CN113015816A - Improved 7XXX aluminum alloys - Google Patents

Abstract

Novel 7xxx aluminum alloys are disclosed. The new 7xxx aluminum alloys typically contain 0.05 to 1.0 wt% Ag. In one approach, the novel 7xxx aluminum alloys comprise 0.05 to 1.0 wt % Ag; 5.5 to 9.0 wt % Zn; 1.2 to 2.6 wt % Cu; 1.3 to 2.5 wt % Mg; up to 0.60 wt % Mn; Up to 1.0 wt% of at least one grain structure control material, wherein the at least one grain structure control material is selected from Zr, Cr, V, Hf, other rare earth elements, and combinations thereof; up to 0.30 wt% Fe; up to 0.30 wt% Si; up to 0.15 wt% Ti; up to 0.08 wt% Sc; and up to 0.05 wt% Li, the balance being aluminum, optional incidental elements and impurities.

Description

Improved 7XXX aluminum alloys

Technical Field

The present application relates to improved 7xxx aluminum alloys and products made therefrom.

Background

Aluminum alloys can be used in a variety of applications. However, it is difficult to improve one property of an aluminum alloy without degrading the other. For example, it is difficult to increase the strength of wrought aluminum alloys without affecting other properties such as fracture toughness or corrosion resistance. 7xxx (based on Al-Zn-Mg) is susceptible to corrosion. See, for example, Bonn, W.Gruhl, "The stress resonance behaviour of high stress AIZnMg Alloys", a paper published at The International Meeting of The Italian metallurgy Association (International Meeting of associates Italian two metals), "Aluminum Alloys in air research Industries", Dovery, 1976, month 10.

Some 7xxx aluminum alloy products have been described by the patent owners, particularly in U.S. Pat. nos. 6,972,110 and 8,673,209 and international patent application publication nos. WO2016/183030 and WO 2018/237196.

Disclosure of Invention

In general, the present patent application relates to improved 7xxx aluminum alloys and products made therefrom. The new 7xxx aluminum alloys typically include from 0.05 to 1.0 wt.% Ag. In one approach, a new 7xxx aluminum alloy includes (and, in some cases, consists essentially of, or consists of) 0.05 to 1.0 wt.% Ag; 5.5 to 9.0 wt.% Zn; 1.2 to 2.6 wt.% Cu; 1.3 to 2.5 wt.% Mg; up to 0.60 wt.% Mn; at most 1.0 wt% of at least one grain structure control material, wherein the at least one grain structure control material is selected from the group consisting of Zr, Cr, V, Hf, other rare earth elements, and combinations thereof; up to 0.15 wt% Ti; up to 0.20 wt.% Fe; up to 0.15 wt.% Si; sc of not more than 0.08 wt%; and not more than 0.05 wt.% Li. The balance of the novel 7xxx aluminum alloys are typically aluminum, optional incidental elements, and impurities. In one approach, the new 7xxx aluminum alloys include a high combined amount of copper and magnesium, such as at least 3.0 wt.% (i.e., + (wt.% of Cu)% (% wt.% of Mg) ≧ 3.0 wt.%). The novel 7xxx aluminum alloys may realize an improved combination of properties, such as an improved combination of two or more of strength, fracture toughness, elongation, and stress corrosion cracking resistance, among others.

i. Composition comprising a metal oxide and a metal oxide

As noted above, the new 7xxx aluminum alloys typically include 0.05 to 1.0 wt.% Ag. The use of silver in combination with other elements in the novel 7xxx aluminum alloys may result in novel 7xxx aluminum alloy products having an improved combination of properties, such as an improved combination of two or more of strength, elongation, fracture toughness, and stress corrosion cracking resistance, among others. In one embodiment, a new 7xxx aluminum alloy includes at least 0.06 wt.% Ag. In another embodiment, a new 7xxx aluminum alloy includes at least 0.07 wt.% Ag. In yet another embodiment, a new 7xxx aluminum alloy includes at least 0.08 wt.% Ag. In another embodiment, a new 7xxx aluminum alloy includes at least 0.09 wt.% Ag. In yet another embodiment, a new 7xxx aluminum alloy includes at least 0.10 wt.% Ag. In another embodiment, a new 7xxx aluminum alloy includes at least 0.15 wt.% Ag. In yet another embodiment, a new 7xxx aluminum alloy includes at least 0.20 wt.% Ag. In another embodiment, a new 7xxx aluminum alloy includes at least 0.225 wt.% Ag. In yet another embodiment, a new 7xxx aluminum alloy includes at least 0.25 wt.% Ag. In one embodiment, a new 7xxx aluminum alloy includes not greater than 0.7 wt.% Ag. In another embodiment, a new 7xxx aluminum alloy includes not greater than 0.5 wt.% Ag. In yet another embodiment, a new 7xxx aluminum alloy includes not greater than 0.4 wt.% Ag. In another embodiment, a new 7xxx aluminum alloy includes not greater than 0.35 wt.% Ag. In yet another embodiment, a new 7xxx aluminum alloy includes not greater than 0.325 wt.% Ag. In another embodiment, a new 7xxx aluminum alloy includes not greater than 0.30 wt.% Ag.

