Patent Description:
The present disclosure relates to metallurgy generally and more specifically to methods for making aluminum alloy products having improved intergranular and stress corrosion cracking resistance.

High strength aluminum alloys are desirable for use in a variety of applications, such as the automotive and aerospace industries. Exemplary high strength aluminum alloys include 7xxx series aluminum alloys. During the processing of a 7xxx series aluminum alloy, the alloy may undergo heat treatment followed by rapid quenching to lock in solutionized alloying elements and provide for suitable intergranular and stress corrosion cracking resistance and desirable mechanical properties. If quenching does not take place on a suitable time scale, the resultant product may be susceptible to intergranular and stress corrosion cracking and/or have unsuitable mechanical properties.

The fast quench rates required for 7xxx series aluminum alloy processing leave extremely small operating windows between the hot treatment step and the quenching step. Such a small window means that a product made from a 7xxx series aluminum alloy may need to be immediately quenched after the hot processing step, leaving little to no time for other processing steps such as hot forming or transferring the hot product between locations. Fast quench rates may also be undesirable because they often employ specialized equipment and increase processing complexity.

<CIT> is directed to an Al-Zn-Mg alloy sheet comprising, in mass percent, Zn in a content of <NUM>% to <NUM>%, Mg in a content of <NUM>% to <NUM>%, Cu in a content of <NUM>% to <NUM>%, and wherein, the Zn content [Zn] and the Mg content [Mg] satisfies [Zn] ≥ - <NUM>[Mg]+<NUM>, grain-boundary precipitates observed with a transmission electron microscope at <NUM>-total magnification have an average compositional ratio of Zn to Mg of from <NUM> to <NUM> in a microstructure of the sheet subjected to a natural aging at room temperature subsequent to a solution treatment and quenching, intergranular precipitates observed with a transmission electron microscope at <NUM>-total magnification have an average compositional ratio of Zn to Mg of from <NUM> to <NUM> in a microstructure of the sheet further subjected to one of a two-stage artificial aging and a single-stage artificial aging after the natural aging at room temperature, wherein the two-stage artificial aging comprises a first-stage heat treatment at a temperature of from <NUM>° C to <NUM>° C for <NUM> hours or longer, and a second-stage heat treatment at a temperature of from <NUM>° C to <NUM>° C for <NUM> hours or longer, and the single-stage artificial aging comprises a heat treatment at a temperature of from <NUM>° C to <NUM>° C for <NUM> to <NUM> hours.

<CIT> is directed to a method for the manufacture of an aluminum alloy member in which the member made from a heat-treatable aluminum alloy material is subjected to a solution heat treatment at <NUM> to <NUM> followed by a quenching treatment in which quenching with a quenching rate of <NUM>/s or more in a temperature range from the temperature of the solution heat treatment to at least <NUM> is carried out and finally holding the material at a holding temperature of -<NUM> or higher and <NUM> or lower to suppress natural ageing and afterwards performing a forming treatment characterized therein that in tensile tests, which are carried out at <NUM> on a test specimen of the material prior the forming operation, the tensile strength is <NUM> MPa or less and the yield strength is <NUM> MPa or less.

<CIT> is directed to a 7xxx aluminum alloy comprising <NUM> - <NUM> wt. % Zn, <NUM> - <NUM> wt. % Cu, <NUM> - <NUM> wt. % Mg, <NUM> - <NUM> wt. % Fe, <NUM> - <NUM> wt. % Si, <NUM> - <NUM> wt. % Zr, up to <NUM> wt. % Mn, up to <NUM> wt. % Cr, up to <NUM> wt. % Ti, up to <NUM> wt. % of impurities, with the remainder as Al, and optionally further comprising up to <NUM> % of one or more of Mo, Nb, Be, B, Co, Sn, Sr, V, In, Hf, Ag, Sc, and Ni and/or optionally further comprising up to <NUM> % of a rare earth element selected from the group consisting of Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu.

The term embodiment and like terms are intended to refer broadly to all of the subject matter of this disclosure 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 claims below. Embodiments of the present disclosure covered herein are defined by the claims below, not this summary. This summary is a high-level overview of various aspects of the disclosure 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 of this disclosure, any or all drawings and each claim.

Described herein are rolled aluminum alloy products and methods of making aluminum alloy products having quench insensitivity and improved strength values. The methods of making aluminum alloy products include heating a rolled aluminum alloy product. The rolled aluminum alloy product includes a 7xxx series aluminum alloy product having from <NUM> wt. % to <NUM> wt. % Zn, from <NUM> wt. % to <NUM> wt. % Cu, from <NUM> wt. % to <NUM> wt. % Mg, from <NUM> wt. % to <NUM> wt. % Fe, from <NUM> wt. % to <NUM> wt. % Si, from <NUM> wt. % to <NUM> wt. % Zr, from <NUM> wt. % to <NUM> wt. % Mn, from <NUM> wt. % to <NUM> wt. % Cr, from <NUM> wt. % to <NUM> wt. % Ti, and remainder Al, with a maximum of <NUM> wt. % for the sum of all impurities, or having from <NUM> wt. % to <NUM> wt. % Zn, from <NUM> wt. % to <NUM> wt. % Cu, from <NUM> wt. % to <NUM> wt. % Mg, from <NUM> wt. % to <NUM> wt. % Fe, from <NUM> wt. % to <NUM> wt. % Si, from <NUM> wt. % to <NUM> wt. % Zr, from <NUM> wt. % to <NUM> wt. % Mn, from <NUM> wt. % to <NUM> wt. % Cr, from <NUM> wt. % to <NUM> wt. % Ti, up to <NUM> wt. % of impurities, and remainder Al. The rolled aluminum alloy product further includes up to <NUM> wt. % of one or more of Mo, Nb, Be, B, Co, Sn, Sr, V, In, Hf, Ag, Sc and Ni.

The methods described herein include heating the rolled aluminum alloy product to a first temperature of from <NUM> to <NUM>. For example, the first temperature may be from <NUM> to <NUM>. In some embodiments, the first temperature may be a solutionizing temperature. After heating the rolled aluminum alloy product to the first temperature, the rolled aluminum alloy product is maintained at the first temperature or within <NUM> of the first temperature for a time duration of from <NUM> seconds to <NUM> minutes. The method also includes quenching the rolled aluminum alloy product at a quench rate from <NUM>/s to <NUM>/s to generate a heat-treated aluminum alloy product. In some embodiments, the quench rate may be from <NUM>/s to <NUM>/s, while in other embodiments, the quench rate may be from <NUM>/s to <NUM>/s. Optionally, the quench rate may be from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, or from <NUM>/s to <NUM>/s.

In some embodiments, quenching the rolled aluminum alloy product may include a first quenching at a first quench rate to an intermediate temperature and a second quenching at a second quench rate to the second temperature. The second quench rate may be greater than the first quench rate. The rolled aluminum alloy product is quenched until the rolled aluminum alloy product reaches a second temperature of from <NUM> to <NUM>. Optionally, the second temperature may be an ambient temperature. In some embodiments, quenching the rolled aluminum alloy product may include a die quenching process, a water quenching process, and/or a forced air quenching process. As an example, the first quench rate may correspond to or occur when the aluminum alloy product is removed from the heating system but before the product is introduced to the quenching system (e.g., a die quench). The initial drop in temperature due to exposure to ambient conditions may be or correspond to the first quench rate. Optionally, the second quenching may then correspond to the quenching that occurs during an active quenching process, such as a die quenching process.

Heating and quenching the rolled aluminum alloy product may correspond to a solutionizing heat treatment process, in some embodiments. Optionally, the method may further include subjecting the rolled aluminum alloy product to a hot forming process after heating the rolled aluminum alloy product. In some cases, the method may also include aging the heat-treated aluminum alloy product, such as in a T6 temper or T7 temper. For example, the heat-treated aluminum alloy product may optionally be further heated to a temperature from <NUM> to <NUM> and maintained at the temperature for <NUM> hours to <NUM> hours. Other aging and tempering processes, practices, and conditions may be utilized, such as those described in U. Patent Application publication <CIT>.

