Patent Description:
The present disclosure generally provides aluminum alloy products having a selectively recrystallized microstructure at the surface of the product. The disclosure also provides methods of making aluminum alloy products, such as through casting and rolling. The disclosure also provides various end uses of such products, such as in automotive, transportation, electronics, and industrial applications.

Aluminum alloy products are desirable for use in a number of different applications, especially those where light weight, strength, and durability are desirable. For example, aluminum alloys are increasingly replacing steel as a structural component of automobiles and other transportation equipment. Because aluminum alloys are generally about <NUM> times less dense than steel, the use of such materials reduces the weight of the equipment and allows for substantial improvements in energy efficiency. Even so, the use of aluminum alloy products can pose certain challenges.

One particular challenge relates to the tendency of aluminum alloy products to undergo recrystallization during and following certain processing steps. In metallurgy, recrystallization refers to the process by which deformed grains (e.g., formed as the result of rolling or other mechanical shaping activities) reorient and convert into defect-free grains that nucleate and gradually replace the deformed grains. Recrystallization generally improves the ductility of the material, but generally does so at the expense of strength and hardness. Thus, in applications where strength and hardness are important, such as in certain applications where aluminum alloys may be used to replace steel, recrystallization can limit the use of certain aluminum alloys as steel replacement, <CIT> and <CIT> disclose methods of making rolled products from 7xxx series aluminum alloys, the methods involving an inter annealing step.

The covered embodiments of this disclosure are defined by the claims, not this summary. This summary provides 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. The subject matter should be understood by reference to appropriate portions of the entire specification, any or all drawings, and each claim.

The subject matter of the present invention is defined in the appended claims. The present disclosure provides novel aluminum alloy articles that have surface portions with a higher degree of recrystallization or recrystallization quotient than portions in the interior of the article, where a higher portion of the aluminum alloy material has a recovered and/or unrecrystallized microstructure. Even though the aluminum alloy articles of the present disclosure are made from a monolithic aluminum alloy material, they possess certain benefits of cladded aluminum alloy materials, such as strength in the core of the article and ductility in the clad of the article. The present disclosure also provides methods of making such aluminum alloy articles. The aluminum alloy article is a rolled article, such as an aluminum alloy sheet, where the material near the surface of the sheet has a recrystallized microstructure and the material in the interior of the sheet has a recovered and/or unrecrystallized microstructure. The resulting article exhibits the strength benefits of material in a recovered and/or unrecrystallized microstructure coupled with desirable bendability and corrosion properties of material in a recrystallized microstructure.

The present disclosure provides an aluminum alloy article, which is comprised of an aluminum alloy material and further comprises: (a) a first surface portion; (b) a second surface portion opposing the first surface portion; and (c) an intermediate portion between the first surface portion and the second surface portion; wherein the first surface portion and the second surface portion comprise a rolled surface; and wherein the aluminum alloy material of the first surface portion and the second surface portion have a higher degree of recrystallization or recrystallization quotient than the aluminum alloy material of the intermediate portion. In some embodiments, the aluminum alloy article is an ingot, a strip, a shate, a slab, a billet, or other aluminum alloy product. The aluminum alloy article is a rolled aluminum alloy article, which is formed by a process that includes rolling the aluminum alloy article, for example, until a desired thickness is achieved. In some embodiments, the rolled aluminum alloy article is an aluminum alloy sheet, shate, plate, extrusion, casting or forging in any suitable temper, e.g., an O temper or a temper ranging from the T1 to T9 tempers, and any suitable gauge. The aluminum alloy article is made from a 7xxx series alloy as provided herein.

The present disclosure also provides a method of making an aluminum alloy article as defined in the claims. In some embodiments thereof, the aluminum alloy articles are subjected to a final solution heat treatment, for example, the article can be solution heat treated either through a CASH (continuous annealing and solution heat treatment) or hot stamping process.

The disclosure also provides an aluminum alloy article made by the processes disclosed herein.

Described herein are articles of manufacture comprising the disclosed aluminum alloy articles. The article of manufacture comprises a rolled aluminum alloy article. Examples of such articles of manufacture include, but are not limited to, a component of an automobile, truck, trailer, train, railroad car, airplane, such as a body panel or other part for any of the foregoing, a bridge, a pipeline, a pipe, a tubing, a boat, a ship, a storage container, a storage tank, an article of furniture, a window, a door, a railing, a functional or decorative architectural piece, a pipe railing, an electrical component, a conduit, a beverage container, a food container, or a foil. In some embodiments, the articles of manufacture are automotive or transportation body parts, including motor vehicle body parts (e.g., bumpers, side beams, roof beams, cross beams, pillar reinforcements, inner panels, outer panels, side panels, hood inners, hood outers, and trunk lid panels). The articles of manufacture can also include aerospace products and electronic device housings.

Additional aspects and embodiments are set forth in the detailed description, claims, non-limiting examples, and drawings, which are included herein.

The present disclosure provides aluminum alloy articles that exhibit a novel combination of recrystallized, and recovered and/or unrecrystallized, microstructure, and methods of making such articles. These articles can exhibit increased strength over articles made from fully recrystallized material, while retaining the bendability and corrosion resistance that such materials generally possess.

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.

In this description, reference is made to alloys identified by AA numbers and other related designations, such as "series" or "7xxx. " 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.

As used herein, a plate generally has a thickness of greater than about <NUM>. For example, a plate may refer to an aluminum product having a thickness of greater than about <NUM>, greater than about <NUM>, greater than about <NUM>, greater than about <NUM>, greater than about <NUM>, greater than about <NUM>, greater than about <NUM>, greater than about <NUM>, or greater than about <NUM>.

As used herein, a shate (also referred to as a sheet plate) generally has a thickness of from about <NUM> to about <NUM>. For example, a shate may have a thickness of about <NUM>, about <NUM>, about <NUM>, about <NUM>, about <NUM>, about <NUM>, about <NUM>, about <NUM>, about <NUM>, about <NUM>, about <NUM>, or about <NUM>.

As used herein, a sheet generally refers to an aluminum product having a thickness of less than about <NUM>. For example, a sheet may have a thickness of less than about <NUM>, less than about <NUM>, less than about <NUM>, less than about <NUM>, less than about <NUM>, or less than about <NUM> (e.g., about <NUM>).

As used herein, the term slab indicates an alloy thickness in a range of <NUM> to <NUM>. For example, a slab may have a thickness of about <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or <NUM>.

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 T1 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.

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.

As used herein, the meaning of "room temperature" can include a temperature of from about <NUM> to about <NUM>, for example about <NUM>, about <NUM>, about <NUM>, about <NUM>, about <NUM>, about <NUM>, about <NUM>, about <NUM>, about <NUM>, about <NUM>, about <NUM>, about <NUM>, about <NUM>, about <NUM>, about <NUM>, or about <NUM>. As used herein, the meaning of "ambient conditions" can include temperatures of about room temperature, relative humidity of from about <NUM> % to about <NUM> %, and barometric pressure of from about <NUM> millibar (mbar) to about <NUM> mbar. For example, relative humidity can be about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM>%, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, about <NUM> %, or anywhere in between. For example, barometric pressure can be about <NUM> mbar, about <NUM> mbar, about <NUM> mbar, about <NUM> mbar, about <NUM> mbar, about <NUM> mbar, about <NUM> mbar, about <NUM> mbar, about <NUM> mbar, about <NUM> mbar, about <NUM> mbar, about <NUM> mbar, about <NUM> mbar, about <NUM> mbar, about <NUM> mbar, about <NUM> mbar, or anywhere in between.

