WO2025217113A1 - Methods of processing 6xxx series aluminum alloys and related products - Google Patents

Abstract

6xxx series aluminum alloys can be processed to produce aluminum alloy products with improved strength while maintaining a high elongation. For example, said processing method can include solutionizing a rolled aluminum alloy product comprising a 6xxx series aluminum alloy. Then, the solutionized aluminum alloy product can undergo a pre-aging step before a cold rolling step. The cold rolling step can reduce the gauge of the aluminum alloy product by 5% to 30%. Then, the cold rolled, pre-aged aluminum alloy product can undergo an artificially aging step that is performed at a higher temperature than the pre-aging. The resultant artificially aged aluminum alloy product can have a yield strength of 375 MPa to 475 MPa and a total elongation of 15% or greater.

Description

METHODS OF PROCESSING 6XXX SERIES

ALUMINUM ALLOYS AND RELATED PRODUCTS

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 63/631,561, filed April 9, 2024, which is hereby incorporated by reference in its entirety for all intents and purposes.

FIELD

[0002] The disclosure is directed to 6xxx series aluminum alloy products and methods of processing said products, where said products have improved strength and ductility properties.

BACKGROUND

[0003] Aluminum (Al) alloys are increasingly replacing steel and other metals in multiple applications, such as automotive, transportation, industrial, and electronics-related applications. In some applications, such alloys may need to exhibit high strength, high formability, and/or low weight. However, producing aluminum alloy products having the aforementioned properties is a challenge, as conventional methods and compositions may not achieve the necessary requirements, specifications, and/or performances required for the different applications when produced via established methods. For example, a conventional processing route for 6xxx series aluminum alloys may include many processing steps such as ingot homogenization, hot rolling, and cold rolling, followed by a final solutionizing step. The material state of the aluminum alloy products produced in this manner are in a T4 temper, which have a low strength. Natural aging of these T4 aluminum alloy products at ambient temperature incrementally increases strength. However, peak strength of the aluminum alloy products can be achieved by an artificial aging heat treatment step, which in many 6xxx series aluminum alloys is achieved after aging at 180 °C for 10 hours of soaking. The material state of said aluminum alloy products after such aging typically has a T6 temper. However, this conventional processing route reduces the ductility (or elongation properties) of the 6xxx series aluminum alloy product. So, while the 6xxx series aluminum alloy product may have high strength, said product has reduced formability and a tendency to crack if deformed too much. SUMMARY

[0004] Covered embodiments of the invention 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.

[0005] In an aspect, described herein are processes for producing a 6xxx series aluminum alloy product that include solutionizing a rolled aluminum alloy product comprising a 6xxx series aluminum alloy; optionally, pre-aging the solutionized aluminum alloy product; cold rolling the aluminum alloy product with a gauge reduction of 5% to 30%; and artificially aging (also referred to herein as re-aging if the pre-aging step is performed) the aluminum alloy product after cold rolling (e.g., a cold rolled, pre-aged aluminum alloy sheet) at 120 °C to 180 °C for at least 4 hours to produce a final-aged aluminum alloy product, wherein the artificial aging is at a higher temperature than the pre-aging. In some aspects, the foregoing method can further comprise: between the solutionizing and the pre-aging, coiling the solutionized aluminum alloy product; and preheating the solutionized aluminum alloy product to a temperature of 60 °C to 140 °C during the coiling. In some aspects, the foregoing method can further comprise: casting or extruding the 6xxx series aluminum alloy; homogenizing the cast or extruded aluminum alloy product; and hot rolling and/or cold rolling the homogenized aluminum alloy product to produce the rolled aluminum alloy product.

[0006] In some examples, the pre-aging is performed at 60 °C to 140 °C for at least 8 hours. In some examples, the artificial aging (or re-aging) is performed at 120 °C to 180 °C for at least 4 hours. In some examples, the artificially aged (or re-aged) aluminum alloy product has a higher strength and/or a higher ductility than a 6xxx aluminum alloy product with a T6 temper or a T8 temper. In some examples, the cold rolling of the pre-aged aluminum alloy product includes three passes or less. In some examples, the after cold rolling, the aluminum alloy product has a gauge from 0.1 mm to 6 mm.

[0007] In some examples, the artificially aged aluminum alloy product has a yield strength of 375 MPa to 475 MPa. In some examples, the artificially aged aluminum alloy product has an ultimate tensile strength of 425 MPa to 525 MPa. In some examples, the artificially aged aluminum alloy product has a value for an ultimate tensile strength (UTS) minus a yield strength (YS) of 30 MPa to 65 MPa (UTS - YS = 30 MPa to 65 MPa). In some examples, the artificially aged aluminum alloy product has an n-value of 0.7 or greater. In some examples, the artificially aged aluminum alloy product has a uniform elongation of 10% or greater. In some examples, the artificially aged aluminum alloy product has a total elongation of 15% or greater.

[0008] In another aspect, described herein are processes for producing a 6xxx series aluminum alloy product that include solutionizing a rolled aluminum alloy product comprising a 6xxx series aluminum alloy; artificially pre-aging the solutionized aluminum alloy product between 60 °C to 140 °C for at least 8 hours; cold rolling the pre-aged aluminum alloy product with three passes or less; and artificially aging the cold rolled, pre-aged aluminum alloy product at 120 °C to 180 °C for at least 4 hours to produce an artificially aged aluminum alloy product, wherein the artificially aging is conducted at a higher temperature than the pre-aging. In some aspects, the foregoing method can further comprise: between the solutionizing and the artificially pre-aging, coiling the solutionized aluminum alloy product; and preheating the solutionized aluminum alloy product to 60 °C to 140 °C during the coiling. In some aspects, the foregoing method can further comprise: casting or extruding the 6xxx series aluminum alloy; homogenizing the cast or extruded aluminum alloy product; and hot rolling and/or cold rolling the homogenized aluminum alloy product to produce the rolled aluminum alloy product. [0009] In some examples, the artificially re-aged aluminum alloy product has a higher strength and/or a higher ductility than a 6xxx aluminum alloy product of the same 6xxx aluminum alloy but processed to achieve a T6 temper or a T8 temper. In some examples, the aluminum alloy product after cold rolling has a gauge from 0.1 mm to 6 mm.

[0010] In some examples, the artificially re-aged aluminum alloy product has a yield strength of 375 MPa to 475 MPa. In some examples, the artificially re-aged aluminum alloy product has an ultimate tensile strength of 425 MPa to about 525 MPa. In some examples, the artificially re-aged aluminum alloy product has a value for an ultimate tensile strength minus a yield strength of 30 MPa to 65 MPa. In some examples, the artificially aged aluminum alloy product has an n-value of 0.7 or greater. In some examples, the artificially aged aluminum alloy product has a uniform elongation of 10% or greater. In some examples, the artificially aged aluminum alloy product has a total elongation of 15% or greater.

[0011] In another aspect, described herein is a 6xxx series aluminum alloy product produced by any of the foregoing processes. [0012] In another aspect, described herein is an aluminum alloy product that includes a 6xxx series aluminum alloy, wherein the aluminum alloy product has a yield strength of 375 MPa to 475 MPa and a total elongation of 15% or greater. In some examples, the aluminum alloy product has an ultimate tensile strength of 425 MPa to about 525 MPa. In some examples, the aluminum alloy product has a value for the ultimate tensile strength minus the yield strength of 30 MPa to 65 MPa. In some examples, the aluminum alloy product has an n-value of 0.7 or greater. In some examples, the aluminum alloy product has a uniform elongation of 10% or greater.

[0013] Further aspects, obj ects, and advantages of the invention will become apparent upon consideration of the detailed description that follow.

BRIEF DESCRIPTION OF THE FIGURES

[0014] FIG. 1 is a flow diagram of at least a portion of an example method for preparing an aluminum alloy product according to the present disclosure.

[0015] FIG. 2 illustrates a plot of the tensile stress-strain curves for two aluminum alloy products with one being processed by a conventional method and the other by a method according to at least one embodiment of the present disclosure.

[0016] FIG. 3A is a plot of the engineering stress versus engineering strain in the L- Orientation (test with loading axis parallel to the rolling direction of the aluminum alloy product) for Samples G-K.

[0017] FIG. 3B is a plot of the engineering stress versus engineering strain in the T- Orientation (test with loading axis perpendicular to the rolling direction of the aluminum alloy product) for Samples G-K.

[0018] FIG. 4A is a plot of the engineering stress versus engineering strain in the L- Orientation for Samples L-N.

[0019] FIG. 4B is a plot of the engineering stress versus engineering strain in the T- Orientation for Samples L-N.

[0020] FIG. 5A is a plot of the engineering stress versus engineering strain in the L- Orientation for Samples O-R.

[0021] FIG. 5B is a plot of the engineering stress versus engineering strain in the T- Orientation for Samples O-R.

[0022] FIGS. 6A and 6B are transmission electron microscopy (TEM) images with atomic scale resolution of the strengthening precipitate, specifically, Q’ precipitates, from Sample P. DETAILED DESCRIPTION OF THE INVENTION

[0023] Described herein are 6xxx series aluminum alloy products having high strength and high elongation and methods of producing such products. The 6xxx series aluminum alloy products can be used in automotive, transportation, industrial, battery, and electronics applications, to name a few.

[0024] Advantageously, the 6xxx series aluminum alloy products produced by the methods described herein have a high strength while also maintaining a high elongation. Further, the aluminum alloy products have a high n-value that indicates a potential for deformational hardening along with better room temperature sheet formability. As a result, the aluminum alloy products are deformable at room temperature because of the high elongation so that after deformation said products maintain or increase in strength. For industries where metal products like sheets are deformed into specific shapes, this advantageously enables aluminum alloy products to be shaped from sheets or other forms into the desired shapes by traditional methods while potentially increasing the material’s strength and, because of the high elongation, mitigating cracking during deformation.