The heat-treated aluminum alloy product may exhibit desirable and/or improved mechanical properties. For example, the heat-treated aluminum alloy product generated by quenching the rolled aluminum alloy product may exhibit a strain ratio of from <NUM> to <NUM>. For example, the heat-treated aluminum alloy product may exhibit a strain ratio of from <NUM> to <NUM> when the quench rate is about or less than <NUM>/s. The strain ratio may be determined according to an ASTM G129 standard test method, such as ASTM G129-<NUM>(<NUM>), Standard Practice for Slow Strain Rate Testing to Evaluate the Susceptibility of Metallic Materials to Environmentally Assisted Cracking, ASTM International, West Conshohocken, PA, <NUM> or according to an ASTM G139 standard test method, such as ASTM G139-<NUM>(<NUM>), Standard Test Method for Determining Stress-Corrosion Cracking Resistance of Heat-Treatable Aluminum Alloy Products Using Breaking Load Method, ASTM International, West Conshohocken, PA, <NUM>. In some embodiments, the heat-treated aluminum alloy product may exhibit an ultimate tensile strength of from <NUM> MPa to <NUM> MPa. For example, the heat-treated aluminum alloy product may exhibit an ultimate tensile strength of from <NUM> MPa to <NUM> MPa when the quench rate is about or less than <NUM>/s. In some embodiments, the heat-treated aluminum alloy product may exhibit a yield strength of from <NUM> MPa to <NUM> MPa. For example, the heat-treated aluminum alloy product may exhibit a yield strength of from <NUM> MPa to <NUM> MPa when the quench rate is about or less than <NUM>/s. In some embodiments, the heat-treated aluminum alloy product may exhibit a uniform elongation of from <NUM>% to <NUM>%. For example, the heat-treated aluminum alloy product may exhibit a uniform elongation of from <NUM>% to <NUM>% when the quench rate is about or less than <NUM>/s. In some embodiments, the heat-treated aluminum alloy product may exhibit a total elongation of from <NUM>% to <NUM>%. For example, the heat-treated aluminum alloy product may exhibit a total elongation of from <NUM>% to <NUM>% when the quench rate is about or less than <NUM>/s. In some embodiments, the heat-treated aluminum alloy product may exhibit precipitate-free zone widths from <NUM> to <NUM>. For example, the heat-treated aluminum alloy product may exhibit precipitate-free zone widths from <NUM> to <NUM> when the quench rate is about or less than <NUM>/s.

The heat-treated aluminum alloy product may also exhibit superior corrosion resistance. The heat-treated aluminum alloy product generated by quenching may exhibit a corrosion depth of from <NUM> to <NUM> as determined according to an ASTM G110 standard test method. For example, the heat-treated aluminum alloy product may exhibit a corrosion depth from <NUM> to <NUM> or from <NUM> to <NUM> when the quench rate is about <NUM>/s. In some cases, the corrosion depth may include at least one of pitting corrosion or intergranular corrosion. In some embodiments, the corrosion may include intergranular corrosion when the quench rate is about <NUM>/s or less. Optionally, the corrosion may not include intergranular corrosion when the quench rate is greater than or about <NUM>/s.

Optionally, the mechanical properties and corrosion resistance of the heat-treated aluminum alloy products may exceed those stated above when subjected to faster quenching, but it will be appreciated that quenching at rates of less than or about <NUM>/s may allow for more flexibility in handling and processing the hot aluminum alloy product immediately after heat-treatment without the final heat-treated aluminum alloy product suffering from poor mechanical properties or corrosion resistance. In this way, by using the aluminum alloy products described herein, the quenching process may be less complex and more forgiving and may simplify heat-treatment, quenching, stamping, or other processes.

A heat-treated aluminum alloy product is described herein, generated according to the method defined in the claims. The heat-treated aluminum alloy product includes a 7xxx series aluminum alloy product as defined in claim <NUM>. In some embodiments, the heat-treated aluminum alloy product may be a formed aluminum alloy product, a hot formed aluminum alloy product, and/or in a T6 temper or T7 temper.

The product may be a heat-treated aluminum alloy product having improved mechanical properties. For example, the heat-treated aluminum alloy product may exhibit a strain ratio of from <NUM> to <NUM>. For example, the heat-treated aluminum alloy product may exhibit a strain ratio of from <NUM> to <NUM> when a quench rate is less than or about <NUM>/s. The strain ratio may be determined according to an ASTM G129 and/or ASTM G139 standard test method. In some embodiments, the heat-treated aluminum alloy product may exhibit an ultimate tensile strength of from <NUM> MPa to <NUM> MPa, such as from <NUM> MPa to <NUM> MPa, <NUM> MPa to <NUM> MPa, <NUM> MPa to <NUM> MPa, <NUM> MPa to <NUM> MPa, <NUM> MPa to <NUM> MPa, <NUM> MPa to <NUM> MPa, <NUM> MPa to <NUM> MPa, <NUM> MPa to <NUM> MPa, <NUM> MPa to <NUM> MPa, <NUM> MPa to <NUM> MPa, <NUM> MPa to <NUM> MPa, <NUM> MPa to <NUM> MPa, <NUM> MPa to <NUM> MPa, <NUM> MPa to <NUM> MPa, or <NUM> MPa to <NUM> MPa. For example, the heat-treated aluminum alloy product may exhibit an ultimate tensile strength of from <NUM> MPa to <NUM> MPa when a quench rate is less than or about <NUM>/s. In some embodiments, the heat-treated aluminum alloy product may exhibit a yield strength of from <NUM> MPa to <NUM> MPa, such as from <NUM> MPa to <NUM> MPa, <NUM> MPa to <NUM> MPa, <NUM> MPa to <NUM> MPa, <NUM> MPa to <NUM> MPa, <NUM> MPa to <NUM> MPa, <NUM> MPa to <NUM> MPa, <NUM> MPa to <NUM> MPa, <NUM> MPa to <NUM> MPa, <NUM> MPa to <NUM> MPa, <NUM> MPa to <NUM> MPa, <NUM> MPa to <NUM> MPa, <NUM> MPa to <NUM> MPa, <NUM> MPa to <NUM> MPa, <NUM> MPa to <NUM> MPa, <NUM> MPa to <NUM> MPa, <NUM> MPa to <NUM> MPa, <NUM> MPa to <NUM> MPa, <NUM> MPa to <NUM> MPa, <NUM> MPa to <NUM> MPa, or <NUM> MPa to <NUM> MPa. For example, the heat-treated aluminum alloy product may exhibit a yield strength of from <NUM> MPa to <NUM> MPa when a quench rate is less than or about <NUM>/s. In some embodiments, the heat-treated aluminum alloy product may exhibit a uniform elongation of from <NUM>% to <NUM>%, such as 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>%. For example, the heat-treated aluminum alloy product may exhibit a uniform elongation of from <NUM>% to <NUM>% when a quench rate is less than or about <NUM>/s. In some embodiments, the heat-treated aluminum alloy product may exhibit a total elongation of from <NUM>% to <NUM>%, such as 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>%. For example, the heat-treated aluminum alloy product may exhibit a total elongation of from <NUM>% to <NUM>% when a quench rate is less than or about <NUM>/s. In some embodiments, the heat-treated aluminum alloy product may exhibit precipitate-free zone widths from <NUM> to <NUM>, such as 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>, 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>. For example, the heat-treated aluminum alloy product may exhibit precipitate-free zone widths from <NUM> to <NUM> when a quench rate is less than or about <NUM>/s.

The product may include a heat-treated aluminum alloy product having superior corrosion resistance. For example, the heat-treated aluminum alloy product may exhibit a corrosion depth of from <NUM> to <NUM> as determined according to an ASTM G110 standard test method, such as 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>, 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>, 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>. In some embodiments, the heat-treated aluminum alloy product may exhibit a corrosion depth from <NUM> to <NUM> or from <NUM> to <NUM> when a quench rate is less than or <NUM>/s.

The heat-treated aluminum alloy product is generated by heating a rolled aluminum alloy product to a first temperature. The rolled aluminum alloy product includes a 7xxx series aluminum alloy as defined in claim <NUM>. The rolled aluminum alloy product is heated to a temperature from <NUM> to <NUM>. The rolled aluminum alloy product is maintained at the first temperature or within <NUM> of the first temperature for a time duration of from <NUM> seconds to <NUM> minutes, such as from <NUM> seconds to <NUM> seconds, from <NUM> seconds to <NUM> minute, from <NUM> minute to <NUM> minutes, from <NUM> minutes to <NUM> minutes, from <NUM> minutes to <NUM> minutes, from <NUM> minutes to <NUM> minutes, from <NUM> minutes to <NUM> minutes, or from <NUM> minutes to <NUM> minutes. The rolled aluminum alloy product is also quenched at a quench rate from <NUM>/s to <NUM>/s, such as from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, or from <NUM>/s to <NUM>/s. The product is generated by the methods described herein.

Automotive and aerospace products are also described herein. An automotive product may incorporate a product as described herein. For example, the automotive product may incorporate a heat-treated aluminum alloy product as described above. An aerospace product may incorporate a product as described herein. For example, the aerospace product may incorporate a heat-treated aluminum alloy product as described above. Optionally, an automotive product may incorporate a product generated according to any of the methods described herein. For example, the automotive product may incorporate a heat-treated aluminum alloy product generated by any of the methods described above. Similarly, an aerospace product may incorporate a product generated according to any of the methods described herein. For example, the aerospace product may incorporate a heat-treated aluminum alloy product generated by any of the methods described above.

Other objects and advantages will be apparent from the following detailed description of non-limiting examples.

Described herein are aluminum alloy products and methods of making aluminum alloy products processed in a way that achieves improved quench sensitivity. Quench sensitivity commonly refers to the impact of quenching on a metal product's properties, such as mechanical properties and corrosion resistance. Quenching refers to a rapid cooling of a metal product from a first temperature, such as a heat treatment temperature, to a lower temperature, such as room temperature. During processing, aluminum alloy products undergo a heat treatment in which the aluminum alloy product is heated to a first high temperature, such as from <NUM> to <NUM>. The aluminum alloy products may be subjected to heat treatments, such as those described in <CIT>. One objective of quenching is to preserve a metastable solid solution formed by the heat treatment. When a product is cooled at a sufficient rate from the first temperature to a second temperature, often near or at room temperature, a solid solution in which solutes remain in the alloy solution may be achieved. Solute retention may be desirable because precipitation of the solute out of solution during quenching can lead to localized overaging, loss of grain-boundary corrosion resistance, and, importantly, poor response to age hardening treatments. Retention of the solute in the solid solution may allow for solute atoms to be available to form zones of homogenous precipitation which are important for strengthening the metal product during age hardening treatments. Another goal of quenching may be to maintain a desirable number of vacant lattice sites to assist in promoting low-temperature diffusion during the aging stage of precipitation hardening.

