Formable, corrosion-resistant aluminum alloy for structural components.

Abstract

Described herein are formable, high-strength, corrosion-resistant aluminum alloy compositions and products, and methods for their preparation and processing. The methods for preparing and processing the aluminum alloy products include casting the aluminum alloy and performing compatible rolling and downstream heat treatment steps. The resulting aluminum alloy compositions and products exhibit high strength and formability properties while also exhibiting corrosion resistance.

Description

[Technical Field]

[0001] Priority claims This application claims priority to U.S. Provisional Application No. 63 / 385,865, filed December 2, 2022, the entire contents and disclosure of which are incorporated herein by reference.

[0002] This disclosure relates to the fields of materials science, materials chemistry, metallurgy, aluminum alloys, aluminum manufacturing, and related fields. In particular, this disclosure provides novel 7xxx series aluminum alloys with high formability and improved corrosion resistance. This disclosure also provides various methods of manufacturing and processing 7xxx series aluminum alloy products. [Background technology]

[0003] High-strength and formable aluminum alloys are desired for improved product performance in many applications, including, among others, automotive and other transportation applications (e.g., including, but not limited to, trucks, trailers, trains, aerospace applications, and marine applications), as well as electronics applications. In some cases, such alloys must exhibit, among other properties, high strength and high formability (e.g., the ability to be formed into a desired shape). For example, 7xxx series aluminum alloys are widely used in such applications due to their improved combination of properties, including strength and formability, and their ability to be heat treated to increase such properties. Because aluminum alloys are generally 2.8 times less dense than steel, the use of such materials reduces vehicle weight and allows for significant improvements in vehicle fuel economy. Even so, using currently available aluminum alloys in automotive applications presents certain challenges.

[0004] 7xxx series aluminum alloys with low copper (Cu) content (e.g., less than 0.50 wt% Cu) are prone to stress corrosion cracking (SCC). This may occur because the MgZn2 phase is highly anodic relative to the aluminum matrix, resulting in voids in the microstructure, allowing environmental factors to have a significant effect on the aluminum alloy. Cu can act as a cathodic element in the microstructure, thus reducing the difference between the grains and the matrix. Therefore, low Cu-containing 7xxx series alloys may be more susceptible to SCC. Summary of the Invention

[0005] The embodiments included in this disclosure are defined by the claims, not by this Summary. This Summary is a high-level overview of various aspects of the invention and introduces some concepts that are further described in the Detailed Description section below. This Summary is not intended to identify key features or important features of the claimed subject matter, nor is it intended to be used in isolation to determine the scope of the claimed subject matter. The subject matter should be understood by reference to the entire specification, any or all drawings, and appropriate portions of each claim.

[0006] Described herein are novel aluminum alloy compositions and methods for producing formable, high-strength, and corrosion-resistant aluminum alloy products, the methods including casting a molten aluminum alloy to form an ingot or slab, hot rolling the ingot or slab to produce a sheet, subjecting the sheet to a solution heat treatment to form a solution-treated sheet, pre-aging the solution-treated sheet to form a pre-aged sheet, and subjecting the pre-aged sheet to at least one paint bake heat treatment to form an aluminum alloy product, wherein the aluminum alloy includes Mg and Cu, and the aluminum alloy product has a service strength of at least 370 MPa. In some embodiments, homogenizing and cold rolling are optional; for example, the method may include casting, hot rolling, solution heat treating, pre-aging, and subsequent aging. In some embodiments, the method may include the steps of casting, hot rolling, cold rolling, solution heat treating, pre-aging, and aging. In some embodiments, the method may include casting, homogenizing, hot rolling, solution heat treating, pre-aging, and aging. In some embodiments, the method may include the steps of casting, homogenizing, hot rolling, cold rolling, solution heat treating, pre-aging, and aging. In some embodiments, pre-aging is performed at a temperature of 50 to 200°C for a period of 1 to 24 hours. In some embodiments, the sheet may be cold rolled before solutionizing. In some embodiments, homogenizing includes heating the ingot or slab to a temperature of at least 450°C and maintaining the ingot or slab at a temperature of at least 450°C for a time period of at least 90 minutes. In some embodiments, the ingot or slab may be hot rolled to a thickness of less than 7 mm and cold rolled to a thickness of less than 4 mm. In some embodiments, the method may include further steps, such as artificially aging the pre-aged sheet before at least one paint bake treatment. In some embodiments, artificial aging may be carried out at a temperature of 80 to 250° C. for a period of 30 minutes to 72 hours. In some embodiments, the methods and compositions may include preparing an aluminum alloy product.The aluminum alloy product may have an ultimate tensile strength of at least 420 MPa after a 40-day immersion test according to SCC-ASTM G47.

[0007] In some embodiments, the aluminum alloy comprises 0-0.25 wt% Si, 0-0.40 wt% Fe, 0.0-0.40 wt% Cu, 0.0-0.30 wt% Mn, 0.0-3.6 wt% Mg, 0.0-0.10 wt% Cr, 0.0-4.5 wt% Zn, 0.0-0.10 wt% Ti, 0.0-0.20 wt% Zr, up to 0.15 wt% impurities, and Al, wherein Cu and Mg are present in amounts less than 3.6 wt%. In some embodiments, the aluminum alloy comprises 0-0.25 wt% Si, 0.0-0.40 wt% Fe, 0.0-0.40 wt% Cu, 0.10-0.30 wt% Mn, 2.3-3.6 wt% Mg, 0.0-0.10 wt% Cr, 3.5-4.5 wt% Zn, 0.0-0.10 wt% Ti, 0.0-0.20 wt% Zr, up to 0.15 wt% impurities, and Al, wherein Cu and Mg are present in a total amount less than 3.6 wt%. In some embodiments, the aluminum alloy comprises 0-0.25 wt% Si, 0.0-0.40 wt% Fe, 0.11-0.40 wt% Cu, 0.10-0.30 wt% Mn, 2.3-3.6 wt% Mg, 0.0-0.10 wt% Cr, 3.5-4.5 wt% Zn, 0.0-0.10 wt% Ti, 0.0-0.20 wt% Zr, up to 0.15 wt% impurities, and Al, wherein Cu and Mg are present in a total amount less than 3.6 wt%. In some embodiments, the aluminum alloy comprises 0-0.25 wt% Si, 0.0-0.40 wt% Fe, 0.0-0.40 wt% Cu, 0.10-0.30 wt% Mn, 2.3-3.6 wt% Mg, 0.0-0.10 wt% Cr, 3.5-4.5 wt% Zn, 0.0-0.10 wt% Ti, 0.05-0.20 wt% Zr, up to 0.15 wt% impurities, and Al, wherein Cu and Mg are present in a total amount less than 3.6 wt%.

[0008] In some embodiments, the method can include at least one paint bake, for example, at least two paint bakes. In some embodiments, the method can include at least one paint bake, where the at least one paint bake is performed at a temperature of 75-250°C for a period of 15 minutes to 3 hours. In some embodiments, the method can include at least one paint bake, where the at least one paint bake is performed at a temperature of 100-200°C for a period of 15 minutes to 2 hours. In some embodiments, the method can include at least one paint bake, where the at least one paint bake is performed at a temperature of 150-180°C for a period of 15 minutes to 45 minutes.

[0009] In some embodiments, the aluminum alloy product is formable at room temperature. In some embodiments, the aluminum alloy product is formable at temperatures below room temperature. In some embodiments, the aluminum alloy product has a service strength of at least 390 MPa in a T4 temper after at least two paint bake cycles. In some embodiments, the aluminum alloy product has a service strength of at least 400 MPa in a T6 temper after at least two paint bake cycles.

[0010] Further aspects, objects, and advantages will become apparent from consideration of the detailed description. [Brief explanation of the drawings]

[0011] [Figure 1] 1A-C provide graphs of yield strength, ultimate tensile strength, and total elongation of 2.0 mm water-quenched (WQ) (A), 2.4 mm (AQ) (B), and 2.4 mm WQ (C) aluminum alloy compositions described herein during the natural aging response according to some embodiments described herein. [Figure 2] 1A-B provide graphs of yield strength, ultimate tensile strength, and total elongation of aluminum alloy compositions described herein after multiple paint bake cycles and in T4 temper (A) or T6 temper (B) conditions, according to some embodiments described herein. [Figure 3] FIG. 1 provides a graph of a lap bend of an exemplary aluminum alloy described herein after the T4 and T6 tempers compared to Comparative Example 1, according to some embodiments described herein. [Figure 4] AB provide photographs (A) and die depths (B) of various rivet and die designs in the aluminum alloys described herein according to some embodiments described herein. [Figure 5] 1 provides photographs of 2.0 mm WQ, 2.4 mm AC, and 2.4 mm WQ aluminum alloys under 30 kA and 34 Ka according to some embodiments described herein. [Figure 6] AB provides a graph of forming depth for the Swift Cup drawing test described herein (A) and the resulting values ​​for the aluminum alloys of Example 1 and Comparative Example 3 (B) according to some embodiments described herein. [Figure 7] AB provides a graph of forming depth (A) of the round cup draw test described herein, and the resulting values ​​(B) of the aluminum alloys of Example 1 and Comparative Example 3, according to some embodiments described herein. [Figure 8] 1 provides a graph of maximum strain versus minimum strain according to some embodiments described herein compared to Comparative Examples 1-3 and Example 1 described herein. [Figure 9] AB provide graphs of stress versus strain (A) for Comparative Examples 1-3 and Example 1, and photographs of formability (B) for Comparative Examples 1-3 and Example 1, according to some embodiments described herein. [Figure 10] 1 provides springback section diagrams of Comparative Examples 1-3 and Example 1 according to some embodiments described herein. [Figure 11]1A-C provide graphs of maximum intergranular corrosion (IGC) of aluminum alloys after 24 and 48 hours (A), as well as microscope images of pitting corrosion of 2.4mm WQ T4+PB (B) and 2.4mm AQ T4+PB (C), according to some embodiments described herein. [Figure 12] 1 provides microscopic images of peel tests of exemplary aluminum alloys according to some embodiments described herein. [Figure 13] 1A-C provide graphs of maximum tensile stress (A), maximum axial strain (B), and resulting data (C) according to some embodiments described herein. [Figure 14] 1 provides scanning transmission electron microscope (STEM) images of aluminum alloy compositions described herein according to some embodiments described herein. DETAILED DESCRIPTION OF THE INVENTION

[0012] Described herein are novel 7xxx series aluminum alloys that exhibit high corrosion resistance while maintaining a high strength-to-weight ratio, formability, and weldability. Specifically, the inclusion of trace alloy elements (e.g., zirconium (Zr)) and major components (e.g., copper (Cu) and magnesium (Mg)) improves the corrosion resistance and reduces stress corrosion cracking in products formed from the aluminum alloy without causing substantial loss of strength or formability. Without being bound by theory, it is believed that the inclusion of Cu, Mg, and the trace element Zr creates multiple nucleation sites within the microstructure, thus reducing the susceptibility of the aluminum alloy to intergranular corrosion and stress corrosion cracking.

[0013] Aluminum alloys exhibit uniform and good corrosion resistance due to the presence of a passive film (e.g., a few nanometers thick) that is naturally formed by oxidation in air. However, the passive film can easily be dissolved at localized sites when exposed to a corrosive environment (e.g., a chloride-containing electrolyte), resulting in localized corrosion. In particular, low-Cu-content 7xxx aluminum alloys are susceptible to SCC in corrosive environments. The SCC resistance of some 7xxx aluminum alloys can be improved by heat treatment and tempering.

[0014] The novel 7xxx series aluminum alloys described herein contain increased amounts of Cu and Mg and the trace element Zr to improve SCC resistance while maintaining high strength and formability. 7xxx series aluminum alloys containing increased amounts of the major elements Cu and Mg (e.g., 0.10-0.40 wt% and greater than 2.0 wt%, respectively) and the trace element Zr (e.g., 0.01-0.20 wt%) significantly improve SCC resistance as described herein. Furthermore, improved methods for producing high-strength aluminum alloys are described herein. For example, the natural aging of the aluminum alloys described herein may be improved by incorporating Zr in amounts between 0.01 wt% and 0.20 wt%. Indeed, 7xxx series aluminum alloys with Zr and increased levels of Cu and Mg have improved room-temperature formability and reduced alloy SCC when compared to conventional 7xxx series alloys. The 7xxx series aluminum alloys described herein, as a result of the incorporation of high levels of Cu, Mg, and Zr, have reduced segregation at grain boundaries, which synergistically reduces intergranular corrosion and improves resistance to SCC, thus improving the strength and room temperature formability of the aluminum alloys.

