXAMPLE 5

[0056] Alloys were prepared in industrial scale, and the compositions of the alloys were as shown in Table 9.

[0057] Round ingots with Φ480mm were prepared by alloy smelting, degassing, removal of inclusion, and semi-continuous casting conditions well known in the art, wherein the conditions for the homogenization treatment of the ingots of Alloys 27#, 28#, and 29# were selected as: (405±5°C/10h) + (475±5°C/18h) + (505±5°C/12h), and the other alloys were subject to conventional annealing treatment of 470-500°C/36h, and air cooling. After peeling, milling and sawing, an extrusion billet with size of Φ450 mm was obtained. The billet was pre-heated at 430±10°C for 4h, and extruded for deformation to give a 35 x 400mm large-sized strip with the extrusion temperature controlled at approximately 380°C±10°C. By selecting appropriate process parameters in a range of 475-540°C according to the characteristics of the alloys themselves, the alloy strip was subject to solid solution treatment, water quenching immediately before 1.5-2% tensile straightening treatment, and a typical aging treatment, wherein Alloys 27#, 28# and 29# were subject to two-stage aging treatment of 90±3°C/24h + 140±3°C/24h, Alloy 30# was subject to an aging treatment of 121±5°C/6h + 163±5°C/20h, Alloy 31# was subject to an aging treatment of 190±5°C/12h, and Alloy 32# was subject to an aging treatment of 165±5°C/8h, so that the alloys obtained better comprehensive performance matching.

[0058] The samples were cut according to the relevant methods, and tested in accordance with the relevant test standards for density (GB/T 1423), tensile properties (GB/T 16865), fracture toughness (GB/T 4161), fatigue properties (GB/T 3075), exfoliation corrosion (GB/T 22639) and intergranular corrosion of the alloy in accordance with the relevant testing standards, which were taken as common performance indexes of alloys for evaluation. The results are shown in Table 10.

Table 9. Compositions of Experimental Alloys

Alloy No.	Alloy of the present disclosure	Mg (wt%)	Zn (wt%)	Si (wt%)	Cu (wt%)	Mn (wt%)	Zr (wt%)	Content of main impurities (wt%)	Remark
	(Y/N)
27#	Y	8.55	2.97	0.47	/	/	0.11	Fe=0.15, Ti=0.02
28#	Y	8.09	2.9	0.53	/	/	0.11	Fe=0.15, Ti=0.02
29#	Y	7.15	2.29	0.24	/	/	0.11
30#	N	2.25	6.21	0.06	2.3	0.05	0.11	Fe=0.15, Ti=0.02	7050
31#	N	1.5	0.12	0.25	4.35	0.6	/	Fe=0.15, Ti=0.02	2024
32#	N	0.55	0.1	0.7	0.15	0.25	/		6005A

Note: The compositions of Alloys 30#, 31# and 32# are respectively taken from the medium values of the composition ranges of 7050, 2024 and 6005A aluminum alloys registered by the International Aluminum Association.

Table 10. Performance Test Results of Experimental Alloys

Experimenta l alloy		Tensile property			Fracture toughnes s	Fatigue performanc e	Corrosion properties		Densit y
Alloy No.	State	Rm (MPa )	Rp0.2 (MPa )	A (%)	KIC (MPa·m1/2 )	Under X stress conditions, R=0.1, cycle 120,000 times	Exfoliatio n Corrosion	Intergranula r	g/cm3
27#	TX	605	511	11.5	33.4	Pass (X=241MPa)	N	Level 2	2.64
28#	TX	589	492	13. 4	35.1	Pass (X=241MPa)	N	Level 2	2.64
29#	TX	476	329	19	37.5	Pass (X=241MPa)	N	Pitting corrosion	2.64
30#	T74	521	469	12. 1	36.6	Pass (X=241MPa)	EB	Level 4	2.83
31#	T8	494	464	8.7	40.1	Pass (X=241MPa)	EB	Level 3	2.78
32#	T6	282	189	14	24.5	Pass (X=120MPa)	PA	Level 3	2.71

[0059] As seen from Table 10, Alloys 27#, 28# and 29# of the present disclosure have low density, good toughness and corrosion resistance, which have obvious comprehensive performance advantages, low density, high strength level, and high fracture toughness, fatigue resistance and corrosion resistance, as compared with the 7050 alloy (30# alloy), 2024 alloy (31# alloy) and 6005A alloy (32# alloy) prepared under the same conditions.

[0060] FIGs. 3 and 4 show the comparison of specific strength, fracture toughness and corrosion resistance of Alloys 27#, 28#, 29# of the present disclosure, 7050 alloy (30# alloy), 2024 alloy (31# alloy) and 6005A alloy (32# alloy), respectively. It can be seen that the alloy product of the present disclosure shows a good match between mechanical properties and corrosion properties.

[0061] The foregoings are the only exemplary embodiments of the present disclosure, and are not used to limit the scope of the present disclosure, which is determined by the appended claims.