Some metal products, such as aluminum alloy products, may be particularly sensitive to solute loss. Particularly during age hardening treatments, solute loss may affect the resulting properties of an aluminum alloy product. Solute loss refers to the solutes that are chemically bonded with other elements, rendering them unavailable for precipitation hardening. When quench rates are not sufficiently rapid, then solute atoms are prone to diffuse to the grain boundaries, as well as the vacancies that migrate to disordered regions. Such movement of solute atoms is often irretrievable and may permanently affect the properties of the metal product. For example, some metal products that are not quenched at a sufficient rate may exhibit higher rates of intergranular corrosion and stress cracking corrosion, and have reduced yield strength, tensile strength, and grain elongation. Accordingly, the most desirable mechanical properties attainable may be generally associated with high quench rates.

However, achieving high quench rates may be costly, complex, or require time-sensitive processes which minimize opportunity for additional processing between heat treatment steps and quenching steps. Moreover, high quench rates may undesirably affect a metal product's properties. High quench rates may also result in distortion and development of residual stress within the microstructure of the product, in some cases. Aluminum alloy products may be prone to distortion during quenching due to aluminum's high linear expansion coefficient, for example. The coefficient of linear expansion of aluminum is twice that of steel and thus, during large temperature swings, significant amounts of strain can develop due to thermal expansion or contraction. Accordingly, a balance between a quench rate that sufficiently retains most of the hardening elements and compounds in solution and minimizes distortion and residual stress may be desirable to make an aluminum alloy product having optimal properties.

One approach to balancing the effects of quenching involves multi-step aging processes. Often these multi-step aging processes include at least one rapid quench step. For example, the initial quench from the first temperature may be rapid to maintain the solid solution. However, multi-step aging processes may be complex, costly, and time consuming. Accordingly, as described herein, methods and metal products are provided for achieving desirable properties using only a single step aging process, despite use of smaller quench rates. Additionally, the disclosed methods and metal products may exhibit quench insensitivity, resulting in improved mechanical properties, such as improved strength values, even at low quench rates.

In particular, the disclosed methods and techniques may provide for quench-insensitive 7xxx series aluminum alloys and products subjected to only a single step aging process. The quench-insensitive 7xxx series aluminum alloys described herein may have improved intergranular corrosion and stress corrosion cracking resistance without rapid quenching. Exemplary 7xxx series aluminum alloys for use in the disclosed methods and techniques are described in <CIT>.

As used herein, the terms "invention," "the invention," "this invention" and "the present invention" are intended to refer to the invention as disclosed in 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 "<NPL>" or "<NPL>.

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>).

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, 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" or "ambient environment" 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 present description, 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.

<FIG> provide cross-sectional views of a corrosion profile for a quench-sensitive aluminum alloy product quenched at various quench rates. A quench-sensitive aluminum alloy product may be a product made according to conventional methods and techniques. Corrosion profiles may be generated by subjecting the aluminum alloy product to a heat treatment process, followed by quenching at the indicated rate, and then subjecting the quenched aluminum alloy product to a standard corrosion test for determining or evaluating corrosion resistance, such as the American Society for Testing and Materials (ASTM) G139 Standard Test Method for Determining Stress-Corrosion Cracking Resistance or ASTM G110 Standard Practice for Evaluating Intergranular Corrosion Resistance of Heat Treatable Aluminum Alloys by Immersion in Sodium Chloride + Hydrogen Peroxide Solution. The corrosion profile may be obtained by sectioning the tested product and obtaining a cross sectional micrograph image.

For example, <FIG> depict a corrosion profile for a quench-sensitive aluminum alloy product identified as aluminum alloy product <NUM>. Aluminum alloy product <NUM> may be an AA7075 aluminum alloy product. Other exemplary quench-sensitive aluminum alloy products <NUM> may include AA7022, AA7185, AA6056, AA7020, AA7049, AA7249, or AA7149. Although the discussion herein for <FIG>, <FIG>, and <FIG> describes aluminum alloy products, the figures and related discussion may also be applicable to other types of metal products, in general.

In embodiments, quench sensitivity may be determined based on quench rate and the type of corrosion exhibited by the aluminum alloy product upon corrosion testing. During corrosion testing of quenched products, various types of corrosion may be exhibited. For example, pitting corrosion may be exhibited in which cavities or holes, representing material loss, are formed within the aluminum alloy. In other examples, intergranular corrosion may be exhibited. Intergranular corrosion, also known as intercrystalline corrosion or interdendritic corrosion, may be characterized as a form of localized corrosion in which grain boundaries and material immediately adjacent to the grain boundaries are attacked. In some cases, quench sensitivity may be determined based on the form of corrosion and/or the transition from one form of corrosion to another. For example, quench sensitivity may correspond to a change in corrosion morphology, such as a switch from pitting corrosion to intergranular corrosion when a product is subjected to various quench rates. In some cases, the slower an aluminum alloy product may be quenched without exhibiting intergranular corrosion in a corrosion test, the more quench-insensitive the aluminum alloy product may be. Intergranular corrosion may be more undesirable than pitting corrosion because of the ability of intergranular corrosion to more easily propagate cracks under stress conditions.

As illustrated in <FIG>, when a quench-sensitive aluminum alloy product is quenched at a rapid quench rate of <NUM>/s pitting corrosion <NUM> may be exhibited in a corrosion test. Pitting corrosion <NUM> may be identified by localized pockets of material loss from the aluminum alloy product <NUM>. Aluminum alloy product <NUM> may be quenched using water quenching to achieve the rapid quench rate of <NUM>/s. Water is commonly used for quenching aluminum alloy products. Common methods of water quenching may include cold water immersion, hot water immersion, boiling water, or water spray. Other quench methods also frequently used include polyalkylene glycol solutions, air blasts, still air (i.e., holding the aluminum alloy product at room temperature), liquid nitrogen, fast quenching oils, or brine solutions. Depending on the aluminum alloy product, desired properties, and required quenching rates, various quench methods may be selected.

<FIG> illustrates that pitting corrosion <NUM> may also be exhibited when aluminum alloy product <NUM> is quenched at a rate of <NUM>/s and subjected to a corrosion test. The corrosion morphology changes between <FIG>. As shown in the corrosion profile of <FIG>, intergranular corrosion <NUM> may be exhibited when aluminum alloy product <NUM> is quenched at a rate of <NUM>/s or below and subjected to a corrosion test. Intergranular corrosion <NUM> may be identified by formation of localized fracturing along the grain boundaries of aluminum alloy product <NUM>. In corrosion profiles, such as those provided in <FIG>, intergranular corrosion <NUM> may be identified by slightly more delicate fracturing within the bulk of aluminum alloy product <NUM> as compared to large fracturing or pockets of material loss exhibited by pitting corrosion <NUM>. Intergranular corrosion <NUM> may also be exhibited when aluminum alloy product <NUM> is quenched at a rate of <NUM>/s and subjected to a corrosion test. The change in corrosion morphology from pitting corrosion <NUM> to intergranular corrosion <NUM> between the quench rates of <NUM>/s and <NUM>/s may indicate that aluminum alloy product <NUM> is quench sensitive or requires a high quench rate to achieve resistance to intergranular corrosion. Moreover, this quench sensitivity of aluminum alloy product <NUM> may indicate that aluminum alloy product <NUM> may have fewer desirable properties, such as reduced stress corrosion cracking resistance or reduced strength values.

<FIG> provide corrosion profiles for a heat-treated aluminum alloy product according to methods and techniques disclosed herein. The heat-treated aluminum alloy products provided herein may be quench-insensitive aluminum alloy products. In <FIG>, the heat-treated aluminum alloy product is identified as aluminum alloy product <NUM>. Aluminum alloy product <NUM> may be or comprise a 7xxx series aluminum alloy as described herein. These alloys may exhibit improved quench insensitivity and unexpectedly high strength values after quenching, such as high tensile and yield strengths, which may be maintained when subjected to corrosion testing. The properties of the aluminum alloy products disclosed herein may be achieved due to their compositions and the methods by which they are made and processed. Advantageously, the final properties of these aluminum alloy products may be achieved while undergoing a single step aging treatment. Additionally, the aluminum alloy products may be relatively quench insensitive, meaning that they can be quenched at slower quench rates without resulting in undesirable changes to properties, allowing for additional processing time between the heat treatment process and the quenching process, reduced quenching costs, and/or reduced distortion. An aluminum alloy as described herein may optionally have an elemental composition as provided in Table <NUM> (not according to the invention).

An aluminum alloy as described herein may have an elemental composition as provided in Table <NUM> (not according to the invention).

