6000 series aluminum alloy with high recycled content and its preparation method

Abstract

Described herein are novel aluminum alloys, including recycled aluminum alloy materials, that exhibit high strength and formability. The aluminum alloys described herein, suitable for use as, for example, automotive components, exhibit high strength and formability despite having higher amounts of Si, Fe, and Mn than conventional AA6016 aluminum alloy. The present disclosure provides an environmentally friendly, cost-effective alternative to the use of AA6016 aluminum alloy, and exhibits mechanical properties that are comparable to or better than AA6016 aluminum alloy.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of and priority to U.S. Provisional Patent Application No. 63 / 382,313, filed November 4, 2022, which is incorporated herein by reference in its entirety for all intents and purposes.

[0002] This disclosure relates to the fields of metallurgy, aluminum alloys, aluminum fabrication, and related fields. In particular, this disclosure provides novel 6000 series aluminum alloys produced from a large amount of recycled aluminum alloy material. This disclosure also provides various end uses for such products in automotive, transportation, electronics, industrial, aerospace, and other applications. [Background technology]

[0003] Aluminum alloys are used in many different applications requiring a combination of strength and durability. 6000 series aluminum alloys, for example, are widely used in automotive applications due to their excellent combination of properties, including strength-to-weight ratio, formability, weldability, and general corrosion resistance. For example, 6000 series aluminum alloys are commonly used in automotive structural applications in place of steel. Because aluminum alloys are generally about 2.8 times less dense than steel, the use of such materials reduces vehicle weight, allowing for significant improvements in vehicle fuel efficiency.

[0004] Yet, currently available 6000 series aluminum alloys require significant amounts of primary aluminum and alloying elements to achieve target specifications, which limits the amount of recycled aluminum material that can be used to produce the aluminum alloy. Attempts to modify the aluminum alloy composition of 6000 series aluminum alloys have been unsuccessful because mechanical properties (e.g., strength and formability) are significantly affected by changes in the aluminum alloy composition. For example, the composition of AA6016 is tightly controlled to achieve desired performance characteristics. Therefore, to produce AA6016 aluminum alloy for structural components, little or no recycled aluminum alloy material is used because the aluminum alloy can tolerate only small amounts of impurities that can affect the aluminum alloy's properties.

[0005] Many original equipment manufacturers (OEMs) require recycled aluminum alloys to comply with federal regulations or limit their carbon footprint. OEMs require aluminum alloys made from a large amount of recycled aluminum alloy material and little primary aluminum. This is because the manufacturing process for primary aluminum is labor-intensive and generates significant carbon emissions. However, as noted above, 6000 series aluminum alloys have a tightly controlled composition range to meet specific performance characteristics. Furthermore, recycled aluminum alloy materials may contain a mixture of different aluminum alloy compositions, making it difficult to manufacture 6000 series aluminum alloys with tightly controlled composition ranges. Therefore, when recycled aluminum alloy materials are used to manufacture 6000 series aluminum alloys, significant amounts of primary aluminum and additional alloying elements are required to adjust the composition to produce aluminum alloy products (e.g., automotive parts), resulting in a decrease in recycled content. Furthermore, adding primary aluminum increases carbon dioxide production and costs, which harms the environment and is costly. Summary of the Invention

[0006] 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.

[0007] Described herein are aluminum alloys that offer a more cost-effective, renewable alternative to the use of conventional 6000 series aluminum alloys. In some embodiments, the present disclosure relates to aluminum alloys comprising 1.0-2.0 wt% Si, 0.20-1.0 wt% Fe, up to 0.20 wt% Cu, 0.20-0.80 wt% Mn, 0.20-0.70 wt% Mg, up to 0.10 wt% Cr, up to 0.20 wt% Zn, up to 0.15 wt% Ti, up to 0.15 wt% Ni, up to 0.25 wt% impurities, and Al, wherein the aluminum alloy comprises a combined content of at least 2.2 wt% Si, Fe, and Mn, and the aluminum alloy comprises no more than 20 wt% primary aluminum alloy. In some embodiments, the aluminum alloy includes 1.20-2.0 wt% Si, 0.30-0.90 wt% Fe, 0.01-0.20 wt% Cu, 0.25-0.70 wt% Mn, 0.25-0.60 wt% Mg, up to 0.10 wt% Cr, up to 0.15 wt% Zn, up to 0.10 wt% Ti, up to 0.10 wt% Ni, up to 0.23 wt% impurities, and Al. In some embodiments, the aluminum alloy includes 1.30-1.80 wt% Si, 0.40-0.90 wt% Fe, 0.01-0.15 wt% Cu, 0.30-0.70 wt% Mn, 0.30-0.60 wt% Mg, up to 0.10 wt% Cr, up to 0.15 wt% Zn, up to 0.10 wt% Ti, up to 0.05 wt% Ni, up to 0.22 wt% impurities, and Al. In some embodiments, the aluminum alloy includes 1.40-1.70 wt% Si, 0.50-0.90 wt% Fe, 0.05-0.15 wt% Cu, 0.40-0.70 wt% Mn, 0.30-0.50 wt% Mg, max 0.05 wt% Cr, max 0.10 wt% Zn, max 0.05 wt% Ti, max 0.05 wt% Ni, max 0.21 wt% impurities, and Al.In some embodiments, the aluminum alloy includes 1.55-1.70 wt% Si, 0.60-0.90 wt% Fe, 0.05-0.10 wt% Cu, 0.50-0.70 wt% Mn, 0.35-0.45 wt% Mg, 0.01-0.03 wt% Cr, 0.01-0.05 wt% Zn, 0.01-0.03 wt% Ti, 0.01-0.05 wt% Ni, up to 0.20 wt% impurities, and Al. In some embodiments, the (Mn+Cr):Fe ratio is greater than 0.70. In some embodiments, the aluminum alloy includes 0.60-0.90 wt% Fe and 0.40-0.70 wt% Mn. In some embodiments, the combined content of Fe and Si is at least 1.5 wt%. In some embodiments, the combined content of Si, Fe, and Mn is from 2.2 wt% to 3.6 wt%. In some embodiments, the aluminum alloy comprises at least 50 wt% recycled aluminum alloy material. In some embodiments, the aluminum alloy has a yield strength of at least 130 MPa. In some embodiments, the aluminum alloy has an ultimate tensile strength of at least 200 MPa. In some embodiments, the aluminum alloy has a total elongation of at least 15%. In some embodiments, the aluminum alloy has a β bend angle value of less than 140° per specification VDA238-100.

[0008] In some embodiments, a method for producing an aluminum alloy is provided, the method comprising casting an aluminum alloy to form a casting, the aluminum alloy comprising max 1.0-2.0 wt% Si, 0.20-1.0 wt% Fe, max 0.20 wt% Cu, 0.20-0.80 wt% Mn, 0.20-0.70 wt% Mg, max 0.10 wt% Cr, max 0.20 wt% Zn, max 0.15 wt% Ti, max 0.15 wt% Ni, max 0.15 wt% impurities, and Al; The aluminum alloy comprises a combined content of at least 2.2 wt% Si, Fe, and Mn, and the aluminum alloy comprises 10 wt% or less of a primary aluminum alloy. The method includes forming the casting, diffusion annealing the casting, hot rolling the casting to produce a hot rolled product, cold rolling the hot rolled product to produce a final gauge rolled product, and optionally annealing the final gauge rolled product. In some embodiments, casting the aluminum alloy includes providing more than 50 wt% recycled aluminum alloy material. In some embodiments, the recycled aluminum alloy material comprises end-of-life aluminum alloy scrap. In some embodiments, the aluminum alloy comprises 0.60-0.90 wt% Fe and 0.40-0.70 wt% Mn, and the (Mn+Cr):Fe ratio is greater than 0.50. In some embodiments, the aluminum alloy product is prepared by the methods described herein. In some embodiments, the aluminum alloy product is an automotive part or an electronics housing.

