WO2024097460A1 - High recycle content 6xxx series aluminum alloys and methods for preparing the same - Google Patents

Abstract

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

Description

HIGH RECYCLE CONTENT 6XXX SERIES ALUMINUM ALLOYS AND

METHODS FOR PREPARING THE SAME

CROSS-REFERENCE TO RELATED APPLICATION

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

FIELD

[0002] The present disclosure relates to the fields of metallurgy, aluminum alloys, aluminum fabrication, and related fields. In particular, the present disclosure provides novel 6xxx series aluminum alloys produced from high amounts of recycled aluminum alloy materials. The disclosure also provides various end uses of such products, such as in automotive, transportation, electronics, industrial, aerospace, and other applications.

BACKGROUND

[0003] Aluminum alloys are used in many different applications that require a combination of strength and durability. 6xxx series aluminum alloys are widely used in, for example, automobile applications, due to their superior combination of properties including strength-to-weight ratio, formability, weldability, and general corrosion resistance. For example, 6xxx series aluminum alloys are commonly used for 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 the weight of the vehicle and allows for substantial improvements in fuel economy.

[0004] Even so, currently available 6xxx series aluminum alloys require significant amounts of primary aluminum and alloying elements to achieve target specification, 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 6xxx series aluminum alloys have not been successful primarily because the mechanical properties (e.g., strength and formability) are significantly affected by changes in the aluminum alloy composition. For example, the composition of the AA6016 is strictly controlled to achieve desired performance properties. Therefore, very little or no recycled aluminum alloy materials are used to produce AA6016 aluminum alloys for structural components because the aluminum alloy can tolerate very little amounts of impurities that may affect the properties of the aluminum alloy. [0005] Many original equipment manufacturers (OEMs) require recycle-friendly aluminum alloys to comply with federal regulations or to limit their carbon footprint. OEMs require aluminum alloys that are produced from high amounts of recycled aluminum alloy materials and less primary aluminum. This is because the process for producing primary aluminum is labor-intensive and produces significant amounts of carbon emissions. However, as noted above, 6xxx series aluminum alloys have strictly controlled compositional ranges to meet specific performance properties. Additionally, recycled aluminum alloy materials may include a mixture of different aluminum alloy compositions making it difficult to produce 6xxx series aluminum alloys that have strictly controlled compositional limits. Therefore, if recycled aluminum alloy materials are used to produce 6xxx series aluminum alloys, significant amounts of primary aluminum and additional alloying elements are needed to adjust the composition to produce aluminum alloy products (e.g., automobile parts), which decreases the recycled content. Moreover, additional primary aluminum increases the carbon dioxide production and increases costs, leading to environmental harm and high costs.

SUMMARY

[0006] Covered embodiments of the present disclosure are defined by the claims, not this summary. This summary is a high-level overview of various aspects of the invention and introduces some of the concepts that are further described in the Detailed Description section below. This summary is not intended to identify key or essential 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 appropriate portions of the entire specification, any or all drawings and each claim.

[0007] Described herein are aluminum alloys that provide a more cost-effective and recycle-friendly material alternative to the use of conventional 6xxx series aluminum alloys. In some embodiments, the present disclosure relates to an aluminum alloy including 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. % of impurities, and Al, wherein the aluminum alloy comprises a combined content of Si, Fe, and Mn of at least 2.2 wt. %; wherein the aluminum alloy comprises 20 wt. % or less of primary aluminum alloy. In some embodiments, 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, 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.% of impurities, and Al. In some embodiments, 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, 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.% of impurities, and Al. In some embodiments, 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, up to 0.05 wt. % Cr, up to 0.10 wt. % Zn, up to 0.05 wt. % Ti, up to 0.05 wt. % Ni, up to 0.21 wt.% of impurities, and Al. In some embodiments, 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. In some embodiments, a ratio of (Mn+Cr):Fe is greater than 0.70. In some embodiments, the aluminum alloy comprises 0.60 - 0.90 wt. % Fe and 0.40 - 0.70 wt. % Mn. In some embodiments, a 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. % of recycled aluminum alloy materials. 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 P bend angle value according to Specification VDA 238-100 less than 140°.

[0008] In some embodiments, a method for producing an aluminum alloy is provided. The method includes casting an aluminum alloy to form a cast product, wherein the aluminum alloy comprises up to 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 0.15 wt. % of impurities, and Al, wherein the aluminum alloy comprises a combined content of Si, Fe, and Mn of at least 2.2 wt. %, wherein the aluminum alloy comprises 10 wt. % or less of primary aluminum alloy; homogenizing the cast product; hot rolling the cast product 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 comprises providing greater than 50 wt. % of recycled aluminum alloy materials. In some embodiments, the recycled aluminum alloy materials 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 wherein a ratio of (Mn+Cr):Fe is greater than 0.50. In some embodiments, an aluminum alloy product is prepared by the method described herein. In some embodiments, the aluminum alloy product is an automobile part or an electronic housing.

[0009] Further aspects, objects, and advantages will become apparent upon consideration of the detailed description and figures that follow.

BRIEF DESCRIPTION OF THE FIGURES

[0010] FIG. 1 provides a graph of the total elongation (A80) (measured in %) of example aluminum alloys in a T4 temper (red) and in a T8x temper (blue) (e.g., A80 after thermal treatment at a temperature of about 185 °C for about 20 minutes after 2% pre-straining) when measured in a longitudinal (L) direction, a transverse (T) direction, and in a diagonal (D) direction, each respective to the rolling direction, according to some embodiments described herein.

[0011] FIG. 2 provides a graph of the yield strength (Rp0.2) (measured in MPa) of example aluminum alloys in a T4 temper (red) and in a T8x temper (blue) (e.g., Rp0.2 after thermal treatment at a temperature of about 185 °C for about 20 minutes after 2% prestraining) when measured in a longitudinal (L) direction, a transverse (T) direction, and in a diagonal (D) direction, each respective to the rolling direction, according to some embodiments described herein.

[0012] FIG. 3 provides a graph of the ultimate tensile strength (Rm) (measured in MPa) of example aluminum alloys in a T4 temper (red) and in a T8x temper (blue) (e.g., Rm after thermal treatment at a temperature of about 185 °C for about 20 minutes after 2% prestraining) when measured in a longitudinal (L) direction, a transverse (T) direction, and in a diagonal (D) direction, each respective to the rolling direction, according to some embodiments described herein.