Claims

1. A lightweight, high-strength, corrosion-resistant aluminum alloy material comprising: Mg 6.0-10.0 wt%, Zn 1.0-3.5 wt%, Si 0.1-1.3 wt%, and at least one of Mn, Cu, Zr, Sc, and Ti elements in total amount of less than or equal to 0.8%, and a balance of Al and inevitable impurities.

2. The lightweight, high-strength, corrosion-resistant aluminum alloy material of claim 1, comprising: Mg 6.3-9.9 wt%, Zn 1.1-2.9 wt%, Si 0.15-1.0 wt%, and at least one of the elements Mn, Cu, Zr, Sc, and Ti elements in total amount of less than or equal to 0.6 wt%, and a balance of Al and inevitable impurities.

3. The lightweight, high-strength, corrosion-resistant aluminum alloy material of claim 2, comprising: Mg 6.6-9.0 wt%, Zn 1.3-2.9 wt%, and Si 0.15-0.8 wt%.

4. The lightweight, high-strength, corrosion-resistant aluminum alloy material of claim 2, comprising: Mg 7.1-8.8 wt%, Zn 1.5-2.8 wt%, and Si 0.25-0.7 wt%.

5. The lightweight, high-strength, corrosion-resistant aluminum alloy material of claim 2, comprising: Mg 7.3-8.5 wt%, Zn 1.5-2.7 wt%, and Si 0.4-0.6 wt%.

6. The lightweight, high-strength, corrosion-resistant aluminum alloy material of claim 2, wherein contents of Mg, Zn, and Si satisfy the relationship of: 2.5 ≤ (9 x Mg) / [( 1 x Si) + (8 x Zn)] ≤ 6.

7. The lightweight, high-strength, corrosion-resistant aluminum alloy material of claim 2, comprising: Mn 0.10-0.50 wt%.

8. The lightweight, high-strength, corrosion-resistant aluminum alloy material of claim 2, comprising: Cu 0.10-0.50 wt%.

9. The lightweight, high-strength, corrosion-resistant aluminum alloy material of claim 2, comprising: Ti 0.01-0.15 wt%.

10. The lightweight, high-strength, corrosion-resistant aluminum alloy material of claim 2, comprising: Zr 0.05-0.25 wt%.

11. The lightweight, high-strength, corrosion-resistant aluminum alloy material of claim 2, comprising: Sc 0.05-0.30 wt%.

12. The lightweight, high-strength, corrosion-resistant aluminum alloy material of claim 11, comprising: Sc 0.05-0.20 wt%.

13. The lightweight, high-strength, corrosion-resistant aluminum alloy material of claim 12, wherein contents of Sc and Zr satisfy: 0.15 wt% ≤ (Sc + Zr) wt% ≤ 0.35 wt%.

14. The lightweight, high-strength, corrosion-resistant aluminum alloy material of claim 2, wherein the inevitable impurities comprises elements that are unintentionally introduced as impurities during manufacturing process of alloy ingot, wherein Fe ≤ 0.40 wt%, each of other impurity elements are ≤ 0.20 wt%, and a total amount is ≤ 0.50 wt%.

15. The lightweight, high-strength, corrosion-resistant aluminum alloy material of claim 14, wherein the inevitable impurities comprises elements that are unintentionally introduced as impurities during manufacturing process of alloy ingot, wherein Fe ≤ 0.20 wt%, each of other impurity elements are ≤ 0.10 wt%, and a total amount is ≤ 0.25 wt%.

16. The lightweight, high-strength, corrosion-resistant aluminum alloy material of claim 15, wherein Fe ≤ 0.10 wt%.

17. A method for producing deformed aluminum alloy materials, comprising the steps of:

(1) producing an ingot of the aluminum alloy material of any one of claims 1-16;

(2) homogenizing and/or pre-heating the produced ingot;

(3) thermally deforming the ingot to a desired processed material or a pre-processed material by one or more thermal deformation process selected from the group consisting of extrusion, rolling and forging;

(4) optionally processing the pre-processed material to the desired processed material by reheating and cold deformation;

(5) solution heat treating the processed material;

(6) rapidly cooling the treated processed material to room temperature; and

(7) naturally or artificially aging the cooled processed materials to give an aged processed alloy material.

18. The method of claim 17, wherein, in step (1), the ingot is manufactured by means of smelting, degassing, removal of inclusion and semi-continuous casting; during the smelting process, Mg, Zn is used as the core to accurately control the element content, and through online component detection and analysis, the ratio between alloying elements can be quickly supplemented and adjusted, and the entire ingot manufacturing process is completed.

19. The method of claim 18, wherein, in step (1), 0.0002~0.005 wt% Be is added in the form of Al-Be intermediate alloy during smelting to change the properties of the oxide film and reduce oxidation burning loss and inclusions.

20. The method of claim 18, wherein, in step (1), it also includes applying electromagnetic field, ultrasonic field or mechanical stirring at or near the crystallizer site.