[0015] Definitions and Explanations: As used herein, the terms "invention," "the invention," "this invention," and "the present invention" are intended to refer broadly to all of the subject matter of this patent application and the claims that follow. Any reference to a specification containing these terms should be understood neither to limit the subject matter described herein nor to limit the meaning or scope of the claims that follow.

[0016] This description refers to alloys identified by aluminum industry designations such as "series" or "7xxx." For an understanding of the numbering systems most commonly used to name and identify aluminum and its alloys, see "International Alloy Designations and Chemical Composition Limits for Wrought Aluminum and Wrought Aluminum Alloys" or "Registration Record of Aluminum Association Alloy Designations and Chemical Composition Limits for Aluminum Alloys in the Form of Castings and Ingots" (both published by the Aluminum Association).

[0017] The following aluminum alloys are described in terms of elemental composition in weight percent (wt% or %) based on the total weight of the alloy. In the specific example of each alloy, the balance of the composition is aluminum, and the maximum wt% of the sum of all impurities is 0.15%. The wt% of the aluminum alloy may total up to 100 wt% and may include Al in amounts that total 100 wt%.

[0018] As used herein, the meaning of "a," "an," or "the" includes singular and plural references unless the context clearly indicates otherwise.

[0019] As used herein, sheet generally has a thickness of greater than 15 mm and up to 200 mm. For example, plate can refer to an aluminum alloy product having a thickness of greater than 15 mm, greater than 20 mm, greater than 25 mm, greater than 30 mm, greater than 35 mm, greater than 40 mm, greater than 45 mm, greater than 50 mm, greater than 100 mm, or up to 200 mm.

[0020] As used herein, a sheet (also called a sheet plate) generally has a thickness of 4 mm to 15 mm. For example, the sheet may have a thickness of 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, or 15 mm.

[0021] As used herein, sheet refers to an aluminum product having a thickness of less than 4 mm (e.g., less than 3 mm, less than 2 mm, less than 1 mm, less than 0.5 mm, less than 0.3 mm, or less than 0.1 mm). For example, the sheet may have a thickness of 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, 2.6 mm, 2.7 mm, 2.8 mm, 2.9 mm, 3 mm, 3.1 mm, 3.2 mm, 3.3 mm, 3.4 mm, 3.5 mm, 3.6 mm, 3.7 mm, 3.8 mm, 3.9 mm, or 4 mm.

[0022] As used herein, formability refers to the ability of a material to deform into a desired shape without forming errors such as fracture, tearing, necking, selvage, or wrinkling, springback, or galling. In engineering, formability can be classified by the mode of deformation. Examples of deformation modes include drawing, stretching, bending, stretch-flanging, etc.

[0023] In this application, reference may be made to alloy tempers or tempers. To understand the descriptions of the most commonly used alloy tempers, please refer to American National Standards (ANSI) H35 on Alloy and Temper Designation Systems. The F state or temper refers to the aluminum alloy as produced. The O state or temper refers to the aluminum alloy after annealing. The Hxx state or temper, also referred to herein as the H temper, refers to an aluminum alloy that is not heat treatable after cold rolling, with or without heat treatment (e.g., annealing). Suitable H tempers include the HX1, HX2, HX3, HX4, HX5, HX6, HX7, HX8, or HX9 tempers. The T1 state or temper refers to an aluminum alloy that has been cooled from hot working and naturally aged (e.g., at room temperature). The T2 state or temper refers to an aluminum alloy that has been cooled from hot working, cold worked, and naturally aged. The T3 condition or temper refers to an aluminum alloy that has been solution heat treated, cold worked, and naturally aged. The T4 condition or temper refers to an aluminum alloy that has been solution heat treated and naturally aged. The T5 condition or temper refers to an aluminum alloy that has been hot worked, cooled, and artificially aged (at an elevated temperature). The T6 condition or temper refers to an aluminum alloy that has been solution heat treated and artificially aged. The T7 condition or temper refers to an aluminum alloy that has been solution heat treated and artificially overaged. The T8x condition or temper refers to an aluminum alloy that has been solution heat treated, cold worked, and artificially aged. The T9 condition or temper refers to an aluminum alloy that has been solution heat treated, artificially aged, and cold worked. The W condition or temper refers to an aluminum alloy after solution heat treatment.

[0024] As used herein, the terms "cast metal product," "cast product," "cast aluminum alloy product," and the like are used interchangeably and refer to products produced by direct chill casting (including direct chill simultaneous casting) or semi-continuous casting, continuous casting (including, for example, by use of a twin belt caster, twin roll caster, block caster, or any other continuous casting machine), electromagnetic casting, hot top casting, or any other casting process.

[0025] As used herein, the meaning of "room temperature" can include temperatures between 15°C and 30°C, for example, 15°C, 16°C, 17°C, 18°C, 19°C, 20°C, 21°C, 22°C, 23°C, 24°C, 25°C, 26°C, 27°C, 28°C, 29°C, or 30°C.

[0026] All ranges disclosed herein should be understood to include any endpoints and any and all subranges subsumed therein. For example, a range stated as "1 to 10" should be considered to include any and all subranges between the minimum value of 1 and the maximum value of 10, inclusive. That is, all subranges begin with a minimum value of 1 or greater, e.g., 1 to 6.1, and end with a maximum value of 10 or less, e.g., 5.5 to 10.

[0027] Alloy composition The properties of an aluminum alloy are determined in part by the composition of the aluminum alloy, and in certain aspects, the alloy composition can influence or even determine whether the alloy has suitable properties for a desired application.

[0028] The alloys and products described herein are novel aluminum compositions that exhibit desirable mechanical and physical properties, such as formability, strength, and microstructure, which can be achieved, at least in part, due to the elemental composition of the aluminum.

[0029] In some examples, the aluminum alloys described herein may have the following elemental compositions as shown in Table 1: [Table 1]

[0030] In some examples, the aluminum alloys described herein may have the following elemental compositions as shown in Table 2: [Table 2]

[0031] In some examples, the aluminum alloys described herein may have the following elemental compositions as shown in Table 3: [Table 3]

[0032] In some examples, the aluminum alloys described herein may have the following elemental compositions as shown in Table 4: [Table 4]

[0033] Silicon (Si) In some examples, the aluminum alloys described herein include Si in an amount of up to 0.25%, e.g., 0.00% to 0.25%, 0.01% to 0.25%, 0.05% to 0.25%, 0.00% to 0.15%, or 0.00% to 0.20%, based on the total weight of the alloy. For example, the alloy may contain 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.20%, 0.21%, 0.22%, 0.23%, 0.24%, or 0.25% Si. In some cases, Si is absent (i.e., 0%) in the alloy. All values ​​are expressed in wt%.

[0034] Iron (Fe) In some examples, the aluminum alloys described herein also include Fe in an amount up to 0.40%, e.g., 0.00%-0.40%, 0.10%-0.40%, 0.00%-0.30%, or 0.10%-0.40%, based on the total weight of the alloy. For example, the alloy may include 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.20%, 0.21%, 0.22%, 0.23%, 0.24%, 0.25%, 0.26%, 0.27%, 0.28%, 0.29%, 0.30%, 0.31%, 0.32%, 0.33%, 0.34%, 0.35%, 0.36%, 0.37%, 0.38%, 0.39%, 0.40%, 0.41%, 0.42%, 0.43%, 0.44%, 0.45%, 0.46%, 0.47%, 0.48%, 0.49%, 0.50%, 0.51%, 0.52%, 0.53%, 0.54%, 0.55%, 0.56%, 0.57%, 0.58%, 0.59%, 0.60%, 0.61%, 0.62%, 0.63%, 0.64%, 0.65%, 0.66%, 0.67%, 0.68%, 0.69%, 0. The alloy may contain 0.21%, 0.22%, 0.23%, 0.24%, 0.25%, 0.26%, 0.27%, 0.28%, 0.29%, 0.30%, 0.31%, 0.32%, 0.33%, 0.34%, 0.35%, 0.36%, 0.37%, 0.38%, 0.39%, or 0.40% Fe. In some cases, Fe is absent (i.e., 0%) in the alloy. All values ​​are expressed in wt%.

[0035] Copper (Cu) In some examples, the aluminum alloys described herein include Cu in an amount up to 0.40%, e.g., 0.00% to 0.40%, 0.00% to 0.30%, or 0.11% to 0.40%, based on the total weight of the alloy. For example, the alloy may include 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.20%, 0.21%, 0.22%, 0.23%, 0.24%, 0.25%, 0.26%, 0.27%, 0.28%, 0.29%, 0.30%, 0.31%, 0.32%, 0.33%, 0.34%, 0.35%, 0.36%, 0.37%, 0.38%, 0.39%, 0.40%, 0.41%, 0.42%, 0.43%, 0.44%, 0.45%, 0.46%, 0.47%, 0.48%, 0.49%, 0.50%, 0.51%, 0.52%, 0.53%, 0.54%, 0.55%, 0.56%, 0.57%, 0.58%, 0.59%, 0.60%, 0.61%, 0.62%, 0.63%, 0.64%, 0.65%, 0.66%, 0.67%, 0.68%, 0.69%, 0.70%, 0.71%, The alloy may contain 0.21%, 0.22%, 0.23%, 0.24%, 0.25%, 0.26%, 0.27%, 0.28%, 0.29%, 0.30%, 0.31%, 0.32%, 0.33%, 0.34%, 0.35%, 0.36%, 0.37%, 0.38%, 0.39%, or 0.40% Cu. In some cases, Cu is absent (i.e., 0%) in the alloy. All expressed in wt%.

[0036] Manganese (Mn) In some examples, the aluminum alloys described herein may include Mn in an amount of up to 0.30%, e.g., 0.00% to 0.30%, 0.05% to 0.30%, or 0.10% to 0.30%, based on the total weight of the alloy. For example, the alloy may contain 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.20%, 0.21%, 0.22%, 0.23%, 0.24%, 0.25%, 0.26%, 0.27%, 0.28%, 0.29%, or 0.30% Mn. In some cases, Mn is absent (i.e., 0%) in the alloy. All values ​​are expressed in wt%.