[0013] FIG. 4 provides a graph of the P bend angle values according to Specification VDA 238-100 (measured in °) of example aluminum alloys in a T4 temper when measured in a longitudinal (L) direction and a transverse (T) direction, each respective to the rolling direction, according to some embodiments described herein.

[0014] FIG. 5 provides a graph of the total elongation (A80) (measured in %) of example alloys in a T4 temper when measured in a longitudinal (L) direction, a transverse (T) direction, and a diagonal (D) direction, each respective to the rolling direction, according to some embodiments described herein.

[0015] FIG. 6 provides a graph of the uniform elongation (Ag) (measured in %) of example alloys in a T4 temper when measured in a longitudinal (L) direction, a transverse (T) direction, and a diagonal (D) direction, each respective to the rolling direction, according to some embodiments described herein.

[0016] FIG. 7 provides a graph of n5 values (unitless) of example alloys in a T4 temper when measured in a longitudinal (L) direction, a transverse (T) direction, and a diagonal (D) direction, each respective to the rolling direction, according to some embodiments described herein.

[0017] FIG. 8 provides a graph of the bendability (rlO) of example alloys when measured in a longitudinal (L) direction and a transverse (T) direction, each respective to the rolling direction, according to some embodiments described herein.

[0018] FIG. 9A provides images of the electron back-scatter diffraction (EBSD) profiles of the example alloys, and FIG. 9B provides a graph of the grain size (pm) in both the Dx and Dy directions of the example alloys, according to some embodiments described herein.

[0019] FIG. 10A provides a graph of the texture components (measured in volume %) in the microstructure of example alloys, according to some embodiments described herein.

[0020] FIG. 10B provides a table of the texture components (measured in volume %) shown in FIG. 10 A, according to some embodiments described herein.

[0021] FIG. 11 provides a graph of the simulated r values of example alloys at 0°, 45°, and 90° angles, according to some embodiments described herein.

[0022] FIG. 12 provides scanning electron microscopy (SEM) images of example alloys (scale bar is 20 pm) of the example alloys, according to some embodiments described herein.

[0023] FIG. 13 provides a graph of the area fraction (measured in %) of intermetallics (blue) and microvoids (orange) of the example alloys, according to some embodiments described herein.

DETAILED DESCRIPTION

[0024] Described herein are novel 6xxx series aluminum alloys including high amounts of recycled aluminum alloy materials and less than 20 wt. % primary aluminum alloy, which exhibit comparable strength, elongation, and bendability to conventional 6xxx series aluminum alloys. Among other things, the 6xxx series aluminum alloys described herein include higher amounts of silicon (Si), iron (Fe), and manganese (Mn) than conventional AA6016 aluminum alloy. In some embodiments, the present disclosure provides a 6xxx series aluminum alloy that can tolerate significant amounts of Si, Fe, and Mn compared to conventional AA6016 aluminum alloy, thereby enabling use of higher amounts of the recycled aluminum alloy materials. For example, the 6xxx series aluminum alloy can include greater than 50 wt. % of end-of-life aluminum alloy scrap (e.g., castings, extrusions, and aluminum alloy sheets from automobiles). Despite including high amounts of recycled aluminum alloy materials, the 6xxx series aluminum alloys described herein exhibit equivalent or better strength, elongation, and bendability than conventional AA6016 aluminum alloys. The balance of alloying elements in the aluminum alloy composition results in an aluminum alloy microstructure having intermetallic phases that result in these beneficial properties.

[0025] Conventional AA6016 aluminum alloys require a strictly controlled composition to meet minimum strength requirements while still maintaining formability to produce complex geometries. In general, greater strength is required for aluminum alloys used to produce automotive parts (e.g., structural components), which has dictated that automobile parts be fabricated from an aluminum alloy such as an AA6016 aluminum alloy. This limits the amount of recycled aluminum alloy materials that can be used to produce an AA6016 aluminum alloy. Therefore, to produce automobile parts with large amounts of recycled aluminum alloy materials, such as end-of-life aluminum alloy scrap, it requires the use of more alloying elements and primary aluminum to produce AA6016 aluminum alloy, which significantly increases the cost of materials and associated CO2 emissions to produce these materials. This limits the amount of the recycled aluminum alloy materials that can be used to produce automobile parts.

[0026] The aluminum alloys described herein include a synergistic combination of alloying elements that allows for the use of higher amounts of recycled aluminum alloy materials. The use of more recycled aluminum alloy materials provides for an environmentally friendly 6xxx series aluminum alloy. The aluminum alloys described herein include a carefully balanced amount of Si, Fe, and Mn, which beneficially provides for using higher amounts of recycled aluminum alloy materials to produce 6xxx series aluminum alloys while providing good strength, elongation, and bendability. For example, recycled aluminum alloy materials may include high amounts of Fe, thereby necessitating the aluminum alloy to tolerate higher amounts of Fe (e.g., greater than 0.50 wt. %) than conventional 6xxx series aluminum alloys. To maintain the intermetallic phases for good elongation and strength, the amount of Mn and Si in the aluminum alloy are also adjusted to allow for the use of higher amounts of Fe. Specifically, the aluminum alloys described herein promote formation of alpha-phase intermetallics while elongated beta-phase intermetallics (e.g., with sharp edges) are reduced. Surprisingly, the aluminum alloys described herein include a balanced amount of Si, Fe, and Mn that satisfies the equation (Mn+Cr):Fe > 0.70, which produces an aluminum alloy with the desired properties.

[0027] The aluminum alloys described herein exhibit high strength and formability despite having higher amounts of recycled aluminum alloy materials. The aluminum alloys described herein incorporate higher amounts of recycled aluminum alloy materials and less primary aluminum, as compared to traditional AA6016 aluminum alloys, and still maintain good mechanical properties for structural aluminum alloys. For example, the aluminum alloys described herein may include more than 50% recycled aluminum alloy materials and less than 10% primary aluminum, and still exhibit properties similar to AA6016 aluminum alloys. The aluminum alloys described herein provide a cost-effective alternative to the use of AA6016 aluminum alloys for structural components.

Definitions and Descriptions

[0028] 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 below. Statements containing these terms should be understood not to limit the subject matter described herein or to limit the meaning or scope of the patent claims below.

[0029] In this description, reference is made to alloys identified by aluminum industry designations, such as “series” or “xxx.” For an understanding of the number designation system most commonly used in naming and identifying 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 Compositions Limits for Aluminum Alloys in the Form of Castings and Ingot,” both published by The Aluminum Association.