The alloys described herein include 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 alloy may 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. Optionally, the alloy may include 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>%, 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>%, 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>%, 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>%, 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>%, 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>%, 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>%, 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>%, 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>%, from <NUM>% to <NUM>%, or from <NUM>% to <NUM>% Zn. All are expressed in wt.

The alloys described include copper (Cu) in an amount of from <NUM>% to <NUM>% or from <NUM>% to <NUM>% based on the total weight of the alloy. For example, the alloy may 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>%, or <NUM>% Cu. Optionally, the alloy may include 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>%, 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>%, from <NUM>% to <NUM>%, from <NUM>% to <NUM>%, from <NUM>% to <NUM>%, from <NUM>% to <NUM>%, or from <NUM>% to <NUM>% Cu. All are expressed in wt.

The alloys described herein include magnesium (Mg) in an amount of from <NUM>% to <NUM>% or from <NUM>% to <NUM>%. In some cases, the alloy can include <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, or <NUM>% Mg. Optionally, the alloy can include 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>% Mg. All are expressed in wt.

Optionally, the combined content of Zn, Cu, and Mg may range 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 may be <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, or <NUM>%. Optionally, the combined content of Zn, Cu, and Mg may be 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>%, 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>%. All are expressed in wt.

The alloys described herein include iron (Fe) in an amount of from <NUM>% to <NUM>% or from <NUM>% to <NUM>% based on the total weight of the alloy. For example, the alloy may include <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, or <NUM>%Fe. Optionally, the alloy may include 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>%, from <NUM>% to <NUM>%, from <NUM>% to <NUM>%, or from <NUM>% to <NUM>%
Fe. All are expressed in wt.

The alloys described herein include silicon (Si) in an amount of from <NUM>% to <NUM>% or from <NUM>% to <NUM>% based on the total weight of the alloy. For example, the alloy may include <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, or <NUM>% Si. Optionally, the alloy may include 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>% Si. All are expressed in wt.

The alloys described herein include zirconium (Zr) in an amount of from <NUM>% to <NUM>% or from <NUM>% to <NUM>% based on the total weight of the alloy. For example, the alloy may include <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, or <NUM>% Zr. Optionally, the alloy may include 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>% Zr. All are expressed in wt.

The alloys described herein include manganese (Mn) in an amount from <NUM>% to <NUM>% or <NUM>% to <NUM>% based on the total weight of the alloy. For example, the alloy may include <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, or <NUM>% Mn. Optionally, the alloy may include 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>% Mn. All are expressed in wt.

The alloys described herein include chromium (Cr) in an amount from <NUM>% to <NUM>% or from <NUM>% to <NUM>% based on the total weight of the alloy. For example, the alloy may include <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, or <NUM>% Cr. Optionally, the alloy may include 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>% Cr. All are expressed in wt.

The alloys described herein include titanium (Ti) in an amount from <NUM>% to <NUM>% or from <NUM>% to <NUM>% based on the total weight of the alloy. For example, the alloy may 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>%, or <NUM>% Ti. Optionally, the alloy may include from <NUM>% to <NUM>%, or from <NUM>% to <NUM>% Ti. All are expressed in wt.

The alloys described herein may include one or more of Mo, Nb, Be, B, Co, Sn, Sr, V, In, Hf, Ag, and Ni 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 alloy may include <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, or <NUM>% of one or more of Mo, Nb, Be, B, Co, Sn, Sr, V, In, Hf, Ag, and Ni. Optionally, the alloy may include 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>%, 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>% of one or more of Mo, Nb, Be, B, Co, Sn, Sr, V, In, Hf, Ag, and Ni. All are expressed in wt.

The alloy compositions described herein may further include other minor elements, sometimes referred to as impurities, for example in amounts of <NUM>% or below, <NUM>% or below, <NUM>% or below, <NUM>% or below, or <NUM>% or below. These impurities may include, but are not limited to Ga, Ca, Bi, Na, Pb, or combinations thereof. Accordingly, Ga, Ca, Bi, Na, or Pb may be present in alloys in amounts of <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 expressed in wt. The remaining percentage or remainder of any alloy is aluminum.

Aluminum alloy product <NUM> of <FIG> may include a novel aluminum alloy, as provided herein. The composition and method of making aluminum alloy product <NUM> may provide for quench insensitivity and improved strength values as compared to aluminum alloy product <NUM> depicted in <FIG>. <FIG> may exhibit one aspect of aluminum alloy product <NUM>'s quench insensitivity. Similar to <FIG>, aluminum alloy product <NUM> may be quenched at various quenched rates, subjected to corrosion testing, and a corrosion profile provided for each of the different quench rates to illustrate quench sensitivity. Starting at <FIG>, aluminum alloy product <NUM> corresponds to quenching at a rate of <NUM>/s. A quench rate of <NUM>/s may be achieved via water quenching. When quenched at a rapid quench rate of <NUM>/s and subjected to corrosion testing, aluminum alloy product <NUM> may exhibit pitting corrosion <NUM>, identified by cavities of material loss. Similarly, at <FIG>, pitting corrosion <NUM> may also be exhibited when aluminum alloy product <NUM> is subjected to a quench rate of <NUM>/s and corrosion testing and to a quench rate of <NUM>/s and corrosion testing. In embodiments, a change in corrosion morphology from pitting corrosion <NUM> to intergranular corrosion <NUM> may occur at slower quench rates. For example, as provided at <FIG>, intergranular corrosion <NUM> may be exhibited when aluminum alloy product <NUM> is quenched at <NUM>/s and subjected to corrosion testing. In some cases, aluminum alloy product <NUM> may exhibit intergranular corrosion <NUM> upon corrosion testing when the quench rate is at <NUM>/s or less. However, in other cases, little or no intergranular corrosion <NUM> may be exhibited by aluminum alloy product <NUM> upon corrosion testing when the quench rate is greater than or about <NUM>/s, such as from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, or from <NUM>/s to <NUM>/s. Slow quench rates, such as quench rates lower than <NUM>/s, lower than <NUM>/s, lower than <NUM>/s, or lower than <NUM>/s, may be achieved by air quenching. Air quenching may include air blasting aluminum alloy product <NUM> or holding aluminum alloy product <NUM> at room temperature. Further details regarding quenching are described below.

<FIG> also provide corrosion profiles for a heat-treated aluminum alloy product according to this disclosure at various quench rates. The heat-treated aluminum alloy products may be a quench-insensitive aluminum alloy product and is identified in <FIG> as aluminum alloy product <NUM>. Aluminum alloy product <NUM> may include a novel aluminum alloy as provided herein. As such, aluminum alloy product <NUM> may exhibit improved quench insensitivity and corresponding improved strength values, particularly when compared to aluminum alloy product <NUM> depicted in <FIG>. Aluminum alloy <NUM> may be quenched according to the quenching methods described herein. Similar to the previously described figures, aluminum alloy <NUM> may be quenched at a rapid quench rate of <NUM>/s. As depicted at <FIG>, aluminum alloy product <NUM> may exhibit pitting corrosion <NUM> when quenched at this rapid quench rate and subjected to corrosion testing. Pitting corrosion <NUM> may also be exhibited at lower quench rates. As shown in <FIG>, aluminum alloy product <NUM> may exhibit pitting corrosion <NUM> upon corrosion testing when quenched at quench rates of <NUM>/s and <NUM>/s. The corrosion morphology may change to intergranular corrosion <NUM> when the quench rate is slowed below <NUM>/s, such as to <NUM>/s, as illustrated in <FIG>. Accordingly, <FIG> and <FIG> may illustrate one aspect of quench insensitivity exhibited by the novel aluminum alloys provided herein, specifically showing that the corrosion morphology exhibited upon quench testing does not change to intergranular corrosion <NUM> until quench rates are lower than <NUM>/s.

While <FIG> may illustrate the type of corrosion formed when a quenched aluminum alloy product is subjected to corrosion testing, <FIG> quantifies the extent to which each type of corrosion is exhibited within the product upon testing. <FIG> provides an illustrative graph showing a comparison of corrosion depths for regions of corrosion at different quench rates for a quench-sensitive aluminum alloy product versus heat-treated aluminum alloy products made according to this disclosure. <FIG> provides three separate graphs positioned side-by-side for ease of comparison of the different aluminum alloy products. <FIG> includes graphs <NUM>, <NUM>, and <NUM>, each providing data for a different aluminum alloy product being quenched at various rates. Each of the aluminum alloy products represented in <FIG> may have undergone the same processing before being subjected to corrosion testing in accordance with standards ASTM G110, ASTM G129, and/or ASTM G139. These standards provide for aluminum corrosion testing that provides for repeatable measurements of corrosion susceptibility for a particular material. Following ASTM G110 standard, each of the aluminum alloy products used for <FIG> may be immersed in sodium chloride and hydrogen peroxide solution. Each of the aluminum alloy products may be immersed for <NUM> hours and/or <NUM> hours. Data corresponding to each of the aluminum alloy products were collected and used to generate graphs <NUM>, <NUM>, and <NUM>.