Definitions and Descriptions

[0025] The terms “invention,” “the invention,” “this invention” and “the present invention” used herein 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.

[0026] As used herein, the meaning of “a,” “an,” or “the” includes singular and plural references unless the context clearly dictates otherwise.

[0027] As used herein, the meaning of “metals” includes pure metals, alloys and metal solid solutions unless the context clearly dictates otherwise.

[0028] In this description, reference is made to alloys identified by aluminum industry designations, such as “series” or “6xxx .” 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. [0029] As used herein, a plate generally has a thickness of greater than about 15 mm. For example, a plate may refer to an aluminum alloy product having a thickness of greater than 15 mm, greater than 20 mm, greater than 25 mm, greater than 30 mm, greater than 35 mm, greater than 40 mm, greater than 45 mm, greater than 50 mm, or greater than 100 mm.

[0030] 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 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, or 15 mm.

[0031] As used herein, a sheet generally refers to an aluminum alloy product having a thickness of less than about 4 mm. For example, a sheet may have a thickness of less than 4 mm, 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.

[0032] Reference is 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.”

[0033] 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 0.3 % for the sum of the impurities.

[0034] Incidental elements, such as grain refiners and deoxidizers, or other additives may be present in the invention and may add other characteristics on their own without departing from or significantly altering the alloy described herein or the characteristics of the alloy described herein.

[0035] As used herein, terms such as “cast metal product,” “cast product,” “cast aluminum alloy product,” and the like are interchangeable and refer to a product produced by direct chill casting (including direct chill co-casting) or semi -continuous casting, continuous casting (including, for example, by use of a twin belt caster, a twin roll caster, a block caster, or any other continuous caster), electromagnetic casting, hot top casting, or any other casting method. [0036] 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. As used herein, the meaning of “ambient conditions” can include temperatures of about room temperature, relative humidity of from about 20% to about 100%, and barometric pressure of from about 975 millibar (mbar) to about 1050 mbar. For example, relative humidity can be about 20%, about 21%, about 22%, about 23%, about 24%, about 25%, about 26%, about 27%, about 28%, about 29%, about 30%, about 31%, about 32%, about 33%, about 34%, about 35%, about 36%, about 37%, about 38%, about 39%, about 40%, about 41%, about 42%, about 43%, about 44%, about 45%, about 46%, about 47%, about 48%, about 49%, about 50%, about 51%, about 52%, about 53%, about 54%, about 55%, about 56%, about 57%, about 58%, about 59%, about 60%, about 61%, about 62%, about 63%, about 64%, about 65%, about 66%, about 67%, about 68%, about 69%, about 70%, about 71%, about 72%, about 73%, about 74%, about 75%, about 76%, about 77%, about 78%, about 79%, about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, about 99%, about 100%, or anywhere in between. For example, barometric pressure can be about 975 mbar, about 980 mbar, about 985 mbar, about 990 mbar, about 995 mbar, about 1000 mbar, about 1005 mbar, about 1010 mbar, about 1015 mbar, about 1020 mbar, about 1025 mbar, about 1030 mbar, about 1035 mbar, about 1040 mbar, about 1045 mbar, about 1050 mbar, or anywhere in between.

[0037] All ranges disclosed herein are to be understood to encompass 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. Unless stated otherwise, the expression “up to” when referring to the compositional amount of an element means that element is optional and includes a zero percent composition of that particular element. Unless stated otherwise, all compositional percentages are in weight percent (wt. %).

6xxx Series Aluminum Alloy Compositions

[0038] Described below are 6xxx series aluminum alloys, which can, for example, have the following elemental composition as provided in Table 1.

Table 1

[0039] In other examples, the 6xxx series aluminum alloys can have the following elemental composition as provided in Table 2.

Table 2

[0040] In other examples, the 6xxx series aluminum alloys can have the following elemental composition as provided in Table 3.

Table 3

[0041] It is to be understood that, in various embodiments of the alloys described herein, including those in Tables 1-3, the predominant element is aluminum (Al), sometimes called “remainder Al.” In other words, the term “remainder” can be used to describe predominant aluminum (Al) content in the aluminum alloys described herein.

[0042] In certain examples, the disclosed alloy includes silicon (Si) in an amount from about 0.2 % to about 2 % (e.g., from 0.2 % to 1.7 %, from 0.5 % to 2 %, from 0.5 % to 1.7 %, from 0.4 % to 1.3 %, or from 0.6 % to 1.3 %) based on the total weight of the alloy. For example, the alloy can include 0.2 %, 0.3 %, 0.4 %, 0.5 %, 0.6 %, 0.7 %, 0.8 %, 0.9 %, 1.0 %, 1.1 %, 1.2 %, 1.3 %, 1.4 %, 1.5 %, 1.6 %, 1.7 %, 1.8 %, 1.9 %, or 2.0 % Si. All expressed in wt. % based on the total weight of the aluminum alloy.

[0043] In certain examples, the disclosed alloy includes iron (Fe) in an amount from about 0.05 % to about 0.7 % (e.g., from 0.05 % to 0.6 %, from 0.2 % to 0.6 %, from 0.1 % to 0.5 %, from 0.2 % to 0.5 %, or from 0.2 % to 0.4 %) based on the total weight of the alloy. For example, the alloy can include 0.05 %, 0.06 %, 0.07 %, 0.08 %, 0.09 %, 0.10 %, 0.11 %, 0.12 %, 0.13 %, 0.14 %, 0.15 %, 0.16 %, 0.17 %, 0.18 %, 0.19 %, 0.20 %, 0.21 %, 0.22 %, 0.23 %, 0.24 %, 0.25 %, 0.26 %, 0.27 %, 0.28 %, 0.29 %, 0.30 %, 0.31 %, 0.32 %, 0.33 %, 0.34 %,

0.35 %, 0.36 %, 0.37 %, 0.38 %, 0.39 %, 0.40 %, 0.41 %, 0.42 %, 0.43 %, 0.44 %, 0.45 %,

0.46 %, 0.47 %, 0.48 %, 0.49 %, 0.50 %, 0.51 %, 0.52 %, 0.53 %, 0.54 %, 0.55 %, 0.56 %,

0.57 %, 0.58 %, 0.59 %, 0.60 %, 0.61 %, 0.62 %, 0.63 %, 0.64 %, 0.65 %, 0.66 %, 0.67 %,

0.68 %, 0.69 %, or 0.70 % Fe. All expressed in wt. % based on the total weight of the aluminum alloy.

[0044] In certain examples, the disclosed alloy includes copper (Cu) in an amount from about 0.01 % to about 2 % (e.g., from 0.05 % to 2 %, from 0.05 % to 1.5 %, from 0.05 % to 1 %, or from 0.1 % to 1 %) based on the total weight of the alloy. For example, the alloy can include 0.01 %, 0.05 %, 0.10 %, 0.15 %, 0.20 %, 0.25 %, 0.30 %, 0.35 %, 0.40 %, 0.45 %, 0.50 %, 0.55 %, 0.60 %, 0.65 %, 0.70 %, 0.75 %, 0.80 %, 0.85 %, 0.90 %, 0.95 %, 1.00 %, 1.05%, 1.10 %, 1.15 %, 1.20 %, 1.25 %, 1.30 %, 1.35 %, 1.40 %, 1.45 %, 1.50 %, 1.55 %, 1.60 %, 1.65 %, 1.70 %, 1.75 %, 1.80 %, 1.85 %, 1.90 %, 1.95 %, or 2.00 % Cu. All expressed in wt. % based on the total weight of the aluminum alloy.

[0045] In certain examples, the alloy can include manganese (Mn) in an amount from about 0.01 % to about 0.5 % (e.g., from 0.01 % to 0.25 %, from 0.05 % to 0.5 %, from 0.05 % to 0.25 %, or from 0.05 % to 0.2 %) 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 %, 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 %, or 0.50 % Mn. All expressed in wt. % based on the total weight of the aluminum alloy.

[0046] In certain examples, the disclosed alloy includes magnesium (Mg) in an amount from about 0.2 % to about 2 % (e.g., from 0.3 % to 1.7 %, from 0.4 % to 1.7 %, from 0.5 % to 1.7 %, from 0.3 % to 1.5 %, from 0.4 % to 1.5 %, from 0.5 % to 1.5 %, or from 0.5 % to 1.3

%) based on the total weight of the alloy. For example, the alloy can include 0.20 %, 0.25 %,

0.30 %, 0.35 %, 0.40 %, 0.45 %, 0.50 %, 0.55 %, 0.60 %, 0.65 %, 0.70 %, 0.75 %, 0.80 %,

0.85 %, 0.90 %, 1.00 %, 1.05 %, 1.10 %, 1.15 %, 1.20 %, 1.25 %, 1.30 %, 1.35 %, 1.40 %,

1.45 %, 1.50 %, 1.55 %, 1.60 %, 1.65 %, 1.70 %, 1.75 %, 1.80 %, 1.85 %, 1.90 %, 1.95 %, or 2.00 % Mg. All expressed in wt. % based on the total weight of the aluminum alloy.