All ranges disclosed herein are to be understood to encompass any and all subranges subsumed therein. For example, a stated range of "<NUM> to <NUM>" should be considered to include any and all subranges between (and inclusive of) the minimum value of <NUM> and the maximum value of <NUM>; that is, all subranges beginning with a minimum value of <NUM> or more, e.g. <NUM> to <NUM>, and ending with a maximum value of <NUM> or less, e.g., <NUM> to <NUM>. 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.

As used herein, the meaning of "a," "an," and "the" includes singular and plural references unless the context clearly dictates otherwise.

In the following examples, the aluminum alloy products and their components are described in terms of their elemental composition in weight percent (wt. In each alloy, the remainder is aluminum, with a maximum wt. % of <NUM> % for the sum of all impurities.

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.

Unavoidable impurities, including materials or elements may be present in the alloy in minor amounts due to inherent properties of aluminum or leaching from contact with processing equipment. Some impurities typically found in aluminum include iron and silicon. The alloy, as described, may contain no more than about <NUM> wt. % of any element besides the alloying elements, incidental elements, and unavoidable impurities.

The present disclosure provides an aluminum alloy article, comprising an aluminum alloy material and having a first surface portion; a second surface portion opposing the first surface portion; and an intermediate portion between the first surface portion and the second surface portion; wherein the aluminum alloy material of the first surface portion and the second surface portion have a higher degree of recrystallization or recrystallization quotient than the aluminum alloy material of the intermediate portion. The first surface portion and the second surface portion each comprise a rolled surface.

The aluminum alloy material is a 7xxx series aluminum alloy. In some embodiments, the aluminum alloy material is a 7xxx series aluminum alloy that comprises, among other standard elements, an amount of zirconium (Zr), for example, from <NUM> wt. % to <NUM> wt. %, based on the total elemental composition of the alloy.

In some embodiments where the aluminum alloy material is a 7xxx series aluminum alloy, the aluminum alloy material can be selected from any suitable 7xxx series aluminum alloy, including, but not limited to, the following 7xxx series aluminum alloys: AA7011, AA7019, AA7020, AA7021, AA7039, AA7072, AA7075, AA7085, AA7108, AA7108A, AA7015, AA7017, AA7018, AA7019A, AA7024, AA7025, AA7028, AA7030, AA7031, AA7033, AA7035, AA7035A, AA7046, AA7046A, AA7003, AA7004, AA7005, AA7009, AA7010, AA7011, AA7012, AA7014, AA7016, AA7116, AA7122, AA7023, AA7026, AA7029, AA7129, AA7229, AA7032, AA7033, AA7034, AA7036, AA7136, AA7037, AA7040, AA7140, AA7041, AA7049, AA7049A, AA7149,<NUM>, AA7249, AA7349, AA7449, AA7050, AA7050A, AA7150, AA7250, AA7055, AA7155, AA7255, AA7056, AA7060, AA7064, AA7065, AA7068, AA7168, AA7175, AA7475, AA7076, AA7178, AA7278, AA7278A, AA7081, AA7181, AA7185, AA7090, AA7093, AA7095, and AA7099.

In some embodiments, the aluminum alloy material has the elemental composition set forth in Table <NUM>.

Optionally, the aluminum alloy material includes zinc (Zn) in an amount of from <NUM>% to <NUM>% (e.g., from <NUM>% to <NUM>%, from <NUM>% to <NUM>%, from <NUM>% to <NUM>%, or from <NUM>% to <NUM>%) based on the total weight of the alloy. For example, the aluminum alloy material can include <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM> %, <NUM>%, <NUM> %, <NUM> %, <NUM> %, <NUM> %, <NUM> %, <NUM>%, <NUM> %, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM> %, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>% <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM> %, <NUM>%, <NUM> %, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM> %, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, or <NUM>% Zn. All are expressed in wt.

Optionally, the aluminum alloy material includes copper (Cu) in an amount of from <NUM>% to <NUM>% (e.g., from <NUM>% to <NUM>%, from <NUM>% to <NUM>%, or from <NUM>% to <NUM>%) based on the total weight of the alloy. For example, the aluminum alloy material can include <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>% <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, or <NUM>% Cu. All are expressed in wt.

Optionally, the aluminum alloy material includes magnesium (Mg) in an amount of from <NUM>% to <NUM>% (e.g., from <NUM>% to <NUM>%, from <NUM>% to <NUM>%, or from <NUM>% to <NUM>%). For example, the aluminum alloy material can include <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, or <NUM>% Mg. All are expressed in wt.

Optionally, the aluminum alloy material includes a combined content of Zn, Cu, and Mg ranging from <NUM>% to <NUM>% (e.g., from <NUM>% to <NUM>%, from <NUM>% to <NUM>%, from <NUM>% to <NUM>%, or from <NUM>% to <NUM>%). For example, the combined content of Zn, Cu, and Mg can be <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, or <NUM>%. All are expressed in wt.

Optionally, the aluminum alloy material includes iron (Fe) in an amount of from <NUM>% to <NUM>% (e.g., from <NUM>% to <NUM>% or from <NUM>% to <NUM>%) based on the total weight of the alloy. For example, the aluminum alloy material can include <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>% <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>% <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, or <NUM>% Fe. All are expressed in wt.

Optionally, the aluminum alloy material includes silicon (Si) in an amount of from <NUM>% to <NUM>% (e.g., from <NUM>% to <NUM>% or from <NUM>% to <NUM>%) based on the total weight of the alloy. For example, the aluminum alloy material can include <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>% <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM> %, <NUM>%, <NUM> %, <NUM>%, <NUM> %, <NUM> %, <NUM>%, <NUM>%, or <NUM>% Si. All are expressed in wt.

Optionally, the aluminum alloy material includes zirconium (Zr) in an amount of from <NUM>% to <NUM>% (e.g., from <NUM>% to <NUM>%, or from <NUM>% to <NUM>% or from <NUM>% to <NUM>%) based on the total weight of the alloy. For example, the aluminum alloy material can include <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>% Zr. In other examples, the alloys can include Zr in an amount less than <NUM>% (e.g., <NUM>%, <NUM>%, <NUM>%, or <NUM>%) based on the total weight of the alloy. All are expressed in wt.

In some instances, the presence of Zr in the alloy may form Al<NUM>Zr dispersoids, which can assist in pinning the grain boundaries of the aluminum alloy material. In the region of the aluminum alloy article near a rolled surface, the higher strain introduced from the rolling process can at least partially overcome the pinning and allow for a higher degree of recrystallization or recrystallization quotient. Meanwhile, in the interior portions of the aluminum alloy article, the pinning is not overcome and recrystallization occurs to a much lower degree. In some embodiments, Al<NUM>Zr dispersoids are present in the aluminum alloy material, the dispersoids having a number-average diameter ranging from <NUM> to <NUM>.

Optionally, the aluminum alloy material includes manganese (Mn) in an amount of up to <NUM>% (e.g., from <NUM>% to <NUM>% or from <NUM>% to <NUM>%) based on the total weight of the alloy. For example, the aluminum alloy material can include <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, or <NUM>% Mn. In some cases, Mn is not present in the alloy (i.e., <NUM>%). All are expressed in wt.

Optionally, the aluminum alloy material includes chromium (Cr) in an amount of up to <NUM>%, or up to <NUM>% (e.g., from <NUM>% to <NUM>%, from <NUM>% to <NUM>%, or from <NUM>% to <NUM>%) based on the total weight of the alloy. For example, the aluminum alloy material can include <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, or <NUM>% Cr. In some cases, Cr is not present in the alloy (i.e., <NUM>%). All are expressed in wt.