[0009] Further aspects, objects, and advantages will become apparent from consideration of the detailed description and drawings that follow. [Brief explanation of the drawings]

[0010] [Figure 1]FIG. 1 provides a graph of total elongation (A80) (measured in %) of exemplary aluminum alloys in T4 temper (red) and T8x temper (blue) as measured in the longitudinal (L), transverse (T), and diagonal (D) directions relative to the rolling direction, respectively (e.g., A80 after 2% pre-strain and heat treatment at a temperature of about 185° C. for about 20 minutes), according to some embodiments described herein. [Figure 2] FIG. 1 provides a graph of yield strength (Rp0.2) (measured in MPa) of exemplary aluminum alloys in T4 temper (red) and T8x temper (blue) as measured in the longitudinal (L), transverse (T), and diagonal (D) directions relative to the rolling direction, respectively (e.g., Rp0.2 after 2% pre-strain and heat treatment at a temperature of about 185° C. for about 20 minutes), according to some embodiments described herein. [Figure 3] FIG. 1 provides a graph of ultimate tensile strength (Rm) (measured in MPa) of exemplary aluminum alloys in T4 temper (red) and T8x temper (blue) as measured in the longitudinal (L), transverse (T), and diagonal (D) directions relative to the rolling direction, respectively (e.g., Rm after 2% pre-strain and heat treatment at a temperature of about 185° C. for about 20 minutes), according to some embodiments described herein. [Figure 4] FIG. 1 provides a graph of β-bend angle values ​​(measured in degrees) per specification VDA238-100 for an exemplary aluminum alloy in the T4 temper when measured in the longitudinal (L) and transverse (T) directions relative to the rolling direction, respectively, according to some embodiments described herein. [Figure 5] FIG. 1 provides a graph of total elongation (A80) (measured in %) of example alloys in the T4 temper as measured in the longitudinal (L), transverse (T), and diagonal (D) directions relative to the rolling direction, respectively, according to some embodiments described herein. [Figure 6] FIG. 1 provides a graph of uniform elongation (Ag) (measured in %) of example alloys in the T4 temper as measured in the longitudinal (L), transverse (T), and diagonal (D) directions relative to the rolling direction, respectively, according to some embodiments described herein. [Figure 7]FIG. 1 provides a graph of n5 values ​​(unitless) of example alloys in the T4 temper as measured in the longitudinal (L), transverse (T), and diagonal (D) directions relative to the rolling direction, respectively, according to some embodiments described herein. [Figure 8] 1 provides a graph of bend formability (r10) of example alloys as measured in the longitudinal (L) and transverse (T) directions, respectively, relative to the rolling direction, according to some embodiments described herein. [Figure 9] FIG. 1A provides an image of an electron backscatter diffraction (EBSD) profile of an example alloy, and FIG. 1B provides a graph of grain size (mm) in both the Dx and Dy directions for the example alloy, according to some embodiments described herein. [Figure 10A] 1 provides a graph of texture components (measured in volume %) within the microstructure of example alloys according to some embodiments described herein. [Figure 10B] 10A according to some embodiments described herein provides a table of the texture components (measured in volume %) shown in FIG. 10A. [Figure 11] 1 provides a graph of simulated r-values ​​of example alloys at angles of 0°, 45°, and 90°, according to some embodiments described herein. [Figure 12] 1 provides a scanning electron microscope (SEM) image of an example alloy (scale bar 20 μm) according to some embodiments described herein. [Figure 13] 1 provides a graph of intermetallic (blue) and microporosity (orange) area fraction (measured in %) of example alloys, according to some embodiments described herein. DETAILED DESCRIPTION OF THE INVENTION

[0011] Described herein are novel 6000 series aluminum alloys that contain a significant amount of recycled aluminum alloy material and less than 20 wt.% primary aluminum alloy, and exhibit strength, elongation, and bend formability comparable to conventional 6000 series aluminum alloys. In particular, the 6000 series aluminum alloys described herein contain greater amounts of silicon (Si), iron (Fe), and manganese (Mn) than conventional AA6016 aluminum alloys. In some embodiments, the present disclosure provides 6000 series aluminum alloys that can tolerate significant amounts of Si, Fe, and Mn compared to conventional AA6016 aluminum alloys, thereby enabling the use of greater amounts of recycled aluminum alloy material. For example, the 6000 series aluminum alloys can contain greater than 50 wt.% end-of-life aluminum alloy scrap (e.g., castings, extrusions, and aluminum alloy sheet from automobiles). Despite the inclusion of a significant amount of recycled aluminum alloy material, the 6000 series aluminum alloys described herein exhibit strength, elongation, and bend formability comparable to or greater than conventional AA6016 aluminum alloys. When the alloying elements in the aluminum alloy composition are balanced, the aluminum alloy microstructure has intermetallic phases that provide these beneficial properties.

[0012] Conventional AA6016 aluminum alloys require a tightly controlled composition to meet minimum strength requirements while still maintaining formability for producing complex shapes. Generally, higher strength is required for aluminum alloys used in the manufacture of automotive parts (e.g., structural parts), leading to demands that automotive parts be manufactured from aluminum alloys such as AA6016 aluminum alloy. This limits the amount of recycled aluminum alloy material that can be used to manufacture AA6016 aluminum alloy. Therefore, manufacturing automotive parts using large amounts of recycled aluminum alloy material, such as end-of-life aluminum alloy scrap, requires the use of more alloying elements and primary aluminum to manufacture AA6016 aluminum alloy, significantly increasing the material costs and associated CO2 emissions for producing these materials. This limits the amount of recycled aluminum alloy material that can be used to manufacture automotive parts.

[0013] The aluminum alloys described herein contain a synergistic combination of alloying elements that allows for the use of greater amounts of recycled aluminum alloy material. The use of greater amounts of recycled aluminum alloy material results in environmentally friendly 6000 series aluminum alloys. The aluminum alloys described herein contain carefully balanced amounts of Si, Fe, and Mn, advantageously allowing for the use of greater amounts of recycled aluminum alloy material to produce 6000 series aluminum alloys while still providing good strength, elongation, and bendability. For example, recycled aluminum alloy material may contain a large amount of Fe, which may require the aluminum alloy to tolerate greater amounts of Fe (e.g., greater than 0.50 wt%) than conventional 6000 series aluminum alloys. The amounts of Mn and Si in the aluminum alloy are also adjusted to allow for the use of greater amounts of Fe, while maintaining intermetallic phases for good elongation and strength. Specifically, the aluminum alloys described herein promote the formation of intermetallic alpha phases, while reducing elongated intermetallic beta phases (e.g., with sharp edges). Surprisingly, the aluminum alloys described herein contain balanced amounts of Si, Fe, and Mn that satisfy the formula (Mn+Cr):Fe>0.70, producing aluminum alloys with desirable properties.

[0014] The aluminum alloys described herein exhibit high strength and formability despite having a higher amount of recycled aluminum alloy material. The aluminum alloys described herein maintain the good mechanical properties of structural aluminum alloys despite containing a higher amount of recycled aluminum alloy material and less primary aluminum compared to conventional AA6016 aluminum alloy. For example, the aluminum alloys described herein may contain more than 50% recycled aluminum alloy material and less than 10% primary aluminum, yet exhibit properties similar to AA6016 aluminum alloy. The aluminum alloys described herein provide a cost-effective alternative to the use of AA6016 aluminum alloy for structural components.

[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. It should be understood that statements containing these terms do not limit the subject matter described herein or the meaning or scope of the claims that follow.