[0047] In certain aspects, the alloy includes chromium (Cr) in an amount of up to about 0.4 % (e.g., from 0 % to 0.4 %, from 0.01 % to 0.4 %, from 0.01 % to 0.35 %, from 0.01 % to 0.3 %, from 0.1 % to 0.35 %, or from 0.1 % to 0.3 %) 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 %, 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 %, or 0.40 % Cr. In some cases, the disclosed alloy does not include Cr (i.e., 0 %). All expressed in wt. % based on the total weight of the aluminum alloy. [0048] In certain examples, the disclosed alloy includes zinc (Zn) in an amount of up to about 4 % (e.g., from 0 % to 4 %, from 0.005 % to 4 %, from 0 % to 3 %, from 0.005 % to 3 %, from 0 % to 2 %, from 0.005 % to 2 %, from 0 % to 1 %, from 0.005 % to 1 %, from 0 % to 0.5 %, from 0.005 % to 0.5 %, from 0.005 % to 0.25 %, or from 0.005 % to 0.15 %) based on the total weight of the alloy. For example, the alloy can include 0.005 %, 0.01 %, 0.05 %, 0.15 %, 0.20 %, 0.25 %, 0.30 %, 0.35 %, 0.40 %, 0.45 %, 0.50 %, 0.55 %, 0.60 %, 0.65 %,

0.70 %, 0.75 %, 0.80 %, 0.85 %, 0.90 %, 0.95 %, 1.00 %, 1.05 %, 1.10 %, 1.15 %, 1.20 %,

1.25 %, 1.30 %, 1.35 %, 1.40 %, 1.45 %, 1.50 %, 1.55 %, 1.60 %, 1.65 %, 1.70 %, 1.75 %,

1.80 %, 1.85 %, 1.90 %, 1.95 %, 2.00 %, 2.05 %, 2.10 %, 2.15 %, 2.20 %, 2.25 %, 2.30 %,

2.35 %, 2.40 %, 2.45 %, 2.50 %, 2.55 %, 2.60 %, 2.65 %, 2.70 %, 2.75 %, 2.80 %, 2.85 %,

2.90 %, 2.95 %, 3.00 %, 3.05 %, 3.10 %, 3.15 %, 3.20 %, 3.25 %, 3.30 %, 3.35 %, 3.40 %,

3.45 %, 3.50 %, 3.55 %, 3.60 %, 3.65 %, 3.70 %, 3.75 %, 3.80 %, 3.85 %, 3.90 %, 3.95 %, or 4.00 % Zn. In some cases, the disclosed alloy does not include Zn (i.e., 0 %). All expressed in wt. % based on the total weight of the aluminum alloy.

[0049] In certain aspects, the alloy includes titanium (Ti) in an amount of up to about 0.2 % (e.g., from 0 % to 0.2 %, from 0.001 % to 0.2 %, from 0 % to 0.15 %, from 0.001 % to 0.15 %, from 0 % to 0.1 %, or from 0.001 % to 0.1 %) based on the total weight of the alloy. For example, the alloy can include 0.001 %, 0.005 %, 0.010 %, 0.015 %, 0.020 %, 0.025 %, 0.030 %, 0.035 %, 0.040 %, 0.045 %, 0.050 %, 0.055 %, 0.060 %, 0.065 %, 0.070 %, 0.075 %, 0.080 %, 0.085 %, 0.090 %, 0.095 %, 0.100 %, 0.105 %, 0.110 %, 0.115 %, 0.120 %, 0.125 %, 0.130 %, 0.135 %, 0.140 %, 0.145 %, 0.150 %, 0.155 %, 0.160 %, 0.165 %, 0.170 %, 0.175 %, 0.180 %, 0.185 %, 0.190 %, 0.195 %, or 0.20 % Ti. In some cases, the disclosed alloy does not include Ti (i.e., 0 %). All expressed in wt. % based on the total weight of the aluminum alloy.

[0050] In certain aspects, the alloy includes zirconium (Zr) in an amount of up to about 0.2 % (e.g., from 0 % to 0.2 %, from 0.01 % to 0.2 %, from 0 % to 0.1 %, from 0.01 % to 0.1 %, from 0.01 % to 0.07 %, or from 0.01 % to 0.05 %) based on the total weight of the alloy. For example, the alloy can include 0.010 %, 0.015 %, 0.020 %, 0.025 %, 0.030 %, 0.035 %, 0.040

%, 0.045 %, 0.050 %, 0.055 %, 0.060 %, 0.065 %, 0.070 %, 0.075 %, 0.080 %, 0.085 %, 0.090

%, 0.095 %, 0.100 %, 0.110 %, 0.115 %, 0.120 %, 0.125 %, 0.130 %, 0.135 %, 0.140 %, 0.145

%, 0.150 %, 0.155 %, 0.160 %, 0.165 %, 0.170 %, 0.175 %, 0.180 %, 0.185 %, 0.190 %, 0.195

%, or 0.20 % Zr. In some cases, the disclosed alloy does not include Zr (i.e., 0 %). All expressed in wt. % based on the total weight of the aluminum alloy. [0051] Optionally, the alloy can further include other minor elements, sometimes referred to as impurities, in amounts of about 0.1 % or below, 0.09 % or below, 0.08 % or below, 0.07 % or below, 0.06 % or below, 0.05 % or below, 0.04 % or below, 0.03 % or below, 0.02 % or below, or 0.01 % or below or each of said impurities. These impurities may include, but are not limited to, scandium (Sc), vanadium (V), nickel (Ni), yttrium (Y), hafnium (Hf), thallium (Th), gallium (Ga), tin (Sn), lead (Pb), bismuth (Bi), strontium (Sr), calcium (Ca), or combinations thereof. Accordingly, Sc, V, Ni, Y, Hf, Th, Ga, Sn, Pb, Bi, Sr, or Ca, if present, may each independently be present in an alloy in amounts of 0.1 % or below, 0.09 % or below, 0.08 % or below, 0.07 % or below, 0.06 % or below, 0.05 % or below, 0.04 % or below, 0.03 % or below, 0.02 % or below, or 0.01 % or below. In certain aspects, the sum of all impurities does not exceed 0.30 % (e.g., does not exceed 0.20 %, does not exceed 0.15 %, or does not exceed 0.10 %). In certain aspect, the apply compositions may be devoid of (not comprise or comprise at 0.00 %) one or more of: Sc, V, Ni, Y, Hf, Th, Ga, Sn, Pb, Bi, Sr, and Ca. All expressed in wt. % based on the total weight of the aluminum alloy.

[0052] The remaining percentage of the aluminum alloy may be aluminum, e.g., remainder

Al.

[0053] Optionally, the aluminum alloy as described herein can be a 6xxx series aluminum alloy according to one of the following aluminum alloy designations: AA6101, AA6101A, AA6101B, AA6201, AA6201A, AA6401, AA6501, AA6002, AA6003, AA6103, AA6005, AA6005A, AA6005B, AA6005C, AA6105, AA6205, AA6305, AA6006, AA6106, AA6206, AA6306, AA6008, AA6009, AA6010, AA6110, AA6110A, AA6011, AA6111, AA6012, AA6012A, AA6013, AA6113, AA6014, AA6015, AA6016, AA6016A, AA6116, AA6018, AA6019, AA6020, AA6021, AA6022, AA6023, AA6024, AA6025, AA6026, AA6027, AA6028, AA6031, AA6032, AA6033, AA6040, AA6041, AA6042, AA6043, AA6151, AA6351, AA6351A, AA6451, AA6951, AA6053, AA6055, AA6056, AA6156, AA6060, AA6160, AA6260, AA6360, AA6460, AA6460B, AA6560, AA6660, AA6061, AA6061A, AA6261, AA6361, AA6162, AA6262, AA6262A, AA6063, AA6063A, AA6463, AA6463A, AA6763, A6963, AA6064, AA6064A, AA6065, AA6066, AA6068, AA6069, AA6070, AA6081, AA6181, AA6181A, AA6082, AA6082A, AA6182, AA6091, or AA6092.

Methods of Preparing Aluminum Alloy Products

[0054] Methods of producing aluminum alloy products that simultaneously improve strength and ductility are also described herein. The methods described herein include steps for treating a hot and/or cold rolled cast aluminum alloy to produce aluminum alloy products with improved strength and ductility.

[0055] FIG. 1 illustrates a nonlimiting example method for preparing an aluminum alloy product according to the present disclosure. A solutionizing step is performed on an aluminum alloy comprising a 6xxx series aluminum alloy that has undergone one or more steps to produce a hot and/or cold rolled aluminum alloy product (also simply referred to as a “rolled aluminum alloy product”). After the solutionizing step, the rolled aluminum alloy product is quenched using a quenching media achieving a quench rate between 100 °C/sec to 1,000 °C/sec. The resultant solutionized aluminum alloy product then undergoes an pre-aging step, where, optionally, a preheating step is performed before the pre-aging step. The resultant pre-aged aluminum alloy product undergoes a cold rolling step before undergoing an artificially re-aging step to produce the aluminum alloy product. As further described below and herein, the methods of the present disclosure are tailored to include a combination of pre-aging, cold rolling, and artificially re-aging that results in products having the desired properties.

[0056] Without being limited by theory, it is believed that, in the pre-aging step, the solutionized aluminum alloy product may undergo atomic scale structural ordering such as formation of Guinier-Preston zones (GP-zones) and/or Cu-containing precursor particles. Then, the cold rolling step introduces a large amount of mobile dislocations from deformation. These dislocations interact with the atomic scale Cu-containing precursor particles. The Cu- containing precursor particles may act as obstacles and provide some degree of resistance to the passage of dislocations depending on the particle-matrix interface coherency. Preferably, the cold rolling step is limited to a small thickness reduction (e.g., 5% to 30%). While more cold rolling passes increase the matrix strength, increasing amounts of cold reduction may cause the leading dislocations on the glide plane to overcome the resistance of the Cu- containing precursor particles and shear the Cu-containing precursor particles, which may lead to nano-voids that reduce the elongation of the aluminum alloy product. The artificially reaging step may then grow the pre-existing Cu-containing precursor particles within the grain matrix that increase the strength of the aluminum alloy product. Therefore, the synergistic combination of pre-aging, minimal cold rolling, and artificially re-aging may result in a 6xxx series aluminum alloy product with an increase in both elongation and strength.

[0057] The 6xxx series aluminum alloy can undergo a variety of steps before the solutionizing step. In some examples, after casting the 6xxx series aluminum alloy, processing steps can include one or more of: a quenching step, a homogenizing step, a preheating step before the homogenizing step, a coiling step at various points during the processing, a hot rolling step, and a cold rolling step. As indicated above, at least one of the hot rolling step and the cold rolling step is performed before the solutionizing. After the artificially re-aging step, the 6xxx series aluminum alloy product can optionally undergo a variety of steps. In some examples, after the artificially re-aging step, processing steps can include a coating step and/or a paint baking step.