Optionally, the aluminum alloy material includes titanium (Ti) in an amount of up to <NUM>% (e.g., from <NUM>% to <NUM>%, from <NUM>% to <NUM>%, or from <NUM>% to <NUM>%) based on the total weight of the alloy. For example, the alloy can include <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>% <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>% <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>% , <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, or <NUM>% Ti. In some cases, Ti is not present in the alloy (i.e., <NUM>%). All are expressed in wt.

Optionally, the aluminum alloy material includes one or more elements selected from the group consisting of Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu in an amount of up to <NUM>% (e.g., from <NUM>% to <NUM>%, from <NUM>% to <NUM>%, or from <NUM>% to <NUM>%), based on the total weight of the alloy. For example, the aluminum alloy material can include <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, or <NUM> % of one or more elements selected from the group consisting of Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. All are expressed in wt.

Optionally, the aluminum alloy material includes one or more elements selected from the group consisting of Mo, Nb, Be, B, Co, Sn, Sr, V, In, Hf, Ag, Sc, and Ni in an amount of up to <NUM>% (e.g., from <NUM>% to <NUM>%, from <NUM>% to <NUM>%, or from <NUM>% to <NUM>%), based on the total weight of the alloy. For example, the aluminum alloy material can include <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, or <NUM> % of one or more elements selected from the group consisting of Mo, Nb, Be, B, Co, Sn, Sr, V, In, Hf, Ag, Sc, and Ni. All are expressed in wt.

Optionally, the aluminum alloy material includes other minor elements, sometimes referred to as impurities, in amounts of <NUM>% or below, <NUM>% or below, <NUM>% or below, <NUM>% or below, <NUM>% or below, <NUM>% or below, <NUM>% or below, <NUM>% or below, <NUM>% or below, <NUM>% or below, <NUM>% or below, <NUM>% or below, <NUM>% or below, <NUM>% or below, or <NUM>% or below. In some embodiments, these impurities include, but are not limited to, Ga, Ca, Bi, Na, Pb, or combinations thereof. Accordingly, in some embodiments, one or more elements selected from the group consisting of Ga, Ca, Bi, Na, and Pb may be present in the aluminum alloy material in amounts of <NUM>% or below, <NUM>% or below, <NUM>% or below, <NUM>% or below, <NUM>% or below, <NUM>% or below, <NUM>% or below, <NUM>% or below, <NUM>% or below, <NUM>% or below, <NUM>% or below, <NUM>% or below, <NUM>% or below, <NUM>% or below, or <NUM>% or below. The sum of all impurities does not exceed <NUM>% (e.g., <NUM>%). All are expressed in wt. The remaining percentage of the alloy is aluminum.

The alloy compositions disclosed herein, including the aluminum alloy material of any of foregoing embodiments, have aluminum (Al) as a major component, for example, in an amount of at least <NUM>% of the alloy. Optionally, the alloy compositions have at least <NUM>% Al, or at least <NUM>% Al, or at least <NUM>% Al, or at least <NUM>% Al, or at least <NUM>% Al, or at least <NUM>% Al, or at least <NUM>% Al, or at least <NUM>% Al, or at least <NUM>% Al, or at least <NUM>% Al, or at least <NUM>% Al, or at least <NUM>% Al, or at least <NUM>% Al, or at least <NUM>% Al. All are expressed in wt.

The aluminum alloy articles disclosed herein can be any suitable aluminum alloy article. As noted above, the articles have a first surface portion and an opposing second surface portion. In some cases, the surface of the first surface portion and the surface of the second surface portion represent opposite sides of an article, such that the two surfaces may be parallel or generally parallel to each other or disposed away from each other and separated by a thickness, e.g., a first thickness, which may represent a distance between the two surfaces along a line perpendicular to the two surfaces or the shortest distance between the two surfaces.

As noted above, the first surface portion comprises a rolled surface and the second surface portion comprises a rolled surface, i.e. the surfaces of an article formed by rolling a cast aluminum product, such as a slab, an ingot, a shate, a sheet, a plate and the like. In some embodiments, these rolled surfaces are formed according to the processes set forth below. The rolled surface of the first surface portion and the rolled surface of the second surface portion are formed by a process that comprises cold rolling. The cold rolling is preceded by hot rolling.

The aluminum alloy article can have any suitable physical configuration. Optionally, the aluminum alloy article is a rolled aluminum alloy plate, shate or sheet. In some embodiments, the aluminum alloy article is a rolled aluminum alloy shate. The rolled aluminum alloy shate can have any suitable thickness, but, in some embodiments, it has a thickness ranging from <NUM> to <NUM>, or no more than <NUM>, or no more than <NUM>, or no more than <NUM>, or no more than <NUM>, or no more than <NUM>, or no more than <NUM>, or no more than <NUM>, or no more than <NUM>, or no more than <NUM>, or no more than <NUM>. In some embodiments, the aluminum alloy article is a rolled aluminum alloy sheet. The rolled aluminum alloy sheet can have any suitable thickness, but, in some embodiments, it has a thickness ranging from <NUM> to <NUM>, or no more than <NUM>, or no more than <NUM>, or no more than <NUM>, or no more than <NUM>, or no more than <NUM>, or no more than <NUM>. In some embodiments, the aluminum alloy article is a rolled aluminum alloy shate or a rolled aluminum alloy sheet having a thickness of <NUM>, or <NUM>, or <NUM>, or <NUM>, or <NUM>, or <NUM>, or <NUM>, or <NUM>, or <NUM>, or <NUM>, or <NUM>, or <NUM>, or <NUM>, or <NUM>, or <NUM>, or <NUM>, or <NUM>, or <NUM>.

The disclosure refers to certain "surface portion(s)," such as a first surface portion and a second surface portion. Such surface portions include a surface of the article, i.e. a rolled surface, and a certain amount of material (e.g., a uniform depth of material) beneath the surface and along the thickness of the article (i.e., the line running perpendicular to the respective surfaces of the first surface portion and the second surface portion). Optionally, the first surface portion extends from the surface of the first surface portion to a depth of no more than <NUM>%, or no more than <NUM>%, or no more than <NUM>%, or no more than <NUM>%, or no more than <NUM>%, or no more than <NUM>%, or no more than <NUM>%, or no more than <NUM>%, of the thickness of the aluminum alloy article. In some embodiments, the second surface portion extends from the surface of the second surface portion to a depth of no more than <NUM>%, or no more than <NUM>%, or no more than <NUM>%, or no more than <NUM>%, or no more than <NUM>%, or no more than <NUM>%, or no more than <NUM>%, or no more than <NUM>%, of the thickness of the aluminum alloy article. In some embodiments, the first surface portion and the second surface portion are of the same depth, i.e., are symmetrical in depth with respect to the midpoint of the distance between the two surfaces. In some other embodiments, however, the first surface portion and the second surface portion have different depths.

The disclosure also refers to an "intermediate portion" that lies between the first surface portion and the second surface portion. Optionally, the intermediate portion includes the remaining material between the two surfaces that is not included in the first surface portion and the second surface portion, such that the intermediate portion extends from the depth of the first surface portion to the depth of the second surface portion. Thus, in some embodiments, all material between the two surfaces is included in either the first surface portion, the second surface portion, or the intermediate portion. Optionally, the intermediate portion does not include all of the remaining material between the two surfaces that is not included in the first surface portion and the second surface portion. In some embodiments, the intermediate portion lies between the depth of the first surface portion and the depth of the second surface portion, includes the midpoint in the thickness between the depth of the first surface portion and the depth of the second surface portion, and includes no more than <NUM>%, or no more than <NUM>%, or no more than <NUM>%, or no more than <NUM>%, or no more than <NUM>%, or no more than <NUM>%, or no more than <NUM>%, or no more than <NUM>%, or no more than <NUM>%, or no more than <NUM>%, or no more than <NUM>%, or no more than <NUM>%, of the thickness between the depth of the first surface portion and the depth of the second surface portion. In some embodiments, the midpoint in the thickness between the depth of the first surface portion and the depth of the second surface portion lies at the midpoint in the thickness of the intermediate portion.