[0016] This description refers to alloys identified by aluminum industry designations such as "series" or "000 series." For an understanding of the numbering systems most commonly used to name and identify aluminum and its alloys, please refer to "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] As used herein, the meaning of "a," "an," or "the" includes singular and plural references unless the context clearly indicates otherwise.

[0018] As used herein, plate generally has a thickness of greater than about 15 mm. For example, plate may refer to an aluminum product having a thickness of greater than about 15 mm, greater than about 20 mm, greater than about 25 mm, greater than about 30 mm, greater than about 35 mm, greater than about 40 mm, greater than about 45 mm, greater than about 50 mm, or greater than about 100 mm.

[0019] As used herein, a sheet (also called a sheet plate) generally has a thickness of about 4 mm to about 15 mm. For example, the sheet may be about 4 mm, about 5 mm, about 6 mm, about 7 mm, about 8 mm, about 9 mm, about 10 mm, about 11 mm, about 12 mm, about 13 mm, about 14 mm, or about 15 mm thick.

[0020] As used herein, sheet refers to aluminum castings having a thickness of less than about 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 can be about 0.1 mm, about 0.2 mm, about 0.3 mm, about 0.4 mm, about 0.5, about 0.6 mm, about 0.7 mm, about 0.8 mm, about 0.9 mm, about 1 mm, about 1.1 mm, about 1.2 mm, about 1.3 mm, about 1.4 mm, about 1.5 mm, about 1.6 mm, about 1.7 mm, about 1.8 mm, about 1.9 mm, about 2 mm, about 2.1 mm, about 2.2 mm, about 2.3 mm, about 2.4 mm, about 2.5 mm, about 2.6 mm, about 2.7 mm, about 2.8 mm, about 2.9 mm, about 3 mm, about 3.1 mm, about 3.2 mm, about 3.3 mm, about 3.4 mm, about 3.5 mm, about 3.6 mm, about 3.7 mm, about 3.8 mm, about 3.9 mm, or about 4 mm thick.

[0021] As used herein, formability refers to the ability of a material to deform into a desired shape without fracture, tearing, necking, selvage, or forming errors such as wrinkling, springback, or galling. In engineering, formability can be classified by the mode of deformation. Examples of deformation modes include drawing, stretching, bending, and stretch-flanging.

[0022] As used herein, primary aluminum refers to an aluminum material containing at least about 99.7 wt% aluminum. Primary aluminum is produced from the primary transformation of raw materials to aluminum (e.g., the processing of bauxite to alumina and the electrolysis of alumina to aluminum).

[0023] As used herein, yield stress (also called yield strength) refers to the point at which an aluminum alloy begins to plastically deform and is no longer able to return to its original state.

[0024] Reference may be made herein to alloy tempers or states. 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.

[0025] As used herein, the term "room temperature" can include temperatures of about 15°C to about 30°C, such as about 15°C, about 16°C, about 17°C, about 18°C, about 19°C, about 20°C, about 21°C, about 22°C, about 23°C, about 24°C, about 25°C, about 26°C, about 27°C, about 28°C, about 29°C, or about 30°C.

[0026] All ranges disclosed herein should be understood to encompass both endpoints and any and all subranges subsumed therein. For example, a stated range of "1 to 10" should be considered to include all subranges from a minimum value of 1 to a 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] The following aluminum alloys are described in terms of elemental composition in weight percent (wt%) based on the total weight of the alloy, with the balance being aluminum, and the maximum wt% of the sum of all impurities being 0.15% in each specific example of the alloy.

[0028] Alloy composition Described below are novel 6000 series aluminum alloys. In certain embodiments, the alloys exhibit high strength, high formability, and corrosion resistance. The alloy properties are achieved in part due to the alloy's composition and in part due to the method of processing the alloy to produce the described products (i.e., plate, sheet, and sheet). In some cases, the novel aluminum alloys described herein may include elevated levels of Si, Mn, Fe, and / or Cr compared to conventional AA6016 aluminum alloy, as further described below. In some examples, the aluminum alloys described herein may have the following elemental compositions as shown in Table 1: [Table 1]

[0029] In some examples, the aluminum alloys described herein may have the following elemental compositions as shown in Table 2: [Table 2]

[0030] In some examples, the aluminum alloys described herein may have the following elemental compositions as shown in Table 3: [Table 3]

[0031] In some examples, the aluminum alloy may have the following elemental composition as presented in Table 4: [Table 4]

[0032] In some examples, the aluminum alloy may have the following elemental composition as presented in Table 5: [Table 5]

[0033] Silicon (Si) In some examples, the aluminum alloys described herein contain 1.0% to 2.0% (e.g., 1.20% to 2.0%, 1.30% to 1.80%, 1.40% to 1.70%, 1.50% to 1.70%, or 1.55% to 1.70%) of Si based on the total weight of the alloy. For example, the alloy may contain 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% Si. ,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. The aluminum alloy composition may contain 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%, or 2.00% Si. All values ​​are expressed in wt%. In some embodiments, aluminum alloy compositions containing less than 1.0 wt% Si may limit the amount of recycled aluminum alloy material that can be used in the aluminum alloy composition. For example, end-of-life aluminum alloy scrap (e.g., castings, extrusions, and used aluminum sheet) may contain significant amounts of Si. In some embodiments, the aluminum alloys described herein may include more than 1.50 wt% Si to allow for higher amounts of recycled aluminum alloy material.

[0034] Iron (Fe) In some examples, the aluminum alloys described herein also include Fe in an amount between 0.20% and 0.90% (e.g., between 0.30% and 0.90%, between 0.40% and 0.90%, between 0.50% and 0.90%, or between 0.60% and 0.90%) based on the total weight of the alloy. For example, alloys may contain 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%, May contain 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%, or 0.90% Fe, all expressed in wt%. As discussed herein, including less than 0.20 wt% Fe in the aluminum alloy composition may limit the amount of recycled aluminum alloy material that can be used in the aluminum alloy. In some embodiments, the aluminum alloys described herein may include more than 0.50 wt% Fe to allow for greater amounts of recycled aluminum alloy material.

[0035] Copper (Cu) In some examples, the aluminum alloys described herein include Cu in an amount of up to 0.20% (e.g., 0.01%-0.20%, 0.01%-0.15%, 0.05%-0.15%, or 0.05%-0.10%) 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%, or 0.20% Cu. All amounts are expressed in wt%. The aluminum alloy may contain 0.01 wt% to 0.20 wt% Cu to compensate for the reduced Mg content to strengthen the aluminum alloy. In some embodiments, aluminum alloys containing less than 0.05 wt% Cu may have insufficient strength properties. In some embodiments, aluminum alloys containing more than 0.20 wt% Cu may have excessive strength, reduced formability, and susceptibility to corrosion.

[0036] Manganese (Mn) In some examples, the aluminum alloys described herein can include 0.20% to 0.70% Mn (e.g., 0.25% to 0.70%, 0.30% to 0.70%, 0.40% to 0.70%, or 0.50% to 0.70%) based on the total weight of the alloy. For example, the alloy can include 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%, or 0.50% Mn. The aluminum alloy may contain 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%, or 0.70% Mn. All values ​​are expressed in wt%. In some embodiments, aluminum alloys containing the aforementioned amounts of Mn may result in intermetallic phases that promote formability. In some embodiments, aluminum alloys containing more than 0.70 wt% Mn may result in intermetallic phases that may reduce formability and final workability.

[0037] Magnesium (Mg) In some examples, the aluminum alloys described herein can include Mg in an amount between 0.20% and 0.70% (e.g., between 0.25% and 0.60%, between 0.30% and 0.60%, between 0.30% and 0.50%, or between 0.35% and 0.45%) based on the total weight of the alloy. For example, the alloy can include 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%, or 0.46% Mg. May contain 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%, or 0.70% Mg, all expressed as wt%.