[0030] As used herein, the meaning of “a,” “an,” or “the” includes singular and plural references unless the context clearly dictates otherwise.

[0031] As used herein, a plate generally has a thickness of greater than about 15 mm. For example, a 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.

[0032] As used herein, a shate (also referred to as a sheet plate) generally has a thickness of from about 4 mm to about 15 mm. For example, a shate may have a thickness of 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.

[0033] As used herein, a sheet generally refers to an aluminum product 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, a sheet may have a thickness of 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.

[0034] As used herein, formability refers to the ability of a material to undergo deformation into a desired shape without fracturing, tearing-off, necking, earing, or shaping errors such as wrinkling, spring-back, or galling occurring. In engineering, formability may be classified according to deformation modes. Examples of deformation modes include drawing, stretching, bending, and stretch-flanging.

[0035] As used herein, primary aluminum refers to an aluminum material including about at least 99.7 wt. % aluminum. Primary aluminum is produced from the prime transformation of raw material into aluminum (e.g., processing of bauxite into alumina and electrolysis of alumina into aluminum).

[0036] As used herein, yield stress (also referred to as yield strength) refers to the point at which an aluminum alloy begins to plastically deform and can no longer return to its original state.

[0037] Reference may be made in this application to alloy temper or condition. For an understanding of the alloy temper descriptions most commonly used, see “American National Standards (ANSI) H35 on Alloy and Temper Designation Systems.” An F condition or temper refers to an aluminum alloy as fabricated. An O condition or temper refers to an aluminum alloy after annealing. An Hxx condition or temper, also referred to herein as an H temper, refers to a non-heat treatable aluminum alloy after cold rolling with or without thermal treatment (e.g., annealing). Suitable H tempers include HX1, HX2, HX3 HX4, HX5, HX6, HX7, HX8, or HX9 tempers. A TI condition or temper refers to an aluminum alloy cooled from hot working and naturally aged (e.g., at room temperature). A T2 condition or temper refers to an aluminum alloy cooled from hot working, cold worked and naturally aged. A T3 condition or temper refers to an aluminum alloy solution heat treated, cold worked, and naturally aged. A T4 condition or temper refers to an aluminum alloy solution heat treated and naturally aged. A T5 condition or temper refers to an aluminum alloy cooled from hot working and artificially aged (at elevated temperatures). A T6 condition or temper refers to an aluminum alloy solution heat treated and artificially aged. A T7 condition or temper refers to an aluminum alloy solution heat treated and artificially overaged. A T8x condition or temper refers to an aluminum alloy solution heat treated, cold worked, and artificially aged. A T9 condition or temper refers to an aluminum alloy solution heat treated, artificially aged, and cold worked. A W condition or temper refers to an aluminum alloy after solution heat treatment.

[0038] As used herein, the meaning of “room temperature” can include a temperature of from about 15 °C to about 30 °C, for example 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.

[0039] All ranges disclosed herein are to 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 any and all subranges between (and inclusive of) the minimum value of 1 and the maximum value of 10; that is, all subranges beginning with a minimum value of 1 or more, e.g. 1 to 6.1, and ending with a maximum value of 10 or less, e.g., 5.5 to 10.

[0040] The following aluminum alloys are described in terms of their elemental composition in weight percentage (wt. %) based on the total weight of the alloy. In certain examples of each alloy, the remainder is aluminum, with a maximum wt. % of 0.15 % for the sum of the impurities.

Alloy Compositions

[0041] Described below are novel 6xxx series aluminum alloys. In certain aspects, the alloys exhibit high strength, high formability, and corrosion resistance. The properties of the alloys are achieved due to in part to the composition of the alloys and in part to the methods of processing the alloys to produce the described products (i.e., plates, shates, and sheets). In some cases, the novel aluminum alloys described herein can include higher levels of Si, Mn, Fe, and/or Cr compared to conventional AA6016 aluminum alloys, as further described below. In some examples, an aluminum alloy as described herein can have the following elemental composition as provided in Table 1. Table 1

[0042] In some examples, the aluminum alloy as described herein can have the following elemental composition as provided in Table 2.

Table 2

[0043] In some examples, the aluminum alloy as described herein can have the following elemental composition as provided in Table 3.

Table 3

[0044] In some examples, the aluminum alloy can have the following elemental composition as provided in Table 4.

Table 4

[0045] In some examples, the aluminum alloy can have the following elemental composition as provided in Table 5.

Table 5

Silicon (Si)

[0046] In some examples, the aluminum alloy described herein includes Si in an amount of from 1.0 % to 2.0 % (e.g., from 1.20 % to 2.0 %, from 1.30 % to 1.80 %, from 1.40 % to 1.70 %, from 1.50 % to 1.70 %, or from 1.55 % to 1.70 %) based on the total weight of the alloy. For example, the alloy can include 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 %, or 2.00 % Si. All expressed in wt. %. In some embodiments, an aluminum alloy composition including less than 1.0 wt. % Si may limit the amount of recycled aluminum alloy materials that can be used in the aluminum alloy composition. For example, end-of-life aluminum alloy scrap (e.g., castings, extrusions, used aluminum sheets) may include high amounts of Si. In some embodiments, an aluminum alloy described herein can include greater than 1.50 wt. % Si to tolerate higher amounts recycled aluminum alloy materials.

Iron (Fe)

[0047] In some examples, the aluminum alloy described herein also includes Fe in an amount of from 0.20 % to 0.90 % (e.g., from 0.30 % to 0.90 %, from 0.40 % to 0.90 %, from 0.50 % to 0.90, or from 0.60 % to 0.90 %) 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 %, 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 %, 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 materials that can be used in the aluminum alloy. In some embodiments, an aluminum alloy described herein can include greater than 0.50 wt. % Fe to tolerate higher amounts recycled aluminum alloy materials.

Copper (Cu)

[0048] In some examples, the aluminum alloy described herein includes Cu in an amount up to 0.20 % (e.g., from 0.01 % to 0.20 %, from 0.01 % to 0.15 %, from 0.05 % to 0.15 %, or from 0.05 % to 0.10 %) based on the total weight of the alloy. For example, the alloy can 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 expressed in wt. %. The aluminum alloy may include 0.01 wt. % to 0.20 wt. % Cu to compensate for the reduced content of Mg to strengthen the aluminum alloy. In some embodiments, aluminum alloys including less than 0.05 wt. % Cu may lead to insufficient strength properties. In some embodiments, an aluminum alloy including greater than 0.20 wt. % Cu may lead to excess strength, poor formability, and susceptibility to corrosion.