21. The method of claim 17, wherein, in step (2), the homogenizing is carried out by means selected from the group consisting of:

(i) a single-stage homogenization treatment in a range of 360-490°C for a total time of 12-60 h; and

(ii) a two- or multi-stage homogenization treatment in a range of 360-500°C for a total time of 12-60 h.

22. The method of claim 17, wherein, in steps (3) and (4), the pre-heating temperature and reheating temperature before each thermal deformation process are 370-460°C, and the processing time is 1-8 h.

23. The method of claim 17, wherein step (4) further comprises an intermediate annealing treatment at 350-450°C for 0.5-6 h between the cold deformation passes.

24. The method of claim 17, wherein, in step (5), the solid solution treatment requires to further adjust the sub-grain size and the recrystallized microstructure ratio in the material according to the performance requirements, and is carried out by means selecting from the group consisting of:

(i) a single-, two-, or multi-stage solid solution treatment in a range of 440-500°C for total 0.5-8 h; and

(ii) a progressive heating solid solution treatment in a range of 440-500°C for total 0.5-5 h.

25. The method of claim 23, wherein a progressive heating solid solution treatment is used with a heating rate of ≤ 60°C/min.

26. The method of claim 17, wherein, in step (6), the processed material is rapidly cooled to room temperature using a method selected from the group consisting of spray quenching, immersion quenching, strong air cooling and combinations thereof.

27. The method of claim 17, wherein, in step (7), the artificial aging treatment is carried out by means selected from the group consisting of:

(i) after completion of quenching and cooling, a natural aging at room temperature for ≥ 48 h;

(ii) within 2 h after completion of quenching and cooling, an artificial aging treatment in a range of 70-240°C for total 6-60 h; and

(iii)after completion of quenching and cooling, a combination of natural aging and artificial aging with an artificial aging temperature of 70-240°C and a time of 6-60 h.

28. The method of claim 17, further comprising, between steps (6) and (7), steps of straightening and/or pre-deforming the cooled processed material, wherein the straightening can be carried out by means of roller straightening, stretch straightening, stretch bending straightening and any combination thereof to improve the straightness of the processed materials, and the pre-deformation can be carried out by means of stretching, compression and any combination thereof to reduce the residual stress formed by quenching and cooling, so as to facilitate subsequent processing and application.

29. The method of claim 17, wherein the processed material are wires, rods, pipes, sheets, plates, or forging products.

30. The lightweight, high-strength, corrosion-resistant aluminum alloy material of any one of claims 1 to 16 or the lightweight, high-strength, corrosion-resistant aluminum alloy material produced according to the method of any one of claims 17 to 29, having a density of ≤ 2.68g/cm³, a tensile strength of ≥ 400MPa, and an exfoliation corrosion resistance of not lower than EA level.

31. The lightweight, high-strength, corrosion-resistant aluminum alloy material of claim 30, having a density of ≤ 2.66g/cm³, a tensile strength of ≥ 410MPa, and an exfoliation corrosion performance of not lower than EA level.

32. The lightweight, high-strength, corrosion-resistant aluminum alloy material of claim 31, having a density of ≤ 2.64g/cm³, a tensile strength of ≥ 420MPa, and an exfoliation corrosion performance of not lower than PC level.

33. A method for producing casting aluminum alloy materials, comprising the steps of:

(1) preparing an aluminum alloy ingot of the aluminum alloy material of any one of claims 1-16 using smelting, degasification, removal of inclusion, sand- or metal-mold casting, or die casting, wherein during the smelting process, the concentrations of elements are accurately controlled by taking Mg and Cu as core elements; and the ratios among alloying elements are rapidly supplemented and adjusted by on-line detection and analysis of components so as to complete the casting production;

(2) solid solution heat treating the produced aluminum casting, comprising: allowing the aluminum alloy casting to undergo a single-, two-, or multi-stage solid solution treatment in a range of 440-500°C for total 0.5-8h, or a progressive heating solid solution treatment in a range of 440-500°C for total 0.5-5 h; and

(3) naturally or artificially aging the aluminum alloy casting; wherein the natural aging treatment is carried out at room temperature for ≥ 48 h; the artificial aging treatment is carried out in a range of 70-240°C for total 6-60 h; and a combination of natural aging treatment and artificial aging treatment is carried out with the artificial aging temperature of 70-240°C and the artificial aging time of 6-60 h.

34. A product formed by welding the lightweight, high-strength, corrosion-resistant aluminum alloy material of any one of claims 1 to 16, 30 to 32 or a lightweight, high-strength, corrosion-resistant aluminum alloy material prepared by the method of any one of claims 17 to 29, 33 with the same alloy or another alloy by means of friction stir welding, fusion welding, brazing, electron beam welding, or laser welding.

35. A final component obtainable by processing the lightweight, high-strength, corrosion-resistant aluminum alloy material of any one of claims 1 to 16, 30 to 32 or a lightweight, high-strength, corrosion-resistant aluminum alloy material prepared by the method of any one of claims 17 to 29, 33 via various surface treatments, stamping forming, and machining.

36. The final component of claim 35, wherein the final component is a load-bearing structural component.

Drawing