[0037] Magnesium (Mg) In some examples, the aluminum alloys described herein may include Mg in an amount up to 3.60%, e.g., 0.00% to 3.60%, 1.00% to 3.60%, 2.00% to 3.60%, or 2.30% to 3.60%, based on the total weight of the alloy. For example, the alloys described herein may contain 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.20%, 0.21%, 0.22%, 0.23%, 0.24%, 0.25%, 0.26%, 0.27%, 0.28%, 0.29%, 0.30%, 0.31%, 0.32%, 0.33%, 0.34% ,0.35%,0.36%,0.37%,0.38%,0.39%,0.40%,0.41%,0.42%,0.43%,0.44%,0.45%,0.46%,0.47%,0.48%,0.49%,0.50%,0.51%,0.52%,0.53%,0.54%,0.55%,0.56%,0.57%,0.58%,0.59%,0.60%,0.61%,0.62%,0.63%,0.64%,0.65%,0.66%,0.67%,0.68%,0.69%,0.70%,0.71 %,0.72%,0.73%,0.74%,0.75%,0.76%,0.77%,0.78%,0.79%,0.80%,0.81%,0.82%,0.83%,0.84%,0.85%,0.86%,0.87%,0.88%,0.89%,0.90%,0.91%,0.92%,0.93%,0.94%,0.95%,0.96%,0.97%,0.98%,0.99%,1.00%,1.01%,1.02%,1.03%,1.04%,1.05%,1.06%,1.07%,1.0 8%, 1.09%, 1.10%, 1.11%, 1.12%, 1.13%, 1.14%, 1.15%, 1.16%, 1.17%, 1.18%, 1.19%, 1.20%, 1.21%, 1.22%, 1.23%, 1.24%, 1.25%, 1.26%, 1.27%, 1.28%, 1.29%, 1.30%, 1.31%, 1.32%, 1.33%, 1.34%, 1.35%, 1.36%, 1.37%, 1.38%, 1.39%, 1.40%, 1.41%, 1.42%, 1.43%, 1.44%, 1.45%、1.46%、1.47%、1.48%、1.49%、1.50%、1.51%、1.52%、1.53%、1.54%、1.55%、1.56%、1.57%、1.58%、1.59%、1.60%、1.61%、1.62%、1.63%、1.64%、1.65%、1.66%、1.67%、1.68%、1.69%、1.70%、1.71%、1.72%、1.73%、1.74%、1.75%、1.76%、1.77%、1.78%、1.79%、1.80%、1.81%、1.82%、1.83%、1.84%、1.85%、1.86%、1.87%、1.88%、1.89%、1.90%、1.91%、1.92%、1.93%、1.94%、1.95%、1.96%、1.97%、1.98%、1.99%、2.00%、2.01%、2.02%、2.03%、2.04%、2.05%、2.06%、2.07%、2.08%、2.09%、2.10%、2.11%、2.12%、2.13%、2.14%、2.15%、2.16%、2.17%、2.18%、2.19%、2.20%、2.21%、2.22%、2.23%、2.24%、2.25%、2.26%、2.27%、2.28%、2.29%、2.30%、2.31%、2.32%、2.33%、2.34%、2.35%、2.36%、2.37%、2.38%、2.39%、2.40%、2.41%、2.42%、2.43%、2.44%、2.45%、2.46%、2.47%、2.48%、2.49%、2.50%、2.51%、2.52%、2.53%、2.54%、2.55%、2.56%、2.57%、2.58%、2.59%、2.60%、2.61%、2.62%、2.63%、2.64%、2.65%、2.66%、2.67%、2.68%、2.69%、2.70%、2.71%、2.72%、2.73%、2.74%、2.75%、2.76%、2.77%、2.78%、2.79%、2.80%、2.81%、2.82%、2.83%、2.84%、2.85%、2.86%、2.87%、2.88%、2.89%、2.90%、2.91%、2.92%、2.93%、2.94%、2.95%、2.96%、2.97%、2.98%、2.99%、3.00%、3.01%、3.02%、3.03%、3.04%、3.05%、3.06%、3.07%、3.08%、3.09%、3.10%、3.11%, 3.12%, 3.13%, 3.14%, 3.15%, 3.16%, 3.17%, 3.18%, 3.19%, 3.20%, 3.21%, 3.22%, 3.23%, 3.24%, 3.25%, 3.26%, 3.27%, 3.28%, 3.29%, 3.30%, 3.31%, 3.32%, 3.33%, 3.34%, 3.35%, 3.36%, It may contain 3.37%, 3.38%, 3.39%, 3.40%, 3.41%, 3.42%, 3.43%, 3.44%, 3.45%, 3.46%, 3.47%, 3.48%, 3.49%, 3.50%, 3.51%, 3.52%, 3.53%, 3.54%, 3.55%, 3.56%, 3.57%, 3.58%, 3.59%, or 3.60% Mg, all expressed as wt%.

[0038] Chromium (Cr) In some examples, the aluminum alloys described herein contain Cr in an amount up to 0.10%, e.g., 0.01%-0.10%, 0.05%-0.10%, 0.01%-0.05%, or 0.01%-0.05%, based on the total weight of the alloy. For example, the alloy may contain 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, or 0.10% Cr. In some cases, Cr is absent (i.e., 0%) in the alloy. All values ​​are expressed in wt%.

[0039] Zinc (Zn) In some examples, the aluminum alloys described herein include Zn in an amount up to 4.50%, e.g., 0.00% to 4.50%, 0.50% to 4.00%, 1.50% to 4.50%, 2.50% to 4.50%, or 3.50% to 4.50%, based on the total weight of the alloy. For example, alloys may contain 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.20%, 0.21%, 0.22%, 0.23%, 0.24%, 0.25%, 0.26%, 0.27%, 0.28%, 0.29%, 0.30%, 0.31%, 0.32%, 0.33%, 0.34%, 0.35%, 0.36%, 0.37%, 0.38%, 0.39%, 0.40%, 0.41%, 0.42%, 0.43%, 0.44%, 0.45%, 0.46%, 0.47%, 0.48%, 0.49%, 0.50%, 0.51%, 0.52%, 0.53%, 0.54%, 0.55%, 0.56%, 0.57%, 0.58%, 0.59%, 0.60%, 0.61%, 0.62%, 0.63%, 0.64%, 0.65%, 0.66%, 0.67%, 0.68%, 0.69%, 0.70%, 0.71%, 0.72%, 0.73%, 0.74%, 0.75%, 0.76%, 0.77%, 0.78%, 0.79%, 0.80%, 0.81%, 0.82%, 0.83%, 0.84%, 0.85%, 0.86%, 0.87%, 0.88%, 0.89%, 0.90%, 0.91%, 0.92%, 0.93%, 0.94%, 0.95%, 0.96%, 0.97%, 0.98%, 0.99%, 0.99%, 0.99%, 0.99%, 0.99%, 0.10%, 0.106%, 0.108%, 0.109%, 0.109%, 0.110%, 0.111%, 0.112%, 0.113%, 0.114%, 0.115%, 0.116%, 0.117%, 0.118%, 0.119 2%, 0.73%, 0.74%, 0.75%, 0.76%, 0.77%, 0.78%, 0.79%, 0.80%, 0.81%, 0.82%, 0.83%, 0.84%, 0.85%, 0.86%, 0.87%, 0.88%, 0.89%, 0.90%, 0.91%, 0.92%, 0.93%, 0.94%, 0.95%, 0.96%, 0.97%, 0.98%, 0.99%, 1.00%, 1.01%, 1.02%, 1.03%, 1.04%, 1.05%, 1.06%, 1.07%, 1.08% ,1.09%,1.10%,1.11%,1.12%,1.13%,1.14%,1.15%,1.16%,1.17%,1.18%,1.19%,1.20%,1.21%,1.22%,1.23%,1.24%,1.25%,1.26%,1.27%,1.28%,1.29%,1.30%,1.31%,1.32%,1.33%,1.34%,1.35%,1.36%,1.37%,1.38%,1.39%,1.40%,1.41%,1.42%,1.43%,1.44%,1.45%、1.46%、1.47%、1.48%、1.49%、1.50%、1.51%、1.52%、1.53%、1.54%、1.55%、1.56%、1.57%、1.58%、1.59%、1.60%、1.61%、1.62%、1.63%、1.64%、1.65%、1.66%、1.67%、1.68%、1.69%、1.70%、1.71%、1.72%、1.73%、1.74%、1.75%、1.76%、1.77%、1.78%、1.79%、1.80%、1.81%、1.82%、1.83%、1.84%、1.85%、1.86%、1.87%、1.88%、1.89%、1.90%、1.91%、1.92%、1.93%、1.94%、1.95%、1.96%、1.97%、1.98%、1.99%、2.00%、2.01%、2.02%、2.03%、2.04%、2.05%、2.06%、2.07%、2.08%、2.09%、2.10%、2.11%、2.12%、2.13%、2.14%、2.15%、2.16%、2.17%、2.18%、2.19%、2.20%、2.21%、2.22%、2.23%、2.24%、2.25%、2.26%、2.27%、2.28%、2.29%、2.30%、2.31%、2.32%、2.33%、2.34%、2.35%、2.36%、2.37%、2.38%、2.39%、2.40%、2.41%、2.42%、2.43%、2.44%、2.45%、2.46%、2.47%、2.48%、2.49%、2.50%、2.51%、2.52%、2.53%、2.54%、2.55%、2.56%、2.57%、2.58%、2.59%、2.60%、2.61%、2.62%、2.63%、2.64%、2.65%、2.66%、2.67%、2.68%、2.69%、2.70%、2.71%、2.72%、2.73%、2.74%、2.75%、2.76%、2.77%、2.78%、2.79%、2.80%、2.81%、2.82%、2.83%、2.84%、2.85%、2.86%、2.87%、2.88%、2.89%、2.90%、2.91%、2.92%、2.93%、2.94%、2.95%、2.96%、2.97%、2.98%、2.99%、3.00%、3.01%、3.02%、3.03%、3.04%、3.05%、3.06%、3.07%、3.08%、3.09%、3.10%、3.11%, 3.12%, 3.13%, 3.14%, 3.15%, 3.16%, 3.17%, 3.18%, 3.19%, 3.20%, 3.21%, 3.22%, 3.23%, 3.24%, 3.25%, 3.26%, 3.27%, 3.28%, 3.29%, 3.30%, 3.31%, 3.32%, 3.33%, 3.34%, 3.35%, 3.36%, 3.37%, 3.38%, 3.39%, 3.40%, 3.41%, 3.42%, 3.43%, 3.44%, 3.45%, 3.46 %,3.47%,3.48%,3.49%,3.50%,3.51%,3.52%,3.53%,3.54%,3.55%,3.56%,3.57%,3.58%,3.59%,3.60%,3.61%,3.62%,3.63%,3.64%,3.65%,3.66%,3.67%,3.68%,3.69%,3.70%,3.71%,3.72%,3.73%,3.74%,3.75%,3.76%,3.77%,3.78%,3.79%,3.80%,3.81%, 3.82%, 3.83%, 3.84%, 3.85%, 3.86%, 3.87%, 3.88%, 3.89%, 3.90%, 3.91%, 3.92%, 3.93%, 3.94%, 3.95%, 3.96%, 3.97%, 3.98%, 3.99%, 4.00%, 4.01%, 4.02%, 4.03%, 4.04%, 4.05%, 4.06%, 4.07%, 4.08%, 4.09%, 4.10%, 4.11%, 4.12%, 4.13%, 4.14%, 4.15%, 4.16%, 4. The alloy may contain 17%, 4.18%, 4.19%, 4.20%, 4.21%, 4.22%, 4.23%, 4.24%, 4.25%, 4.26%, 4.27%, 4.28%, 4.29%, 4.30%, 4.31%, 4.32%, 4.33%, 4.34%, 4.35%, 4.36%, 4.37%, 4.38%, 4.39%, 4.40%, 4.41%, 4.42%, 4.43%, 4.44%, 4.45%, 4.46%, 4.47%, 4.48%, 4.49%, or 4.50% Zn. In some cases, Zn is absent (i.e., 0%) in the alloy. All values ​​are expressed in wt%.

[0040] Ti (titanium) In some examples, the aluminum alloys described herein contain Ti in an amount up to 0.10%, e.g., 0.00%-0.10%, 0.01%-0.10%, or 0.05%-0.10%, based on the total weight of the alloy. For example, the alloy may contain 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, or 0.10% Ti. In some cases, Ti is absent (i.e., 0%) from the alloy. All values ​​are expressed in wt%.

[0041] Zirconium (Zr) In some examples, the aluminum alloys described herein contain Zr in an amount up to 0.20%, e.g., 0.00%-0.20%, 0.01%-0.20%, or 0.05%-0.20%, based on the total weight of the alloy. For example, the alloy may contain 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, or 0.20% Zr. In some cases, Zr is absent (i.e., 0%) in the alloy. All values ​​are expressed in wt%.