Manganese (Mn)

[0049] In some examples, the aluminum alloy described herein can include Mn in an amount from 0.20 % to 0.70 % (e.g., from 0.25 % to 0.70 %, from 0.30 % to 0.70 %, from 0.40 % to 0.70 %, or from 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 %, 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 expressed in wt. %. In some embodiments, aluminum alloys including the aforementioned amounts of Mn may result in intermetallic phases that promote formability. In some embodiments, an aluminum alloy including greater than 0.70 wt. % Mn may lead to intermetallic phases that can deteriorate the formability and end making performance.

Magnesium (Mg)

[0050] In some examples, the aluminum alloy described herein can include Mg in an amount from 0.20 % to 0.70 % (e.g., from 0.25 % to 0.60 %, from 0.30 % to 0.60 %, from 0.30 % to 0.50 %, or from 0.35 % to 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 %, 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 in wt. %.

Chromium (Cr)

[0051] In some examples, the aluminum alloy described herein includes Cr in an amount of up to 0.10 % (e.g., up to 0.10 %, up to 0.05 %, up to 0.03 %, or from 0.01 % to 0.03 %) based on the total weight of the alloy. For example, the alloy can include 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 not present in the alloy (i.e., 0 %). All expressed in wt. %.

Zinc (Zn)

[0052] In some examples, the aluminum alloy described herein includes Zn in an amount of up to 0.20 % (e.g., up to 0.15 %, up to 0.10 %, from 0.01 % to 0.20 %, from 0.01 % to 0.10 %, or from 0.01 % to 0.03 %) based on the total weight of the alloy. For example, the alloy can 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 % Zn. In some cases, Zn is not present in the alloy (i.e., 0 %). All expressed in wt. %. Titanium (Ti)

[0053] In some examples, the aluminum alloy described herein includes Ti in an amount of up to 0.15 % (e.g., up to 0.10 %, up to 0.05 %, up to 0.03 %, or from 0.01 % to 0.03 %) based on the total weight of the alloy. For example, the alloy can 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 %, or 0.15 % Ti. In some cases, Ti is not present in the alloy (i.e., 0 %). All expressed in wt. %.

Nickel (Ni)

[0054] In some examples, the aluminum alloy described herein includes Ni in an amount of up to 0.15 % (e.g., up to 0.10 %, up to 0.05 %, up to 0.03 %, or from 0.01 % to 0.05 %) based on the total weight of the alloy. For example, the alloy can 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 %, or 0.15 % Ni. In some cases, Ni is not present in the alloy (i.e., 0 %). All expressed in wt. %.

[0055] In some examples, the aluminum alloy described herein can include a combined content of Fe, Mn, and Si in an amount from 2.2 % to 3.6 % (e.g., from 2.3 % to 3.6 %, from 2.4 % to 3.6 %, from 2.6 % to 3.6 %, or from 3.0 % to 3.6 %) based on the total weight of the alloy. For example, the alloy can include a combined content of Fe, Mn, and Si 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, an aluminum alloy including a combined wt. % of Fe, Mn, and Si greater than 2.0 wt. % is well-suited for using end-of-life aluminum alloy scrap that may include higher amounts of these alloying elements. AA6016 alloy can only tolerate a maximum of 2.2 wt. % of Fe, Mn, and Si, thereby liming the amount of recycled aluminum alloy materials that can be used to produce the aluminum alloy. Surprisingly, balancing the aluminum alloy composition to include specific amounts of Fe, Mn, Si, and/or Cr can produce aluminum alloys that incorporate high amounts of recycled aluminum alloy materials (e.g., greater than 50 %) and result in good strength and formability. Additionally, the aluminum alloys described herein can include greater amounts of Cr than AA6016 alloy for better recycling properties.

[0056] In some embodiments, the ratio of (Mn+Cr):Fe is greater than 0.70 (e.g., from 0.70 to 1.5, from 0.70 to 1.4, from 0.70 to 1.3, or from 0.80 to 1.0). For example, the ratio of

(Mn+Cr):Fe in the aluminum alloy described herein can 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 include greater amounts of Fe than AA6016 aluminum alloys, which beneficially allows for higher amounts of recycled aluminum alloy materials to be used to produce the aluminum alloys described herein. The Fe content is balanced with the amounts of Mn and Cr in the aluminum alloy to produce intermetallic phases that contribute to good strength and formability. The aluminum alloys described herein include a ratio of (Mn+Cr):Fe is greater than 0.70 to produce these intermetallic phases. In some embodiments, the aluminum alloy composition described herein promotes formation of alpha-phase intermetallics while elongated beta-phase intermetallics are reduced.

[0057] In some examples, the aluminum alloy described herein can include a combined content of Fe and Si greater than 1.5 % (e.g., from 1.5 % to 3.0 %, from 1.6 % to 2.8 %, from 1.8 % to 2.6 %, or from 2.0 % to 2.0 %) based on the total weight of the alloy. For example, the alloy can include a combined content of Fe and Si 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. %.

Minor Elements

[0058] Optionally, the aluminum alloys described herein can further include other minor elements, sometimes referred to as impurities, in amounts of 0.25 % or below, 0.23 % or below, 0.22 % or below, 0.21 % or below, or 0.20 % or below. These impurities may include, but are not limited to Sc, V, Hf, Zr, Sn, Ga, Ca, Bi, Na, Pb, or combinations thereof. Accordingly, Sc, V, Hf, Zr, Sn, Ga, Ca, Bi, Na, or Pb may be present in alloys in amounts of 0.05 % or below, 0.04 % or below, 0.03 % or below, 0.02 % or below, or 0.01 % or below. The sum of all impurities does not exceed 0.25 % (e.g., 0.20 %). All expressed in wt. %. The remaining percentage of each alloy can be aluminum.

Recycled Content

[0059] The aluminum alloys described herein can tolerate higher amounts of recycled aluminum alloy materials and still exhibit desirable mechanical properties. The impact of the impurities and/or alloying elements on the mechanical properties of the aluminum alloy is reduced by providing a tailored aluminum alloy composition to compensate for the impurities. This enables a higher amount of less expensive, higher impurity recycled aluminum alloy materials (e.g., end-of-life aluminum alloy scrap) for producing aluminum alloys that can still exhibit desirable properties. The aluminum alloy compositions described herein can include higher amounts of recycled aluminum alloy materials with little or no additional primary aluminum and a reduced amount of more expensive alloying elements.