In graph <NUM>, corrosion depth exhibited at various quench rates for a quench-sensitive aluminum alloy product are provided. Graph <NUM> may correspond to aluminum alloy product <NUM> and represents an AA7075 aluminum alloy product. As previously discussed with respect to <FIG>, aluminum alloy product <NUM> may be quench-sensitive and exhibit a change in corrosion morphology from pitting corrosion to intergranular corrosion at higher quench rates. Graph <NUM> illustrates similar results, showing that pitting corrosion <NUM> is exhibited at rapid quench rates, such as <NUM>/s and <NUM>/s. However, once the quench rate is reduced to <NUM>/s, the corrosion morphology may change to intergranular corrosion <NUM>. As highlighted by the box in graph <NUM> labeled "IGC Region", aluminum alloy product <NUM> may exhibit intergranular corrosion <NUM> when quenched at any rate at or below <NUM>/s. In some cases, intergranular corrosion may be observed in corrosion tested AA7075 aluminum alloy products processed using quench rates of from about <NUM>/s to about <NUM>/s or from about <NUM>/s to about <NUM>/s, such as from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, from <NUM>/s to <NUM>/s, or from <NUM>/s to <NUM>/s.

Graph <NUM> also indicates the corrosion depth. Corrosion depth may refer to the extent to which corrosion is exhibited into the bulk of the aluminum alloy from a surface of the aluminum alloy product. In other words, corrosion depth may refer to a depth into the bulk of the aluminum alloy product at which corrosion may be present upon corrosion testing. Graph <NUM> may include or represent data from multiple quench tests for each quench rate or from multiple locations on the corrosion tested samples. As such, the blocks may correspond to an average corrosion depth observed and standard deviation or error bars may indicate the full range of corrosion depth observed during testing.

As illustrated in graph <NUM>, as the quench rate decreases, the depth of corrosion may increase. Limiting corrosion may be desirable and thus a lower corrosion depth may be desirable as well. As illustrated in graph <NUM>, at a quench rate of <NUM>/s, corrosion <NUM> may extend to an average depth of about <NUM> into the aluminum alloy product and may correspond to pitting corrosion, for example. When the quench rate is slowed to <NUM>/s, corrosion <NUM> may extend even further into the aluminum alloy product to an average depth of about <NUM>, and again may correspond to pitting corrosion. When the corrosion morphology changes to intergranular corrosion, the corrosion depth may continue to increase. While the corrosion depth for corrosion <NUM> may decrease slightly when the aluminum alloy product is quenched at a rate of <NUM>/s, this point includes large error bars where the maximum corrosion depth is quite large. The average corrosion depth of corrosion <NUM> for quench rates of from <NUM>/s to <NUM>/s may still be greater than the corrosion depth at rapid quench rates, such as <NUM>/s. Even at a slow quench rate of <NUM>/s, corrosion may extend to a corrosion depth of about <NUM>.

Graphs <NUM> and <NUM> illustrate corrosion depths observed for additional aluminum alloy products according to the present disclosure. The aluminum alloy products for which data are shown in graphs <NUM> and <NUM> may be heat-treated aluminum alloy products. The heat-treated aluminum alloy product may be a quench-insensitive aluminum alloy product such as aluminum alloy products <NUM> and <NUM>. The heat-treated aluminum alloy product observed may be an aluminum alloy product made according to the methods and compositions described herein. For example, such aluminum alloy products may be made from an aluminum alloy having the following elemental composition as provided in Table <NUM>.

As illustrated in graph <NUM>, when the aluminum alloy product 4A is quenched and subjected to corrosion testing, corrosion <NUM> may be observed for most of the quench rates. For example, pitting corrosion may be exhibited even at slow quench rates of <NUM>/s or less. In the data obtained, when quench rates are slowed to <NUM>/s, aluminum alloy product 4A exhibits intergranular corrosion <NUM> (IGC). Moreover, the corrosion exhibited by aluminum alloy product 4A for which data are shown in graph <NUM>, regardless of the type of corrosion, generally has an overall reduced corrosion depth when compared with the quench-sensitive aluminum alloy product of graph <NUM>. Even at the slowest quench rate of <NUM>/s, a lower corrosion depth is observed. While the corrosion depth may increase somewhat as the quench rate decreases, the rate of increase in corrosion depth over the quench rates may be minimal. For example, the corrosion depth of corrosion <NUM> shown in graph <NUM> at a quench rate of <NUM>/s may be about <NUM>, while the corrosion depth at a quench rate of <NUM>/s is only slightly more, at about <NUM>. Overall, the corrosion depth shown in graph <NUM> is relatively constant when compared to the quench-sensitive aluminum alloy product of graph <NUM>. Additionally, as indicated by the standard deviation bars, corrosion depth may also be relatively constant across multiple runs of the same test. The lack of deviation between different trial runs of the same tests (i.e., multiple quenches at the same quench rate) may further show the aluminum alloy product's insensitivity to quenching by indicating that changes in operating conditions may have minimal effect on corrosion susceptibility.

Graph <NUM> may indicate similar quenching insensitivity for another aluminum alloy product 4B as described herein. Similar to the aluminum alloy product 4A for which data are shown in graph <NUM>, corrosion morphology for the aluminum alloy product represented by graph <NUM> may not change from pitting corrosion to intergranular corrosion until a quench rate of or below <NUM>/s. Unexpectedly, corrosion depths may decrease in some cases as the quench rate decreases. This result is unexpected when comparing corrosion depth trends with respect to quench rates on graphs <NUM> and <NUM> which indicate an increase in corrosion depth with decreasing quench rates. In graph <NUM>, rates from <NUM>/s to <NUM>/s may represent that pitting corrosion is the primary corrosion <NUM> extending to corrosion depths of about <NUM> or less. As illustrated by graphs <NUM> and <NUM>, when quench rates of from <NUM>/s to <NUM>/s are used, corrosion depth upon corrosion testing may be from <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, from <NUM> to <NUM>, or from <NUM> to <NUM>. For example, when the quench rate is <NUM>/s the corrosion depth may be from <NUM> to <NUM> or from <NUM> to <NUM>.

As discussed previously, quench sensitivity may impact the properties of an aluminum alloy product, specifically the strength values. Exemplary strength characteristics may include yield strength, tensile strength, grain elongation, and strain ratio. <FIG> provide illustrative graphs depicting comparison data between a quench-sensitive aluminum alloy product and heat-treated aluminum alloy products made according to methods and techniques provided herein. The quench-sensitive aluminum alloy product is represented by the data labeled "C" (black square) on the graphs in <FIG>. In some embodiments, aluminum alloy product C may include a 7xxx series aluminum alloy product made in accordance with conventional methods and techniques. For example, aluminum alloy product C may correspond to an AA7075 aluminum alloy product (similar to aluminum alloy product <NUM>). Data labeled "5A" (red circle) and "5B" (blue triangle) on the graphs in <FIG> represent heat-treated aluminum alloy products that are quench-insensitive aluminum alloy products. Aluminum alloy products 5A and 5B may be made from aluminum alloys having the following elemental compositions as provided in Table <NUM>.

Each of the aluminum alloy products 5A, 5B, and C may be prepared prior to being subjected to the same mechanical testing procedure. To prepare aluminum alloy products 5A, 5B, and C, the aluminum alloy products may be solutionized to a first temperature of <NUM>. The aluminum alloy products may be maintained or held at the first temperature for <NUM> minutes before being quenched in water baths maintained at temperatures of <NUM>, <NUM>, <NUM>, <NUM>, <NUM> to achieve quench rates of <NUM>/s, <NUM>/s, <NUM>/s, <NUM>/s, and <NUM>/s, respectively. To achieve the quench rate of <NUM>/s, the aluminum alloy products may be air quenched. After quenching, the aluminum alloy products may be subjected to a one step aging process. An exemplary aging process may include a T6 or T7 temper or precipitation hardening. For the graphs in <FIG>, the aluminum alloy products may be subjected to an aging process in which the products may be reheated to a temperature of <NUM> for <NUM> hours. After being subjected to this aging process, the aluminum alloy products may be subjected to mechanical testing, corrosion testing in accordance with ASTM G110, stress corrosion evaluation in accordance with ASTM G129, and/or stress corrosion evaluation in accordance with ASTM G139. The following <FIG>, <FIG> provide data gathered from testing of aluminum alloy products 5A, 5B, and C prepared and conducted in accordance with the above discussed processes.

<FIG> provides graph <NUM> illustrating a comparison of yield strengths exhibited by aluminum alloy products 5A, 5B, and C. Yield strength, also known as yield stress, is a material property that defines the stress at which a material begins to plastically deform. Plastic deformation is the permanent distortion of a product under stress such as elongation, compression, buckling, bending, or twisting. Yield strength may be an important component when characterizing the strength of an aluminum alloy product.