[0058] Casting

[0059] The 6xxx series aluminum alloys described herein can be cast using any suitable casting method. The resultant cast aluminum alloy product can, for example, be in the form of an ingot, a billet, a slab, a plate, a shate, or a sheet.

[0060] The casting process can be any suitable casting process. For example, the casting process can include a direct chill (DC) casting process or a continuous casting (CC) process. The CC process can include, but is not limited to, the use of block casters, twin roll casters, or twin belt casters.

[0061] In addition, the 6xxx series aluminum alloys described herein can be formed into extrusions using any suitable method known to those skilled in the art.

[0062] The aluminum alloy, as a cast or extruded ingot, billet, slab, plate, shate, sheet, or extrusion, can then optionally be thermally quenched upon exit from the continuous caster. In some examples, the quench is performed with water. Optionally, the water quenching step can be performed at a rate of up to about 200 °C/s (e.g., from 10 °C/s to 190 °C/s, from 25 °C/s to 175 °C/s, from 50 °C/s to 150 °C/s, from 75 °C/s to 125 °C/s, or from 10 °C/s to 50 °C/s). The water temperature can be from about 20 °C to about 75 °C (e.g., 25 °C, 30 °C, 35 °C, 40 °C, 45 °C, 50 °C, 55 °C, 60 °C, 65 °C, 70 °C, or 75 °C). Optionally, an air-cooling step can be performed at a rate of from about 1 °C/s to about 300 °C/day. The resulting slab can have a thickness of from about 5 mm to about 50 mm (e.g., from 10 mm to 45 mm, from 15 mm to 40 mm, or from 20 mm to 35 mm). For example, the resulting slab can be 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 21 mm, 22 mm, 23 mm, 24 mm, 25 mm, 26 mm, 27 mm, 28 mm, 29 mm, 30 mm, 31 mm, 32 mm, 33 mm, 34 mm, 35 mm, 36 mm, 37 mm, 38 mm, 39 mm, 40 mm, 41 mm, 42 mm, 43 mm, 44 mm, 45 mm, 46 mm, 47 mm, 48 mm, 49 mm, or 50 mm thick.

[0063] Optionally, the cast (or extruded) aluminum alloy can be coiled before a subsequent step.

[0064] Preheating and/or Homogenizing [0065] The cast (or extruded) aluminum alloy product can be homogenized. Homogenization may be performed directly after casting or extruding. Alternatively, the cast (or extruded) aluminum alloy product can be cooled (via quenching or other cooling method) and, optionally, stored before homogenization. When cooled and/or stored, the cast (or extruded) aluminum alloy product can be optionally reheated in a preheating step before a homogenization step. In some examples, the preheating step can include heating the cast (or extruded) aluminum alloy product at a rate of up to about 100 °C/hour (e.g., from 10 °C/hour or 50 °C/hour). The cast (or extruded) aluminum alloy product can be preheated to a temperature of about 350 °C to about 580 °C (e.g., 375 °C to 570 °C, 400 °C to 550 °C, 425 °C to 500 °C, or 500 °C to 580 °C).

[0066] The homogenization step can include heating the cast (or extruded) aluminum alloy product to attain a peak metal temperature (PMT) of at least about 400 °C (e.g., at least 410 °C, at least 420 °C, at least 430 °C, at least 440 °C, at least 450 °C, at least 460 °C, at least 470 °C, at least 480 °C, at least 490 °C, at least 500 °C, at least 510 °C, at least 520 °C, at least 530 °C, at least 540 °C, at least 550 °C, at least 560 °C, at least 570 °C, or at least 580 °C). For example, the cast (or extruded) aluminum alloy product can be heated to a temperature of from about 400 °C to about 600 °C (e.g., from 400 °C to 550 °C, from 425 °C to 550 °C, from 450 °C to 600 °C, from 460 °C to 575 °C, from 470 °C to 570 °C, from 480 °C to 565 °C, from 490 °C to 555 °C, or from 500 °C to 550 °C). In some cases, the heating rate to the PMT can be about 100 °C/hour or less, 75 °C/hour or less, 50 °C/hour or less, 40 °C/hour or less, 30 °C/hour or less, 25 °C/hour or less, 20 °C/hour or less, or 15 °C/hour or less. In other cases, the heating rate to the PMT can be from about 10 °C/min to about 100 °C/min (e.g., from 10 °C/min to 90 °C/min, from 10 °C/min to 70 °C/min, from 10 °C/min to 60 °C/min, from 20 °C/min to 90 °C/min, from 30 °C/min to 80 °C/min, from 40 °C/min to 70 °C/min, or from 50 °C/min to 60 °C/min).

[0067] At the PMT, the cast (or extruded) aluminum alloy product can then be allowed to soak (i.e., held at the PMT) for a period of time. The soak time can be for up to about 36 hours or longer (e.g., from 5 minutes (min) to 36 hours, inclusively). For example, the soak time can be for 5 min, 10 min, 15 min, 20 min, 25 min, 30 min, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 13 hours, 14 hours, 15 hours, 16 hours, 17 hours, 18 hours, 19 hours, 20 hours, 21 hours, 22 hours, 23 hours, 24 hours, 25 hours, 26 hours, 27 hours, 28 hours, 29 hours, 30 hours, 31 hours, 32 hours, 33 hours, 34 hours, 35 hours, 36 hours, or anywhere in between, or longer. [0068] Hot Rolling

[0069] The process can also include a hot rolling step, which can be after the casting or extruding step or after the homogenizing step (if included). The hot rolling step can include a hot reversing mill operation and/or a hot tandem mill operation. The hot rolling step can be performed at a temperature ranging from about 250 °C to about 550 °C (e.g., from 300 °C to 400 °C or from 350 °C to 500 °C). The target entry hot roll temperature may be from about 250 °C to about 550 °C (e.g., from 450 °C to 540 °C). For example, the hot rolling step can be performed at a temperature of about 250 °C, 260 °C, 270 °C, 280 °C, 290 °C, 300 °C, 310 °C, 320 °C, 330 °C, 340 °C, 350 °C, 360 °C, 370 °C, 380 °C, 390 °C, 400 °C, 410 °C, 420 °C, 430 °C, 440 °C, 450 °C, 460 °C, 470 °C, 480 °C, 490 °C, or 500 °C. The entry hot roll temperature can be 450 °C, 455 °C, 460 °C, 465 °C, 470 °C, 475 °C, 480 °C, 485 °C, 490 °C, 495 °C, 500 °C, 505 °C, 510 °C, 515 °C, 520 °C, 525 °C, 530 °C, 535 °C, 540 °C, 545 °C, or 550 °C. The target exit hot roll temperature may be from about 200 °C to about 400 °C. For example, the exit hot roll temperature can be about 200 °C, 205 °C, 210 °C, 215 °C, 220 °C, 225 °C, 230 °C, 235 °C, 240 °C, 245 °C, 250 °C, 255 °C, 260 °C, 265 °C, 270 °C, 275 °C, 280 °C, 285 °C, 290 °C, 295 °C, 300 °C, 305 °C, 310 °C, 315 °C, 320 °C, 325 °C, 330 °C, 335 °C, 340 °C, 345 °C, 350 °C, 355 °C, 360 °C, 365 °C, 370 °C, 375 °C, 380 °C, 385 °C, 390 °C, 395 °C, or 400 °C.

[0070] In the hot rolling step, the aluminum alloy product can be hot rolled to a gauge (or thickness) of about 18 mm or less (e.g., from about 3 mm to about 18 mm). For example, the aluminum alloy product can be hot rolled to a gauge of about 18 mm or less, 17 mm or less, 16 mm or less, 15 mm or less, 14 mm or less, 13 mm or less, 12 mm or less, 11 mm or less, 10 mm or less, 9 mm or less, 8 mm or less, 7 mm or less, 6 mm or less, 5 mm or less, or 4 mm or less. In some cases, the percentage reduction in gauge resulting from the hot rolling step can be from about 35% to about 80% (e.g., 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, or 80%). The percent reduction is calculated as follows: (final gauge-initial gauge)/(initial gauge)* 100).

[0071] Optionally, the hot rolled aluminum alloy product is quenched at the end of the hot rolling step (e.g., upon exit from the tandem mill). Optionally, at the end of the hot rolling step, the hot rolled aluminum alloy product is coiled.

[0072] Cold Rolling

[0073] The process can also include a cold rolling step, which can be after the casting or extruding step, after the homogenizing step (if included), or after the hot rolling step (if included). For example, an aluminum alloy product from any of the foregoing steps (e.g., as an ingot, a billet, a slab, a plate, a shate, or a sheet) can be cold rolled. Preferably, if a cold rolling step is included in the process prior to the solutionizing step, a hot rolling step is included before the cold rolling step. The hot rolled aluminum alloy product (or product from another step) can be cold rolled immediately after the foregoing step or can be stored before being cold rolled.

[0074] The aluminum alloy product from a previous step may be cold rolled from an initial gauge of at least about 5 mm (e.g., at least 6 mm, at least 7 mm, at least 8 mm, at least 9 mm, at least 10 mm, from 5 mm to 18 mm, from 5 mm to 17 mm, from 5 mm to 16 mm, from 5 mm to 15 mm, from 5 mm to 14 mm, from 5 mm to 13 mm, from 5 mm to 12 mm, from 5 mm to 11 mm, from 5 mm to 10 mm, or from 5 mm to 9 mm) to a final gauge of about 12 mm or less (e.g., 11 mm or less, 10 mm or less, 9 mm or less, 8 mm or less, 7 mm or less, 6 mm or less, 5 mm or less, from 2 mm to 12 mm, from 2 mm to 11 mm, from 2 mm to 10 mm, from 2 mm to 9 mm, from 2 mm to 8 mm, from 2 mm to 7 mm, from 2 mm to 6 mm, or from 2 mm to 5 mm). For example, the initial gauge of the aluminum alloy product in the cold rolling step can be about 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, or 18 mm. Further, the final gauge of the aluminum alloy product in the cold rolling step can be about 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, or 12 mm. In some cases, the percentage reduction in gauge (calculated as described above) resulting from the cold rolling step can be from about 25% to about 80% (e.g., 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, or 80%).