[0060] In some embodiments, the aluminum alloy composition described herein provides a composition that is well-suited for utilizing multiple sources of recycled aluminum alloy materials. In some embodiments, the aluminum alloys described herein are produced from mixed alloy scrap comprising one or more of end-of-life (EOL) aluminum articles (e.g., aluminum-intensive vehicles), unsegregated automotive scrap (e.g., containing one or more of 5xxx, 6xxx, and/or 7xxx series aluminum alloys from wrought and cast alloys), twitch, and recycled aluminum alloy parts (e.g., a heat exchanger, braze alloy scrap, etc.). The mixed alloy scrap is very low cost and using mixed alloy scrap to produce aluminum alloys can provide a significant cost reduction and reduce overall carbon emissions. In some embodiments, the recycled aluminum alloy materials may include taint tabor scrap, Twitch scrap from end-of-life vehicles, and industrial scrap. In some embodiments, the recycled aluminum alloy materials may include end-of-life aluminum alloy wires and aluminum litho plates. As described herein, using these recycled aluminum alloy materials can achieve desirable mechanical properties, while using very low-cost recycled scrap.

[0061] As discussed herein, the aluminum alloy composition described herein provides a tailored composition that allows the use of more recycled aluminum alloy materials, particularly EOL scrap, for producing aluminum alloy articles and reduces the amount of both primary aluminum and additional alloying elements. In some aspects, the aluminum alloys described herein include a high amount of EOL scrap at or greater than 25 %, e.g., at or greater than 30 %, at or greater than 35 %, at or greater than 40 %, at or greater than 45 %, at or greater than 50 %, at or greater than 55 %, at or greater than 60 %, at or greater than 65 %, at or greater than 70 %, or at or greater than 75 %. In terms of ranges, the aluminum alloys described herein can include from 25 % to 100 % EOL scrap (e.g., from 25 % to 95 %, from 30 % to 90 %, from 35 % to 85 %, from 40 % to 80 %, from 50 % to 70 %, or from 35 % to 50 %).

[0062] In some aspects, the aluminum alloys described herein include 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 are expressed in wt. %. Properties

[0063] In some examples, an aluminum alloy product (e.g., an aluminum alloy sheet) produced from the aluminum alloys described herein can have a yield strength (Rp0.2) of 130 MPa or greater. For example, an aluminum alloy product 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 from 130 MPa to 250 MPa (e.g., from 140 MPa to 250 MPa, from 150 MPa to 240 MPa, or from 160 MPa to 240 MPa), or anywhere in between. The aluminum alloy products described herein can exhibit the yield strengths as described herein when measured in a longitudinal (L) direction, a transverse (T) direction, and/or in a diagonal (D) direction, each respective to the rolling direction.

[0064] In some examples, an aluminum alloy product 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 from 200 MPa to 400 MPa (e.g., from 220 MPa to 380 MPa, from 240 MPa to 360 MPa, or from 250 MPa to 340 MPa), or anywhere in between. The aluminum alloy products described herein can exhibit the ultimate tensile strengths as described herein when measured in a longitudinal (L) direction, a transverse (T) direction, and/or in a diagonal (D) direction, each respective to the rolling direction.

[0065] In some examples, an aluminum alloy product produced from the aluminum alloys described herein can have a total elongation (A80) from 15% to 30% (e.g., from 16% to 28%, from 18% to 26%, from 19% to 25%, from 20% to 25%, or from 21% to 24%). For example, an aluminum alloy product produced from the aluminum alloys described herein can have a total elongation of about 15 %, 16 %, 17 %, 18 %, 19 %, 20 %, 21 %, 22 %, 23 %, 24 %, 25 %, 26 %, 27 %, 28 %, 29 %, or 30 %, or anywhere in between. The aluminum alloy products described herein can exhibit the total elongations as described herein when measured in a longitudinal (L) direction, a transverse (T) direction, and/or in a diagonal (D) direction, each respective to the rolling direction. [0066] In some examples, an aluminum alloy product produced from the aluminum alloys described herein can have P bend angle values according to Specification VDA 238-100 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°).

Methods of Making Aluminum Alloys

[0067] The aluminum alloys described herein can be cast into a cast product using a direct chill (DC) process or can be cast using a continuous casting (CC) process. The casting process is performed according to standards commonly used in the aluminum industry as known to one of skill in the art. The CC process may include, but is not limited to, the use of twin belt casters, twin roll casters, or block casters. In some examples, the casting process is performed by a CC process to form a slab, a strip, or the like. In some examples, the casting process is a DC casting process to form a cast product.

[0068] The cast product, slab, or strip can then be subjected to further processing steps. Optionally, the further processing steps can be used to prepare aluminum alloy products (e.g., sheets, shates, or plates). Such processing steps include, but are not limited to, a homogenization step, a hot rolling step, and a cold rolling step. The processing steps are described below in relation to a cast product. However, the processing steps can also be used for a cast slab or strip, using modifications as known to those of skill in the art.

[0069] In a homogenization step, a cast product may be heated to a homogenization temperature, such as a temperature ranging from about 400 °C to about 600 °C. For example, the cast product can 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 can be about 70 °C/hour or less, about 60 °C/hour or less, or about 50 °C/hour or less. The cast product may then be allowed to soak (i.e., held at the indicated temperature) for a period of time to form a homogenized product. In some examples, the total time for the homogenization step, including the heating and soaking phases, can be up to about 10 hours.

[0070] Following a homogenization step, a hot rolling step can be performed. The homogenized product can be hot rolled using a rolling mill to produce a hot rolled product. Prior to the start of hot rolling, the homogenized product can be allowed to cool to a desired temperature, such as from about 200 °C to about 425 °C. For example, the homogenized product can be allowed to cool to a temperature of from about 200 °C to about 400 °C, about 250 °C to about 375 °C, about 300 °C to about 425 °C, or from about 350 °C to about 400 °C. The homogenized product can then be hot rolled at a hot rolling temperature, for example, from about 200 °C to about 450 °C, to produce a hot rolled product (e.g., a hot rolled plate, a hot rolled shate, or a hot rolled sheet).