The disclosure provides aluminum alloy articles in which the aluminum alloy material of the first surface portion has a higher degree of recrystallization or recrystallization quotient than the aluminum alloy material of the intermediate portion. The second surface portion also has a higher degree of recrystallization or recrystallization quotient than the aluminum alloy material of the intermediate portion, such that, in the case of an aluminum alloy plate, shate or sheet, the areas nearer to the two surfaces of the plate, shate or sheet have a higher degree of recrystallization or recrystallization quotient than the area lying in the interior of the plate, shate or sheet.

The degree of recrystallization or recrystallization quotient can be determined by any suitable method known in the art. For example, in a micrograph, such as a scanning electron micrograph (SEM) or an optical micrograph (OM), the higher degree of recrystallization recrystallization quotient can be observed in terms of a grain structure having a higher degree of uniformity. In some other examples, electron backscatter diffraction (EBSD) can also be used to assess the degree of recrystallization. The degree of recrystallization is set forth in terms of a "recrystallization quotient," which, as used herein, refers to the formula: <NUM> - LAGB/(MAGB+HAGB). The recrystallization quotient refers to or is representative of a percentage, amount, or volume of material that is recrystallized as compared to a total amount or volume of material. LAGB refers to the quantity of grain boundaries in a given volume having misorientation between adjacent grains of <NUM>° to <NUM>° (i.e., a quantity of low-angle grain boundaries). MAGB refers to the quantity of grain boundaries in a given volume having misorientation between adjacent grains of greater than <NUM>° but no more than <NUM>° (i.e., the quantity of medium-angle grain boundaries). HAGB refers to the quantity of grain boundaries in a given volume having misorientation between adjacent grains of more than <NUM>° (i.e., the quantity of high-angle grain boundaries). Quantities or values of LAGB, MAGB, and HAGB may be determined by measuring the angle of misorientation between adjacent grains, as recorded by EBSD. The recovery or recrystallization of materials may reduce the stored energy in materials when heavily deformed materials are annealed at high temperature. Recovery competes with recrystallization, as both are driven by the stored energy during annealing. Recovery can be defined as annealing processes occurring in deformed materials that occur without the migration of a high-angle grain boundary. The deformed structure is often a cellular structure with walls having dislocation angles. As recovery proceeds, these cell walls undergo a transition towards a genuine subgrain structure. This occurs through a gradual elimination of extraneous dislocations and the rearrangement of the remaining dislocations into low-angle grain boundaries. However, recrystallization is the formation of a new grain structure in a deformed material by the formation and migration of high angle grain boundaries driven by the stored energy of deformation. Therefore, the LAGB is eliminated during the recrystallization process.

The aluminum alloy material of the first surface portion has a recrystallization quotient that is higher than the recrystallization quotient of the aluminum alloy material of the intermediate portion. Optionally, the first surface portion has a recrystallization quotient that at least <NUM> higher (e.g., <NUM>-<NUM>), or at least <NUM> higher, or at least <NUM> higher, or at least <NUM> higher, or at least <NUM> higher, or at least <NUM> higher, or at least <NUM> higher, or at least <NUM> higher, or at least <NUM> higher, or at least <NUM> higher, or at least <NUM> higher, or at least <NUM> higher, or at least <NUM> higher, than the recrystallization quotient of the aluminum alloy material of the intermediate portion.

The aluminum alloy material of the second surface portion has a recrystallization quotient that is higher than the recrystallization quotient of the aluminum alloy material of the intermediate portion. Optionally, the second surface portion has a recrystallization quotient that at least <NUM> higher (e.g., <NUM>-<NUM>), or at least <NUM> higher, or at least <NUM> higher, or at least <NUM> higher, or at least <NUM> higher, or at least <NUM> higher, or at least <NUM> higher, or at least <NUM> higher, or at least <NUM> higher, or at least <NUM> higher, or at least <NUM> higher, or at least <NUM> higher, or at least <NUM> higher, than the recrystallization quotient of the aluminum alloy material of the intermediate portion.

Optionally, the aluminum alloy material of the first surface portion has a recrystallization quotient of at least <NUM>, or at least <NUM>, or at least <NUM>, or at least <NUM>, or at least <NUM>, or at least <NUM>, or at least <NUM>, or at least <NUM>, or at least <NUM>. For example, the first surface portion may have a recrystallization quotient of <NUM> to <NUM>.

Optionally, the aluminum alloy material of the second surface portion has a recrystallization quotient of at least <NUM>, or at least <NUM>, or at least <NUM>, or at least <NUM>, or at least <NUM>, or at least <NUM>, or at least <NUM>, or at least <NUM>, or at least <NUM>. For example, the second surface portion may have a recrystallization quotient of <NUM> to <NUM>.

Optionally, the aluminum alloy material of the intermediate portion has a recrystallization quotient of no more than <NUM>, or no more than <NUM>, or no more than <NUM>, or no more than <NUM>, or no more than <NUM>, or no more than <NUM>, or no more than <NUM>, or no more than <NUM>, or no more than <NUM>. For example, the intermediate portion may have a recrystallization quotient of <NUM> to <NUM> or <NUM> to <NUM>.

Optionally, the aluminum alloy article, when subjected to bendability testing according to Specification VDA <NUM>-<NUM>, has a β angle of no more than <NUM>°, or no more than <NUM>°, no more than <NUM>°, no more than <NUM>°, no more than <NUM>°, no more than <NUM>°, no more than <NUM>°, or no more than <NUM>°, such as between <NUM>° and <NUM>°.

Optionally, the aluminum alloy article, when subjected to exfoliation corrosion testing according to ASTM Test No. G34-<NUM>, has an exfoliation corrosion rating of EA.

In certain aspects, the disclosed aluminum alloy articles are products of a disclosed method. Without intending to limit the scope of the inventions set forth herein, the properties of the aluminum alloy articles set forth herein are partially determined by the formation of certain microstructures during the preparation thereof.

<FIG> provides an overview of a method of making an aluminum alloy article. The method of <FIG> begins at step <NUM> where an aluminum alloy <NUM> is cast to form an aluminum alloy cast product <NUM>, such as an ingot or other cast product. At step <NUM> the aluminum alloy cast product <NUM> is homogenized to form a homogenized aluminum alloy cast product <NUM>. At step <NUM>, the homogenized aluminum alloy cast product <NUM> is subjected to one or more hot rolling passes and one or more cold rolling passes to form a first rolled aluminum alloy product <NUM>. At step <NUM>, the first rolled aluminum alloy product <NUM> is annealed to form a first annealed aluminum alloy product <NUM>. At step <NUM>, the first annealed aluminum alloy product <NUM> is subjected to a second rolling process to form a second rolled aluminum product <NUM>, which may correspond to an aluminum alloy article. Optionally, the second rolled aluminum product <NUM> is subjected to one or more additional forming or stamping processes to form an aluminum alloy article.

The methods disclosed herein comprise a step of casting a molten aluminum alloy to form an aluminum alloy cast product. In some embodiments, the molten alloy may be treated before casting. The treatment can include one or more of degassing, inline fluxing, and filtering. Aluminum alloy cast products can be formed using any casting process performed according to standards commonly used in the aluminum industry as known to one of ordinary skill in the art.