As shown on graph <NUM>, aluminum alloy products 5A and 5B made from the quench insensitive 7xxx series aluminum alloy compositions, as provided above and made according to the techniques provided herein, may exhibit superior yield strength when compared to aluminum alloy product C. For example, aluminum alloy products 5A and 5B may exhibit yield strengths from <NUM> MPa to <NUM> MPa. Specifically, aluminum alloy products 5A and 5B may exhibit yield strengths from <NUM> MPa to <NUM> MPa at quench rates from <NUM>/s to <NUM>/s. For example, aluminum alloy products 5A and 5B may exhibit a yield strength of from <NUM> MPa to <NUM> MPa when the quench rate is <NUM>/s. In some embodiments, quench insensitive aluminum alloy products may exhibit yield strengths from about <NUM> MPa to about <NUM> MPa at quench rates from <NUM>/s to <NUM>/s or yield strengths from about <NUM> MPa to about <NUM> MPa at quench rates from <NUM>/s to <NUM>/s. For example, at a quench rate of <NUM>/s, aluminum alloy products 5A and 5B may exhibit a yield strength of about <NUM> MPa and about <NUM> MPa, respectively. In comparison, aluminum alloy product C may exhibit a yield strength of about <NUM> MPa at a quench rate of <NUM>/s. At quench rates of <NUM>/s and <NUM>/s, aluminum alloy product 5A may exhibit yield strengths of about <NUM> MPa and <NUM> MPa, respectively, and aluminum alloy product 5B may exhibit yield strengths of about <NUM> MPa and <NUM> MPa, respectively. In comparison, aluminum alloy product C may exhibit yield strengths of about <NUM> and <NUM> at quench rates of <NUM>/s and <NUM>/s, respectively.

The improved yield strength of aluminum alloy products 5A and 5B may be even more evident at low quench rates, such as the quench rate of <NUM>/s. At a quench rate of <NUM>/s, aluminum alloy products 5A and 5B exhibit yield strengths of about <NUM> MPa and <NUM> MPa, which may be almost <NUM> MPa higher than the yield strength of aluminum alloy product C at a quench rate of <NUM>/s. At <NUM>/s, aluminum alloy product C exhibits a yield strength of about <NUM> MPa. Advantageously, aluminum alloy products 5A and 5B exhibit a drop in yield strength of less than <NUM>% when the quench rate is slowed from <NUM>/s to <NUM>/s. In comparison, aluminum alloy product C exhibits a drop of over <NUM>%, such as for example <NUM>%, when the quench rate is slowed from <NUM>/s to <NUM>/s.

<FIG> provides graph <NUM> illustrating a comparison of ultimate tensile strength exhibited by aluminum alloy products 5A, 5B, and C. Ultimate tensile strength (UTS) may correspond to the capacity of a material to withstand elongation loads. In contrast to a stress test in which a force exerted on a material tends to reduce the size of the material, tensile strength stress tests the ability of the material to withstand elongation. Ultimate tensile strength can be measured by the maximum stress that a material can withstand while being stretched or pulled before breaking.

Similar to yield strength, aluminum alloy products 5A and 5B may exhibit superior ultimate tensile strength over various quench rates when compared with aluminum alloy product C. As shown on graph <NUM>, aluminum alloy products 5A and 5B exhibit ultimate tensile strengths (also referred to herein as tensile strengths) from <NUM> MPa to <NUM> MPa at quench rates from <NUM>/s to <NUM>/s. For example, aluminum alloy products 5A and 5B may exhibit an ultimate tensile strength of from <NUM> MPa to <NUM> MPa when the quench rate is <NUM>/s. In some embodiments, quench insensitive aluminum alloy products may exhibit tensile strengths from <NUM> MPa to <NUM> MPa at quench rates from <NUM>/s to <NUM>/s. For example, at a quench rate of <NUM>/s, aluminum alloy products A and B exhibit tensile strengths of about <NUM> MPa and about <NUM> MPa, respectively. In comparison, aluminum alloy product C exhibits a tensile strength of about <NUM> MPa at a quench rate of <NUM>/s. At quench rates of <NUM>/s and <NUM>/s, aluminum alloy product 5A exhibits tensile strengths of about <NUM> MPa and about <NUM> MPa, respectively, and aluminum alloy product 5B exhibits tensile strengths of about <NUM> MPa and about <NUM> MPa, respectively. In comparison, aluminum alloy product C exhibits tensile strengths of about <NUM> MPa and about <NUM> MPa at quench rates of <NUM>/s and <NUM>/s, respectively.

Even at slow quench rates, such as <NUM>/s, aluminum alloy products 5A and 5B exhibit higher tensile strengths as compared to aluminum alloy product C. For example, at a quench rate of <NUM>/s, quench insensitive aluminum alloy products may exhibit tensile strengths of from about <NUM> MPa to about <NUM> MPa. As illustrated in <FIG>, the tensile strength at <NUM>/s for aluminum alloy products 5A and 5B are about <NUM> MPa and about <NUM> MPa, respectively. In comparison, aluminum alloy product C exhibits a tensile strength of about <NUM> MPa when quenched at a rate of <NUM>/s.

Turning now to <FIG>, total elongation (TE) of aluminum alloy products 5A, 5B, and C when subjected to stress may be illustrated. Total elongation, expressed as a percentage of change over a fixed gauge, may correspond to the percentage by which a material can be stretched before it breaks. In some embodiments, total elongation may be a rough indicator of formability of aluminum alloy products.

As illustrated by graph <NUM>, aluminum alloy products 5A and 5B may exhibit a total elongation from <NUM>% to <NUM>% for quench rates from <NUM>/s to <NUM>/s. For example, at rapid quench rates, such as <NUM>/s, aluminum alloy products 5A and 5B exhibit a total elongation of about <NUM>% and about <NUM>%, respectively. As the quench rate is slowed to <NUM>/s, <NUM>/s, and <NUM>/s, aluminum alloy product 5A exhibits a total elongation of about <NUM>%, about <NUM>%, and about <NUM>%, respectively. Similarly, aluminum alloy product 5B exhibits a total elongation of <NUM>%, <NUM>%, and <NUM>% when the quench rate is slowed to <NUM>/s, <NUM>/s, and <NUM>/s, respectively. When the quench rate is <NUM>/s, aluminum alloy products 5A and 5B may exhibit a total elongation of from <NUM>% to <NUM>%. In some cases, quench insensitive aluminum alloy products may exhibit a uniform elongation of from <NUM>% to <NUM>%. For example, aluminum alloy products 5A and 5B may exhibit a uniform elongation of from <NUM>% to <NUM>% when the quench rate is <NUM>/s.

As illustrated in <FIG>, aluminum alloy product C may exhibit a total elongation from <NUM>% to <NUM>% for quench rates from <NUM>/s to <NUM>/s. For example, aluminum alloy product C may exhibit a total elongation of more than <NUM>% at a quench rate of <NUM>/s. As the quench rate is slowed to <NUM>/s, <NUM>/s, and <NUM>/s, aluminum alloy product C may exhibit a total elongation of about <NUM>%, about <NUM>%, and about <NUM>%, respectively. Uniform elongation may correspond to the elongation of a material at a maximum load until necking occurs. In some cases, uniform elongation may represent a material's ductility or formability in uniaxial deformation.

<FIG> provides graph <NUM> illustrating a comparison of strain ratio exhibited by aluminum alloy products 5A, 5B, and C. Strain ratio may be a useful measure of the stress corrosion cracking susceptibility. For example, the lower the strain ratio, the greater the stress corrosion cracking susceptibility may be for an aluminum alloy product. As illustrated by graph <NUM>, the strain ratios exhibited by aluminum alloy products 5A and 5B may be consistently higher than the strain ratios exhibited by aluminum alloy product C. Even at slow quench rates, such as <NUM>/s, where intergranular corrosion may be observed, the strain ratios exhibited by aluminum alloy products 5A and 5B may be higher than the strain ratios exhibited by aluminum alloy product C.

In embodiments, quench insensitive aluminum alloy products may exhibit a strain ratio from <NUM> to <NUM> for quench rates from <NUM>/s to <NUM>/s. In other embodiments, the strain ratios may be from <NUM> to <NUM> when quench insensitive aluminum alloy products are quenched at rates from <NUM>/s to <NUM>/s. When the quench rate is <NUM>/s, aluminum alloy products 5A and <NUM> B may exhibit a strain ratio of <NUM> to <NUM>. For example, when aluminum alloy products 5A and 5B are quenched at a rapid rate of <NUM>/s, the strain ratio may be from <NUM> to <NUM>. As illustrated by graph <NUM>, for all of the quench rates tested, aluminum alloy products 5A and 5B may exhibit a strain ratio above <NUM>. In comparison, strain ratios exhibited by aluminum alloy product C may be below <NUM> across all of the quench rates tested. This may indicate that aluminum alloy product C is more susceptible to stress corrosion cracking than aluminum alloy products 5A and 5B.

<FIG> provides graph <NUM>, which illustrates a comparison of precipitate-free zones exhibited by aluminum alloy products 5A, 5B, and C. During an aging process, precipitation may be exhibited when solutes and other hardening compounds precipitate out of the aluminum alloy solution. Zones or pockets in which little or no precipitation is exhibited may be referred to as precipitate-free zones. Precipitate-free zones may be exhibited because precipitates, such as solutes, nucleate heterogeneously on vacancies. A grain boundary may be a sink for vacancies so regions adjacent to boundaries may be unable to nucleate the precipitate, even though the alloy solution may be supersaturated with solute. Precipitate-free zones may be undesirable because they may act as regions of weakness. For example, precipitate-free zones may be more susceptible to corrosive attack than other points within the aluminum alloy. Accordingly, reducing the amount and width of precipitate-free zones may be desirable to improve the strength and corrosion susceptibility of an aluminum alloy product.