[0042] In some non-limiting examples, Cu and Mg can be combined to increase the corrosion resistance exhibited by an aluminum alloy product. In some examples, the combined amount of Cu and Mg present in the composition is between 0.00 wt% and 3.6 wt% (e.g., between 1.0 wt% and 3.0 wt%, between 1.5 wt% and 3.6 wt%, or between 2.30 wt% and 3.60 wt%). For example, the amounts of Cu and Mg combined are 0.01wt%, 0.02wt%, 0.03wt%, 0.04wt%, 0.05wt%, 0.06wt%, 0.07wt%, 0.08wt%, 0.09wt%, 0.10wt%, 0.11wt%, 0.12wt%, 0.13wt%, 0.14wt%, 0.15wt%, 0.16wt%, 0.17wt%, 0.18wt%, 0.19wt%, 0.20wt%, 0.21wt%, 0.22wt%, 0.23wt%, 0.24wt%, 0.25wt%, 0.26wt%, 0.27wt%, 0.28wt%, 0.29wt%, 0.30wt%, 0.31wt%, 0.32wt%, 0.33wt%, 0.34wt%, 0.35wt%, 0.36wt%, 0.37wt%, 0.38wt%, 0.39wt%, 0.40wt%, 0.41wt%, 0.42wt%, 0.43wt%, 0.44wt%, 0.45wt%, 0.46wt%, 0.47wt%, 0.48wt%, 0.49wt%, 0.50wt%, 0.51wt%, 0.52wt%, 0.53wt%, 0.54wt%, 0.55wt%, 0.56wt%, 0.57wt%, 0.58wt%, 0.59wt%, 0.60wt%, 0.61wt%, 0.62wt%, 0. 4wt%, 0.25wt%, 0.26wt%, 0.27wt%, 0.28wt%, 0.29wt%, 0.30wt%, 0.31wt%, 0.32wt%, 0.33wt%, 0.34wt%, 0.35wt%, 0.36wt%, 0.3 7wt%, 0.38wt%, 0.39wt%, 0.40wt%, 0.41wt%, 0.42wt%, 0.43wt%, 0.44wt%, 0.45wt%, 0.46wt%, 0.47wt%, 0.48wt%, 0.49wt%, 0.5 0wt%, 0.51wt%, 0.52wt%, 0.53wt%, 0.54wt%, 0.55wt%, 0.56wt%, 0.57wt%, 0.58wt%, 0.59wt%, 0.60wt%, 0.61wt%, 0.62wt%, 0. 63wt%, 0.64wt%, 0.65wt%, 0.66wt%, 0.67wt%, 0.68wt%, 0.69wt%, 0.70wt%, 0.71wt%, 0.72wt%, 0.73wt%, 0.74wt%, 0.75wt%, 0. 76wt%, 0.77wt%, 0.78wt%, 0.79wt%, 0.80wt%, 0.81wt%, 0.82wt%, 0.83wt%, 0.84wt%, 0.85wt%, 0.86wt%, 0.87wt%, 0.88wt%, 0. 89wt%, 0.90wt%, 0.91wt%, 0.92wt%, 0.93wt%, 0.94wt%, 0.95wt%, 0.96wt%, 0.97wt%, 0.98wt%, 0.99wt%, 1.00wt%, 1.01wt%, 1.02wt%、1.03wt%、1.04wt%、1.05wt%、1.06wt%、1.07wt%、1.08wt%、1.09wt%、1.10wt%、1.11wt%、1.12wt%、1.13wt%、1.14wt%、1.15wt%、1.16wt%、1.17wt%、1.18wt%、1.19wt%、1.20wt%、1.21wt%、1.22wt%、1.23wt%、1.24wt%、1.25wt%、1.26wt%、1.27wt%、1.28wt%、1.29wt%、1.30wt%、1.31wt%、1.32wt%、1.33wt%、1.34wt%、1.35wt%、1.36wt%、1.37wt%、1.38wt%、1.39wt%、1.40wt%、1.41wt%、1.42wt%、1.43wt%、1.44wt%、1.45wt%、1.46wt%、1.47wt%、1.48wt%、1.49wt%、1.50wt%、1.51wt%、1.52wt%、1.53wt%、1.54wt%、1.55wt%、1.56wt%、1.57wt%、1.58wt%、1.59wt%、1.60wt%、1.61wt%、1.62wt%、1.63wt%、1.64wt%、1.65wt%、1.66wt%、1.67wt%、1.68wt%、1.69wt%、1.70wt%、1.71wt%、1.72wt%、1.73wt%、1.74wt%、1.75wt%、1.76wt%、1.77wt%、1.78wt%、1.79wt%、1.80wt%、1.81wt%、1.82wt%、1.83wt%、1.84wt%、1.85wt%、1.86wt%、1.87wt%、1.88wt%、1.89wt%、1.90wt%、1.91wt%、1.92wt%、1.93wt%、1.94wt%、1.95wt%、1.96wt%、1.97wt%、1.98wt%、1.99wt%、2.00wt%、2.01wt%、2.02wt%、2.03wt%、2.04wt%、2.05wt%、2.06wt%、2.07wt%、2.08wt%、2.09wt%、2.10wt%、2.11wt%、2.12wt%、2.13wt%、2.14wt%、2.15wt%、2.16wt%、2.17wt%、2.18wt%、2.19wt%、2.20wt%、2.21wt%、2.22wt%、2.23wt%、2.24wt%、2.25wt%、2.26wt%、2.27wt%, 2.28wt%, 2.29wt%, 2.30wt%, 2.31wt%, 2.32wt%, 2.33wt%, 2.34wt%, 2.35wt%, 2.36wt%, 2.37wt%, 2.38wt%, 2.39wt%, 2.40wt%, 2.41wt%, 2.42wt% 、2.43wt%、2.44wt%、2.45wt%、2.46wt%、2.47wt%、2.48wt%、2.49wt%、2.50w t%、2.51wt%、2.52wt%、2.53wt%、2.54wt%、2.55wt%、2.56wt%、2.57wt%、2.58 wt%、2.59wt%、2.60wt%、2.61wt%、2.62wt%、2.63wt%、2.64wt%、2.65wt%、2. 66wt%、2.67wt%、2.68wt%、2.69wt%、2.70wt%、2.71wt%、2.72wt%、2.73wt%、2 .74wt%、2.75wt%、2.76wt%、2.77wt%、2.78wt%、2.79wt%、2.80wt%、2.81wt%、2.82wt%、2.83wt%、2.84wt%、2.85wt%、2.86wt%、2.87wt%、2.88wt%、2.89wt 2.90wt%, 2.91wt%, 2.92wt%, 2.93wt%, 2.94wt%, 2.95wt%, 2.96wt%, 2.97wt%, 2.98wt%, 2.99wt%, 3.00wt%, 3.01wt%, 3.02wt%, 3.03wt%, 3.04wt%, 3.0 5wt%、3.06wt%、3.07wt%、3.08wt%、3.09wt%、3.10wt%、3.11wt%、3.12wt%、3 .13wt%、3.14wt%、3.15wt%、3.16wt%、3.17wt%、3.18wt%、3.19wt%、3.20wt%、 3.21wt%, 3.22wt%, 3.23wt%, 3.24wt%, 3.25wt%, 3.26wt%, 3.27wt%, 3.28wt%, 3.29wt%, 3.30wt%, 3.31wt%, 3.32wt%, 3.33wt%, 3.34wt%, 3.35wt%, 3.36w t%、3.37wt%、3.38wt%、3.39wt%、3.40wt%、3.41wt%、3.42wt%、3.43wt%、3.4 4wt%、3.45wt%、3.46wt%、3.47wt%、3.48wt%、3.49wt%、3.50wt%、3.51wt%、3.The total weight of the cellulose acetate solution may be 52 wt%, 3.53 wt%, 3.54 wt%, 3.55 wt%, 3.56 wt%, 3.57 wt%, 3.58 wt%, 3.59 wt%, or 3.60 wt%.

[0043] The presence of Cu in an amount of at least 0.10 wt%, Mg in an amount of at least 2.8 wt%, and Cu as the major alloying element (other than Al), in combination with the processing conditions described below, can result in aluminum alloy products with exceptional strength and formability. In some cases, the combination results in aluminum alloy products with high corrosion resistance.

[0044] trace elements Optionally, the aluminum alloys described herein may further contain other trace elements, sometimes referred to as impurities, in amounts of 0.05% or less, 0.04% or less, 0.03% or less, 0.02% or less, or 0.01% or less. These impurities may include, but are not limited to, V, Ni, Hf, Zr, Sn, Ga, Ca, Bi, Na, Pb, or combinations thereof. Thus, V, Ni, Hf, Zr, Sn, Ga, Ca, Bi, Na, or Pb may be present in the alloy in amounts of 0.05% or less, 0.04% or less, 0.03% or less, 0.02% or less, or 0.01% or less. The sum of all impurities does not exceed 0.15% (e.g., 0.1%), all expressed in wt%. The remaining percentage of each alloy may be aluminum.

[0045] The aluminum alloys described herein include at least 40 wt% recycled content, for example, at least 45 wt%, at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, or at least 95 wt% recycled content.

[0046] Processing method Optionally, aluminum alloy products suitable for use in the methods described herein include 7xxx series aluminum alloys. In some cases, 7xxx series aluminum alloys for use in the methods described herein can be 7xxx series aluminum alloys registered with the Aluminum Association, optionally modified to include amounts of Zr, Mg, Zn, and / or any of the other elements described above. 7xxx series aluminum alloys include, for example, AA7003, AA7004, AA7204, AA7005, AA7108, AA7108A, AA7009, AA7010, AA7012, AA7108A, AA7108A, AA7108B, AA7108C ...A, AA7108B, AA7108C, AA7108A, AA7108B, AA7108A, AA7108B, AA7108A, AA7108B, AA7108B, AA7108B, AA7108B, AA7108B, AA7108B, AA7108B, AA7108B, AA7108B, AA7108B, AA7108B, AA7014, AA7015, AA7016, AA7116, AA7017, AA7018, AA7019, AA7019A, AA7020, AA7021, AA7022, AA7122, AA7 023, AA7024, AA7025, AA7026, AA7028, AA7029, AA7129, AA7229, AA7030, AA7031, AA7032, AA7033, AA7034, AA7035, AA7035A, AA7036, AA7136, AA7037, AA7039, AA7040, AA7140, AA7041, AA7042, AA7046, AA7046A, AA 7047, AA7049, AA7049A, AA7149, AA7249, AA7349, AA7449, AA7050, AA7050A, AA7150, AA7055, AA7155, AA72 55, AA7056, AA7060, AA7064, AA7065, AA7068, AA7168, AA7072, AA7075, AA7175, AA7475, AA7076, AA7178, AA7278, AA7278A, AA7081, AA7181, AA7085, AA7185, AA7090, AA7093, AA7095, AA7099, or AA7199.

[0047] In some embodiments, the alloy is a monolithic alloy. In some embodiments, the alloy is a clad aluminum alloy having a core layer and one or two clad layers. In some cases, the core layer can be different from one or both clad layers. The core layer can be, for example, an aluminum alloy described herein (e.g., an aluminum alloy including at least 0.1 wt% Zr, at least 2.3 wt% Mg, at least 0.1 wt% Cu, and Zn as the major alloying element other than Al).

[0048] casting The alloys can be cast using any suitable casting process. For example, molten aluminum alloy compositions including the aluminum alloys described herein can be cast using a continuous casting (CC) process, including, but not limited to, using a twin belt caster, a twin roll caster, or a block caster. In some embodiments, the casting process is carried out using a CC process to form a cast product, such as, for example, a billet, a slab, or a strip.

[0049] In some cases, the resulting cast aluminum alloy product may exit the caster at a temperature (e.g., caster exit temperature) of 370° C. to 450° C. For example, the cast aluminum alloy product may have a caster exit temperature of 370° C., 380° C., 390° C., 400° C., 410° C., 420° C., 430° C., 440° C., 450° C., or any temperature therebetween.

[0050] The resulting cast aluminum alloy product can have a thickness of 5 mm to 50 mm (e.g., 10 mm to 45 mm, 15 mm to 40 mm, or 20 mm to 35 mm), for example, 10 mm. For example, the cast aluminum alloy product can be 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 21 mm, 22 mm, 23 mm, 24 mm, 25 mm, 26 mm, 27 mm, 28 mm, 29 mm, 30 mm, 31 mm, 32 mm, 33 mm, 34 mm, 35 mm, 36 mm, 37 mm, 38 mm, 39 mm, 40 mm, 41 mm, 42 mm, 43 mm, 44 mm, 45 mm, 46 mm, 47 mm, 48 mm, 49 mm, or 50 mm thick.