[0075] Optionally, at the end of the cold rolling step, the cold rolled aluminum alloy product is coiled.

[0076] Solutionizing

[0077] The rolled aluminum alloy product (after a hot rolling step or a cold rolling step) can then undergo a solutionizing step. The solutionizing step can be performed at a temperature ranging from about 420 °C to about 600 °C (e.g., from 480 °C to 550 °C, from 510 °C to 590 °C, or from 500 °C to 530 °C). The solutionizing step can be performed for about 0.1 min to about 1 hours (e.g., for 1 min to 30 min, for 1 min to 15 min, for 1 min, for 10 min, for 20 min, for 30 min, for 40 min, for 50 min, or for 60 min). Optionally, at the end of the solutionizing step (e.g., upon exit from a furnace), the sheet is subjected to a thermal quenching step. The thermal quenching step can be performed using air and/or water. The water temperature can be from about 20 °C to about 75 °C (e.g., 25 °C, 30 °C, 35 °C, 40 °C, 45 °C, 50 °C, 55 °C, 60 °C, 65 °C, 70 °C, or 75 °C). The cooling rate of the quenching may be about 50 °C/second (°C/s) or faster (e.g., from 50 °C/s to 1000 °C/s, from about 50 °C/s to about 900 °C/s, from about 100 °C/s to about 800 °C/s, from about 200 °C/s to about 700 °C/s, from about 250 °C/s to about 600 °C/s, or from about 300 °C/s to about 550 °C/s). For example, quenching can be performed at a rate of about 50 °C/s, 55 °C/s, 60 °C/s, 65 °C/s, 70 °C/s, 75 °C/s, 80 °C/s, 85 °C/s, 90 °C/s, 95 °C/s, 100 °C/s, 150 °C/s, 200 °C/s, 250 °C/s, 300 °C/s, 350 °C/s, 400 °C/s, 450 °C/s, 500 °C/s, 550 °C/s, 600 °C/s, 650 °C/s, 700 °C/s, 750 °C/s, 800 °C/s, 850 °C/s, 900 °C/s, 950 °C/s, 1000 °C/s, or anywhere in between.

[0078] The solutionized aluminum alloy product may have a W temper.

[0079] Optionally, at the end of the solutionizing step and, optionally, thermal quenching step, the solutionized aluminum alloy product is coiled.

[0080] Optional Preheating

[0081] Optionally, the solutionized aluminum alloy product can be preheated before and/or while coiling the solutionized aluminum alloy product before the pre-aging step. The preheating step can heat the solutionized aluminum alloy product to a temperature ranging from about 60 °C to about 140 °C (e.g., from 60 °C to 100 °C , from 80 °C to 120 °C, from 80 °C to 100 °C, or from 90 °C to 110 °C). For example, the preheating step can heat the solutionized aluminum alloy product to a temperature of 60 °C, 65 °C, 70 °C, 75 °C, 80 °C, 85 °C, 90 °C, 95 °C, 100 °C, 105 °C, 110 °C, 115 °C, 120 °C, 125 °C, 130 °C, 135 °C, or 140 °C. The rate of preheating can be from about 10 °C/min to about 100 °C/min (e.g., from about 20 °C/min to about 90 °C/min, from about 30 °C/min to about 80 °C/min, from about 10 °C/min to about 90 °C/min, about 10 °C/min to about 70 °C/min, about 10 °C/min to about 60 °C/min, 40 °C/min to about 70 °C/min, or from about 50 °C/min to about 60 °C/min). In other aspects, the rate of preheating can be from about 10 °C/hour to about 100 °C/hour (e.g., from about 10 °C/hour to about 90 °C/hour, from about 10 °C/hour to about 70 °C/hour, from about 10 °C/hour to about 60 °C/hour, from about 20 °C/hour to about 90 °C/hour, from about 30 °C/hour to about 80 °C/hour, from about 40 °C/hour to about 70 °C/hour, or from about 50 °C/hour to about 60 °C/hour).

[0082] Pre-Aging

[0083] Pre-aging can be performed in batches with the solutionized aluminum alloy product already coiled. As described above, a preheating step can be included in the process prior to coiling the solutionized aluminum alloy product. [0084] As described above, the pre-aging step may cause atomic scale structural ordering in the solutionized aluminum alloy product, for example, to form GP-zones and/or Cu- containing precursor particles.

[0085] Pre-aging of the solutionized aluminum alloy product can be performed at a temperature ranging from about 60 °C to about 140 °C (e.g., from 60 °C to 100 °C, from 80 °C to 120 °C, from 80 °C to 100 °C, or from 90 °C to 110 °C). For example, the pre-aging step can be performed at a temperature of 60 °C, 65 °C, 70 °C, 75 °C, 80 °C, 85 °C, 90 °C, 95 °C, 100 °C, 105 °C, 110 °C, 115 °C, 120 °C, 125 °C, 130 °C, 135 °C, or 140 °C. If the preheating step is included, the preheating step can heat the solutionized aluminum alloy product to a temperature that is within about 50 °C of the pre-aging temperature (e.g., within 40 °C of the pre-aging temperature, within 30 °C of the pre-aging temperature, within 20 °C of the preaging temperature, or within 10 °C of the pre-aging temperature). For example, the temperature of the preheating step may be 50 °C, 45 °C, 40 °C, 35 °C, 30 °C, 25 °C, 20 °C, 15 °C, 10 °C, 5 °C, or 0 °C (i.e., the same temperature) from the temperature of the pre-aging step.

[0086] The solutionized aluminum alloy product can hold at the pre-aging temperature for a period of time. Said period of time can be up to about 24 hours or longer (e.g., from 8 hours to 24 hours, inclusively). For example, the time at the pre-aging temperature can be for 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 13 hours, 14 hours, 15 hours, 16 hours, 17 hours, 18 hours, 19 hours, 20 hours, 21 hours, 22 hours, 23 hours, 24 hours, or anywhere in between, or longer.

[0087] The pre-aged aluminum alloy product may have a partial aging temper having a higher strength than a T4 temper.

[0088] Cold Rolling

[0089] The process includes a cold rolling step after the pre-aging step. The conditions of this cold rolling step are preferably mild with minimal passes and minimal reduction in gauge, as further detailed below. As described above, the cold rolling step increases the strength of the aluminum alloy product, but too much cold rolling detrimentally affects the microstructure causing a reduction in the elongation of the aluminum alloy product.

[0090] The pre-aged aluminum alloy product can be cold rolled from an initial gauge of at least about 2 mm (e.g., at least 3 mm, at least 4 mm, at least 5 mm, at least 6 mm, at least 7 mm, at least 8 mm, at least 9 mm, at least 10 mm, from 2 mm to 18 mm, from 2 mm to 17 mm, from 2 mm to 16 mm, from 2 mm to 15 mm, from 2 mm to 14 mm, from 2 mm to 13 mm, from 2 mm to 12 mm, from 2 mm to 11 mm, from 2 mm to 10 mm, or from 2 mm to 9 mm) to a final gauge of about 12 mm or less (e.g., 11 mm or less, 10 mm or less, 9 mm or less, 8 mm or less, 7 mm or less, 6 mm or less, 5 mm or less, 4 mm or less, 3 mm or less, 2 mm or less, 1 mm or less, from 0.1 mm to 12 mm, from 0.1 mm to 11 mm, from 0.1 mm to 10 mm, from 0.1 mm to 9 mm, from 0.1 mm to 8 mm, from 0.1 mm to 7 mm, from 0.1 mm to 6 mm, from 0.1 mm to 5 mm, from 0.1 mm to 4 mm, from 0.1 mm to 3 mm, from 0.1 mm to 2 mm, or from 0.1 mm to 1 mm). For example, the initial gauge of the aluminum alloy product in the cold rolling step can be about 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, or 18 mm. Further, the final gauge of the aluminum alloy product in the cold rolling step can be about 0.1 mm, 0.3 mm, 0.5 mm, 0.7 mm, 1 mm, 1.5 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, or 12 mm. In some cases, the percentage reduction in gauge (calculated as described above) resulting from the cold rolling step can be less than about 30% (e.g., from 5% to 30%, from 5% to 25%, from 5% to 20%, from 5% to 15%, from 5% to 10%, 5%, 10%, 15%, 20%, 25%, or 30%).

[0091] The number of passes in the cold rolling step can be 3 passes or less (e.g., from 1 pass to 3 passes, 1 pass, 2 passes, or 3 passes).

[0092] The time between the pre-aging step and the cold rolling step is not limited. Preferably, the time between said steps is less than about 1 week (e.g., less than 6 days, less than 5 days, less than 4 days, less than 3 days, less than 2 days, less than 1 day, 1 min to 1 week, 1 min to 6 hours, 1 hour to 12 hours, 8 hours to 36 hours, 1 day to 3 days, or 2 days to 7 days).

[0093] The cold rolling step can be a coil-to-coil step so that the cold rolled, pre-aged aluminum alloy product is coiled prior to the next step.

[0094] Artificially Re-Aging

[0095] The aluminum alloy product after cold rolling can then be artificially aged. If the pre-aging step is included, then this may be referred to as an artificially re-aging step. The artificially re-aging step is believed to increase the strength of the cold rolled aluminum alloy product without sacrificing the elongation because the cold rolling step does not overprocess the aluminum alloy product, which may cause significant detrimental effects to the microstructure of the aluminum alloy product.