As illustrated by graph <NUM>, the width of precipitate-free zones formed during an aging process may increase as quench rate decreases. Aluminum alloy product C may exhibit larger precipitate-free zones during quenching when compared with aluminum alloy products 5A and 5B. For example, at rapid quenching rates, such as <NUM>/s, aluminum alloy product C may exhibit precipitate-free zones having an average width of about <NUM>. In comparison, at a quench rate of <NUM>/s, aluminum alloy products 5A and 5B may exhibit precipitate-free zones having an average width of about <NUM> and <NUM>, respectively. Even at slow quench rates, aluminum alloy product C may exhibit larger precipitate-free zones than aluminum alloy products 5A and 5B. For example, at <NUM>/s, aluminum alloy product C may exhibit precipitate-free zones having an average width of about <NUM>, whereas aluminum alloy products 5A and 5B may exhibit precipitate-free zones having an average width of about <NUM> and <NUM>, respectively.

<FIG> depict images corresponding to the aluminum alloy products 5A and C illustrated in graph <NUM> of <FIG>. For example, the images provided in <FIG> may be taken using scanning transmission electron microscopy (STEM) methods depicting precipitate-free zones <NUM> which may correspond to one or more data points on graph <NUM>. That is, the widths or measurements of precipitate-free zones <NUM> provided in <FIG> may be used in graph <NUM>.

<FIG> correspond to aluminum alloy product C. <FIG> depicts precipitate-free zones <NUM> exhibited after aluminum alloy product C is quenched at a rate of <NUM>/s. <FIG> depict precipitate-free zones <NUM> exhibited after aluminum alloy product C is quenched at rates of <NUM>/s and <NUM>/s. As shown, precipitate-free zones <NUM> may increase in size (e.g., width) as the quench rate is slowed. <FIG> may provide similar images taken using STEM methods depicting precipitate-free zones <NUM> exhibited by aluminum alloy product 5A. <FIG> depicts precipitate-free zones <NUM> exhibited after aluminum alloy product 5A is quenched at <NUM>/s. Similarly, <FIG> depict precipitate-free zones <NUM> exhibited after aluminum alloy product 5A is quenched at <NUM>/s and <NUM>/s, respectively. While the precipitate-free zones <NUM> of aluminum alloy product 5A may become larger as the quench rate is slowed, the width of the precipitate-free zones may be less than that of precipitate-free zones <NUM> exhibited by aluminum alloy product C quenched at the same rate. This is also depicted by the data provided in graph <NUM> of <FIG>. For example, as illustrated in graph <NUM>, when aluminum alloy product 5A is quenched from <NUM>/s to <NUM>/s, then the precipitate free zone widths may range from <NUM> to <NUM>. Specifically, when aluminum alloy product 5A is quenched at <NUM>/s, then aluminum alloy product 5A may exhibit precipitate free zone widths from <NUM> to <NUM>.

It should be noted that while the above discussed improved corrosion resistance and mechanical properties are provided with reference to discrete quench rates, this is not meant to be limiting. Similar properties may be exhibited for a range of quench rates. The improved corrosion resistance and mechanical properties described with reference to <FIG> may be exhibited for the aluminum alloy products provided here in when the quench rate is from <NUM>/s to <NUM>/s. For example, the quench rate may range from <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, <NUM>/s to <NUM>/s, or <NUM>/s to <NUM>/s.

<FIG> provides an overview of a method <NUM> of making a quench-insensitive aluminum alloy product. At block <NUM>, an aluminum alloy product is subjected to one or more rolling or forming processes. The one or more rolling or forming processes may include a hot rolling process at block <NUM>, a cold rolling process at block <NUM>, or both. Optionally, the heat-treated aluminum alloy product may be cold rolled to a final gauge thickness. The final gauge thickness may be from <NUM> to <NUM> (e.g., <NUM>). For example, the heat-treated aluminum alloy product may be cold rolled to a final gauge thickness of <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <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>. The cold rolling may be performed to result in the heat-treated aluminum alloy product having a final gauge thickness that represents an overall gauge reduction by <NUM>%, <NUM>%, <NUM>%, or <NUM>%.

At block <NUM>, the rolled aluminum alloy product is heated. The rolled aluminum alloy product may be a quench-insensitive aluminum alloy product. In embodiments, the rolled aluminum alloy product may include an aluminum alloy having an elemental composition according to those provided in Tables <NUM> and <NUM>. The rolled aluminum alloy product includes a 7xxx series aluminum alloy as defined in the claims. In embodiments, the rolled aluminum alloy product may be a slab, strip, plate, shate, or sheet. Optionally, ingots and/or billets may be used with method <NUM>.

The rolled aluminum alloy product is heated to a first temperature at block <NUM>. The rolled aluminum alloy product may be heated during a heat treatment process. In some embodiments, the heat treatment process may be a solutionizing heat treatment process. During heating, the rolled aluminum alloy product is heated to a first temperature of at least <NUM> to <NUM> (e.g., at least <NUM>, at least <NUM>, at least <NUM>, or at least <NUM>). In some cases, the first temperature may range from <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, or <NUM> to <NUM>. The first temperature may be a solutionizing temperature in some embodiments.

During heating the rolled aluminum alloy product, the heating rate to the first temperature may be <NUM>/hour or less, <NUM>/hour or less, or <NUM>/hour or less.

In embodiments, the heat treatment process may be or include a hot rolling process. The hot rolling process may include a hot reversing mill operation and/or a hot tandem mill operation. The hot rolling process may be performed at a temperature ranging from about <NUM> to about <NUM> (e.g., from about <NUM> to about <NUM> or from about <NUM> to about <NUM>). In the hot rolling process, the rolled aluminum alloy product may be hot rolled to a <NUM> thick gauge or less (e.g., from <NUM> to <NUM> thick gauge). For example, the rolled aluminum alloy product may be hot rolled to a <NUM> thick gauge or less, <NUM> thick gauge or less, <NUM> thick gauge or less, <NUM> thick gauge or less, <NUM> thick gauge or less, <NUM> thick gauge or less, <NUM> thick gauge or less, <NUM> thick gauge or less, or <NUM> thick gauge or less. In some embodiments, the hot rolling process may occur at a different point during method <NUM>. For example, the hot rolling process may occur after a forming or after a quenching step.

The rolled aluminum alloy product may be maintained at the first temperature, or within <NUM> of the first temperature, for a time duration of from <NUM> seconds to <NUM> minutes at block <NUM>. In some cases, the time duration is from <NUM> seconds to <NUM> minutes, <NUM> seconds to <NUM> minutes15 seconds to <NUM> seconds, <NUM> seconds to <NUM> hours, <NUM> seconds to <NUM> hours, <NUM> seconds to <NUM> hour, <NUM> seconds to <NUM> minutes, <NUM> seconds to <NUM> minutes, <NUM> seconds to <NUM> minute, <NUM> minute to <NUM> minutes, <NUM> minutes to <NUM> minutes. Optionally, the rolled aluminum alloy product may be maintained within <NUM> of the first temperature, or within <NUM> of the first temperature for the specified time duration.

At the end of the heat treatment process, the rolled aluminum alloy product may optionally be subjected to one or more forming processes at block <NUM>. For example, at block <NUM>, the rolled aluminum alloy product may be subjected to a hot forming process. In some embodiments, the rolled aluminum alloy product may be hot formed after heating but before the rolled aluminum alloy product is quenched. The rolled aluminum alloy product as provided herein may have good ductility or formability at elevated temperatures. This may allow for the rolled aluminum alloy product to be malleable and achieve better formability. Hot forming the rolled aluminum alloy product when the product is at or near the first temperature may allow for the rolled aluminum alloy product to be formed into a variety of complex shapes. For example, after heating the rolled aluminum alloy product, the product may be transferred to a press or die where it is formed into a desired shape.

The rolled (and optionally formed) aluminum alloy product is quenched at block <NUM>. At block <NUM>, the rolled aluminum alloy product may be quenched to a second temperature of from about <NUM> to about <NUM> in a quenching process to generate a heat-treated aluminum alloy product. The second temperature may be ambient or room temperature in some embodiments. The quenching process may be performed using a slow quenching practice. The quenching rate in the slow quenching practice ranges from <NUM> per second to <NUM> per second. In some cases, the quenching rate may range from about <NUM> per second to about <NUM> per second.

In some embodiments, quenching the rolled aluminum alloy product at block <NUM> may include two or more quenching processes. The rolled aluminum alloy product may be subjected to a first quenching to an intermediate temperature and then subjected to a second quenching until the rolled aluminum alloy product reaches the second temperature. For example, the rolled aluminum alloy product may be quenched from the first temperature to an intermediate temperature via a hot forming process. The intermediate temperature may be above the second temperature. Thus, a second quenching may be required to quench the rolled aluminum alloy product to the second temperature. The second quenching rate may be greater than the first quenching rate.