[0071] The hot rolled product can be cold rolled using cold rolling mills into thinner products, such as a final gauge rolled product. The final gauge rolled product can have a gauge between about 0.5 to about 10 mm, e.g., between about 0.7 to 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. The cold rolling can be performed to result in a final gauge thickness that represents a gauge reduction of up to about 85 % (e.g., 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 % reduction) as compared to a gauge prior to the start of cold rolling. 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 the aluminum alloy can include an interannealing step (e.g., between one or more cold rolling steps).

Methods of Using Aluminum Alloys

[0072] The aluminum alloys described herein can each be used in automotive applications and other transportation applications, including aircraft and railway applications. For example, the aluminum alloys can be used to prepare automotive structural parts, such as bumpers, side beams, roof beams, cross beams, pillar reinforcements (e. g. , 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 railway vehicle applications, to prepare, for example, external and internal panels. In some examples, the aluminum alloys can be used in aerospace structural and non- structural parts or in marine structural or non- structural parts.

[0073] 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., smart phones) and tablet bottom chassis.

[0074] The aluminum alloys described herein can be used to make aluminum alloy products in the form of plates, extrusions, castings, and forgings or other suitable products. The products can be made using techniques as known to those of ordinary skill in the art. In some examples, the aluminum alloys can be used to produce extrusions. For example, the aluminum alloys described herein can be used to produce extruded aluminum alloy products.

[0075] The aluminum alloys and methods described herein can also be used in other applications as 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, an aluminum alloy sheet can be further subjected to surface treatments by an end user for use as an architectural skin panel for aesthetic and structural purposes.

Illustrations

[0076] Illustration 1 is an aluminum alloy 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. % of impurities, and Al, wherein the aluminum alloy comprises a combined content of Si, Fe, and Mn of at least 2.2 wt. %; wherein the aluminum alloy comprises 20 wt. % or less of primary aluminum alloy.

[0077] Illustration 2 is the aluminum alloy of any preceding or subsequent illustration, wherein 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, 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.% of impurities, and Al.

[0078] Illustration 3 is the aluminum alloy of any preceding or subsequent illustration, wherein 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, 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.% of impurities, and Al.

[0079] Illustration 4 is the aluminum alloy of any preceding or subsequent illustration, wherein 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, up to 0.05 wt. % Cr, up to 0.10 wt. % Zn, up to 0.05 wt. % Ti, up to 0.05 wt. % Ni, up to 0.21 wt.% of impurities, and Al.

[0080] Illustration 5 is the aluminum alloy of any preceding or subsequent illustration, wherein 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

[0081] Illustration 6 is the aluminum alloy of any preceding or subsequent illustration, wherein a ratio of (Mn+Cr):Fe is greater than 0.70.

[0082] Illustration 7 is the aluminum alloy of any preceding or subsequent illustration, wherein the aluminum alloy comprises 0.60 - 0.90 wt. % Fe and 0.40 - 0.70 wt. % Mn.

[0083] Illustration 8 is the aluminum alloy of any preceding or subsequent illustration, wherein a combined content of Fe and Si is at least 1.5 wt. %.

[0084] Illustration 9 is the aluminum alloy of any preceding or subsequent illustration, wherein the combined content of Si, Fe, and Mn is from 2.2 wt. % to 3.6 wt. %.

[0085] Illustration 10 is the aluminum alloy of any preceding or subsequent illustration, wherein the aluminum alloy comprises at least 50 wt. % of recycled aluminum alloy materials.

[0086] Illustration 11 is the aluminum alloy of any preceding or subsequent illustration, wherein the aluminum alloy has a yield strength of at least 130 MPa.

[0087] Illustration 12 is the aluminum alloy of any preceding or subsequent illustration, wherein the aluminum alloy has an ultimate tensile strength of at least 200 MPa.

[0088] Illustration 13 is the aluminum alloy of any preceding or subsequent illustration, wherein the aluminum alloy has a total elongation of at least 15%.

[0089] Illustration 14 is the aluminum alloy of any preceding or subsequent illustration, wherein the aluminum alloy has a P bend angle value according to Specification VDA 238- 100 less than 140°.

[0090] Illustration 15 is a method of producing an aluminum alloy, comprising: casting an aluminum alloy to form a cast product, wherein the aluminum alloy comprises up to 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 0.15 wt. % of impurities, and Al, wherein the aluminum alloy comprises a combined content of Si, Fe, and Mn of at least 2.2 wt. %, wherein the aluminum alloy comprises 10 wt. % or less of primary aluminum alloy; homogenizing the cast product; hot rolling the cast product 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.

[0091] Illustration 16 is the method of any preceding or subsequent illustration, wherein casting the aluminum alloy comprises providing greater than 50 wt. % of recycled aluminum alloy materials. [0092] Illustration 17 is the method of any preceding or subsequent illustration, wherein the recycled aluminum alloy materials comprises end-of-life aluminum alloy scrap.

[0093] Illustration 18 is the method of any preceding or subsequent illustration, wherein the aluminum alloy comprises 0.60 - 0.90 wt. % Fe and 0.40 - 0.70 wt. % Mn, and wherein a ratio of (Mn+Cr):Fe is greater than 0.50.

[0094] Illustration 19 is the method of any preceding or subsequent illustration, wherein the aluminum alloy product is prepared by the method of any preceding or subsequent illustration.

[0095] Illustration 20 is the method of any preceding or subsequent illustration, wherein the aluminum alloy product is an automobile part or an electronic housing.

[0096] The following examples will serve to further illustrate the present invention without, however, constituting any limitation thereof. On the contrary, it is to be clearly understood that resort may be had to various embodiments, modifications, and equivalents thereof which, after reading the description herein, may suggest themselves to those skilled in the art without departing from the spirit of the invention.

[0097] During the studies described in the following examples, conventional procedures were followed, unless otherwise stated. Some of the procedures are described below for illustrative purposes.

EXAMPLES

[0098] Sample aluminum alloys were tested to determine the properties of the aluminum alloys described herein. Comparative Example 1 was prepared from a conventional AA6016 aluminum alloy, which is currently employed as an automobile part. Comparative Examples 1 and 2 and the Example Alloy were produced by casting aluminum alloys in steel molds to prepare a 50 x 220 mm ingot. The ingots were scalped into 40 x 220 mm ingots. The scalped ingots were heated to a homogenization temperature of 560 °C at a heating rate of 50 °C/h and held at the homogenization temperature for 11 hours. The homogenized ingots were then hot rolled to produce a 7.3 mm hot rolled products and coil cooling was simulated in a furnace shut down at 400 °C. The hot rolled products were cold rolled to 3.1 mm, then annealed at 560 °C for 25 min, and further cold rolled to 1.2 mm to produce the final -gauge products. The final-gauge products were then solution heat treated at 560 °C for 120 s + 60 s heating. The final-gauge products were then quenched in a water tank. Table 1 provides the aluminum alloy composition for each of Comparative Examples 1 and 2 and the Example Alloy. TABLE 6

*A11 in wt. %. The balance of the composition was aluminum.