As a few non-limiting examples, the casting process can include a Direct Chill (DC) casting process or a Continuous Casting (CC) process. The continuous casting system can include a pair of moving opposed casting surfaces (e.g., moving opposed belts, rolls or blocks), a casting cavity between the pair of moving opposed casting surfaces, and a molten metal injector. The molten metal injector can have an end opening from which molten metal can exit the molten metal injector and be injected into the casting cavity. In some embodiments, the CC process may include, but is not limited to, the use of twin-belt casters, twin-roll casters, or block casters. In some embodiments, the casting process is performed by a CC process to form a cast product in the form of a billet, a slab, a shate, a strip, and the like.

A clad layer in a cast product may be attached to a core layer in a cast product to form a cladded product by any means known to persons of ordinary skill in the art. For example, a clad layer can be attached to a core layer by direct chill co-casting (i.e., fusion casting) as described in, for example, <CIT> and <CIT>; by hot and cold rolling a composite cast ingot as described in <CIT>; or by roll bonding to achieve the required metallurgical bonding between the core and the cladding. The initial dimensions and final dimensions of the clad aluminum alloy products described herein can be determined by the desired properties of the overall final product.

The roll bonding process can be carried out in different manners, as known to those of ordinary skill in the art. For example, the roll-bonding process can include both hot rolling and cold rolling. Further, the roll bonding process can be a one-step process or a multi-step process in which the material is gauged down during successive rolling steps. Separate rolling steps can optionally be separated by other processing steps, including, for example, annealing steps, cleaning steps, heating steps, cooling steps, and the like.

A cast product, such as an ingot, billet, slab, shate, strip, etc., can be processed by any means known to those of ordinary skill in the art. Optionally, the processing steps can be used to prepare sheets. Such processing steps include, but are not limited to, homogenization, hot rolling, cold rolling, solution heat treatment, and an optional pre-aging step, as known to those of ordinary skill in the art. The processing steps can be suitably applied to any cast product, including, but not limited to, ingots, billets, slabs, strips, plates, shates, etc., using modifications and techniques as known to those of skill in the art. Specific processing steps may be used to prepare aluminum alloy articles with particular recrystallization quotient distributions, as described below.

In some cases, the casting process may impact the recrystallization and reforming that may occur during subsequent processing steps. For example, the distribution of dispersoid-forming elements in a cast product, such as an ingot, may impact the ability of a cast product to undergo recrystallization. By selectively segregating dispersoid-forming elements during the casting process, different regions of the cast products and processed products and articles may be more or less prone to undergo recrystallization. Dispersoid forming elements include, for example, Mn, Cr, Ti, Zr, and Sc, which may precipitate out of supersaturated solutions in the form of nano-scale precipitates, which may be, for example, from <NUM> in diameter to <NUM> in diameter. These precipitates may have sizes that do not promote recrystallization nucleation in the way that larger particles do. Instead, these particles may inhibit the motion of dislocations and grain boundaries such that recrystallization is inhibited. The volume or mass fraction of these dispersoids may determine or impact the specific recrystallization behavior in a cast product.

In large-scale castings, depletion or accumulation of alloying elements can occur. This is known as macrosegregation, which may be caused by the relative movement of solid and liquid phases which are of inherently different compositions. The center of an ingot may be particularly susceptible to macrosegregation, such as during casting. For example, this area of an ingot may exhibit depletion of eutectic forming elements, with the relative depletion proportional to casting speed. This property is further elucidated by <NPL>.

Similarly, dispersoid forming elements may also be selectively enriched in the centerline, and the enrichment may also be enhanced by increasing the casting speed. Thus, by varying the casting speed, the distributions of dispersoid-forming elements may be optimized at the center of the ingot, which can impact the rate at which recrystallization may occur. For example, by increasing the casting speed in an ingot containing dispersoid-forming elements, their concentration at the center of the ingot may be increased as compared to slower casting rates. The enhanced dispersoid content in the corresponding solidified ingot can then be used during subsequent processing steps (e.g., rolling, annealing, etc.) to impact the rate of recrystallization at the center of a processed object. In this way, casting can impact the amount and rate of recrystallization at an intermediate portion relative to surface portions during subsequent rolling and annealing steps, for example. Accordingly, methods disclosed herein may optionally utilize a high-rate casting step, such as greater than about <NUM> inches per minute (IPM), such as <NUM>-<NUM> IPM, <NUM>-<NUM> IPM, <NUM>-<NUM> IPM, or <NUM>-<NUM> IPM.

The methods disclosed herein can also optionally comprise a stress relieving step, which includes heating the aluminum alloy cast product prepared from an alloy composition described herein to attain a peak metal temperature (PMT) of at least <NUM> up to <NUM>. In some embodiments, the stress relieving is carried out at a temperature of <NUM>, or <NUM>, or <NUM>, or <NUM>, or <NUM>, or <NUM>, or <NUM>, or <NUM>, or <NUM>, or <NUM>, or <NUM>, or <NUM>, or <NUM>. In general, the heating is carried out for a period of at least <NUM> hours and up to, for example, <NUM> hours. In some embodiments, the heating is carried out for <NUM> hours, or <NUM> hours, or <NUM> hours, or <NUM> hours, or <NUM> hours, or <NUM> hours, or <NUM> hours, or <NUM> hours, or <NUM> hours, or <NUM> hours, or <NUM> hours, or <NUM> hours, or <NUM> hours, or <NUM> hours, or <NUM> hours, or <NUM> hours, or <NUM> hours. During stress relieving, the microstructure of an aluminum alloy cast or rolled product may be modified, such as by a recrystallization process or recovery process.

The homogenization step can include heating an aluminum alloy cast product prepared from an alloy composition described herein to attain a peak metal temperature (PMT) of at least <NUM> (e.g., at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, or at least <NUM>). For example, the aluminum alloy product can be heated to a temperature of from <NUM> to <NUM>, from <NUM> to <NUM>, from <NUM> to <NUM>, from <NUM> to <NUM>, from <NUM> to <NUM>, from <NUM> to <NUM>, or from <NUM> to <NUM>. Optionally, the heating rate to the PMT is <NUM>/hour or less, <NUM>/hour or less, <NUM>/hour or less, <NUM>/hour or less, <NUM>/hour or less, <NUM>/hour or less, <NUM>/hour or less, or <NUM>/hour or less. Optionally, the heating rate to the PMT is from <NUM>/min to <NUM>/min (e.g., <NUM>/min to <NUM>/min, <NUM>/min to <NUM>/min, <NUM>/min to <NUM>/min, from <NUM>/min to <NUM>/min, from <NUM>/min to <NUM>/min, from <NUM>/min to <NUM>/min, or from <NUM>/min to <NUM>/min).

In some instances, the aluminum alloy cast product is then allowed to soak (i.e., held at a particular temperature, such as a PMT) for a period of time. In some embodiments, the aluminum alloy cast product is allowed to soak for up to <NUM> hours (e.g., from <NUM> minutes to <NUM> hours, inclusively). For example, in some embodiments, the aluminum alloy product is soaked at a temperature of at least <NUM> for <NUM> minutes, for <NUM> hour, for <NUM> hours, for <NUM> hours, for <NUM> hours, for <NUM> hours, for <NUM> hours, for <NUM> hours, for <NUM> hours, for <NUM> hours, for <NUM> hours, for <NUM> hours, for <NUM> hours, for <NUM> hours, for <NUM> hours, for <NUM> hours, or for any time period in between.