The heat-treated aluminum alloy product generated by the quenching process may exhibit superior mechanical properties over conventional aluminum alloy products. Specifically, the heat-treated aluminum alloy product as described herein exhibits a strain ratio of from <NUM> to <NUM>. The strain ratio is determined according to an ASTM G129 standard test method. Other exemplary mechanical properties exhibited by the heat-treated aluminum alloy product may include an ultimate tensile strength of from <NUM> MPa to <NUM> MPa, a yield strength of from <NUM> MPa to <NUM> MPa, a uniform elongation of from <NUM>% to <NUM>%, and a total elongation of from <NUM>% to <NUM>%. The heat-treated aluminum alloy generated at block <NUM> may be aluminum alloy products <NUM>, <NUM>, or aluminum alloy products 4A and 4B discussed with reference to <FIG>, or aluminum alloy products 5A and 5B discussed with reference to <FIG>. In some cases, the heat-treated aluminum alloy product may be a hot formed aluminum alloy product when the rolled aluminum alloy product is subjected to a hot forming process. In other cases, the heat-treated aluminum alloy product may be a formed aluminum alloy product when the rolled aluminum alloy product is subjected to one or more forming processes.

At block <NUM>, quenching the rolled aluminum alloy product may include subjecting the rolled aluminum alloy product to a water quenching process. Water quenching processes may include cold water immersion, hot water immersion, boiling water, or water spray. In various embodiments, quenching the rolled aluminum alloy product at block <NUM> may include other methods of quenching. For example, block <NUM> may include a forced air quenching process. Forced air quenching processes may include air blasts or still air procedures. Other quench methods that may be used at block <NUM> may include polyalkylene glycol solutions, liquid nitrogen, fast quenching oils, or brine solutions.

Optionally, blocks <NUM> and <NUM> may be combined. For example, in some cases, the rolled aluminum alloy product may be quenched via a die quenching process. During a hot forming process, the rolled aluminum alloy product may be formed into parts using cold dies. Because the cold dies are cooler than the heated rolled aluminum alloy product, the cold dies may provide rapid quenching to the rolled aluminum alloy product. In some cases, the hot forming process may be considered to be part of the quenching process. In other cases, the rolled aluminum alloy product may be subjected to the hot forming process before or after the quenching process. In further cases, the hot forming process may occur between a first quenching process and a second quenching process.

After the rolled aluminum alloy product is quenched at block <NUM>, the heat-treated aluminum alloy product may be subjected to an aging process at block <NUM>. For example, the heat-treated aluminum alloy product may be subjected to a hardening process such as in a T6 or T7 temper. In some embodiments, the aging process at block <NUM> may include re-heating the heat-treated aluminum alloy product to a temperature from about <NUM> to about <NUM>, maintaining the heat-treated aluminum alloy product at a temperature from about <NUM> to about <NUM> for a period of time, and cooling the sheet to a temperature near or at room temperature. In other cases, the aging process may include re-heating the heat-treated aluminum alloy product to a temperature from about <NUM> to about <NUM>; maintaining the heat-treated aluminum alloy product at a temperature from about <NUM> to about <NUM> for a period of time; heating the heat-treated aluminum alloy product to a temperature greater than about <NUM>; maintaining the heat-treated aluminum alloy product at a temperature greater than about <NUM> (e.g., from about <NUM> to about <NUM>) for a period of time; and cooling the heat-treated aluminum alloy product to room temperature. The heat-treated aluminum alloy product may be maintained at the temperature for a time period greater than <NUM> minutes, <NUM> minutes, <NUM> minutes, <NUM> minutes, <NUM> minutes, <NUM> minutes, <NUM> minutes, <NUM> minutes, <NUM> minutes, <NUM> minutes, <NUM> minutes, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, <NUM> hours, or <NUM> hours. For example, the heat-treated aluminum alloy product may be subjected to an aging process in which the product is re-heated to a temperature <NUM> to <NUM> and maintained at that temperature for <NUM> hours to <NUM> hours.

In some cases, the heat-treated aluminum alloy product may be subjected to paint bake heat treatment, for example, heating the heat-treated aluminum alloy product to a temperature greater than about <NUM> (e.g., <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or higher) and maintaining the heat-treated aluminum alloy product at the temperature greater than about <NUM> (e.g., between about <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or higher) for a period of time (e.g., <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).

Turning now to <FIG>, graph <NUM> illustrates a temperature profile of an aluminum alloy product as a function of time according to embodiments of the present disclosure. Graph <NUM> may depict or correspond to an embodiment of a method of making a quench-insensitive aluminum alloy product. For example, graph <NUM> may correspond to a method of making aluminum alloy product <NUM>, <NUM>, 4A, 4B, 5A, 5B, or any aluminum alloy product having a composition in accordance with Tables <NUM>-<NUM>. Starting at step <NUM>, the rolled aluminum alloy product may be heated from room temperature to a first temperature of <NUM> during a heat treatment process. The heating may take approximately <NUM> seconds, as illustrated. In embodiments, room temperature may correspond to ambient conditions, such as approximately <NUM>. In this embodiment, the heat treatment process may be a solutionizing heat treatment process, indicated by the SHT notation. At step <NUM>, the rolled aluminum alloy product may be held at the first temperature for a time period, such as about <NUM> minutes. After this time period, the rolled aluminum alloy product may be quenched at step <NUM> to generate a heat-treated aluminum alloy product. At step <NUM>, multiple quench rates are illustrated. For example, a quench rate of <NUM>/s, <NUM>/s, <NUM>/s, <NUM>/s, or <NUM>/s may be used at step <NUM>. Quenching at step <NUM> may employ any of the various quenching methods discussed here. In some embodiments, the rolled aluminum alloy product may be quenched down to a second temperature, such as room temperature. Optionally, the heat-treated aluminum alloy product may be maintained at room temperature for <NUM> hours.

In some cases, the heat-treated aluminum alloy product may be subjected to an aging process. At step <NUM>, the heat-treated aluminum alloy product may be subjected to a T6 tempering process. Optionally, a T7 tempering process may be used. As provided on graph <NUM>, at step <NUM> the heat-treated aluminum alloy product may be re-heated to a temperature of <NUM>. The heat-treated aluminum alloy product may be maintained at <NUM> for <NUM> hours before returning to room temperature.

The aluminum alloy products described herein can be used in automotive applications and other transportation applications, including aircraft and railway applications. For example, the disclosed aluminum alloy products can be used to prepare automotive structural parts, such as bumpers, side beams, roof beams, cross beams, pillar reinforcements (e.g., A-pillars, B-pillars, and C-pillars), inner panels, outer panels, side panels, inner hoods, outer hoods, rockers, or trunk lid panels. The aluminum alloy products and methods described herein can also be used in aircraft or railway vehicle applications, to prepare, for example, external and internal panels. The aluminum alloy products described herein can be incorporated within upper wing, lower wing, or other body assemblies for aerospace applications.

The aluminum alloy products and methods described herein can also be used in electronics applications or any other desired application. For example, the aluminum alloy products and methods described herein can be used to prepare housings for electronic devices, including mobile phones and tablet computers. In some examples, the aluminum alloy products can be used to prepare housings for the outer casing of mobile phones (e.g., smart phones), tablet bottom chassis, and other portable electronics.

Claim 1:
A method comprising:
heating a rolled aluminum alloy product to a first temperature of from <NUM> to <NUM> wherein the rolled aluminum alloy product comprises a 7xxx series aluminum alloy comprising:
from <NUM> wt.% to <NUM> wt.% Zn,
from <NUM> wt.% to <NUM> wt.% Cu,
from <NUM> wt.% to <NUM> wt.% Mg,
from <NUM> wt.% to <NUM> wt.% Fe,
from <NUM> wt.% to <NUM> wt.% Si,
from <NUM> wt.% to <NUM> wt.% Zr,
from <NUM> wt.% to <NUM> wt.% Mn,
from <NUM> wt.% to <NUM> wt.% Cr,
from <NUM> wt.% to <NUM> wt.%Ti, and
remainder Al, with a maximum of <NUM> wt.% for the sum of all impurities, and wherein the rolled aluminum alloy product further comprises up to <NUM> wt.% of one or more of Mo, Nb, Be, B, Co, Sn, Sr, V, In, Hf, Ag, Sc and Ni; or
from <NUM> wt.% to <NUM> wt.% Zn,
from <NUM> wt.% to <NUM> wt.% Cu,
from <NUM> wt.% to <NUM> wt.% Mg,
from <NUM> wt.% to <NUM> wt.% Fe,
from <NUM> wt.% to <NUM> wt.% Si,
from <NUM> wt.% to <NUM> wt.% Zr,
from <NUM> wt.% to <NUM> wt.% Mn,
from <NUM> wt.% to <NUM> wt.% Cr,
from <NUM> wt.% to <NUM> wt.% Ti,
up to <NUM> wt.% of impurities, and
remainder Al, and wherein the rolled aluminum alloy product further comprises up to <NUM> wt.% of one or more of Mo, Nb, Be, B, Co, Sn, Sr, V, In, Hf, Ag, Sc and Ni;
maintaining the rolled aluminum alloy product at the first temperature or within <NUM> of the first temperature for a time duration of from <NUM> seconds to <NUM> minutes; and
quenching the rolled aluminum alloy product at a quench rate from <NUM>/s to <NUM>/s thereby generating a heat-treated aluminum alloy product, wherein the rolled aluminum alloy product is quenched until the rolled aluminum alloy product reaches a second temperature of from <NUM> to <NUM>, and wherein the heat-treated aluminum alloy product exhibits a strain ratio of from <NUM> to <NUM>, and wherein the strain ratio is determined according to an ASTM G129 standard test method.