[0096] The artificially aging step or artificially re-aging step can be performed in batches with coils of the cold rolled, pre-aged aluminum alloy product.

[0097] The artificially re-aging step can be performed at a higher temperature than the preaging step. A higher artificially aging temperature compared to the pre-aging temperature may accelerate precipitation growth rate to provide maximum strength in the shortest possible time. The duration of the final aging step may be shorter than conventional aging steps to mitigate excess growth of precipitates that may decrease both strength and ductility in the final aluminum alloy product.

[0098] Artificially aging or artificially re-aging can be performed at a temperature ranging from about 120 °C to about 180 °C (e.g., from 120 °C to 150 °C, from 130 °C to 160 °C, from 140 °C to 170 °C, or from 150 °C to 180 °C). For example, the artificially aging step or artificially re-aging step can be performed at a temperature of 120 °C, 125 °C, 130 °C, 135 °C, 140 °C, 145 °C, 150 °C, 155 °C, 160 °C, 165 °C, 170 °C, 175 °C, or 180 °C. The temperature of the artificially re-aging step can be at least about 10 °C greater than (e.g., at least about 20 °C greater than, at least about 40 °C greater than, or at least about 60 °C greater than) the temperature of the pre-aging step. The temperature of the artificially aging step or artificially re-aging step can be about 10 °C, 15 °C, 20 °C, 25 °C, 30 °C, 35 °C, 40 °C, 45 °C, 50 °C, 55 °C, 60 °C, 65 °C, 70 °C, 75 °C, 80 °C, 85 °C, or 90 °C greater than the temperature of the preaging step.

[0099] The aluminum alloy product can be held at the artificially aging temperature or artificially re-aging temperature for a period of time. Said period of time can be up to about 24 hours or longer (e.g., from 4 hours to 24 hours, inclusively). For example, the time at the preaging temperature or artificially re-aging temperature can be for 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 13 hours, 14 hours, 15 hours, 16 hours, 17 hours, 18 hours, 19 hours, 20 hours, 21 hours, 22 hours, 23 hours, 24 hours, or anywhere in between, or longer.

[0100] The aluminum alloy product after aging or re-aging may have a higher strength and/or higher ductility than a 6xxx aluminum alloy product of the same 6xxx aluminum alloy but processed to achieve a T6 temper or a T8 temper.

[0101] The time between the cold rolling step and the artificially aging step or artificially re-aging step is not limited. Preferably, the time between said steps is less than about 1 week (e.g., less than 6 days, less than 5 days, less than 4 days, less than 3 days, less than 2 days, less than 1 day, 1 min to 1 week, 1 min to 6 hours, 1 hour to 12 hours, 8 hours to 36 hours, 1 day to 3 days, or 2 days to 7 days).

[0102] Coating and/or Paint Baking

[0103] Optionally, the artificially aged aluminum alloy product (i.e., after the foregoing artificially aging step or artificially re-aging step) is subjected to a coating step. Optionally, the coating step can include zinc phosphating (Zn-phosphating) and/or electrocoating (E-coating). The Zn-phosphating and E-coating can be performed according to standards commonly used in the aluminum industry as known to one of skill in the art. Optionally, the coating step can be followed by a paint baking step. The paint baking step can be performed at a temperature of from about 150 °C to about 230 °C (e.g., at about 180 °C or at about 210 °C). The paint baking step can be performed for a time period of about 10 min to about 60 min (e.g., about 30 min or about 45 min).

[0104] Example Methods

[0105] A rolled aluminum alloy product comprising a 6xxx series aluminum alloy produced using any method can be in the form of a sheet, shate, or plate, or any other suitable form. The rolled aluminum alloy product can be solutionized and optionally quenched. The resultant solutionized aluminum alloy product can be pre-aged (e.g., at 60 °C to 140 °C for at least 8 hours). Optionally, the solutionized aluminum alloy product can be preheated before pre-aging. The pre-aged aluminum alloy product can be cold rolled with a thickness reduction of 5% to 30%. The cold rolled, pre-aged aluminum alloy product can then be artificially reaged (e.g., at 120 °C to 180 °C for at least 4 hours), where the artificially re-aging conducted is at a higher temperature than the pre-aging.

[0106] A rolled aluminum alloy product comprising a 6xxx series aluminum alloy produced using any method can be in the form of a sheet, shate, or plate, or any other suitable form. The rolled aluminum alloy product can be solutionized and optionally quenched. The resultant solutionized aluminum alloy product can be pre-aged (e.g., at 60 °C to 140 °C for at least 8 hours). Optionally, the solutionized aluminum alloy product can be preheated before pre-aging. The pre-aged aluminum alloy product can be cold rolled with 3 passes or less. The cold rolled, pre-aged aluminum alloy product can then be artificially re-aged (e.g., at 120 °C to 180 °C for at least 4 hours), where the artificially aging is conducted at a higher temperature than the pre-aging.

[0107] A 6xxx series aluminum alloy can be cast or extruded to produce a cast or extruded aluminum alloy product. The cast or extruded aluminum alloy product can be hot rolled into a form such as a sheet, shate, or plate, or any other suitable form. The hot rolled aluminum alloy product can, optionally, be cold rolled. The rolled aluminum alloy product can then be treated according to any of the preceding example methods.

[0108] A 6xxx series aluminum alloy can be cast or extruded to produce a cast or extruded aluminum alloy product. The cast or extruded aluminum alloy product can be homogenized. The homogenized aluminum alloy product can be hot rolled into a form such as a sheet, shate, or plate, or any other suitable form. The hot rolled aluminum alloy product can, optionally, be cold rolled. The rolled aluminum alloy product can then be treated according to any of the preceding example methods.

[0109] Any of the foregoing methods can also include a coating and/or baking step performed on the aluminum alloy product after the final artificially aging step or artificially reaging step.

[0110] Properties

[OHl] The artificially aged aluminum alloy product (i.e., after the final artificially aging step or after the artificially re-aging step) described herein exhibit a combination of desirable properties including high strength and high elongation. The high elongation allows for the artificially aged aluminum alloy product to be ductile and formable, which, in combination with the high strength, allows for more uses of the aluminum alloy product.

[0112] The mechanical properties can be determined using ASTM B557 with 50 mm gauge length for tensile testing.

[0113] The artificially aged aluminum alloy product can have a yield strength ranging from about 375 MPa to about 475 MPa (e.g., from 375 MPa to 425 MPa or from 400 MPa to 475 MPa). For example, the yield strength of the artificially aged aluminum alloy product can be about 375 MPa, 380 MPa, 385 MPa, 390 MPa, 395 MPa, 400 MPa, 405 MPa, 410 MPa, 415 MPa, 420 MPa, 425 MPa, 430 MPa, 435 MPa, 440 MPa, 445 MPa, 450 MPa, 455 MPa, 460 MPa, 465 MPa, 470 MPa, 475 MPa, or anywhere in between.

[0114] The artificially aged aluminum alloy product can have an ultimate tensile strength ranging from about 425 MPa to about 525 MPa (e.g., from 425 MPa to 500 MPa or from 450 MPa to 525 MPa). For example, the ultimate tensile strength of the artificially aged aluminum alloy product can be about 425 MPa, 430 MPa, 435 MPa, 440 MPa, 445 MPa, 450 MPa, 455 MPa, 460 MPa, 465 MPa, 470 MPa, 475 MPa, 480 MPa, 485 MPa, 490 MPa, 495 MPa, 500 MPa, 505 MPa, 510 MPa, 515 MPa, 520 MPa, 525 MPa, or anywhere in between.

[0115] A value for the ultimate tensile strength minus the yield strength for the artificially aged aluminum alloy product can range from about 30 MPa to about 65 MPa (e.g., from 35 MPa to 65 MPa, from about 40 MPa to about 65 MPa, from about 45 MPa to about 65 MPa, or from 40 MPa to 60 MPa). For example, the value for the ultimate tensile strength minus the yield strength for the artificially aged aluminum alloy product can be about 30 MPa, 31 MPa, 32 MPa, 33 MPa, 34 MPa, 35 MPa, 36 MPa, 37 MPa, 38 MPa, 39 MPa, 40 MPa, 41 MPa, 42 MPa, 43 MPa, 44 MPa, 45 MPa, 46 MPa, 47 MPa, 48 MPa, 49 MPa, 50 MPa, 51 MPa, 52 MPa, 53 MPa, 54 MPa, 55 MPa, 56 MPa, 57 MPa, 58 MPa, 59 MPa, 60 MPa, 61 MPa, 62 MPa, 63 MPa, 64 MPa, 65 MPa, or anywhere in between.

[0116] An n-value, or the strain hardening exponent, indicates how much the material hardens or becomes stronger when plastically deformed. A higher n-value indicates higher formability. The n-value can be measured using ISO 10275 (2007), for example. Unless otherwise specified, the n-value is measured over a strain range from 2% to 8%.

[0117] The artificially aged aluminum alloy product can have an n-value of about 0.07 or greater (e.g., from 0.07 to 0.11 or from 0.08 to 0.10). For example, the n-value of the artificially aged aluminum alloy product can be about 0.070, 0.075, 0.080, 0.085, 0.090, 0.095, 0.100, 0.105, 0.110, or anywhere in between.

[0118] The high formability can be measured, for example, by measuring total elongation or uniform elongation. ISOZEN A80 is one appropriate standard that can be used for testing the total elongation (EN 10002 parts 1-5, (2001)). ASTM B557 is one appropriate standard that can be used for testing and/or calculating the uniform elongation.

[0119] The artificially aged aluminum alloy product can have a uniform elongation from about 10% or greater (e.g., from 10% to 20% or from 12% to 18%). For example, the uniform elongation of the artificially aged aluminum alloy product can be about 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, or anywhere in between.