In some embodiments, the homogenization described herein can be carried out in a two-stage homogenization process. In some embodiments, the homogenization process can include the above-described heating and soaking steps, which can be referred to as the first stage, and can further include a second stage. In the second stage of the homogenization process, the temperature of the aluminum alloy cast product is increased to a temperature higher than the temperature used for the first stage of the homogenization process. The aluminum alloy cast product temperature can be increased, for example, to a temperature at least <NUM> higher than the aluminum alloy cast product temperature during the first stage of the homogenization process. For example, the aluminum alloy cast product temperature can be increased to a temperature of at least <NUM> (e.g., at least <NUM>, at least <NUM>, or at least <NUM>). The heating rate to the second stage homogenization temperature can be <NUM>/hour or less, <NUM>/hour or less, or <NUM>/hour or less. The aluminum alloy cast product is then allowed to soak for a period of time during the second stage. In some embodiments, the aluminum alloy cast product is allowed to soak for up to <NUM> hours (e.g., from <NUM> minutes to <NUM> hours, inclusively). For example, the aluminum alloy cast product can be soaked at the temperature of at least <NUM> for <NUM> minutes, for <NUM> hour, for <NUM> hours, for <NUM> hours, for <NUM> hours, for <NUM> hours, for <NUM> hours, for <NUM> hours, for <NUM> hours, for <NUM> hours, or for <NUM> hours. In some embodiments, following homogenization, the aluminum alloy cast product is allowed to cool to room temperature in the air.

Following the homogenization step, one or more hot rolling passes are performed. In certain cases, the aluminum alloy products are laid down and hot rolled at a temperature ranging from <NUM> to <NUM> (e.g., from <NUM> to <NUM>, or from <NUM> to <NUM>).

In certain embodiments, the aluminum alloy product is hot rolled to a <NUM> to <NUM> thick gauge (e.g., from <NUM> to <NUM> thick gauge), which is referred to as a shate. For example, the aluminum alloy product can be hot rolled to a <NUM> thick gauge, a <NUM> thick gauge, a <NUM> thick gauge, a <NUM> thick gauge, a <NUM> thick gauge, a <NUM> thick gauge, a <NUM> thick gauge, a <NUM> thick gauge, a <NUM> thick gauge, a <NUM> thick gauge, or a <NUM> thick gauge, or anywhere in between.

In certain other embodiments, the aluminum alloy product can be hot rolled to a gauge greater than <NUM> thick (i.e., a plate). For example, the aluminum alloy product can be hot rolled to a <NUM> thick gauge, a <NUM> thick gauge, a <NUM> thick gauge, a <NUM> thick gauge, a <NUM> thick gauge, a <NUM> thick gauge, a <NUM> thick gauge, a <NUM> thick gauge, a <NUM> thick gauge, or a <NUM> thick gauge, or any suitable gauge in between or above <NUM> thick.

In other cases, the aluminum alloy product can be hot rolled to a gauge no more than <NUM> (i.e., a sheet). In some embodiments, the aluminum alloy product is hot rolled to a <NUM> to <NUM> thick gauge, which is referred to as a sheet. For example, the aluminum alloy product can be hot rolled to a <NUM> thick gauge, a <NUM> thick gauge, a <NUM> thick gauge, or a <NUM> thick gauge, or anywhere in between.

Following the hot rolling, one or more cold rolling passes are performed. In certain embodiments, the rolled product from the hot rolling step (e.g., the plate, shate, or sheet) can be cold rolled to a thin gauge shate or sheet. In some embodiments, this thin-gauge shate or sheet is cold rolled to have a thickness (i.e., a first thickness) ranging from <NUM> to <NUM>, or from <NUM> to <NUM>, or from <NUM> to <NUM>, or from <NUM> to <NUM>. In some embodiments, this thin-gauge shate or sheet is cold rolled to have a thickness <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or <NUM>, or anywhere in between.

In some embodiments, the one or more cold rolling passes reduce the thickness of rolled aluminum product by at least <NUM>%, or at least <NUM>%, or at least <NUM>%, or at least <NUM>%, or at least <NUM>%, or at least <NUM>%, or at least <NUM>%, or at least <NUM>%, or at least <NUM>%. In some embodiments, the one or more cold rolling passes reduce the cast product to a thickness (i.e., a first thickness) of no more than <NUM>, or no more than <NUM>, or no more than <NUM>, or no more than <NUM>, or no more than <NUM>, or no more than <NUM>.

Following one or more cold rolling passes, annealing is performed. This can also be referred to as an intermediate annealing or inter-annealing, as it is performed in the middle of the rolling process, as one or more additional rolling passes are carried out after the annealing.

The annealing step can include heating the rolled aluminum product from room temperature to a temperature from <NUM> to <NUM> (e.g., from <NUM> to <NUM>, from <NUM> to <NUM>, from <NUM> to <NUM>, from <NUM> to <NUM>, from <NUM> to <NUM>, from <NUM> to <NUM>, from <NUM> to <NUM>, from <NUM> to <NUM>, from <NUM> to <NUM>, from <NUM> to <NUM>, from <NUM> to <NUM>, from <NUM> to <NUM>, or from <NUM> to <NUM>).

This intermediate annealing step can, for example, lead to certain beneficial texture features in the resulting article. In particular, the intermediate annealing assists in the formation of the recrystallized microstructure on surface of the article and the recovered and/or unrecrystallized structure in the middle of the article. In some examples, the texture on surface of the article will be dominated by recrystallization components, including cube, cube_ND, and cube_RD, rather than deformation type components, such as Bs, S, and Cu. Therefore, the bending performance of the article is improved without reducing the strength.

The plate, shate, or sheet can soak at the intermediate annealing temperature for a period of time. In one non-limiting example, the plate, shate, or sheet is allowed to soak for up to approximately <NUM> hours (e.g., from about <NUM> to about <NUM> minutes, inclusively). For example, the plate, shate, or sheet can be soaked at the temperature of from about <NUM> to about <NUM> for <NUM> minutes, <NUM> minutes, <NUM> minutes, <NUM> minutes, <NUM> minutes, <NUM> minutes, <NUM> minutes, <NUM> minutes, <NUM> minutes, <NUM> minutes, <NUM> minutes, <NUM> minutes, <NUM> minutes, <NUM> minutes, <NUM> minutes, <NUM> minutes, <NUM> minutes, <NUM> minutes, <NUM> minutes, <NUM> minutes, <NUM> minutes, or <NUM> minutes, or anywhere in between.

In some embodiments, the intermediate annealing of the rolled aluminum alloy product is carried out at a temperature of no more than <NUM>, or no more than <NUM>, or no more than <NUM>, or no more than <NUM>, or no more than <NUM>, or no more than <NUM>, or no more than <NUM>, or no more than <NUM>, above the minimum recrystallization temperature of the aluminum alloy. In some embodiments, the intermediate annealing of the rolled aluminum alloy product is carried out at a temperature above the minimum recrystallization temperature of the aluminum alloy for no more than <NUM> hours, or no more than <NUM> hours, or no more than <NUM> hours, or no more than <NUM> hours, or no more than <NUM> hours.

The intermediate annealing comprises multiple annealing sub-steps. The annealing is carried out at a first temperature above the minimum recrystallization temperature for a first period of time and at a second temperature above the minimum recrystallization temperature for a second period of time The first temperature above the minimum recrystallization temperature is greater than the second temperature above the minimum recrystallization temperature. Annealing may, for example, subject the surface portions to higher temperature annealing conditions at earlier times than the intermediate portion. By using a two (or more) step intermediate annealing process in which the temperature at the second step is lower than that at the first step, the surface portions of the rolled aluminum alloy product may be subjected to recrystallization conditions for longer periods of time than the intermediate portion. This may also occur in a single step intermediate annealing process in which a single annealing temperature is used, but the effect may be more pronounced in a multiple step annealing process.