[0051] The cast aluminum alloy product may then be subjected to further processing steps. In some non-limiting examples, processing methods include hot rolling, coiling, coil cooling, further processing, solutionizing, and / or aging. In some cases, further processing may include homogenizing and hot rolling to final gauge. In other cases, further processing steps may include homogenizing, cooling, and cold rolling to final gauge. In still other cases, further processing steps may include cold rolling to final gauge.

[0052] hot rolling The casting step can be followed by a hot rolling step. In some cases, the hot rolling step can be performed immediately after casting. The hot rolling step can include a hot reversing mill operation and / or a hot tandem mill operation. The hot rolling step can be performed at a temperature ranging from 250°C to 500°C (e.g., 300°C to 400°C, or 350°C to 430°C). For example, the hot rolling step can be carried out at 250°C, 260°C, 270°C, 280°C, 290°C, 300°C, 310°C, 320°C, 330°C, 340°C, 350°C, 360°C, 370°C, 380°C, 390°C, 400°C, 410°C, 420°C, 430°C, 440°C, 450°C, 460°C, 470°C, 480°C, 490°C, 500°C, or any temperature therebetween.

[0053] In the hot rolling step, the cast aluminum alloy product can be hot rolled to a thickness of 15 mm or less (e.g., 2 mm to 10 mm) to provide an aluminum alloy hot band. For example, the cast aluminum alloy product can be hot rolled to 15 mm gauge or less, 14 mm gauge or less, 13 mm gauge or less, 12 mm gauge or less, 11 mm gauge or less, 10 mm gauge or less, 9 mm gauge or less, 8 mm gauge or less, 7 mm gauge or less, 6 mm gauge or less, 5 mm gauge or less, 4 mm gauge or less, 3 mm gauge or less, or 2 mm gauge or less. In some cases, the thickness reduction achieved by the hot rolling step can be at least 40% (e.g., 40% to 50%). For example, the thickness of the cast aluminum alloy product can be reduced by 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, or 80%. In some cases, the aluminum alloy hot band can exit the hot reversing mill and / or hot tandem mill (i.e., hot mill) at a temperature of 300° C. to 400° C. For example, the aluminum alloy hot band can have a hot mill exit temperature of 300° C., 310° C., 320° C., 330° C., 340° C., 350° C., 360° C., 370° C., 380° C., 390° C., 400° C., or any temperature therebetween.

[0054] Coiling and coil cooling Optionally, the aluminum alloy hot band can be wound into a hot band coil upon exiting the hot mill. In some further examples, the hot band coil is cooled in air (referred to as coil cooling). The coil cooling step can be performed at a rate of 12.5°C per hour (°C / h) to 3600°C / h. For example, the coil cooling step can be performed at a rate of 12.5°C / h, 25°C / h, 50°C / h, 100°C / h, 200°C / h, 400°C / h, 800°C / h, 1600°C / h, 3200°C / h, 3600°C / h, or any rate therebetween. The hot band coil can be cooled to a temperature of 300°C to 400°C. For example, the hot band coil can be cooled to a temperature of 300°C, 310°C, 320°C, 330°C, 340°C, 350°C, 360°C, 370°C, 380°C, 390°C, or 400°C.

[0055] In some examples, the air-cooled coil can be stored for a period of time. For example, the coil can be maintained at a temperature of 300°C to 400°C for 1 hour or more (e.g., 2 hours or more, 5 hours or more, 10 hours or more, 1 day or more, 2 days or more, or 1 week or more).

[0056] Homogenizing, hot rolling to final gauge, coil cooling, and cold rolling to final gauge Optionally, homogenization can be performed after hot rolling, coiling, and coil cooling. The homogenization step can involve heating the hot band coil to a peak metal temperature (PMT) of 450°C or at least 450°C (e.g., at least 460°C, at least 470°C, at least 480°C, at least 490°C, at least 500°C, at least 510°C, at least 520°C, at least 530°C, at least 540°C, at least 550°C, at least 560°C, at least 570°C, or at least 580°C). For example, the hot band coil can be heated to a temperature of 450°C to 580°C, 460°C to 575°C, 465°C to 570°C, 470°C to 565°C, 475°C to 555°C, or 480°C to 550°C. In some cases, the heating rate to the PMT can be 100° C. / hr or less, 75° C. / hr or less, 50° C. / hr or less, 40° C. / hr or less, 30° C. / hr or less, 25° C. / hr or less, 20° C. / hr or less, or 15° C. / hr or less. In other cases, the heating rate to the PMT can be between 10° C. / min and 100° C. / min (e.g., between 10° C. / min and 90° C. / min, between 15° C. / min and 70° C. / min, between 20° C. / min and 60° C. / min, between 20° C. / min and 50° C. / min, or between 30° C. / min and 40° C. / min).

[0057] The hot band coil is then allowed to soak (i.e., held at the indicated temperature) for a period of time. According to one non-limiting example, the hot band coil is soaked for up to 36 hours (e.g., 30 minutes, 2 hours, or 36 hours). For example, the hot band coil can be soaked for the indicated time period: 30 minutes, 60 minutes (i.e., 1 hour), 90 minutes, 120 minutes (i.e., 2 hours), 150 minutes, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 13 hours, 14 hours, 15 hours, 16 hours, 17 hours, 18 hours, 19 hours, 20 hours, 21 hours, 22 hours, 23 hours, 24 hours, 25 hours, 26 hours, 27 hours, 28 hours, 29 hours, 30 hours, 31 hours, 32 hours, 33 hours, 34 hours, 35 hours, 36 hours, or any time therebetween.

[0058] In some non-limiting examples, no homogenization step is performed.

[0059] Optionally, the homogenized hot band coil can be hot rolled to provide a final gauge aluminum alloy product. Hot rolling to final gauge can be performed after the homogenization step, for example, using a finishing mill. The hot rolling step can be performed at a temperature ranging from 250°C to 500°C (e.g., 300°C to 400°C, or 350°C to 430°C). For example, the hot rolling step can be performed at temperatures ranging from 250°C, 260°C, 270°C, 280°C, 290°C, 300°C, 310°C, 320°C, 330°C, 340°C, 350°C, 360°C, 370°C, 380°C, 390°C, 400°C, 410°C, 420°C, 430°C, 440°C, 450°C, 460°C, 470°C, 480°C, 490°C, 500°C, or any temperature range therebetween.

[0060] Hot rolling to a final gauge step can further reduce the thickness of the hot band to a final gauge of 0.5 mm to 6 mm. For example, hot rolling to a final gauge step can result in an aluminum alloy product having a gauge of 6 mm or less, 5.5 mm or less, 5 mm or less, 4.5 mm or less, 4 mm or less, 3.5 mm or less, 3 mm or less, 2.5 mm or less, 2 mm or less, 1.5 mm or less, 1 mm or less, 0.5 mm, or any gauge therebetween.

[0061] Optionally, after homogenization, the homogenized hot band coil can undergo coil cooling and cold rolling. The homogenized hot band coil can be cooled in air at a rate of 12.5°C per hour (°C / h) to about 3600°C / h. For example, the coil cooling step can be performed at a rate of 12.5°C / h, 25°C / h, 50°C / h, 100°C / h, 200°C / h, 400°C / h, 800°C / h, 1600°C / h, 3200°C / h, 3600°C / h, or any rate therebetween. After coil cooling, a cold rolling step can optionally be performed. During the cold rolling step, the homogenized hot band coil can be cold rolled to a thickness of 0.1 mm to 6 mm (e.g., 0.5 mm to 5 mm). For example, the homogenized hot band coil can be cold rolled to a thickness of less than 4 mm to provide a final gauge aluminum alloy product. For example, the final gauge aluminum alloy product can have a thickness of 6 mm or less, 5.5 mm or less, 5 mm or less, 4.5 mm or less, 4 mm or less, 3.5 mm or less, 3 mm or less, 2.5 mm or less, 2 mm or less, 1.5 mm or less, 1 mm or less, 0.5 mm, or any thickness therebetween. Optionally, the cold rolling step can be performed without the homogenizing step and / or the hot rolling step.

[0062] In some cases, an exemplary sequence of steps used to further process the hot band coil to provide a final gauge aluminum alloy product includes homogenizing the hot band coil to provide a homogenized hot band coil and hot rolling the homogenized hot band coil to provide a final gauge aluminum alloy product. In other cases, an exemplary sequence of steps used to further process the hot band coil to provide a final gauge aluminum alloy product includes homogenizing the hot band coil to provide a homogenized hot band coil, cooling the homogenized hot band coil, and cold rolling the homogenized hot band coil to provide a final gauge aluminum alloy product. In yet other cases, further processing the hot band coil to provide a final gauge aluminum alloy product includes cold rolling the hot band coil to provide a final gauge aluminum alloy product.

[0063] Solid solution The methods described herein further include solutionizing the final gauge aluminum alloy product. The solutionizing step can include heating or cooling the final gauge aluminum alloy product to a solution temperature of 450°C or higher (e.g., 460°C-600°C, 465°C-575°C, 470°C-550°C, 475°C-525°C, or 480°C-500°C), as needed. The final gauge aluminum alloy product can be soaked at the solution temperature for a period of time. In certain embodiments, the final gauge aluminum alloy product is soaked for at least 30 seconds (e.g., 60 seconds-120 seconds, inclusive). For example, the final gauge aluminum alloy product may be immersed at a temperature of 450°C or greater for 30 seconds, 35 seconds, 40 seconds, 45 seconds, 50 seconds, 55 seconds, 60 seconds, 65 seconds, 70 seconds, 75 seconds, 80 seconds, 85 seconds, 90 seconds, 95 seconds, 100 seconds, 105 seconds, 110 seconds, 115 seconds, 120 seconds, 125 seconds, 130 seconds, 135 seconds, 140 seconds, 145 seconds, 150 seconds, 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, 35 minutes, 40 minutes, 45 minutes, 50 minutes, 55 minutes, 60 minutes, 65 minutes, 70 minutes, 75 minutes, 80 minutes, 85 minutes, 90 minutes, 95 minutes, 100 minutes, 105 minutes, 110 minutes, 115 minutes, or 120 minutes, or any time in between. In certain embodiments, solution treatment is carried out immediately after the hot rolling or cold rolling step.

[0064] Quenching The methods described herein include a quenching step. As used herein, the term "quenching" can include rapidly reducing the temperature of a solution-treated, final-gauge aluminum alloy product as described above. In the quenching step, the product can be quenched with a liquid (e.g., water), a gas (air), any other suitable quenching medium, or any combination thereof. In certain embodiments, the product can be quenched using water having a water temperature between 40°C and 75°C. In certain embodiments, the product is quenched using forced air.

[0065] In certain embodiments, the product can be cooled to a temperature of 25°C to 65°C in a quenching step based on the gauge selected, with the quenching rate varying between 50°C / s and 400°C / s. For example, the quenching rate can be 50°C to 375°C / s, 60°C to 375°C / s, 70°C to 350°C / s, 80°C to 325°C / s, 90°C to 300°C / s, 100°C to 275°C / s, 125°C to 250°C / s, 150°C to 225°C / s, or 175°C to 200°C / s.

[0066] Pre-aging In some cases, a pre-aging step can be performed. Without being bound by theory, the pre-aging step at least partially counteracts changes in mechanical properties caused by natural aging of the aluminum alloy product. Optionally, the pre-aging step can be performed before or after the solution treatment step. The pre-aging step can include heating the final gauge aluminum alloy product to a pre-aging temperature of 50°C to 300°C (e.g., 75°C to 250°C, 100°C to 300°C, 100°C to 275°C, or 100°C to 250°C). For example, the pre-aging process may be performed on the final gauge aluminum alloy product at temperatures of 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, 155°C, 160°C, 165°C, 170°C, 175°C, 176°C, 177°C, 178°C, 180°C, 185°C, 186°C, 187°C, 188°C, 189°C The pre-aging process may include heating to a temperature of 0°C, 175°C, 180°C, 185°C, 190°C, 195°C, 200°C, 205°C, 210°C, 215°C, 220°C, 225°C, 230°C, 235°C, 240°C, 245°C, 250°C, 255°C, 260°C, 265°C, 270°C, 275°C, 280°C, 285°C, 290°C, 295°C, or 300°C. The final gauge aluminum alloy product may be maintained at the pre-aging temperature for a period of up to 72 hours (e.g., 1 hour to 72 hours). For example, the final gauge aluminum alloy product may be maintained for 72 hours or less, 60 hours or less, 48 ​​hours or less, 36 hours or less, 24 hours or less, 12 hours or less, 6 hours or less, 5 hours or less, 4 hours or less, 3 hours or less, 2 hours or less, 1 hour or less, or any time in between.