[0038] Chromium (Cr) In some examples, the aluminum alloys described herein contain Cr in an amount of up to 0.10% (e.g., up to 0.10%, up to 0.05%, up to 0.03%, or 0.01%-0.03%) 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 from the alloy (i.e., 0%). All values ​​are expressed in wt%.

[0039] Zinc (Zn) In some examples, the aluminum alloys described herein contain Zn in an amount of up to 0.20% (e.g., up to 0.15%, up to 0.10%, 0.01%-0.20%, 0.01%-0.10%, or 0.01%-0.03%) 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% Zn. In some cases, Zn is absent (i.e., 0%) in the alloy. All amounts are expressed in wt%.

[0040] Titanium (Ti) In some examples, the aluminum alloys described herein contain Ti in an amount of up to 0.15% (e.g., up to 0.10%, up to 0.05%, up to 0.03%, or 0.01% to 0.03%) 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%, or 0.15% Ti. In some cases, Ti is absent (i.e., 0%) in the alloy. All amounts are expressed in wt%.

[0041] Nickel (Ni) In some examples, the aluminum alloys described herein contain Ni in an amount of up to 0.15% (e.g., up to 0.10%, up to 0.05%, up to 0.03%, 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%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, or 0.15% Ni. In some cases, Ni is absent (i.e., 0%) in the alloy. All amounts are expressed in wt%.

[0042] In some examples, the aluminum alloys described herein may include a combined Fe, Mn, and Si content in an amount between 2.2% and 3.6% (e.g., between 2.3% and 3.6%, between 2.4% and 3.6%, between 2.6% and 3.6%, or between 3.0% and 3.6%) based on the total weight of the alloy. For example, the alloy may include a combined Fe, Mn, and Si content of 2.2%, 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3.0%, 3.1%, 3.2%, 3.3%, 3.4%, 3.5%, or 3.6% (all expressed in wt%). In some embodiments, aluminum alloys including a combined wt% of Fe, Mn, and Si greater than 2.0 wt% are suitable for use with end-of-life aluminum alloy scrap, which may contain higher amounts of these alloying elements. The AA6016 alloy can only tolerate a maximum of 2.2 wt% Fe, Mn, and Si, which can limit the amount of recycled aluminum alloy material that can be used to produce the aluminum alloy. Surprisingly, by balancing the aluminum alloy composition to include specific amounts of Fe, Mn, Si, and / or Cr, aluminum alloys can be produced that incorporate large amounts (e.g., greater than 50%) of recycled aluminum alloy material, resulting in better strength and formability. Furthermore, the aluminum alloys described herein can include higher amounts of Cr than the AA6016 alloy for better recycling properties.

[0043] In some embodiments, the ratio of (Mn+Cr):Fe is greater than 0.70 (eg, 0.70 to 1.5, 0.70 to 1.4, 0.70 to 1.3, or 0.80 to 1.0). For example, the ratio of (Mn+Cr):Fe in the aluminum alloys described herein may be 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, 1.08, 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, or 1.50. The aluminum alloys described herein contain a higher amount of Fe than AA6016 aluminum alloy, advantageously allowing for the use of a larger amount of recycled aluminum alloy material to produce the aluminum alloys described herein. The Fe content is balanced with the amount of Mn and Cr in the aluminum alloy to produce intermetallic phases that contribute to good strength and formability. The aluminum alloys described herein contain a (Mn+Cr):Fe ratio of greater than 0.70 to produce these intermetallic phases. In some embodiments, the aluminum alloys described herein promote the formation of intermetallic alpha phases while reducing elongated intermetallic beta phases.

[0044] In some examples, the aluminum alloys described herein may include a combined Fe and Si content of greater than 1.5% (e.g., 1.5%-3.0%, 1.6%-2.8%, 1.8%-2.6%, or 2.0%-2.0%) based on the total weight of the alloy. For example, the alloy may include a combined Fe and Si content of 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2.0%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, or 3.0%, all expressed in wt%.

[0045] trace elements Optionally, the aluminum alloys described herein may further contain other trace elements, sometimes referred to as impurities, in amounts of 0.25% or less, 0.23% or less, 0.22% or less, 0.21% or less, or 0.20% or less. These impurities may include, but are not limited to, Sc, V, Hf, Zr, Sn, Ga, Ca, Bi, Na, Pb, or combinations thereof. Thus, Sc, V, 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 0.25% (e.g., 0.20%). All amounts are expressed in wt%. The remaining percentage of each alloy may be aluminum.

[0046] Recycled material content The aluminum alloys described herein can tolerate higher amounts of recycled aluminum alloy material and still exhibit desirable mechanical properties. The impact of impurities and / or alloying elements on the mechanical properties of the aluminum alloy is reduced by providing an aluminum alloy composition tailored to compensate for the impurities. This allows for the production of aluminum alloys that can exhibit desirable properties despite using higher amounts of cheaper, more impure recycled aluminum alloy material (e.g., end-of-life aluminum alloy scrap). The aluminum alloy compositions described herein can include higher amounts of recycled aluminum alloy material with little or no additional primary aluminum and reduced amounts of more expensive alloying elements.

[0047] In some embodiments, the aluminum alloy compositions described herein provide compositions suitable for utilizing multiple sources of recycled aluminum alloy material. In some embodiments, the aluminum alloys described herein are produced from mixed alloy scrap, including one or more of end-of-life (EOL) aluminum articles (e.g., aluminum-intensive vehicles), unsorted automotive scrap (e.g., including one or more of 5000-series, 6000-series, and / or 7000-series aluminum alloys made from wrought and cast alloys), twitch, and recycled aluminum alloy parts (e.g., heat exchangers, brazing alloy scrap, etc.). Mixed alloy scrap is very low cost, and using it to produce aluminum alloys can provide significant cost savings and reduce overall carbon emissions. In some embodiments, recycled aluminum alloy materials can include taint tabor scrap, twitch scrap from end-of-life vehicles, and industrial scrap. In some embodiments, recycled aluminum alloy materials can include end-of-life aluminum alloy wire and aluminum litho plate. As described herein, the use of these recycled aluminum alloy materials can achieve desirable mechanical properties while using very low-cost recycled scrap.

[0048] As discussed herein, the aluminum alloy compositions described herein provide tailored compositions that allow for the use of more recycled aluminum alloy materials, particularly EOL scrap, to produce aluminum alloy articles, and reduce the amount of both primary aluminum and additional alloying elements. In some embodiments, the aluminum alloys described herein include a significant amount of EOL scrap, such as 25% or more, e.g., 30% or more, 35% or more, 40% or more, 45% or more, 50% or more, 55% or more, 60% or more, 65% or more, 70% or more, or 75% or more. In terms of ranges, the aluminum alloys described herein can include 25% to 100% EOL scrap (e.g., 25% to 95%, 30% to 90%, 35% to 85%, 40% to 80%, 50% to 70%, or 35% to 50%).

[0049] In some embodiments, the aluminum alloys described herein contain less than 20% primary aluminum, e.g., less than 19%, less than 18%, less than 17%, less than 16%, less than 15%, less than 14%, less than 13%, less than 12%, less than 11%, or less than 10%, all expressed in wt%.