Following the intermediate annealing, further rolling is performed, such as cold rolling. In some embodiments, one or more additional cold rolling passes are performed. This additional rolling brings the aluminum alloy product to a final thickness (i.e., a second thickness). In some embodiments, the final thickness ranges from <NUM> to <NUM>. In some embodiments, the final thickness is <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or <NUM>. In some further such embodiments, the final thickness is no more than <NUM>, or no more than <NUM>, or no more than <NUM>, or no more than <NUM>, or no more than <NUM>, or no more than <NUM>, or no more than <NUM>, or no more than <NUM>, or no more than <NUM>, or no more than <NUM>.

Optionally, following the intermediate annealing and/or the additional rolling, additional finishing steps can be carried out, including, but not limited to, one or more of solutionizing, quenching, ageing, and coiling.

In some embodiments, a solution heat treatment step can be carried out. The solution heat treatment step can include heating the aluminum alloy product from room temperature to a temperature of from <NUM> to <NUM>. For example, the solution heat treatment step can include heating the aluminum alloy product from room temperature to a temperature of from <NUM> to <NUM>, from <NUM> to <NUM>, or from <NUM> to <NUM>. In some examples, the heating rate for the solution heat treatment step can be from <NUM>/hour to <NUM>/hour (e.g., <NUM>/hour, <NUM>/hour, <NUM>/hour, <NUM>/hour, <NUM>/hour, <NUM>/hour, <NUM>/hour, <NUM>/hour, <NUM>/hour, <NUM>/hour, <NUM>/hour, <NUM>/hour, <NUM>/hour, <NUM>/hour, <NUM>/hour, <NUM>/hour, <NUM>/hour, <NUM>/hour, <NUM>/hour, <NUM>/hour, or <NUM>/hour).

In some embodiments, the aluminum alloy product can then be cooled to a temperature of about <NUM> at a quench speed that can vary between about <NUM>/s to <NUM>/s in a quenching step that is based on the selected gauge. For example, the quench rate can be from about <NUM>/s to about <NUM>/s, from about <NUM>/s to about <NUM>/s, from about <NUM>/s to about <NUM>/s, from about <NUM>/s to about <NUM>/s, from about <NUM>/s to about <NUM>/s, from about <NUM>/s to about <NUM>/s, from about <NUM>/s to about <NUM>/s, from about <NUM>/s to about <NUM>/s, or from about <NUM>/s to about <NUM>/s.

In the quenching step, the aluminum alloy product is rapidly quenched with a liquid (e.g., water) and/or gas or another selected quench medium. In certain aspects, the aluminum alloy product can be rapidly quenched with water. In certain embodiments, the aluminum alloy product is quenched with air.

In some embodiments, the aluminum alloy product can be artificially aged for a period of time to result in the T6 or T7 temper. In certain embodiments, the aluminum alloy product can be artificially aged (AA) at about <NUM> to <NUM> (e.g., <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or <NUM>) for a period of time. Optionally, the aluminum alloy product can be cold worked and artificially aged for a period from about <NUM> minutes to about <NUM> hours (e.g., <NUM> minutes, <NUM> minutes, <NUM> hour, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, or <NUM> hours, or anywhere in between).

In some embodiments, an annealing step during or after production can also be applied to produce the aluminum alloy product in a coil form for improved productivity or formability. For example, an alloy in coil form can be supplied in the O temper, using a hot or cold rolling step and an annealing step following the hot or cold rolling step. Forming may occur in O temper, which is followed by solution heat treatment, quenching and artificial aging/paint baking.

In certain aspects, to produce an aluminum alloy product in coil form and with high formability compared to F temper, an annealing step can be applied to the coil. Without intending to limit the invention, the purpose for the annealing and the annealing parameters may include (<NUM>) releasing the work-hardening in the material to gain formability; (<NUM>) recrystallizing or recovering the material without causing significant grain growth; (<NUM>) engineering or converting texture to be appropriate for forming and for reducing anisotropy during formability; and (<NUM>) avoiding the coarsening of pre-existing precipitation particles.

In one or more aspects, the disclosure provides aluminum alloy articles formed by the processes set forth above, or any embodiments thereof.

Described herein is an article of manufacture, which is comprised of an aluminum alloy product disclosed herein. The article of manufacture is comprised of a rolled aluminum alloy product. Examples of such articles of manufacture include, but are not limited to, an automobile, a truck, a trailer, a train, a railroad car, an airplane, a body panel or part for any of the foregoing, a bridge, a pipeline, a pipe, a tubing, a boat, a ship, a storage container, a storage tank, a an article of furniture, a window, a door, a railing, a functional or decorative architectural piece, a pipe railing, an electrical component, a conduit, a beverage container, a food container, or a foil.

In some other embodiments, the aluminum alloy articles disclosed herein can be used in automotive and/or transportation applications, including motor vehicle, aircraft, and railway applications, or any other desired application. In some examples, the aluminum alloy products disclosed herein can be used to prepare motor vehicle body part products, 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 according to the invention can also be used in aircraft or railway vehicle applications, to prepare, for example, external and internal panels.

In some other embodiments, the aluminum alloy articles disclosed herein can be used in electronics applications. For example, the aluminum alloy products disclosed herein can also be used to prepare housings for electronic devices, including mobile phones and tablet computers. In some examples, the alloys can be used to prepare housings for the outer casing of mobile phones (e.g., smart phones) and tablet bottom chassis.

In some other embodiments, the aluminum alloy articles disclosed herein can be used in industrial applications. For example, the aluminum alloy products disclosed herein can be used to prepare products for the general distribution market.

In some other embodiments, the aluminum alloy articles disclosed herein can be used as aerospace body parts. For example, the aluminum alloy articles disclosed herein can be used to prepare structural aerospace body parts, such as a wing, a fuselage, an aileron, a rudder, an elevator, a cowling, or a support. In some other embodiments, the aluminum alloy articles disclosed herein can be used to prepare non-structural aerospace body parts, such as a seat track, a seat frame, a panel, or a hinge.

The following examples serve to further illustrate certain embodiments of the present disclosure without, at the same time, however, constituting any limitation thereof.

Six aluminum alloys (A1/Alloy A1, A2/Alloy A2, A3/Alloy A3, A4/Alloy A4, A5/Alloy A5, and A6/Alloy A6) were prepared, whose elemental composition is set forth in Table <NUM> below. The elemental compositions are provided in weight percentages.

The test aluminum alloy sheets with chemical composition corresponding to Alloys A1-A6 from Table <NUM> (Example <NUM>), were cast by Direct Chill (DC) casting. All were stress relieved and homogenized, and subsequently hot-rolled to a hot band having a gauge of <NUM>. Each was then subjected to cold rolling. For each, the hot band went through <NUM> passes of cold rolling from <NUM> to <NUM> and <NUM>, respectively.

Inter-annealing of Alloys A1, A2 and A3 was performed at <NUM> gauge, with a <NUM>/hr ramping rate to <NUM>, soaked for <NUM> minutes, then furnace cooled to <NUM> and soaked for <NUM> minutes. The coils were allowed to cool to room temperature in air. A final cold rolling was then performed on these three samples, Alloys A1, A2, and A3. The coils were cold rolled to final gauge of <NUM> with <NUM> pass.

For Alloys A4, A5, and A6, the hot band of <NUM> gauge was cold rolled to <NUM>, then to <NUM>, then to <NUM>, and then to <NUM>, without any inter-annealing steps.