[0099] As shown in Table 6, Comparative Example 1 (AA6016 aluminum alloy) includes lower amounts of Si, Fe, and Mn compared to Example 1. The total amount of Si, Fe, and Mn for Comparative Example 1 was 1.5 wt. %, whereas Example 1 included 2.96 wt. % of Si, Fe, and Mn. Therefore, 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 materials compared to AA6016 aluminum alloy. Although Comparative Example 2 includes higher amounts of Si, Fe, and Mn than Example 1, Comparative Example 2 demonstrated poor mechanical properties as provided below in Table 7. The data demonstrates that the carefully balanced amounts of alloying elements in the aluminum alloys described herein can incorporate higher levels of recycled aluminum alloy materials while achieving good mechanical properties. Additionally, Example 1 can incorporate higher amounts of recycled aluminum alloy materials in place of primary aluminum because the aluminum alloys can tolerate higher amounts of Si, Fe, Mn, and Cr.

TABLE 7

[00100] FIG. 1 provides a graph of the total elongation (A80) of Example 1 and Comparative Examples 1 and 2 in a T4 temper (red) and in a T8x temper (blue) (e.g., A80 after thermal treatment at a temperature of about 185 °C for about 20 minutes after 2% prestraining) when measured in a longitudinal (L) direction, a transverse (T) direction, and in a diagonal (D) direction, each respective to the rolling direction. As shown in FIG. 1, Example Alloy 1 exhibited a total elongation greater than 20 % in all directions when in a T4 temper. Comparative Example 2 had a substantially lower total elongation (19.5 % or lower) and Comparative Example 1 exhibited a similar total elongation to Example Alloy 1. Example Alloy 1 demonstrated that 6xxx series aluminum alloys having a carefully balanced composition can achieve good elongation properties despite using higher amounts of recycled aluminum alloy materials.

[00101] FIG. 2 provides a graph of the yield strength (Rp0.2) of Example 1 and Comparative Examples 1 and 2 in a T4 temper (red) and in a T8x temper (blue) (e.g., Rp0.2 after thermal treatment at a temperature of about 185 °C for about 20 minutes after 2% prestraining) when measured in a longitudinal (L) direction, a transverse (T) direction, and in a diagonal (D) direction, each respective to the rolling direction. Additionally, FIG. 3 provides a graph of the ultimate tensile strength (Rm) of Example 1 and Comparative Examples 1 and 2 in a T4 temper (red) and in a T8x temper (blue) (e.g., Rm after thermal treatment at a temperature of about 185 °C for about 20 minutes after 2% pre-straining) when measured in a longitudinal (L) direction, a transverse (T) direction, and in a diagonal (D) direction, each respective to the rolling direction. Example 1 had a similar yield strength and ultimate tensile strength to Comparative Example 2, and had a higher yield strength and ultimate tensile strength in all directions compared to Comparative Example 1. Example 1 exhibited a yield strength greater than 130 MPa and an ultimate tensile strength greater than 250 MPa. The yield strength and ultimate tensile strength values of Example 1 meet the minimum strength requirements for many applications. Additionally, Example 1 demonstrates that increasing the Fe and Si content to increase the recycle content of the alloy composition led to a yield strength and ultimate tensile strength that was higher than Comparative Example 1. These results indicate that by increasing the recycled content, the resulting properties are consistent or better than current commercially available aluminum alloys. Additionally, the results demonstrate that Example 1 has a 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 down-gauging in structural applications to provide light weight products compared to standard AA6016 aluminum alloys.

[00102] FIG. 4 provides a graph of the P bend angle values according to Specification VDA 238-100 (measured in °) of Example 1 and Comparative Examples 1 and 2 in a T4 temper when measured in a longitudinal (L) direction and a transverse (T) direction. The results of these tests are shown in FIG. 4. Example Alloy 1 demonstrated good bending properties that were comparable to Comparative Examples 1 and 2. Surprisingly, Example Alloy 1 achieved better bending properties than Comparative Example 1.

Example 2

[00103] Sample aluminum alloys were tested to determine the properties of the aluminum alloys described herein. Comparative Example 3 was prepared from a conventional AA6121 aluminum alloy, which is currently employed as an automobile part. Comparative Example 2 is an aluminum alloy produced from recycled materials that has an aluminum alloy composition outside the scope of the invention. Comparative Examples 1 and 2, and Example Alloy 2 were produced by casting aluminum alloys in steel molds to prepare a 50 mm ingot. The ingots were heated to a homogenization temperature of 560 °C for 8 hours and held at the homogenization temperature for 11 hours. The homogenized ingots were then hot rolled to produce a 7.3 mm hot rolled products and the final hot rolling exit temperature was 350 °C. The hot rolled products were cold rolled to 3.1 mm, then annealed at 560 °C for 25 min, air cooled, and further cold rolled to 1.2 mm to produce the final -gauge products. The finalgauge products were then solution heat treated at 560 °C for 120 s + 60 s heating. The finalgauge products were then water quenched. Table 8 provides the aluminum alloy composition for each of Comparative Examples 3 and 4 and the Example Alloy 2.

TABLE 8

*A11 in wt. %. The balance of the composition was aluminum.

[00104] FIG. 5 provides a graph of the total elongation (A80) (measured in %) of Example 2 and Comparative Examples 3 and 4 in a T4 temper when measured in a longitudinal (L) direction, a transverse (T) direction, and a diagonal (D) direction, each respective to the rolling direction. As shown in FIG. 5, Example Alloy 2 demonstrated good total elongation properties that were similar to Comparative Example 3. Example Alloy 2 achieved better total elongation in the longitudinal, transverse, and diagonal directions than Comparative Example 4.

[00105] FIG. 6 provides a graph of the uniform elongation (Ag) (measured in %) of Example 2 and Comparative Examples 3 and 4 in a T4 temper when measured in a longitudinal (L) direction, a transverse (T) direction, and a diagonal (D) direction. Example Alloy 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.