[0120] The artificially aged aluminum alloy product can have a total elongation from about 15% or greater (e.g., from 15% to 25% or from 15% to 20%). For example, the total elongation of the artificially aged aluminum alloy product can be about 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, or anywhere in between.

Uses and Applications

[0121] The artificially aged aluminum alloy products described herein including a 6xxx series aluminum alloy and optionally coated and/or baked can be used in automotive and/or transportation applications, including vans, campers, mobile homes, trucks, bodies in white, cabs of trucks, trailers, buses, motorcycles, scooters, bicycles, boats, ships, shipping containers, trains, train engines, rail passenger cars, rail freight cars, planes, drones, and spacecraft, or any other desired application. In some examples, the artificially aged aluminum alloy products can be used to prepare vehicle body part products, such as bumpers, inner panels, outer panels, side panels, inner hoods, outer hoods, or trunk lid panels. The artificially aged aluminum alloy products described herein can also be used in aircraft or railway vehicle applications, to prepare, for example, external and internal panels.

[0122] Because of the high strength in combination with the high elongation, the artificially aged aluminum alloy products described herein may be particularly useful in replacing steel components in transportation vehicles such as in a chassis or a component part of a chassis.

[0123] Additionally, because of the high strength in combination with the high elongation, the artificially aged aluminum alloy products described herein can also be used in battery applications including electric vehicle battery enclosures, battery plates, and battery shates, or any other desired structural component of a battery.

[0124] The artificially aged aluminum alloy products described herein can also be used in electronics applications. For example, the artificially aged aluminum alloy products described herein can be used to prepare housings for electronic devices, including mobile phones and tablet computers. In some examples, the artificially aged aluminum alloy products can be used to prepare housings for the outer casing of mobile phones (e.g., smart phones) and tablet bottom chassis.

[0125] In some cases, the artificially aged aluminum alloy products described herein can be used in industrial applications. For example, the artificially aged aluminum alloy products described herein can be used to prepare products for the general distribution market.

[0126] Reference has been made in detail to various examples of the disclosed subject matter, one or more examples of which were set forth above. Each example was provided by way of explanation of the subject matter, not limitation thereof. In fact, it will be apparent to those skilled in the art that various modifications and variations may be made in the present subject matter without departing from the scope or spirit of the disclosure. For instance, features illustrated or described as part of one embodiment may be used with another embodiment to yield a still further embodiment.

[0127] The following examples will serve to further illustrate the present invention without, at the same time, 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. 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

[0128] Example 1. Two aluminum alloy sheets were prepared using the same 6xxx series aluminum alloy. The Comparative Sample was prepared by casting the 6xxx series aluminum alloy and hot rolling the cast aluminum alloy to an aluminum alloy sheet. The aluminum alloy sheet was then solutionized and quenched to a T4 temper. Then, the aluminum alloy sheet was coiled and aged to a T6 temper. The Inventive Sample was prepared by the same casting, hot rolling, solutionizing, and quenching procedures as the Comparative Sample to produce an aluminum alloy sheet with a W temper. Then, the aluminum alloy sheet was preheated to 80 °C while coiling. The preheated, coiled aluminum alloy sheet was pre-aged at 100 °C for 24 hours. Then, the pre-aged aluminum alloy sheet was cold rolled in a single pass (about 18% reduction) and re-coiled. The resultant coil was re-aged to at 140 °C for 24 hours.

[0129] Table 4 provides the mechanical properties of the two samples, and FIG. 2 is a plot of the tensile stress-strain curves for the two samples.

Table 4

[0130] Example 2. Aluminum alloy sheets were prepared using the same 6xxx series aluminum alloy. The aluminum alloy sheets were prepared by casting the 6xxx series aluminum alloy and hot rolling the cast aluminum alloy to 5 mm thickness. Then, a further treatment was performed. Treatments A-E are provided in Table 5. Treatment F is a conventional treatment resulting in a T6 final temper.

Table 5

[0131] Table 6 provides the transverse mechanical properties for the samples, specifically, yield strength (YS), ultimate tensile strength (UTS), and total elongation (TE). The sample letter indicates which of Treatments A-F the aluminum sheet underwent.

Table 6

[0132] The same experiments were performed with the same 6xxx series aluminum alloys as Table 5 except the sheets were hot rolled to 4.0 mm and the cold rolling was a 25% reduction to 3.0 mm. Table 7 provides the transverse mechanical properties for the samples.

Table 7

[0133] The same experiments were performed with the same 6xxx series aluminum alloys as Table 5 except the sheets were hot rolled to 3.0 mm and the cold rolling was a 16% reduction to 2.5 mm. Table 8 provides the transverse mechanical properties for the samples.

Table 8

[0134] Samples Cl, C2, and C3 for their respective comparative samples have the highest yield strength while maintaining a UTS minus YS of about 50 MPa to about 61 MPa, which is a measure of ductility and indication of a work hardening range. A higher work hardening range may allow for formability at room temperature.

[0135] Example 3. This example illustrates the impact of pre-aging step on the mechanical properties of the final 6xxx aluminum alloy product. The 6xxx aluminum sheet processing steps remain the same for the various samples except the pre-aging step following the solution heat treatment. The solution heat treatment for all these samples was conducted at a temperature of 530 °C, followed by immediate quenching in water kept at 55 °C. Following quenching, the next steps for the different samples were according to the following:

• For Sample G, no pre-aging step was applied. Accordingly, the 6xxx aluminum product went through cold rolling immediately after solution heat treatment.

• For Sample H, the 6xxx aluminum product was pre-aged at 60 °C followed by continuously cooling to room temperature in 24 hours.

• For Sample I, the 6xxx aluminum product was pre-aged at 80 °C followed by continuously cooling to room temperature in 24 hours. • For Sample J, the 6xxx aluminum product was pre-aged at 100 °C for 24 hours followed by naturally cooling to room temperature.

• For Sample K, the 6xxx aluminum product was naturally aged for three years after solution heat treating.

[0136] Then, each of the aluminum alloy products were cold rolled between 25% to 30% reduction at room temperature. Then, all aluminum alloys products were artificially re-aged at 140 °C for 24 hours and naturally cooled to room temperature before mechanically tested for tensile properties.

[0137] FIG. 3A is a plot of the engineering stress versus engineering strain in the L- Orientation (test with loading axis parallel to the rolling direction of the aluminum alloy product) for Samples G-K. FIG. 3B is a plot of the engineering stress versus engineering strain in the T-Orientation (test with loading axis perpendicular to the rolling direction of the aluminum alloy product) for Samples G-K. Table 9 provides the tensile property data for Samples G-K. All tensile tests were conducted following ASTM B557 testing specifications at room temperature. Abbreviations: YS = Yield Strength, UTS = Ultimate Tensile Strength, UE = Uniform Elongation, TE = Total Elongation, L = Longitudinal orientation, T = Transverse Orientation.

Table 9 [0138] The tensile properties in the final rolled product are slightly impacted by the prior pre-aging condition. The best combination of strength and elongation are obtained when the pre-aging step creates a uniform distribution of precipitate pre-cursors (GP zones). The sample with three-year natural aging following solution heat treatment produces the best mechanical test results. Both high yield strength and higher uniform elongations are also achieved for a pre-aging temperature 80 °C and 100 °C.

[0139] Example 4. This example illustrates the impact of the amount of cold rolling on the mechanical properties of the final 6xxx aluminum alloy product. The 6xxx aluminum sheet processing steps remained the same for the various samples except the amount of cold rolling. The samples started as a 6xxx aluminum alloy that had undergone hot rolling to a 5.0 mm thickness. Then, the samples were solution heat treated at 540 °C followed by quenching in water kept at 55 °C. Following water quenching, a pre-aging heat treatment at 100 °C for 24 hours was applied. Then, cold rolling reductions between 20% to 50% of total thickness reductions (Sample L 20% reduction, Sample M 33% reduction, Sample N 50% reduction) were applied. Finally, all samples were artificially re-aged at 140 °C for 24 hours.

[0140] FIG. 4A is a plot of the engineering stress versus engineering strain in the L- Orientation for Samples L-N. FIG. 4B is a plot of the engineering stress versus engineering strain in the T-Orientation for Samples L-N. Table 10 provides the tensile property data for Samples L-N. All tensile tests were conducted following ASTM B557 testing specifications at room temperature.

Table 10 [0141] With increasing the amount of cold rolling reduction, the strength increases, while the elongation decreases. Although a 6xxx aluminum product with a yield strength greater than 400 MPa can be produced just by increasing the cold rolling amount, the product may not possess sufficient ductility for room temperature forming operations which is an intended application of this product within the transportation industry.

[0142] Example 5. This example illustrates the impact of the re-aging process on the mechanical properties of the final 6xxx aluminum alloy product. The 6xxx aluminum sheet processing steps remained the same for the various samples except the re-aging step. The samples started as a 6xxx aluminum alloy that had undergone hot rolling and cold rolling to a 3.0 mm thickness. Then, the samples were solution heat treated using a peak metal temperature of 555 °C followed by quenching in room temperature water. Following water quenching, a pre-aging heat treatment at 100 °C for 24 hours was applied. Then within 10 days of pre-aging, a cold rolling reduction of 15% of total thickness reductions was applied. Finally, all samples were artificially re-aged (Sample O T6 temper, Sample P 140 °C for 24 hours, Sample Q 160 °C for 24 hours, Sample R 180 °C for 24 hours.

[0143] FIG. 5A is a plot of the engineering stress versus engineering strain in the L- Orientation for Samples O-R. FIG. 5B is a plot of the engineering stress versus engineering strain in the T-Orientation for Samples O-R. Table 10 provides the tensile property data for Samples O-R. All tensile tests were conducted following ASTM B557 testing specifications at room temperature.