Solution heat treatment of test blanks of samples of Alloys A1-A6 were carried out, where the samples were heated up using a furnace to a PMT of <NUM> and soaked for <NUM> minutes, before being taken out of the furnace and quenched in warm water at <NUM> at a quench rate of around <NUM>/sec. Artificial aging of samples of Alloys A1-A6 was carried out using a furnace at <NUM> and soaked for <NUM> hours to bring the samples to T6 temper.

Optical microscopy (OM) was carried out for aluminum alloy sheets made of the alloys of Example <NUM>, such as according to Example <NUM>. <FIG> shows an optical micrograph (OM) of a cross-section of a sample of Alloy A1 that was lab rolled with inter-annealing, and which shows recovered and/or unrecrystallized microstructure through the thickness of the sample. <FIG> shows an optical micrograph (OM) of a cross-section of a sample of Alloy A1 that was plant rolled with inter-annealing. The sample of Alloy A1 of <FIG> includes a first surface portion <NUM>, an intermediate portion <NUM>, and a second surface portion <NUM>.

"Plant Rolled" samples were cold-rolled according to standard plant cold rolling processes. "Lab Rolled" samples were cold-rolled in a laboratory setting from <NUM> to <NUM> by conducting <NUM> different passes, each of which reduced the thickness by about <NUM>.

<FIG> shows a surface portion from <FIG>, showing recrystallized microstructure, corresponding to at least a portion of first surface portion <NUM> or second surface portion <NUM>. In <FIG>, the grain structure of the sample can be seen, with individual grains not spread significantly in the surface portion, indicating that the crystal structure has been recovered and/or is unrecrystallized by the inter-annealing process. <FIG> shows nine modified reduced-size versions of <FIG>, generated by reducing FIG. 3B to <NUM> individual colors in order to highlight various colors shown in <FIG> as black.

<FIG> shows a center section from <FIG>, showing recovered and/or unrecrystallized microstructure, corresponding to at least a portion of intermediate portion <NUM>. In <FIG>, the remnants of grains that were significantly spread during the initial rolling process can be seen. The remnants do not all recrystallize during the inter-annealing process and many regions remain spread in the center portion, reflecting the recovered and/or unrecrystallized nature of the intermediate portion <NUM>. <FIG> shows nine modified reduced-size versions of <FIG>, generated by reducing FIG. 3D to <NUM> individual colors in order to highlight various colors shown in <FIG> as black.

<FIG> shows an optical micrograph of a sample of Alloy A5 that was plant rolled without inter-annealing during the cold rolling process, showing spread grains as horizontal structures in <FIG>. <FIG> shows a section from the center portion in <FIG> corresponding to at least a portion of the intermediate portion, showing recovered and/or unrecrystallized microstructure. <FIG> shows a surface portion from <FIG>, showing recrystallized microstructure.

Electron backscattering diffraction (EBSD) disorientation mapping was carried out on certain samples. Mapping of a cross-section of samples of Alloy A1 that were rolled to a final gauge and finished with a T6 temper is shown in <FIG>, <FIG>, and <FIG>. The low angle boundaries (<NUM>-<NUM>) are marked as darker-color horizontal lines, while the medium to high angle boundaries (><NUM>) are marked as lighter-color horizontal lines. <FIG> provides mapping for an Alloy A1 sample that was lab rolled, without inter-annealing during the cold rolling process, which has a uniform microstructure with recovered and/or unrecrystallized microstructure through the whole thickness, while <FIG> provides mapping for an Alloy A1 sample that was plant rolled, with inter-annealing during the cold rolling process, which shows the recrystallization microstructure near the surface and recovered and/or unrecrystallized microstructure in the center (i.e., intermediate portion). <FIG> shows mapping for an Alloy A5 sample that was plant rolled, without inter-annealing during the cold rolling process, which has a microstructure between that shown in <FIG> and <FIG>. Quantitative results from these images are presented in Table <NUM> below.

The recrystallization quotient (RQ) was calculated using the EBSD measurements described in Example <NUM>. Orientation mapping was performed on a square grid across a cross-sectionally cut area. The mapped area was divided into three equally sized areas spanning the thickness of the sheet, and the recrystallization quotient was calculated for each area. Table <NUM> reports the values of the recrystallization quotient for each of the samples described in Example <NUM>. The "Surface RQ" refers to RQ for the two surface areas (i.e., surface portions), "Center RQ" refers to the RQ for the center area (i.e., intermediate portion), and the "Overall RQ" refers to the RQ across the thickness of the entire sample. Note that "IA" refers to inter-annealing performed during the cold rolling process.

The "Plant Rolled" samples were cold-rolled according to standard plant cold rolling processes. The "Lab Rolled" sample was cold-rolled in a laboratory setting from <NUM> to <NUM> by conducting <NUM> different passes, each of which reduced the thickness by about <NUM>.

The bendability was measured for samples of aluminum alloy sheets prepared according to Example <NUM>. The bendability for the samples was measured according to Spec VDA-<NUM>-<NUM>. The samples were tested in the longitudinal and transverse directions in T6 temper. <FIG> shows the <NUM>-point bend results of Alloys A1, A2, A5 (without IA) and a sample of AA7075 sheet. The angle reported was β angle, thus the lower the better. For Alloys A1 and A2, the left bar is for the longitudinal direction and the right bar is for the transverse direction. For Alloys A5 and the AA7076 sample, only the longitudinal direction is shown. All were tested in the T6 temper.

The exfoliation corrosion (EXCO) was measured for certain aluminum alloy sheets prepared according to Example <NUM>. The EXCO was measured according to the procedure set forth in ASTM-G34, which involved the continuous immersion of test materials in a solution containing <NUM> sodium chloride, <NUM> potassium nitrate, and <NUM> nitric acid at <NUM> ± <NUM>. The susceptibility to exfoliation was determined by visual examination, with performance ratings established by reference to standard photographs (see the G34 test procedure). Visual examination was conducted, along with longitudinal cross-section metallographic examination. <FIG> show photographs of tested aluminum alloy sheets, as identified in Table <NUM> below.

The yield strength was measured for certain aluminum alloy sheets prepared according to Example <NUM>. The yield strength was tested in accordance to ASTM E8 with <NUM>" standard gauge length. <FIG> shows the results of yield strength testing on certain samples, where L, T, and D stand for longitudinal, transverse and diagonal, respectively, with respect to rolling direction. For Alloy A1, Alloy A2, Alloy A3, and Alloy A6, the three bars show the results of testing in the longitudinal, transverse, and diagonal directions, respectively, from left to right. For Alloy A5, the two bars show the results of testing in the longitudinal and transverse directions, respectively, from left to right.

Claim 1:
A method of making an aluminum alloy article, the method comprising:
casting an aluminum alloy to form an aluminum alloy cast product;
homogenizing the aluminum alloy cast product to form a homogenized aluminum alloy cast product;
subjecting the homogenized aluminum alloy cast product to a first rolling process to form a first rolled aluminum alloy product having a first thickness, wherein the first rolling process comprises one or more hot rolling passes followed by one or more cold rolling passes;
annealing the first rolled aluminum alloy product at a temperature of not more than <NUM> above a minimum recrystallization temperature of the aluminum alloy to form a first annealed aluminum alloy product; and
subjecting the first annealed aluminum alloy product to a second rolling process to form a second rolled aluminum alloy product having a second thickness,
wherein the annealing is carried out at a first temperature above the minimum recrystallization temperature for a first period of time and at a second temperature above the minimum recrystallization temperature for a second period of time, wherein the first temperature above the minimum recrystallization temperature is greater than the second temperature above the minimum recrystallization temperature, and
wherein the aluminum alloy is a 7xxx series aluminum alloy.