[0050] characteristics In some examples, aluminum alloy products (e.g., aluminum alloy sheets) produced from the aluminum alloys described herein can have a yield strength (Rp0.2) of 130 MPa or greater. For example, aluminum alloy products produced from the aluminum alloys described herein can have a yield strength of 135 MPa or greater, 140 MPa or greater, 145 MPa or greater, 150 MPa or greater, 155 MPa or greater, 160 MPa or greater, 165 MPa or greater, 170 MPa or greater, 175 MPa or greater, 180 MPa or greater, 185 MPa or greater, 190 MPa or greater, 195 MPa or greater, or 200 MPa or greater. In some cases, the yield strength is between 130 MPa and 250 MPa (e.g., between 140 MPa and 250 MPa, between 150 MPa and 240 MPa, or between 160 MPa and 240 MPa), or anywhere therebetween. The aluminum alloy products described herein may exhibit yield strength as described herein when measured in the longitudinal (L), transverse (T), and / or diagonal (D) directions, respectively, relative to the rolling direction.

[0051] In some examples, aluminum alloy products produced from the aluminum alloys described herein can have an ultimate tensile strength (Rm) of about 200 MPa or greater. For example, the aluminum alloy products can have an ultimate tensile strength of 210 MPa or greater, 220 MPa or greater, 230 MPa or greater, 240 MPa or greater, 250 MPa or greater, 260 MPa or greater, 270 MPa or greater, 280 MPa or greater, 290 MPa or greater, or 300 MPa or greater. In some cases, the ultimate tensile strength is between 200 MPa and 400 MPa (e.g., between 220 MPa and 380 MPa, between 240 MPa and 360 MPa, or between 250 MPa and 340 MPa), or any range therebetween. The aluminum alloy products described herein can exhibit ultimate tensile strengths as described herein when measured in the longitudinal (L), transverse (T), and / or diagonal (D) directions, respectively, relative to the rolling direction.

[0052] In some examples, aluminum alloy products produced from the aluminum alloys described herein may have a total elongation (A80) of 15% to 30% (e.g., 16% to 28%, 18% to 26%, 19% to 25%, 20% to 25%, or 21% to 24%). For example, aluminum alloy products produced from the aluminum alloys described herein may have a total elongation of about 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, or 30%, or any value therebetween. The aluminum alloy products described herein may exhibit a total elongation as described herein when measured in the longitudinal (L), transverse (T), and / or cross-sectional (D) directions, respectively, relative to the rolling direction.

[0053] In some examples, aluminum alloy products produced from the aluminum alloys described herein may have a β bend angle value per specification VDA238-100 of less than 140° (e.g., less than 135°, less than 130°, less than 125°, less than 120°, less than 110°, less than 100°, less than 90°, or less than 80°).

[0054] Aluminum alloy manufacturing method The aluminum alloys described herein can be cast into castings using a vertical semi-continuous casting (direct chill) (DC) process or can be cast using a thin plate horizontal continuous casting (CC) process. The casting process is conducted according to standards commonly used in the aluminum industry, as known to those skilled in the art. The CC process can include, but is not limited to, the use of a twin-belt continuous caster, a twin-roll continuous caster, or a block caster. In some examples, the casting process is conducted by the CC process to form slabs, strip, etc. In some examples, the casting process is a DC casting process to form castings.

[0055] The castings, slabs, or strip can then undergo further processing steps. Optionally, further processing steps can be used to prepare aluminum alloy products (e.g., sheets, sheets, or plates). Such processing steps include, but are not limited to, diffusion annealing, hot rolling, and cold rolling. The processing steps are described below in relation to castings. However, the processing steps can also be used with cast slabs or strip, using modifications known to those skilled in the art.

[0056] In the diffusion annealing step, the casting may be heated to a diffusion annealing temperature, e.g., a temperature ranging from about 400°C to about 600°C. For example, the casting may be heated to a temperature of 400°C, 410°C, 420°C, 430°C, 440°C, 450°C, 460°C, 470°C, 480°C, 490°C, 500°C, 510°C, 520°C, 530°C, 540°C, 550°C, 560°C, 570°C, 580°C, 590°C, or 600°C. In some embodiments, the heating rate to the peak metal temperature may be about 70°C / hour or less, about 60°C / hour or less, or about 50°C / hour or less. The casting may then be allowed to soak (i.e., held at the prescribed temperature) for a period of time to form a diffusion annealed product. In some examples, the total duration of the diffusion annealing step, including the heating and soaking phases, can be up to about 10 hours.

[0057] The diffusion annealing step can be followed by a hot rolling step. The diffusion annealed product can be hot rolled using a roll mill to produce a hot rolled product. Before hot rolling begins, the diffusion annealed product is allowed to cool to a desired temperature, for example, about 200°C to about 425°C. For example, the diffusion annealed product can be allowed to cool to a temperature of about 200°C to about 400°C, about 250°C to about 375°C, about 300°C to about 425°C, or about 350°C to about 400°C. The diffusion annealed product can then be hot rolled at a hot rolling temperature (e.g., about 200°C to about 450°C) to produce a hot rolled product (e.g., a hot rolled plate, a hot rolled sheet, or a hot rolled sheet).

[0058] The hot rolled product can be cold rolled using a cold roll mill to produce a thinner product, such as a final gauge rolled product. The final gauge rolled product may have a gauge of between about 0.5 and about 10 mm, for example, between about 0.7 and about 6.5 mm. Optionally, the final gauge rolled product can have a gauge of about 0.5 mm, about 1.0 mm, about 1.5 mm, about 2.0 mm, about 2.5 mm, about 3.0 mm, about 3.5 mm, about 4.0 mm, about 4.5 mm, about 5.0 mm, about 5.5 mm, about 6.0 mm, about 6.5 mm, about 7.0 mm, about 7.5 mm, about 8.0 mm, about 8.5 mm, about 9.0 mm, about 9.5 mm, or about 10.0 mm. Cold rolling may be carried out to result in a final gauge thickness representing a gauge reduction of up to about 85% (e.g., a reduction of up to about 10%, up to about 20%, up to about 30%, up to about 40%, up to about 50%, up to about 60%, up to about 70%, up to about 80%, or up to about 85%) compared to the gauge before cold rolling began. In some embodiments, the cold rolling step may include one or more cold rolling steps to achieve the desired gauge thickness reduction. Optionally, the process for producing an aluminum alloy may include intermediate annealing steps (e.g., between one or more cold rolling steps).

[0059] How to use aluminum alloys The aluminum alloys described herein can be used in transportation applications, such as automotive applications and other aircraft, rail, and other applications. For example, the aluminum alloys can be used to prepare automotive structural components such as bumpers, side beams, roof beams, cross beams, pillar reinforcements (such as A-pillars, B-pillars, and C-pillars), inner panels, outer panels, side panels, inner hoods, outer hoods, or trunk lid panels. The aluminum alloys and methods described herein can also be used in aircraft or rail vehicle applications, for example, to prepare exterior and interior panels. In some examples, the aluminum alloys can be used in aerospace structural and nonstructural components or marine structural or nonstructural components.

[0060] The aluminum alloys and methods described herein can also be used in electronics applications. For example, the aluminum alloys and methods described herein can be used to prepare housings for electronic devices, including mobile phones and tablet computers. In some examples, the aluminum alloys can be used to prepare housings for the outer casings of mobile phones (e.g., smartphones) and the bottom chassis of tablets.

[0061] The aluminum alloys described herein can be used to manufacture aluminum alloy products in the form of plates, extrusions, castings, and forgings, or other suitable product forms. The products can be manufactured using techniques known to those skilled in the art. In some instances, the aluminum alloys can be used to manufacture extruded products. For example, the aluminum alloys described herein can be used to manufacture extruded aluminum alloy products.

[0062] The aluminum alloys and methods described herein can also be used in other applications, if desired. The aluminum alloys described herein can be provided as aluminum alloy sheets and / or plates suitable for further processing by an end user. For example, the aluminum alloy sheets can be further subjected to surface treatments by the end user for use as architectural exterior panels for aesthetic and structural purposes.