Table 11

[0144] Increasing the re-aging temperature results in coarsening of strengthening precipitates, which is expected to increase the yield strength. Along with the coarsening these precipitates also increasingly achieved lattice coherency with the aluminum matrix, which explains the increase in overall strength. During plastic deformation, the coarse precipitates pose a greater obstacle strength to the passing of dislocations. Such a hard interaction of dislocation and coarse precipitate increase the local stresses at the particle matrix interface which nucleate nano-voids at the precipitate matrix interface and ultimately result in reduced ductility (or total elongation). FIGS. 6A and 6B are transmission electron microscopy (TEM) images with atomic scale resolution of the strengthening precipitate, specifically, Q’ precipitates, from Sample P.

[0145] Typically, in a peak aged 6xxx aluminum product (in T6 temper), the strengthening precipitates appear as rods whose lengths can be as long as tens of nanometer. In these samples, the strengthening Q’ precipitates are much smaller and range from 3 nm to 6 nm.

ILLUSTRATIVE ASPECTS

[0146] As used below, any reference to a series of aspects (e.g., “Aspects 1-4”) or nonenumerated group of aspects (e.g., “any previous or subsequent aspect”) is to be understood as a reference to each of those aspects disjunctively (e.g., “Aspects 1-4” is to be understood as “Aspects 1, 2, 3, or 4 ”).

[0147] Aspect 1. A method of producing an aluminum alloy product, comprising: solutionizing a rolled aluminum alloy product comprising a 6xxx series aluminum alloy; optionally, pre-aging the solutionized aluminum alloy product; cold rolling the pre-aged aluminum alloy product with a gauge reduction of 5% to 30%; and artificially aging the cold rolled, pre-aged aluminum alloy product at 120 °C to 180 °C for at least 4 hours to produce an artificially aged aluminum alloy product, wherein the artificially aging is conducted at a higher temperature than the pre-aging.

[0148] Aspect 2. The method of any previous or subsequent aspect, wherein the pre-aging is performed at 60 °C to 140 °C for at least 8 hours.

[0149] Aspect 3. The method of any previous or subsequent aspect, wherein the artificially aging is performed at 120 °C to 150 °C for at least 4 hours. [0150] Aspect 4. The method of any previous or subsequent aspect, wherein the artificially aged aluminum alloy product has a higher strength and/or a higher ductility than a 6xxx aluminum alloy product of the same 6xxx aluminum alloy but processed to achieve a T6 temper or a T8 temper.

[0151] Aspect 5. The method of any previous or subsequent aspect, wherein the cold rolling of the pre-aged aluminum alloy product includes three passes or less.

[0152] Aspect 6. The method of any previous or subsequent aspect, wherein after cold rolling, the aluminum alloy product has a gauge from 0.1 mm to 6 mm.

[0153] Aspect 7. The method of any previous or subsequent aspect, wherein the artificially aged aluminum alloy product has a yield strength of 375 MPa to 475 MPa.

[0154] Aspect 8. The method of any previous or subsequent aspect, wherein the artificially aged aluminum alloy product has an ultimate tensile strength of 425 MPa to about 525 MPa.

[0155] Aspect 9. The method of any previous or subsequent aspect, wherein the artificially aged aluminum alloy product has a value for an ultimate tensile strength minus a yield strength of 30 MPa to 65 MPa.

[0156] Aspect 10. The method of any previous or subsequent aspect, wherein the artificially aged aluminum alloy product has an n-value of 0.7 or greater.

[0157] Aspect 11. The method of any previous or subsequent aspect, wherein the artificially aged aluminum alloy product has a uniform elongation of 10% or greater.

[0158] Aspect 12. The method of any previous or subsequent aspect, wherein the artificially aged aluminum alloy product has a total elongation of 15% or greater.

[0159] Aspect 13. The method of any previous or subsequent aspect further comprising: between the solutionizing and the pre-aging, coiling the solutionized aluminum alloy product; and preheating the solutionized aluminum alloy product to a temperature of 60 °C to 140 °C during the coiling.

[0160] Aspect 14. The method of any previous or subsequent aspect further comprising: casting or extruding the 6xxx series aluminum alloy; homogenizing the cast or extruded aluminum alloy product; and hot rolling and/or cold rolling the homogenized aluminum alloy product to produce the rolled aluminum alloy product.

[0161] Aspect 15. A method of producing an aluminum alloy product, comprising: solutionizing a rolled aluminum alloy product comprising a 6xxx series aluminum alloy; preaging the solutionized aluminum alloy product at 60 °C to 140 °C for at least 8 hours; cold rolling the pre-aged aluminum alloy product with three passes or less; and artificially aging the cold rolled, pre-aged aluminum alloy product at 120 °C to 180 °C for at least 4 hours to produce an artificially aged aluminum alloy product, wherein the artificially aging is conducted at a higher temperature than the pre-aging.

[0162] Aspect 16. An aluminum alloy product (e.g., an aluminum alloy product produced by the method of any previous or subsequent aspect) comprising: a 6xxx series aluminum alloy, wherein the aluminum alloy product has a yield strength of 375 MPa to 475 MPa and a total elongation of 15% or greater.

[0163] Aspect 17. The aluminum alloy product of any previous or subsequent aspect, wherein the aluminum alloy product has an ultimate tensile strength of 425 MPa to 525 MPa. [0164] Aspect 18. The aluminum alloy product of any previous or subsequent aspect, wherein the aluminum alloy product has a value for the ultimate tensile strength minus the yield strength of 30 MPa to 65 MPa.

[0165] Aspect 19. The aluminum alloy product of any previous or subsequent aspect, wherein the aluminum alloy product has an n-value of 0.7 or greater.

[0166] Aspect 20. The aluminum alloy product of any previous or subsequent aspect, wherein the aluminum alloy product has a uniform elongation of 10% or greater.

[0167] All patents and publications cited herein are incorporated by reference in their entirety. The foregoing description of the embodiments, including illustrated embodiments, has been presented only for the purpose of illustration and description and is not intended to be exhaustive or limiting to the precise forms disclosed. Numerous modifications, adaptations, and uses thereof will be apparent to those skilled in the art.

Claims

WHAT IS CLAIMED IS:

1. A method of producing an aluminum alloy product, comprising: solutionizing a rolled aluminum alloy product comprising a 6xxx series aluminum alloy; optionally, pre-aging the solutionized aluminum alloy product; cold rolling the aluminum alloy product with a gauge reduction of 5% to 30%; and artificially aging the aluminum alloy product after cold rolling to produce an artificially aged aluminum alloy product at 120 °C to 180 °C for at least 4 hours, wherein the artificially aging is conducted at a higher temperature than the pre-aging.

2. The method of claim 1, wherein the pre-aging is performed at 60 °C to 140 °C for at least 8 hours.

3. The method of any of claims 1-2, wherein the artificially aging is performed at 120 °C to 150 °C for at least 4 hours.

4. The method of any of claims 1-3, wherein the artificially aged aluminum alloy product has a higher strength and/or a higher ductility than a 6xxx aluminum alloy product with a 6xxx aluminum alloy product of the same 6xxx aluminum alloy but processed to achieve a T6 temper or a T8 temper.

5. The method of any of claims 1-4, wherein the cold rolling of the pre-aged aluminum alloy product includes three passes or less.

6. The method of any of claims 1-5, wherein the cold aluminum alloy product after cold rolling has a gauge from 0.1 mm to 6 mm.

7. The method of any of claims 1-6, wherein the artificially aged aluminum alloy product has a yield strength of 375 MPa to 475 MPa.

8. The method of any of claims 1-7, wherein the artificially aged aluminum alloy product has an ultimate tensile strength of 425 MPa to 525 MPa.

9. The method of any of claims 1-8, wherein the artificially aged aluminum alloy product has a value for an ultimate tensile strength minus a yield strength of 30 MPa to 65 MPa.

10. The method of any of claims 1-9, wherein the artificially aged aluminum alloy product has an n-value of 0.7 or greater.

11. The method of any of claims 1-10, wherein the artificially aged aluminum alloy product has a uniform elongation of 10% or greater.

12. The method of any of claims 1-11, wherein the artificially aged aluminum alloy product has a total elongation of 15% or greater.

13. The method of any of claims 1-12 further comprising: between the solutionizing and the pre-aging, coiling the solutionized aluminum alloy product; and preheating the solutionized aluminum alloy product to a temperature of 60 °C to 140 °C during the coiling.

14. The method of any of claims 1-13 further comprising: casting or extruding the 6xxx series aluminum alloy; homogenizing the cast or extruded aluminum alloy product; and hot rolling and/or cold rolling the homogenized aluminum alloy product to produce the rolled aluminum alloy product.

15. A method of producing an aluminum alloy product, comprising: solutionizing a rolled aluminum alloy product comprising a 6xxx series aluminum alloy; pre-aging the solutionized aluminum alloy product at 60 °C to 140 °C for at least 8 hours; cold rolling the pre-aged aluminum alloy product with three passes or less; and artificially aging the cold rolled, pre-aged aluminum alloy product at 120 °C to 180 °C for at least 4 hours to produce an artificially aged aluminum alloy product, wherein the artificially aging is conducted at a higher temperature than the pre-aging.

16. An aluminum alloy product comprising: a 6xxx series aluminum alloy, wherein the aluminum alloy product has a yield strength of 375 MPa to 475 MPa and a total elongation of 15% or greater.

17. The aluminum alloy product of claim 16, wherein the aluminum alloy product has an ultimate tensile strength of 425 MPa to 525 MPa.

18. The aluminum alloy product of claim 17, wherein the aluminum alloy product has a value for the ultimate tensile strength minus the yield strength of 30 MPa to 65 MPa.

19. The aluminum alloy product of any of claims 16-18, wherein the aluminum alloy product has an n-value of 0.7 or greater.

20. The aluminum alloy product of any of claims 16-19, wherein the aluminum alloy product has a uniform elongation of 10% or greater.