[0067] Aging After solutionizing, a quenching and / or pre-aging step, one or more aging steps can be performed, which can include one or more of natural aging, artificial aging, paint baking, and post-forming heat treatment.

[0068] Optionally, the aging can include a natural aging step. Natural aging can include maintaining the final gauge aluminum alloy product at room temperature for a period of time. For example, the final gauge aluminum alloy product can be maintained at room temperature for up to 12 weeks (e.g., 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 1 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks, 11 weeks, or 12 weeks).

[0069] Aluminum alloy products prepared according to the methods described herein can be subjected to optional pre-aging and natural aging before delivery. The aluminum alloy products can achieve high yield strength after end-user processing, for example, by deformation (e.g., stamping, pressing, forming, or any suitable deformation process) and / or by aging or heat treatment (e.g., coating and paint baking, artificial aging, post-forming heat treatment, or any suitable end-user heat treatment). Optionally, after the optional pre-aging and / or natural aging step, the aluminum alloy products described herein are subjected to, for example, a forming process, a coating process, an artificial aging process, and / or a paint baking process.

[0070] Optionally, aging can include an artificial aging step, which can involve heating the final gauge aluminum alloy product to an artificial aging temperature of 80°C to 250°C (e.g., 80°C to 225°C, 100°C to 225°C, 100°C to 225°C, 110°C to 220°C, 115°C to 210°C, or 120°C to 210°C, 125°C to 225°C, 140°C to 225°C, 160°C to 225°C, 180°C to 225°C, 200°C to 225°C, and all combinations of the endpoints). The artificial aging step can include maintaining the artificial aging temperature for a period of from 30 minutes to 72 hours (e.g., 1 hour, 2 hours, 4 hours, 8 hours, 10 hours, 12 hours, 15 hours, 20 hours, 24 hours, 30 hours, 48 ​​hours, 60 hours, or 72 hours, inclusive of all combinations of endpoints).

[0071] In some embodiments, an optional coating procedure (e.g., painting, electrocoating, or zinc phosphating, to name a few) can be performed. After coating, the final gauge aluminum alloy product can be subjected to further heat treatment, including paint baking, post-forming heat treatment, any suitable OEM heat treatment process, or any combination thereof. Paint baking can further strengthen the aluminum alloy product to provide a high-strength aluminum alloy product, optionally with an intricate formed surface. In some cases, the paint baking procedure can include heating the aluminum alloy product to a paint baking temperature of 75°C to 250°C and maintaining the aluminum alloy product at the paint baking temperature for a period of up to 3 hours (e.g., 15 minutes to 2 hours, 15 minutes to 45 minutes, or 30 minutes to 1 hour). In some embodiments, at least one paint baking step may be performed at a temperature of 75 to 250°C for 15 minutes to 3 hours, at a temperature of 100 to 200°C for 15 minutes to 2 hours, or at a temperature of 150 to 180°C for 15 minutes to 45 minutes.

[0072] In some further cases, a post-forming heat treatment can be performed. The post-forming heat treatment procedure can include heating the final gauge aluminum alloy product to a post-forming heat treatment temperature of 100°C to 250°C and maintaining this temperature for 1 hour to 24 hours (e.g., 2 hours to 12 hours). In some embodiments, the methods of forming the aluminum alloys described herein can include at least one paint bake. In some embodiments, the methods of making the aluminum alloys described herein can include at least two paint bakes. The methods of making the aluminum alloys described herein can include one to five paint bakes. For example, the methods of making the aluminum alloys described herein can include one paint bake, two paint bakes, three paint bakes, four paint bakes, five paint bakes, or more than five paint bakes.

[0073] Alloy Product Properties The aluminum alloy products described herein can have high strength and formability properties before and after aging as described herein. In some aspects, the aluminum alloy products are formable at temperatures below room temperature, for example, from 0 to a maximum of 15°C. In some embodiments, the aluminum alloy products are formable at ambient (room) temperatures and at temperatures up to 40°C.

[0074] The aluminum alloy product may have a service strength (yield strength as entered into service after final heat treatment, including natural and artificial aging) in the T4 temper, such as after at least two paint bake cycles, of at least 390 MPa, e.g., at least 395 MPa, at least 400 MPa, at least 405 MPa, at least 410 MPa, at least 415 MPa, at least 420 MPa, at least 425 MPa, at least 430 MPa, at least 435 Pa, at least 440 Pa, at least 445 MPa, at least 450 MPa, at least 455 MPa, at least 460 MPa, at least 465 MPa, at least 470 MPa, at least 475 MPa, and up to 500 MPa.

[0075] In some cases, the aluminum alloy product achieves an increase in elongation and an increase in yield strength after aging compared to the elongation and yield strength achieved by the aluminum alloy product before aging. The increase in elongation can be at least 1% (e.g., 1.5% to 5%, or 2% to 3%). For example, the increase in elongation may be 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, or greater than 5%.

[0076] The increase in yield strength can be at least 15 MPa (e.g., 15 MPa to 150 MPa). For example, the increase in yield strength can be 15 MPa, 16 MPa, 17 MPa, 18 MPa, 19 MPa, 20 MPa, 21 MPa, 22 MPa, 23 MPa, 24 MPa, 25 MPa, 26 MPa, 27 MPa, 28 MPa, 29 MPa, 30 MPa, 31 MPa, 32 MPa, 33 MPa, 34 MPa, 35 MPa, 36 MPa, 37 MPa, 38 MPa, 39 MPa, 40 MPa, 41 MPa, 42 MPa, 43 MPa, 44 MPa, 45 MPa, 46 MPa, 47 MPa, 48 MPa, 49 MPa, 50 MPa, 51 MPa, 52 MPa, 53 MPa, 54 MPa, 55 MPa, 56 MPa, 57 MPa, 58 MPa, 59 MPa, 60 MPa, 61 MPa, 62 MPa, 63 MPa, 64 MPa, 65 MPa, 66 MPa, 67 MPa, 68 MPa, 69 MPa, 70 MPa, 71 MPa, 72 MPa, 73 MPa, 74 MPa, 75 MPa, 76 MPa, 77 MPa, 78 MPa, 79 MPa, 80 MPa, 81 MPa, 82 MPa, 83 MPa, 84 MPa, 85 MPa, 86 MPa, 87 MPa, 88 MPa, 89 MPa, 90 MPa, 91 MPa, 92 MPa, 0MPa, 51MPa, 52MPa, 53MPa, 54MPa, 55MPa, 56MPa, 57MPa, 58MPa, 59MPa, 60MPa, 61MPa, 62MPa, 63MPa, 64MPa, 65MPa, 66MPa, 67MPa, 68MPa , 69MPa, 70MPa, 71MPa, 72MPa, 73MPa, 74MPa, 75MPa, 76MPa, 77MPa, 78MPa, 79MPa, 80MPa, 81MPa, 82MPa, 83MPa, 84MPa, 85MPa, 86MPa, 87M Pa, 88MPa, 89MPa, 90MPa, 91MPa, 92MPa, 93MPa, 94MPa, 95MPa, 96MPa, 97MPa, 98MPa, 99MPa, 100MPa, 101MPa, 102MPa, 103MPa, 104MPa, 10 5MPa, 106MPa, 107MPa, 108MPa, 109MPa, 110MPa, 111MPa, 112MPa, 113MPa, 114MPa, 115MPa, 116MPa, 117MPa, 118MPa, 119MPa, 120MPa, 12 It may be 1 MPa, 122 MPa, 123 MPa, 124 MPa, 125 MPa, 126 MPa, 127 MPa, 128 MPa, 129 MPa, 130 MPa, 131 MPa, 132 MPa, 133 MPa, 134 MPa, 135 MPa, 136 MPa, 137 MPa, 138 MPa, 139 MPa, 140 MPa, 141 MPa, 142 MPa, 143 MPa, 144 MPa, 145 MPa, 146 MPa, 147 MPa, 148 MPa, 149 MPa, 150 MPa, or greater than 150 MPa.

[0077] In some examples, the aluminum alloy product has a yield strength of greater than 350 MPa after processing according to the methods described herein. For example, the aluminum alloy product may have a yield strength of 360 MPa or greater, 365 MPa or greater, 370 MPa or greater, 375 MPa or greater, 380 MPa or greater, 385 MPa or greater, 390 MPa or greater, 395 MPa or greater, 400 MPa or greater, 405 MPa or greater, 410 MPa or greater, 415 MPa or greater, 420 MPa or greater, 425 MPa or greater, 430 MPa or greater, 435 MPa or greater, 440 MPa or greater, 445 MPa or greater, 450 MPa or greater, 455 MPa or greater, 460 MPa or greater, It may have a yield strength of 465 MPa or more, 470 MPa or more, or 475 MPa or more, 480 MPa or more, 485 MPa or more, 490 MPa or more, 495 MPa or more, 500 MPa or more, 505 MPa or more, 510 MPa or more, 515 MPa or more, 520 MPa or more, 525 MPa or more, 530 MPa or more, 535 MPa or more, 540 MPa or more, 545 MPa or more, 550 MPa or more, 555 MPa or more, 560 MPa or more, 565 MPa or more, 570 MPa or more, or 575 MPa or more.

[0078] The increase in ultimate tensile strength can be at least 5 MPa (e.g., 15 MPa to 50 MPa). For example, the increase in yield strength can be 5 MPa, 6 MPa, 7 MPa, 8 MPa, 9 MPa, 10 MPa, 11 MPa, 12 MPa, 13 MPa, 14 MPa, 15 MPa, 16 MPa, 17 MPa, 18 MPa, 19 MPa, 20 MPa, 21 MPa, 22 MPa, 23 MPa, 24 MPa, 25 MPa, 26 MPa, 27 MPa, 28 MPa, 29 MPa, 30 MPa, 31 MPa, 32 MPa, 33 MPa, 34 MPa, 35 MPa, 36 MPa, 37 MPa, 38 MPa, 39 MPa, 40 MPa, 41 MPa, 42 MPa, 43 MPa, 44 MPa, 45 MPa, 46 MPa, 47 MPa, 48 MPa, 49 MPa, 50 MPa, or greater than 50 MPa.

[0079] In some examples, the aluminum alloy product has an ultimate tensile strength of greater than 350 MPa after processing according to the methods described herein. For example, the aluminum alloy product may have an ultimate tensile strength of 360 MPa or greater, 365 MPa or greater, 370 MPa or greater, 375 MPa or greater, 380 MPa or greater, 385 MPa or greater, 390 MPa or greater, 395 MPa or greater, 400 MPa or greater, 405 MPa or greater, 410 MPa or greater, 415 MPa or greater, 420 MPa or greater, 425 MPa or greater, 430 MPa or greater, 435 MPa or greater, 440 MPa or greater, 445 MPa or greater, 450 MPa or greater, 455 MPa or greater, 460 MPa or greater, It may have a yield strength of 465 MPa or more, 470 MPa or more, or 475 MPa or more, 480 MPa or more, 485 MPa or more, 490 MPa or more, 495 MPa or more, 500 MPa or more, 505 MPa or more, 510 MPa or more, 515 MPa or more, 520 MPa or more, 525 MPa or more, 530 MPa or more, 535 MPa or more, 540 MPa or more, 545 MPa or more, 550 MPa or more, 555 MPa or more, 560 MPa or more, 565 MPa or more, 570 MPa or more, or 575 MPa or more.