[0063] Examples Example 1 is an aluminum alloy, wherein the aluminum alloy comprises 1.0-2.0 wt% Si, 0.20-1.0 wt% Fe, max 0.20 wt% Cu, 0.20-0.80 wt% Mn, 0.20-0.70 wt% Mg, max 0.10 wt% Cr, max 0.20 wt% Zn, max 0.15 wt% Ti, max 0.15 wt% Ni, max 0.25 wt% impurities, and Al, wherein the aluminum alloy comprises a combined content of at least 2.2 wt% Si, Fe, and Mn, and wherein the aluminum alloy comprises no more than 20 wt% primary aluminum alloy.

[0064] Example 2 is the aluminum alloy of any of the preceding or subsequent examples, wherein the aluminum alloy comprises 1.20-2.0 wt% Si, 0.30-0.90 wt% Fe, 0.01-0.20 wt% Cu, 0.25-0.70 wt% Mn, 0.25-0.60 wt% Mg, max 0.10 wt% Cr, max 0.15 wt% Zn, max 0.10 wt% Ti, max 0.10 wt% Ni, max 0.23 wt% impurities, and Al.

[0065] Example 3 is the aluminum alloy of any of the preceding or subsequent examples, wherein the aluminum alloy comprises 1.30-1.80 wt% Si, 0.40-0.90 wt% Fe, 0.01-0.15 wt% Cu, 0.30-0.70 wt% Mn, 0.30-0.60 wt% Mg, max 0.10 wt% Cr, max 0.15 wt% Zn, max 0.10 wt% Ti, max 0.05 wt% Ni, max 0.22 wt% impurities, and Al.

[0066] Example 4 is the aluminum alloy of any of the preceding or subsequent examples, wherein the aluminum alloy comprises 1.40-1.70 wt% Si, 0.50-0.90 wt% Fe, 0.05-0.15 wt% Cu, 0.40-0.70 wt% Mn, 0.30-0.50 wt% Mg, max 0.05 wt% Cr, max 0.10 wt% Zn, max 0.05 wt% Ti, max 0.05 wt% Ni, max 0.21 wt% impurities, and Al.

[0067] Example 5 is the aluminum alloy of any of the preceding or subsequent examples, wherein the aluminum alloy comprises 1.55-1.70 wt% Si, 0.60-0.90 wt% Fe, 0.05-0.10 wt% Cu, 0.50-0.70 wt% Mn, 0.35-0.45 wt% Mg, 0.01-0.03 wt% Cr, 0.01-0.05 wt% Zn, 0.01-0.03 wt% Ti, 0.01-0.05 wt% Ni, up to 0.20 wt% impurities, and Al.

[0068] Example 6 is an aluminum alloy as described in any of the preceding or subsequent examples, having a (Mn+Cr):Fe ratio greater than 0.70.

[0069] Example 7 is an aluminum alloy as described in any of the preceding or following examples, wherein the aluminum alloy comprises 0.60-0.90 wt% Fe and 0.40-0.70 wt% Mn.

[0070] Example 8 is an aluminum alloy as described in any of the preceding or subsequent examples, having a combined Fe and Si content of at least 1.5 wt%.

[0071] Example 9 is an aluminum alloy as described in any of the preceding or subsequent examples, having a combined Si, Fe, and Mn content of 2.2 wt% to 3.6 wt%.

[0072] Example 10 is an aluminum alloy as described in any preceding or subsequent example, wherein the aluminum alloy comprises at least 50 wt% recycled aluminum alloy material.

[0073] Example 11 is an aluminum alloy as described in any of the preceding or subsequent examples, wherein the aluminum alloy has a yield strength of at least 130 MPa.

[0074] Example 12 is an aluminum alloy as described in any preceding or subsequent example, wherein the aluminum alloy has an ultimate tensile strength of at least 200 MPa.

[0075] Example 13 is an aluminum alloy as described in any preceding or subsequent example, wherein the aluminum alloy has a total elongation of at least 15%.

[0076] Example 14 is an aluminum alloy as described in any of the preceding or subsequent examples, wherein the aluminum alloy has a β bend angle value of less than 140° according to specification VDA238-100.

[0077] Example 15 is a method of producing an aluminum alloy, the method comprising casting an aluminum alloy to form a casting, the aluminum alloy containing 1.0-2.0 wt% Si, 0.20-1.0 wt% Fe, up to 0.20 wt% Cu, 0.20-0.80 wt% Mn, 0.20-0.70 wt% Mg, up to 0.10 wt% Cr, up to 0.20 wt% Zn, up to 0.15 wt% Ti, up to 0.15 wt% Ni, and up to 0.15 wt% Cr. % impurities, and Al, wherein the aluminum alloy has a combined content of at least 2.2 wt.% Si, Fe, and Mn, and the aluminum alloy includes no more than 10 wt.% primary aluminum alloy; forming the casting; diffusion annealing the casting; hot rolling the casting to produce a hot rolled product; cold rolling the hot rolled product to produce a final gauge rolled product; and optionally annealing the final gauge rolled product.

[0078] Example 16 is the method of any preceding or subsequent example, wherein casting the aluminum alloy includes providing more than 50 wt% recycled aluminum alloy material.

[0079] Example 17 is the method of any preceding or subsequent example, wherein the recycled aluminum alloy material comprises end-of-life aluminum alloy scrap.

[0080] Example 18 is the method of any preceding or subsequent example, wherein the aluminum alloy comprises 0.60-0.90 wt% Fe and 0.40-0.70 wt% Mn, and the ratio of (Mn+Cr):Fe is greater than 0.50.

[0081] Example 19 is the method of any of the preceding or subsequent examples, wherein the aluminum alloy product is prepared by the method of any of the preceding or subsequent examples.

[0082] Example 20 is the method of any preceding or subsequent example, wherein the aluminum alloy product is an automotive part or an electronic device housing.

[0083] The following examples serve to further illustrate the present invention but do not, however, constitute any limitation thereof. On the contrary, it is to be clearly understood that various embodiments, modifications and equivalents thereof may be resorted to, which may suggest themselves to those skilled in the art after reading the description herein without departing from the spirit of the invention.

[0084] During the testing described in the following examples, conventional procedures were followed unless otherwise stated, some of which are described below for illustrative purposes. [Example]

[0085] To determine the properties of the aluminum alloys described herein, aluminum alloy samples were tested. Comparative Example 1 was prepared from conventional AA6016 aluminum alloy, currently used in automotive components. Comparative Examples 1 and 2 and the alloy examples were produced by casting the aluminum alloys in steel molds to produce 50 x 220 mm ingots. The ingots were then faced to produce 40 x 220 mm ingots. The faced ingots were heated to a diffusion annealing temperature of 560°C at a heating rate of 50°C / h and held at the diffusion annealing temperature for 11 hours. The diffusion annealed ingots were then hot rolled to produce 7.3 mm hot-rolled products, simulating coil cooling in a furnace with a 400°C stop. The hot-rolled products were cold-rolled to 3.1 mm, then annealed at 560°C for 25 minutes, and further cold-rolled to 1.2 mm to produce the final gauge products. The final gauge products were then solution heat treated by heating to 560°C for 120 seconds + 60 seconds. The final gauge products were then quenched in a water tank. Table 1 provides the aluminum alloy compositions for each of the Comparative Examples 1 and 2 and the Alloy Example. [Table 6]