[00106] The test samples were subjected to stain hardening tests to evaluate plastic deformation of the aluminum alloys. Strain hardening begins once deformation exceeds the material’s yield strength and continues until the sample or the engineered stamping either fractures or, instead, reaches the targeted strain level or part shape. FIG. 7 provides a graph of the n5 values (unitless) of Example 2 and Comparative Examples 3 and 4 in a T4 temper when measured in a longitudinal (L) direction, a transverse (T) direction, and a diagonal (D) direction. As shown in FIG. 7, Comparative Example 4 had a drop of n5 values in a T4 temper in all directions. Example Alloy 2 exhibited similar n values to Comparative Example 3 due the specific balance of alloying elements.

[00107] Tables 5-7 demonstrate that Example 2 has similar strength, total elongation, a uniform elongation, and n values as Comparative Example 3 despite being produced from high amounts of recycled materials. This is due, in part, to the careful balance of alloying elements in the aluminum alloys described herein. These results indicate that by increasing the recycled content and tailoring the aluminum alloy composition, the resulting properties are consistent with current commercially available aluminum alloys.

[00108] FIG. 8 provides a graph of the bendability (rlO) of Example 2 and Comparative Examples 3 and 4 when measured in a (L) direction, a transverse (T) direction, and a diagonal (45°) direction. As shown in FIG. 8, Example Alloy 1 demonstrated good bendability properties that were similar to Comparative Example 3. In fact, Example Alloy 2 achieved a better bendability in the diagonal direction than Comparative Example 3.

[00109] FIG. 9A provides images of the electron back-scatter diffraction profiles of Example Alloy 2 and Comparative Examples 3 and 4 (scale bar is 200 pm), and FIG. 9B provides a graph of the grain size (pm) in both the Dx and Dy directions of Example Alloy 2 (grey) and Comparative Examples 3 (blue) and 4 (orange). Large grain sizes can have an adverse affect on formability properties. FIG. 9A shows that microstructure of Example 2 comprised fine grains, as confirmed by the graph of the length of the grains in the x (Dx) and y (Dy) directions in FIG. 9B. Example Alloy 2 had substantially smaller grains in the Dx and Dy directions than Comparative Example 3. Example Alloy 2 and Comparative Example 4 comprised higher amounts of Si and Fe than Comparative Example 1 which provides particle stimulated nucleation sites from intermetallics as well as pinning of the grain boundary by dispersoids resulting in finer grains. The finer grains beneficially provide good formability properties of the aluminum alloy.

[00110] FIG. 10A provides a graph of the texture components (measured in volume %) in the microstructure of Example Alloy 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 amounts of texture components (measured in volume %) in the microstructure of Example Alloy 2 and Comparative Examples 3 and 4. Example Alloy 2 had less cube, goss, and Rc texture components than Comparative Example 3. Overall, Example Alloy 2 had greater total amounts of texture components than Comparative Examples 3 and 4. Additionally, Example Alloy 2 had higher amounts of beta fibers than Comparative Example 3. The amounts and types of texture components in Example Alloy 2 can result in good bending performance.

[00111] FIG. 11 provides a graph of the simulated r values of Example Alloy 2 and Comparative Examples 3 and 4 taken at 0°, 45°, and 90° angles. 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 about 0.9, 0.7, and 1.0, respectively.

[00112] FIG. 12 provides images of the microstructure of Example Alloy 2 and Comparative Examples 3 and 4 taken using scanning electron microscopy (SEM). FIG. 13 provides a graph of the area fraction (measured in %) of intermetallics (blue) and microvoids (orange) of Example Alloy 2 and Comparative Examples 3 and 4. Example Alloy 2 had substantially more intermetallics in the 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.

[00113] All patents, publications, and abstracts cited above are incorporated herein by reference in their entireties. Various embodiments of the invention have been described in fulfillment of the various objectives of the invention. It should be recognized that these embodiments are merely illustrative of the principles of the present invention. Numerous modifications and adaptions 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

WHAT IS CLAIMED IS:

1. An aluminum alloy 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. % of impurities, and Al, wherein the aluminum alloy comprises a combined content of Si, Fe, and Mn of at least 2.2 wt. %; and wherein the aluminum alloy comprises 20 wt. % or less of primary aluminum alloy.

2. 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, 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.% of impurities, and Al.

3. 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, 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.% of impurities, and Al.

4. 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, up to 0.05 wt. % Cr, up to 0.10 wt. % Zn, up to 0.05 wt. % Ti, up to 0.05 wt. % Ni, up to 0.21 wt.% of impurities, and Al.

5. 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. The aluminum alloy of any of claims 1-5, wherein a ratio of (Mn+Cr):Fe is greater than 0.70.

7. The aluminum alloy of any of claims 1-6, wherein the aluminum alloy comprises 0.60 - 0.90 wt. % Fe and 0.40 - 0.70 wt. % Mn.

8. The aluminum alloy of any of claims 1-7, wherein a combined content of Fe and Si is at least 1.5 wt. %.

9. The aluminum alloy of any of claims 1-8, wherein the combined content of Si, Fe, and Mn is from 2.2 wt. % to 3.6 wt. %.

10. The aluminum alloy of any of claims 1-9, wherein the aluminum alloy comprises at least 50 wt. % of recycled aluminum alloy materials.

11. The aluminum alloy of any of claims 1-10, wherein the aluminum alloy has a yield strength of at least 130 MPa.

12. The aluminum alloy of any of claims 1-11, wherein the aluminum alloy has an ultimate tensile strength of at least 200 MPa.

13. The aluminum alloy of any of claims 1-12, wherein the aluminum alloy has a total elongation of at least 15%.

14. The aluminum alloy of any of claims 1-13, wherein the aluminum alloy has a P bend angle value according to Specification VDA 238-100 less than 140°.

15. A method of producing an aluminum alloy comprising: casting an aluminum alloy to form a cast product, wherein the aluminum alloy comprises up to 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 0.15 wt. % of impurities, and Al, wherein the aluminum alloy comprises a combined content of Si, Fe, and Mn of at least 2.2 wt. %, wherein the aluminum alloy comprises 10 wt. % or less of primary aluminum alloy; homogenizing the cast product; hot rolling the cast product 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.

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

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

18. The method of any of claims 15-17, wherein the aluminum alloy comprises 0.60 - 0.90 wt. % Fe and 0.40 - 0.70 wt. % Mn, and wherein a ratio of (Mn+Cr):Fe is greater than 0.50.

19. An aluminum alloy product, wherein the aluminum alloy product is prepared by a method comprising any of claims 15-18.

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