[0080] How to use The alloy products and methods described herein can be used in automotive and / or transportation applications, including automotive, aircraft, and railroad applications, or any other desired application. In some examples, the products and methods can be used to make automotive bodywork products, such as bumpers, side beams, roof beams, cross beams, pillar reinforcements (e.g., A-pillars, B-pillars, and C-pillars), interior panels, exterior panels, side panels, interior hoods, exterior hoods, or trunk lid panels. The aluminum alloy products and methods described herein can also be used in aircraft or railroad vehicle applications, for example, to make exterior and interior panels.

[0081] The products and methods described herein can also be used in electronics applications, such as to create exterior and interior enclosures. For example, the products and methods described herein can be used to create housings for electronic devices, including mobile phones and tablet computers. In some embodiments, the products can be used to create housings for the exterior casings of bottom chassis of mobile phones (e.g., smartphones) and tablets.

[0082] In certain aspects, the products and methods can be used to make aerospace body component products. For example, the disclosed products and methods can be used to make aircraft airframe components such as skin alloys.

[0083] The products and methods may be used in any other desired application. [Example]

[0084] Example 1: Mechanical properties of highly formable high-strength aluminum alloy Cast aluminum alloy products were prepared from aluminum alloy compositions containing 0.11 wt% Si, 0.21 wt%, 0.20 wt%, 0.10 wt%, 3.29 wt%, 0.0 wt% Cr, 4.34 wt% Zn, 0.02 wt% Ti, 0.1 wt% Zr, up to 0.15 wt% impurities, and the balance aluminum, using the methods described herein and further below (referred to herein as "Example 1"). Samples of Example 1 were subjected to mechanical testing. In some cases, an additional paint bake step was used, in which the aluminum alloy product was heated to a temperature of 180°C and maintained at this temperature for 30 minutes. In some cases, additional tempers were used on the aluminum alloys to compare mechanical properties under different methods of manufacturing the aluminum alloy products. In some cases, some steps were omitted from the manufacturing process, while other steps were optional, and the manufacturing process and corresponding mechanical properties of the alloys were further tested.

[0085] 1A-1C provide graphs of yield strength, ultimate tensile strength, and total elongation of aluminum alloy compositions described herein during the natural aging response, water-quenched (WQ) at 2.0 mm gauge (A), air-quenched (AQ) at 2.4 mm gauge (B), and WQ at 2.4 mm gauge (C), according to some embodiments described herein. The aluminum alloy of Example 1 was produced by the methods described herein and further pre-aged to a T4 temper (sometimes designated PX) to test the effect of natural aging on the alloy. FIG. 1A shows that the aluminum alloy of Example 1, prepared as described and further rolled to 2.0 mm and water-quenched (WQ), initially had a yield stress of 292 MPa, which increased to 312 MPa after 5.5 months of natural aging. The ultimate tensile strength initially started at 438 MPa and increased to 458 MPa after 5.5 months. Additionally, total elongation increased from 18.9% to 22.4% over a 5.5-month period. Figure 1B shows that the aluminum alloy of Example 1, prepared as described herein and further rolled (AQ) to 2.4 mm, initially had a yield stress of 301 MPa, which increased to 317 MPa after 5.5 months. The ultimate tensile strength increased from 434 MPa to 454 MPa over the same 5.5-month period, and total elongation increased from 18.2% to 19.6%. Figure 1C shows that the aluminum alloy of Example 1, prepared as described herein and further rolled to 2.4 mm and WQ, initially had a yield stress of 308 MPa, which increased to 323 MPa over the same 5.5-month period. The ultimate tensile strength increased from 440 MPa to 455 MPa, and total elongation increased from 18.2% to 20.9% over the same 5.5-month period. The results show that the aluminum alloys described herein and produced by the above-described methods have improved mechanical properties due to natural aging.

[0086] 2A-B provide graphs of the yield strength (YS), ultimate tensile strength (UTS), and total elongation (TE) of aluminum alloy compositions described herein after multiple paint bake cycles and T4 temper (A) or T6 temper (B) conditions, according to some embodiments described herein. The aluminum alloy of Example 1 initially had an average yield strength (YS) of 295 MPa, an ultimate tensile strength of 444 MPa, and a total elongation of 20.1% after two months of natural aging (FIG. 2A). After one paint bake cycle, the yield strength increased to 369 MPa, the ultimate tensile strength (UTS) decreased to 434 MPa, and the total elongation (TE) decreased to 12.8%. By including an additional paint bake cycle, the yield strength increased to 388 MPa, the ultimate tensile strength decreased to 449 MPa, and the total elongation further decreased to 11.8%. Another paint bake cycle resulted in a yield strength of 389 MPa, an ultimate tensile strength of 449 MPa, and a total elongation of 12.9%. The aluminum alloy of Example 1 was subjected to the T6 temper under the same treatment as above. The alloy exhibited improved mechanical properties, including a yield strength of 441 MPa, a UTS of 495 MPa, and a TE of 14.0% (Figure 2B). After one paint bake, the aluminum alloy had a YS of 406 MPa, a UTS of 464 MPa, and a TE of 15.2%. Adding another paint bake reduced the three properties to a YS of 398 MPa, a UTS of 458 MPa, and a TE of 12.5%. After a third paint bake cycle, the resulting aluminum alloy had a UTS of 452 MPa, a YS of 392 MPa, and a TE of 13.0%. These results indicate that the mechanical properties of aluminum alloys in the T4 temper can be improved with additional paint bake cycles, while the mechanical properties of T6 alloys can be reduced with additional paint bake cycles.

[0087] FIG. 3 shows a graph of lap bends for an exemplary aluminum alloy described herein after the T4 and T6 tempers compared to Comparative Example 1, according to some embodiments described herein. The aluminum alloy of Example 1 in the T4 temper produced 0.81 lap bends in the longitudinal direction, 1.02 r / t in the transverse direction, and 0.81 r / t in the d-direction. The same aluminum alloy in the T6 temper had 0.89 r / t in the longitudinal direction, 1.15 r / t in the transverse direction, and 0.89 r / t in the d-direction. Comparative Example 1 in the T4 temper had 0.4 r / t or less in each of the three directions, and Comparative Example 1 in the T82 temper had 0.7 r / t or less in each of the three directions. The aluminum alloy of Example 1 has a higher lap bend rating when compared to currently available alloys under similar temper conditions.

[0088] Figures 4A-B provide photographs (A) and die depths (B) of various rivet and die designs for an aluminum alloy described herein according to some embodiments described herein. The aluminum alloy of Example 1 was rolled to 2.0 mm plate under T4 temper conditions. Two rivet lengths and three different die designs were tested at various depths. As can be seen from the die photograph (Figure 4A), the 5x6H4 / DG10-180 exhibited cracking and reduced performance compared to the 5x6H4 / DC10-150 die. Additionally, the 5x5H4 / DP10-200 exhibited cracking during operation. The flat die was crack-free at a depth of 150 mm, but severe cracking began at 160 mm (Figure 4B). The 5x5H4 pip die reached a maximum depth of 175 mm before severe cracking appeared.

[0089] FIG. 5 provides photographs of 2.0 mm WQ, 2.4 mm AC, and 2.4 mm WQ aluminum alloys under 30 kA and 34 kA according to some embodiments described herein. Spot welds were formed on 2.0 mm WQ, 2.4 mm WQ, and 2.4 mm AC specimens of the aluminum alloy of Example 1. The results show that no visible cracks or pinholes were found in any of the spot welds at any current flow. The emission rate for the 2.0 mm WQ ranged from 30 kA to 33 kA, and the emission rate for the 2.4 mm AC ranged from 32 kA to 34 kA. The 2.4 mm WQ exhibited no emission during testing, demonstrating good weld size.

[0090] To further test the aluminum alloy of Example 1, formability tests were conducted in the form of cup draw tests in both flat (FIG. 6A and B) and round (FIG. 7A and B) conditions. The results of the flat (FIG. 6A and B) formability tests indicate that natural aging after 150 hours did not affect the forming depth of the aluminum alloy of Example 1 under natural aging with pre-aging, but not the T6 temper. Comparative Example 1 under similar conditions experienced a reduction in forming depth from 55 mm to less than 30 mm after 24 hours of pre-aging. Furthermore, while the forming depth decreased in each of the tests for Comparative Example 1 under pre-aging, Example 1 did not experience cracking under any of the conditions tested. Similar results were obtained in the round bottom tests (FIG. 7A and B), except for the pre-aging and T6 tempers. Under those conditions, the forming depth was significantly reduced to less than 33 mm. The aluminum alloy of Example 1 can be fully drawn into cup specimens under natural aging, pre-aging, and T6 tempering, but the formability of a comparable alloy composition decreases sharply after 1 day of natural aging.

[0091] 8 provides a graph of minimum principal strain versus maximum principal strain in accordance with some embodiments described herein compared to Comparative Examples 1-3 and Example 1 described herein. The alloy of Example 1 had a lower forming limit curve when compared to the aluminum alloys of Comparative Examples 1-3. Compared to Comparative Examples 1-3 shown in Table 5, the alloy of Example 1 had a lower forming limit curve, but was approximately twice as strong. [Table 5]

[0092] To test the practical application of the alloy compositions compared to Comparative Examples 1-3, forming tests were conducted (Figure 9A-B). The Comparative Example was drawn to 90 mm without cracking, while Example 1 cracked at a drawing depth of 75 mm. Example 1 also experienced a stress of over 600 MPa at a strain of 0.40, while the stress of the Comparative Alloy was less than 500 MPa at the same strain. To further evaluate the formability of the aluminum alloys, springback tests were conducted (Figure 10). The higher strength material (i.e., the alloy of Example 1) exhibited higher springback, while the thinner gauge material showed a similar trend. Although not shown here, different forming speeds did not have a significant effect.

[0093] 7xxx series aluminum alloys are known to be susceptible to intergranular corrosion. Without being bound by theory, it is believed that the lack of Zr and small amounts of Cu and Mg may contribute to the alloy's susceptibility to IGC. Therefore, the aluminum alloys described herein incorporate Zr and increase Cu and Mg, thereby improving the alloy's IGC, as shown in Figures 11A-C. For example, the 2.0 mm and WQ alloys in the T4 temper and paint-baked condition had an IGC depth of 23 mm after 24 hours and decreased to 16 mm after 48 hours. After the T6 temper, the IGC depth was 24 mm after 24 hours and decreased to 19 mm after 48 hours. The IGC depth of the alloys after the T6 temper and paint-baked condition was increased compared to the T4 temper. Furthermore, the 2.4 mm WQ and AQ alloy samples had increased IGC depth compared to the 2.0 mm WQ sample. For example, the 2.4 mm WQ specimen in the T6 temper had 22 mm of IGC at 24 hours, increasing to 56 mm after 48 hours. Interestingly, the 2.4 mm AQ specimen in the T6 temper showed a decrease in IGC depth between the 24- and 48-hour time cycles. Both microscopic images (Figure 11B and C) showed pitting corrosion in the specimen from T4, which had undergone an additional paint bake treatment. The results show that no IGC erosion was observed after 48 hours, with a maximum of less than 60 mm.

[0094] FIG. 12 provides microscopic images of exfoliation testing of exemplary aluminum alloys according to some embodiments described herein. 2.4 mm WQ alloys after the T4 temper and additional paint bake treatment were imaged at three independent locations to test the alloy for exfoliation. The results, shown in Table 6, further indicate that the alloys exhibited medium and shallow grades during the exfoliation treatment in both the 24-hour and 48-hour time frames. Additionally, the results indicate that the T4 temper with the paint bake treatment performed better overall when compared to the T6 and T6 with paint bake. The results are summarized in Table 6 below. [Table 6]

[0095] Additional stress corrosion cracking (SCC) testing was performed to evaluate the aluminum alloy compositions described herein and additional steps in the manufacturing process for the aluminum alloys. The SCC test performed was SCC-ASTM-G47, an alternative to the 40-day immersion test (Figure 13A-C). The results show that the Example 1 alloy before exposure, under unstressed and stressed conditions, had relatively similar maximum tensile stresses. For example, the T4+PB specimen had a maximum tensile stress of approximately 440 MPa for all three conditions, with a slight improvement observed for the T6+PB specimen. Furthermore, for all three test conditions, the 2.4mm AQ specimen alloy under T4+PB had a maximum tensile stress of approximately 435 MPa, while the T6+PB specimen had a maximum axial strain of approximately 450 MPa. The maximum axial strain also showed similar results for all three test conditions, with both the 2.4mm WQ and 2.4mm AQ specimens showing relatively similar results to the T4+PB specimens and slightly higher maximum axial strains than the T6+PB specimens. However, the results show that while there was no SCC failure in any of the stressed specimens, greater than 80% strength was retained in each case.