[0086] As shown in Table 6, Comparative Example 1 (AA6016 aluminum alloy) contains lower amounts of Si, Fe, and Mn compared to Example 1. The total amount of Si, Fe, and Mn in Comparative Example 1 was 1.5 wt%, while Example 1 contained 2.96 wt% Si, Fe, and Mn. Thus, Example 1 can tolerate higher amounts of these alloying elements. This demonstrates that the aluminum alloys described herein can incorporate higher levels of recycled aluminum alloy material compared to AA6016 aluminum alloy. Although Comparative Example 2 contains higher amounts of Si, Fe, and Mn than Example 1, Comparative Example 2 demonstrated poor mechanical properties, as shown in Table 7 below. The data demonstrate that by carefully balancing the amounts of alloying elements in the aluminum alloys described herein, higher levels of recycled aluminum alloy material can be incorporated while achieving good mechanical properties. Furthermore, Example 1 demonstrates that the aluminum alloy can tolerate higher amounts of Si, Fe, Mn, and Cr, allowing for the incorporation of higher amounts of recycled aluminum alloy material in place of primary aluminum. [Table 7]

[0087] FIG. 1 provides a graph of the total elongation (A80) of Example 1 and Comparative Examples 1 and 2 in the T4 (red) and T8x (blue) tempers, as measured in the longitudinal (L), transverse (T), and diagonal (D) directions relative to the rolling direction, respectively (e.g., A80 after a 2% pre-strain followed by heat treatment at a temperature of about 185°C for about 20 minutes). As shown in FIG. 1, Alloy Example 1 exhibited a total elongation of over 20% in all directions in the T4 temper. Comparative Example 2 exhibited a significantly lower total elongation (19.5% or less), while Comparative Example 1 exhibited a total elongation similar to Alloy Example 1. Alloy Example 1 demonstrated that a 6000 series aluminum alloy with a carefully balanced composition can achieve good elongation properties despite using a larger amount of recycled aluminum alloy material.

[0088] FIG. 2 provides a graph of the yield strength (Rp0.2) (e.g., Rp0.2 after 2% pre-strain and heat treatment at a temperature of about 185°C for about 20 minutes) of Example 1 and Comparative Examples 1 and 2 in the T4 (red) and T8x (blue) tempers, as measured in the longitudinal (L), transverse (T), and diagonal (D) directions, respectively, relative to the rolling direction. Additionally, FIG. 3 provides a graph of the ultimate tensile strength (Rm) (e.g., Rm after 2% pre-strain and heat treatment at a temperature of about 185°C for about 20 minutes) of Example 1 and Comparative Examples 1 and 2 in the T4 (red) and T8x (blue) tempers, as measured in the longitudinal (L), transverse (T), and diagonal (D) directions, respectively, relative to the rolling direction. Example 1 had similar yield and ultimate tensile strengths to Comparative Example 2, and higher yield and ultimate tensile strengths in all directions compared to Comparative Example 1. Example 1 exhibited a yield strength of over 130 MPa and an ultimate tensile strength of over 250 MPa. The yield strength and ultimate tensile strength values ​​of Example 1 meet the minimum strength requirements for many applications. Furthermore, Example 1 demonstrates that increasing the Fe and Si content to increase the regrind content of the alloy composition resulted in higher yield strength and ultimate tensile strength than Comparative Example 1. These results demonstrate that by increasing the regrind content, the resulting properties are comparable to or even better than those of currently available commercially available aluminum alloys. Furthermore, the results demonstrate that Example 1 has higher yield strength and ultimate tensile strength after paint bake (e.g., 2% pre-strain + 185°C for 20 min) than Comparative Example 1. Therefore, the aluminum alloys described herein have the potential for thinning to provide lightweight products in structural applications compared to standard AA6016 aluminum alloy.

[0089] Figure 4 provides a graph of the β bend angle values ​​(measured in degrees) per specification VDA 238-100 for Example 1 and Comparative Examples 1 and 2 in the T4 temper as measured in the longitudinal (L) and transverse (T) directions. The results of these tests are shown in Figure 4. Alloy Example 1 exhibited good bend properties that were comparable to Comparative Examples 1 and 2. Surprisingly, Alloy Example 1 achieved better bend properties than Comparative Example 1.

[0090] Example 2 Aluminum alloy samples were tested to determine the properties of the aluminum alloys described herein. Comparative Example 3 was prepared from a conventional AA6121 aluminum alloy currently used in automotive components. Comparative Example 2 was an aluminum alloy produced from recycled material with an aluminum alloy composition outside the scope of the present invention. Comparative Examples 1 and 2 and Alloy Example 2 were produced by casting the aluminum alloy in a steel mold to produce a 50 mm ingot. The ingot was heated to a diffusion annealing temperature of 560°C for 8 hours and held at the diffusion annealing temperature for 11 hours. The diffusion annealed ingot was then hot rolled to produce a 7.3 mm hot-rolled product, with a final hot-rolling exit temperature of 350°C. The hot-rolled product was cold-rolled to 3.1 mm, then annealed at 560°C for 25 minutes, air-cooled, and further cold-rolled to 1.2 mm to produce the final gauge product. The final gauge products were then solution heat treated by heating to 560°C for 120 seconds + 60 seconds. The final gauge products were then water quenched. Table 8 provides the aluminum alloy compositions for each of Comparative Examples 3 and 4 and Alloy Example 2. [Table 8]

[0091] Figure 5 provides a graph of the total elongation (A80) (measured in %) of Example 2 and Comparative Examples 3 and 4 as measured in the longitudinal (L), transverse (T), and diagonal (D) directions, respectively, relative to the rolling direction. As shown in Figure 5, Alloy Example 2 exhibited similar good total elongation properties as Comparative Example 3. Alloy Example 2 achieved better elongation than Comparative Example 4 in the longitudinal, transverse, and diagonal directions.

[0092] 6 provides a graph of the uniform elongation (Ag) (measured in %) for Example 2 and Comparative Examples 3 and 4 in the T4 temper as measured in the longitudinal (L), transverse (T), and diagonal (D) directions. Alloy Example 2 has similar uniform elongation properties to Comparative Example 3 and better uniform elongation in the longitudinal, transverse, and diagonal directions than Comparative Example 4.

[0093] Test samples were subjected to work-hardening tests to evaluate the plastic deformation of aluminum alloys. Work hardening begins when deformation exceeds the yield strength of the material and continues until the sample or engineering stamping fractures, or alternatively, until the target strain level or part shape is reached. FIG. 7 provides a graph of the n5 values ​​(unitless) of Example 2 and Comparative Examples 3 and 4 in the T4 temper as measured in the longitudinal (L), transverse (T), and diagonal (D) directions. As shown in FIG. 7, Comparative Example 4 had a decrease in n5 value in all directions in the T4 temper. Alloy Example 2 exhibited a similar n value to Comparative Example 3 due to the unique balance of alloying elements.

[0094] Tables 5-7 show that Example 2, despite being made from a large amount of recycled material, has similar strength, total elongation, uniform elongation, and n-value to Comparative Example 3. This is due, in part, to the careful balance of alloying elements in the aluminum alloy described herein. These results demonstrate that by increasing the recycled content and adjusting the composition of the aluminum alloy, the resulting properties are comparable to those of currently available commercially available aluminum alloys.

[0095] Figure 8 provides a graph of the bend formability (r10) of Example 2 and Comparative Examples 3 and 4 as measured in the (L), transverse (T), and oblique (45°) directions. As shown in Figure 8, Alloy Example 1 exhibited good bend formability properties similar to Comparative Example 3. In fact, Alloy Example 2 achieved better bend formability in the oblique direction than Comparative Example 3.