[0096] Additional steps were taken to evaluate the microstructure of the aluminum alloys from the T4 2mm WQ, 2.4mm WQ, and 2.4mm AQ specimens using STEM (Figure 14). Results indicate that no differences in precipitate formation were observed between the 2.0mm and 2.4mm gauges. There is no evidence of grain boundary precipitates, which are less susceptible to quenching due to the low quenching rate and low solute content. The alloy of Example 1 did not show significant changes in the tensile bending behavior of the WQ versus FAC, likely due to its low solute content in the microstructure. The alloy of Example 1 was stabilized by a pre-aging treatment, which improved its yield strength after direct paint bake simulation, indicating its potential for cold forming, and retained its improved mechanical properties after multiple paint bakes and the T6 temper.

[0097] Embodiment Embodiment 1: A method of producing an aluminum alloy product, the method comprising: casting a molten aluminum alloy to form an ingot or a slab; hot rolling the ingot or the slab to produce a sheet; subjecting the sheet to a solution heat treatment to form a solution-treated sheet; pre-aging the solution-treated sheet to form a pre-aged sheet; and subjecting the pre-aged sheet to at least one paint bake heat treatment to form an aluminum alloy product, wherein the aluminum alloy comprises Mg and Cu, and the aluminum alloy product has a use strength of at least 370 MPa.

[0098] Embodiment 2: The method of embodiment 1, wherein the aluminum alloy comprises max. 0.25 wt.% Si, max. 0.4 wt.% Fe, max. 0.4 wt.% Cu, max. 0.3 wt.% Mn, max. 3.6 wt.% Mg, max. 0.1 wt.% Cr, max. 4.5 wt.% Zn, max. 0.1 wt.% Ti, max. 0.2 wt.% Zr, max. 0.15 wt.% impurities, and Al, wherein Cu and Mg are present in a combined amount less than 3.6 wt.%.

[0099] Embodiment 3: The method of embodiment 1, wherein the aluminum alloy comprises 0-0.25 wt% Si, 0-0.4 wt% Fe, 0-0.4 wt% Cu, 0.1-0.3 wt% Mn, 2.3-3.6 wt% Mg, 0-0.1 wt% Cr, 3.5-4.5 wt% Zn, max 0.1 wt% Ti, max 0.2 wt% Zr, max 0.15 wt% impurities, and Al, wherein Cu and Mg are present in a combined amount less than 3.6 wt%.

[0100] Embodiment 4: The method of embodiment 1, wherein the aluminum alloy comprises 0-0.25 wt% Si, 0-0.4 wt% Fe, 0.11-0.4 wt% Cu, 0.1-0.3 wt% Mn, 2.3-3.6 wt% Mg, 0-0.1 wt% Cr, 3.5-4.5 wt% Zn, max 0.1 wt% Ti, max 0.2 wt% Zr, max 0.15 wt% impurities, and Al, wherein Cu and Mg are present in a combined amount less than 3.6 wt%.

[0101] Embodiment 5: The method of embodiment 1, wherein the aluminum alloy comprises 0-0.25 wt% Si, 0-0.4 wt% Fe, 0-0.4 wt% Cu, 0.1-0.3 wt% Mn, 2.3-3.6 wt% Mg, 0-0.1 wt% Cr, 3.5-4.5 wt% Zn, up to 0.1 wt% Ti, 0.05-0.2 wt% Zr, up to 0.15 wt% impurities, and Al, wherein Cu and Mg are present in a combined amount less than 3.6 wt%.

[0102] Embodiment 6: The method of any preceding embodiment, wherein the method further comprises homogenizing the ingot or the slab prior to the hot rolling.

[0103] Embodiment 7: The method of any of the preceding embodiments, wherein the at least one paint baking heat treatment is carried out at a temperature between 75 and 250°C for a period of 15 minutes to 3 hours.

[0104] Embodiment 8: The method of any of the preceding embodiments, wherein the at least one paint baking heat treatment is carried out at a temperature of 100-200°C for a period of 15 minutes to 2 hours.

[0105] Embodiment 9: The method of any of the preceding embodiments, wherein the at least one paint baking heat treatment is carried out at a temperature of 150-180°C for a period of 15 minutes to 45 minutes.

[0106] Embodiment 10: The method of any preceding embodiment, wherein the aluminum alloy product is formable at room temperature.

[0107] Embodiment 11: The method of any preceding embodiment, wherein the aluminum alloy product is formable at temperatures below room temperature.

[0108] Embodiment 12: The method of any preceding embodiment, wherein the aluminum alloy product has a service strength of at least 390 MPa in a T4 temper after at least two paint bake cycles.

[0109] Embodiment 13: The method of any preceding embodiment, wherein the aluminum alloy product has a service strength of at least 400 MPa in a T6 temper after at least two paint bake cycles.

[0110] Embodiment 14: The method of any preceding embodiment, wherein the pre-aging is carried out at a temperature of 50 to 200°C for a period of 1 to 24 hours.

[0111] Embodiment 15: The method of any preceding embodiment, wherein the sheet is cold rolled prior to the solution heat treatment.

[0112] Embodiment 16: The method of embodiment 6, wherein the homogenizing comprises heating the ingot or the slab to a temperature of at least 450°C and maintaining the ingot or the slab at a temperature of at least 450°C for a time period of at least 90 minutes.

[0113] Embodiment 17: The method of any preceding embodiment, wherein the ingot or the slab is hot rolled to a thickness of less than 7 mm and then cold rolled to a thickness of less than 4 mm.

[0114] Embodiment 18: The method of any preceding embodiment, further comprising artificially aging the pre-aged sheet prior to the at least one paint baking treatment.

[0115] Embodiment 19: The method of embodiment 18, wherein the pre-aged sheet is artificially aged at a temperature of 100 to 250°C for 1 to 72 hours.

[0116] Embodiment 20: An aluminum alloy product prepared according to the method of any of the preceding embodiments.

[0117] Embodiment 21: The aluminum alloy product of embodiment 20, wherein the aluminum alloy product has an ultimate tensile strength of at least 420 MPa after 40 days of immersion testing according to SCC-ASTM G47.

[0118] All patents, publications, and abstracts cited above are incorporated herein by reference in their entirety. Various embodiments of the present invention have been described in fulfillment of various objectives of the present invention. It should be recognized that these embodiments are merely illustrative of the principles of the present invention. Numerous changes and modifications thereof will be readily apparent to those skilled in the art without departing from the spirit and scope of the present invention, as defined in the following claims.

Claims

1. A method for producing an aluminum alloy product, comprising: casting the molten aluminum alloy to form an ingot or slab; hot rolling the ingot or the slab to produce a sheet; subjecting the sheet to a solution heat treatment to form a solution-treated sheet; preaging the solution-treated sheet to form a pre-aged sheet; and subjecting the pre-aged sheet to at least one paint bake heat treatment to form the aluminum alloy product; Including, The aluminum alloy contains Mg and Cu, The aluminum alloy product has a use strength of at least 370 MPa. The method.

2. The aluminum alloy is max 0.25 wt% Si, maximum 0.4 wt% Fe, up to 0.4 wt% Cu, up to 0.3 wt% Mn, up to 3.6 wt% Mg, 0.1 wt% max Cr, up to 4.5 wt% Zn, maximum 0.1 wt% Ti, up to 0.2 wt% Zr, impurities up to 0.15 wt. %; and Al Including, Cu and Mg are present in a total amount less than 3.6 wt.%; The method of claim 1.

3. The aluminum alloy is 0 to 0.25 wt. % Si, 0 to 0.4 wt. % Fe, 0 to 0.4 wt. % Cu, 0.1 to 0.3 wt. % Mn, 2.3 to 3.6 wt. % Mg, 0 to 0.1 wt. % Cr, 3.5 to 4.5 wt. % Zn, maximum 0.1 wt% Ti, up to 0.2 wt% Zr, impurities up to 0.15 wt. %; and Al Including, Cu and Mg are present in a total amount less than 3.6 wt.%; 3. The method according to claim 1 or 2.

4. The aluminum alloy is 0 to 0.25 wt. % Si, 0 to 0.4 wt. % Fe, 0.11 to 0.4 wt. % Cu, 0.1 to 0.3 wt. % Mn, 2.3 to 3.6 wt. % Mg, 0 to 0.1 wt. % Cr, 3.5 to 4.5 wt. % Zn, maximum 0.1 wt% Ti, up to 0.2 wt% Zr, impurities up to 0.15 wt. %; and Al Including, Cu and Mg are present in a total amount less than 3.6 wt.%; The method according to any one of claims 1 to 3.

5. The aluminum alloy is 0 to 0.25 wt. % Si, 0 to 0.4 wt. % Fe, 0 to 0.4 wt. % Cu, 0.1 to 0.3 wt. % Mn, 2.3 to 3.6 wt. % Mg, 0 to 0.1 wt. % Cr, 3.5 to 4.5 wt. % Zn, maximum 0.1 wt% Ti, 0.05 to 0.2 wt. % Zr, impurities up to 0.15 wt. %; and Al Including, Cu and Mg are present in a total amount less than 3.6 wt.%; The method according to any one of claims 1 to 4.

6. The method according to any one of claims 1 to 5, wherein the method further comprises homogenizing the ingot or the slab prior to the hot rolling.

7. 7. The method according to any one of claims 1 to 6, wherein said at least one paint baking heat treatment is carried out at a temperature of from 75 to 250°C for a period of from 15 minutes to 3 hours.

8. 8. The method according to any one of claims 1 to 7, wherein said at least one paint baking heat treatment is carried out at a temperature of from 100 to 200°C for a period of from 15 minutes to 2 hours.

9. 9. The method according to any one of claims 1 to 8, wherein said at least one paint baking heat treatment is carried out at a temperature of 150 to 180°C for a period of 15 to 45 minutes.

10. The method of any one of claims 1 to 9, wherein the aluminium alloy product is formable at room temperature.

11. A method according to any one of the preceding claims, wherein the aluminium alloy product is formable at temperatures below room temperature.

12. 12. The method of any one of claims 1 to 11, wherein the aluminium alloy product has a service strength of at least 390 MPa in a T4 temper after at least two paint bake cycles.

13. 13. The method of any one of claims 1 to 12, wherein the aluminium alloy product has a service strength of at least 400 MPa in a T6 temper after at least two paint bake cycles.

14. 14. The method according to any one of claims 1 to 13, wherein the pre-aging is carried out at a temperature of from 50 to 225°C for a period of from 0.5 to 24 hours.

15. A method according to any one of the preceding claims, wherein the sheet is cold rolled prior to the solution heat treatment.

16. 7. The method of claim 6, wherein the homogenizing comprises heating the ingot or the slab to a temperature of at least 450°C and maintaining the ingot or the slab at a temperature of at least 450°C for a time of at least 90 minutes.

17. 17. The method of any one of claims 1 to 16, wherein the ingot or slab may be hot rolled to a thickness of less than 10 mm and then cold rolled to a thickness of less than 4 mm.

18. The method according to any one of claims 1 to 17, further comprising artificially aging the pre-aged sheet before the at least one paint baking treatment.

19. 19. The method of claim 18, wherein the pre-aged sheet is artificially aged at a temperature of 100 to 250°C for 0.5 to 72 hours.

20. An aluminium alloy product prepared according to the method of any one of claims 1 to 20.

21. 21. The aluminum alloy product of claim 20, having an ultimate tensile strength of at least 420 MPa after 40 days immersion testing according to SCC-ASTM G47.

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