[0096] FIG. 9A provides images of electron backscatter diffraction profiles for Alloy Example 2 and Comparative Examples 3 and 4 (scale bar 200 μm). FIG. 9B provides graphs of grain size (μm) in both the Dx and Dy directions for Alloy Example 2 (gray) and Comparative Examples 3 (blue) and 4 (orange). Large grain sizes can have a negative impact on formability properties. FIG. 9A shows that the microstructure of Example 2 was composed of fine grains, as confirmed by the graphs of grain lengths in the x (Dx) and y (Dy) directions in FIG. 9B. Alloy Example 2 had significantly smaller grains in the Dx and Dy directions than Comparative Example 3. Alloy Example 2 and Comparative Example 4 contain higher amounts of Si and Fe than Comparative Example 1, which not only stimulates intermetallic particle nucleation sites but also pins dispersoids to the grain boundaries, resulting in finer grains. Finer grains advantageously result in better formability properties for the aluminum alloy.

[0097] 10A provides a graph of the texture components (measured in volume %) within the microstructures of Alloy Example 2 and Comparative Examples 3 and 4. The volume % of the following texture components were measured: cube, goss, brass, S, Cu, rotated cube (RC), P * , and H. Additionally, FIG. 10B provides a graph of the total amount of texture components (measured in volume %) within the microstructures of Alloy Example 2 and Comparative Examples 3 and 4. Alloy Example 2 had less cube, goss, and Rc texture components than Comparative Example 3. Overall, Alloy Example 2 had a higher total amount of texture components than Comparative Examples 3 and 4. Additionally, Alloy Example 2 had a higher amount of beta fibers than Comparative Example 3. The amount and type of texture components in Alloy Example 2 can result in good bending performance.

[0098] 11 provides a graph of the simulated r-values ​​for Alloy Example 2 and Comparative Examples 3 and 4 taken at angles of 0°, 45°, and 90°. The simulated r-values ​​are similar to the measured r-values ​​for Example 2 and Comparative Examples 3 and 4. For example, the tested r-values ​​for Example 2 and Comparative Examples 3 and 4 were 0.7, 0.8, and 0.6, respectively, while the simulated values ​​at r45 were approximately 0.9, 0.7, and 1.0, respectively.

[0099] Figure 12 provides images of the microstructure of Alloy Example 2 and Comparative Examples 3 and 4 obtained using a scanning electron microscope (SEM). Figure 13 provides a graph of the area fraction (measured in %) of intermetallics (blue) and microvoids (orange) for Alloy Example 2 and Comparative Examples 3 and 4. Alloy Example 2 had substantially more intermetallics in its microstructure than Comparative Example 3. It is contemplated that the area fraction of intermetallics is related to the amount of Fe in the alloy composition.

[0100] 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 accomplishment of various objects of the present invention. It should be recognized that these embodiments are merely illustrative of the principles of the present invention. Numerous modifications and adaptations 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. 1. An aluminum alloy comprising: 1.0-2.0 wt% Si, 0.20-1.0 wt% Fe, max 0.20 wt% Cu, 0.20-0.80 wt% Mn, 0.20-0.70 wt% Mg, max 0.10 wt% Cr, max 0.20 wt% Zn, max 0.15 wt% Ti, max 0.15 wt% Ni, max 0.25 wt% impurities, and Al; the aluminum alloy comprises a combined content of Si, Fe, and Mn of at least 2.2 wt. %; and The aluminum alloy comprises 20 wt % or less of a primary aluminum alloy.

2. 10. The aluminum alloy of claim 1, comprising 1.20-2.0 wt% Si, 0.30-0.90 wt% Fe, 0.01-0.20 wt% Cu, 0.25-0.70 wt% Mn, 0.25-0.60 wt% Mg, max 0.10 wt% Cr, max 0.15 wt% Zn, max 0.10 wt% Ti, max 0.10 wt% Ni, max 0.23 wt% impurities, and Al.

3. 2. The aluminum alloy of claim 1, comprising 1.30-1.80 wt% Si, 0.40-0.90 wt% Fe, 0.01-0.15 wt% Cu, 0.30-0.70 wt% Mn, 0.30-0.60 wt% Mg, max 0.10 wt% Cr, max 0.15 wt% Zn, max 0.10 wt% Ti, max 0.05 wt% Ni, max 0.22 wt% impurities, and Al.

4. 2. The aluminum alloy of claim 1, comprising 1.40-1.70 wt% Si, 0.50-0.90 wt% Fe, 0.05-0.15 wt% Cu, 0.40-0.70 wt% Mn, 0.30-0.50 wt% Mg, max 0.05 wt% Cr, max 0.10 wt% Zn, max 0.05 wt% Ti, max 0.05 wt% Ni, max 0.21 wt% impurities, and Al.

5. 2. The aluminum alloy of claim 1, comprising 1.55-1.70 wt% Si, 0.60-0.90 wt% Fe, 0.05-0.10 wt% Cu, 0.50-0.70 wt% Mn, 0.35-0.45 wt% Mg, 0.01-0.03 wt% Cr, 0.01-0.05 wt% Zn, 0.01-0.03 wt% Ti, 0.01-0.05 wt% Ni, up to 0.20 wt% impurities, and Al.

6. An aluminium alloy according to any one of claims 1 to 5, wherein the ratio (Mn+Cr):Fe is greater than 0.

70.

7. 7. An aluminium alloy according to any one of the preceding claims, wherein the aluminium alloy comprises 0.60 to 0.90 wt% Fe and 0.40 to 0.70 wt% Mn.

8. An aluminium alloy according to any one of the preceding claims, wherein the combined content of Fe and Si is at least 1.5 wt%.

9. 9. An aluminium alloy according to any one of the preceding claims, wherein the combined content of Si, Fe and Mn is from 2.2 wt% to 3.6 wt%.

10. An aluminium alloy according to any one of the preceding claims, wherein the aluminium alloy comprises at least 50 wt% recycled aluminium alloy material.

11. An aluminium alloy according to any one of the preceding claims, wherein the aluminium alloy has a yield strength of at least 130 MPa.

12. An aluminium alloy according to any one of the preceding claims, wherein the aluminium alloy has an ultimate tensile strength of at least 200 MPa.

13. An aluminium alloy according to any one of the preceding claims, wherein the aluminium alloy has a total elongation of at least 15%.

14. 14. An aluminium alloy according to any one of the preceding claims, wherein the aluminium alloy has a β bend angle value according to specification VDA 238-100 of less than 140°.

15. 1. A method for producing an aluminum alloy, comprising: casting an aluminum alloy to form a casting, the aluminum alloy comprising: maximum 1.0-2.0 wt.% Si, 0.20-1.0 wt.% Fe, maximum 0.20 wt.% Cu, 0.20-0.80 wt.% Mn, 0.20-0.70 wt.% Mg, maximum 0.10 wt.% Cr, maximum 0.20 wt.% Zn, maximum 0.15 wt.% Ti, maximum 0.15 wt.% Ni, maximum 0.15 wt.% impurities, and Al, the aluminum alloy having a combined content of at least 2.2 wt.% Si, Fe, and Mn, and the aluminum alloy comprising 10 wt.% or less of a primary aluminum alloy; diffusion annealing the casting; hot rolling the casting to produce a hot rolled product; cold rolling the hot rolled product to produce a final gauge rolled product; optionally annealing said final gauge rolled product; The method comprising:

16. 16. The method of claim 15, wherein casting the aluminum alloy comprises providing greater than 50 wt% recycled aluminum alloy material.

17. 17. The method of claim 16, wherein the recycled aluminum alloy material comprises end-of-life aluminum alloy scrap.

18. 18. The method of any one of claims 15 to 17, wherein the aluminium alloy comprises 0.60-0.90 wt% Fe and 0.40-0.70 wt% Mn, and the ratio (Mn+Cr):Fe is greater than 0.

50.

19. An aluminium alloy product, said aluminium alloy product being prepared by a method comprising that according to any one of claims 15 to 18.

20. 20. The aluminum alloy product of claim 19, wherein the aluminum alloy product is an automotive part or an electronic device housing.

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