As noted above, in one approach, a new 7xxx aluminum alloy may include from 5.5 to 9.0 wt.% Zn. In one embodiment, a new 7xxx aluminum alloy includes at least 5.75 wt.% Zn. In another embodiment, a new 7xxx aluminum alloy includes at least 6.0 wt.% Zn. In yet another embodiment, a new 7xxx aluminum alloy includes at least 6.25 wt.% Zn. In another embodiment, a new 7xxx aluminum alloy includes at least 6.5 wt.% Zn. In yet another embodiment, a new 7xxx aluminum alloy includes at least 6.75 wt.% Zn. In another embodiment, a new 7xxx aluminum alloy includes at least 7.0 wt.% Zn. In one embodiment, a new 7xxx aluminum alloy includes not greater than 8.75 wt.% Zn. In another embodiment, a new 7xxx aluminum alloy includes not greater than 8.5 wt.% Zn. In yet another embodiment, a new 7xxx aluminum alloy includes not greater than 8.25 wt.% Zn. In another embodiment, a new 7xxx aluminum alloy includes not greater than 8.0 wt.% Zn. In another embodiment, a new 7xxx aluminum alloy includes not greater than 7.75 wt.% Zn. In yet another embodiment, a new 7xxx aluminum alloy includes not greater than 7.5 wt.% Zn. In another embodiment, a new 7xxx aluminum alloy includes not greater than 7.25 wt.% Zn. In yet another embodiment, a new 7xxx aluminum alloy includes not greater than 7.0 wt.% Zn. In another embodiment, a new 7xxx aluminum alloy includes not greater than 6.75 wt.% Zn. In yet another embodiment, a new 7xxx aluminum alloy includes not greater than 6.5 wt.% Zn. In another embodiment, a new 7xxx aluminum alloy includes not greater than 6.25 wt.% Zn.

As noted above, in one approach, a new 7xxx aluminum alloy may include from 1.2 to 2.6 wt.% Cu. In one embodiment, a new 7xxx aluminum alloy includes at least 1.3 wt.% Cu. In another embodiment, a new 7xxx aluminum alloy includes at least 1.4 wt.% Cu. In yet another embodiment, a new 7xxx aluminum alloy includes at least 1.5 wt.% Cu. In another embodiment, a new 7xxx aluminum alloy includes at least 1.6 wt.% Cu. In yet another embodiment, a new 7xxx aluminum alloy includes at least 1.7 wt.% Cu. In another embodiment, a new 7xxx aluminum alloy includes at least 1.8 wt.% Cu. In one embodiment, a new 7xxx aluminum alloy includes not greater than 2.3 wt.% Cu. In another embodiment, a new 7xxx aluminum alloy includes not greater than 2.2 wt.% Cu. In yet another embodiment, a new 7xxx aluminum alloy includes not greater than 2.1 wt.% Cu. In another embodiment, a new 7xxx aluminum alloy includes not greater than 2.0 wt.% Cu. In yet another embodiment, a new 7xxx aluminum alloy includes not greater than 1.9 wt.% Cu. In another embodiment, a new 7xxx aluminum alloy includes not greater than 1.8 wt.% Cu.

As noted above, in one approach, a new 7xxx aluminum alloy may include from 1.3 to 2.5 wt.% Mg. In one embodiment, a new 7xxx aluminum alloy includes at least 1.4 wt.% Mg. In another embodiment, a new 7xxx aluminum alloy includes at least 1.45 wt.% Mg. In one embodiment, a new 7xxx aluminum alloy includes not greater than 2.2 wt.% Mg. In another embodiment, a new 7xxx aluminum alloy includes not greater than 2.1 wt.% Mg. In yet another embodiment, a new 7xxx aluminum alloy includes not greater than 2.0 wt.% Mg. In another embodiment, a new 7xxx aluminum alloy includes not greater than 1.9 wt.% Mg. In yet another embodiment, a new 7xxx aluminum alloy includes not greater than 1.8 wt.% Mg. In another embodiment, a new 7xxx aluminum alloy includes not greater than 1.7 wt.% Mg. In yet another embodiment, a new 7xxx aluminum alloy includes not greater than 1.65 wt.% Mg.

As noted above, in one approach, the new 7xxx aluminum alloys may include high combined amounts of copper and magnesium. In one embodiment, the combined amount of copper and magnesium in the novel 7xxx aluminum alloys is at least 3.0 wt.% (i.e., (wt.% of Cu%) + (wt.% of Mg) ≧ 3.0 wt.%). In another embodiment, the combined amount of copper and magnesium in the novel 7xxx aluminum alloys is at least 3.25 wt.% (i.e., (wt.% of Cu%) + (wt.% of Mg) ≧ 3.25 wt.%). In yet another embodiment, the combined amount of copper and magnesium in the novel 7xxx aluminum alloys is at least 3.5 wt.% (i.e., + (wt.% of Cu)% + (wt.% of Mg) ≧ 3.5 wt.%). In another embodiment, the combined amount of copper and magnesium in the novel 7xxx aluminum alloys is at least 3.75 wt.% (i.e., + (wt.% Cu)% > (% Mg) > 3.75 wt.%). In yet another embodiment, the combined amount of copper and magnesium in the novel 7xxx aluminum alloys is at least 4.0 wt.% (i.e., + (wt.% of Cu)% + (wt.% of Mg) ≧ 4.0 wt.%).

As noted above, the new 7xxx aluminum alloys may include up to 0.60 wt.% Mn. In one embodiment, a new 7xxx aluminum alloy includes at least 0.05 wt.% Mn. In another embodiment, a new 7xxx aluminum alloy includes at least 0.10 wt.% Mn. In yet another embodiment, a new 7xxx aluminum alloy includes at least 0.15 wt.% Mn. In another embodiment, a new 7xxx aluminum alloy includes at least 0.20 wt.% Mn. In yet another embodiment, a new 7xxx aluminum alloy includes at least 0.25 wt.% Mn. In one embodiment, a new 7xxx aluminum alloy includes not greater than 0.55 wt.% Mn. In another embodiment, a new 7xxx aluminum alloy includes not greater than 0.50 wt.% Mn. In yet another embodiment, a new 7xxx aluminum alloy includes not greater than 0.45 wt.% Mn. In another embodiment, a new 7xxx aluminum alloy includes not greater than 0.40 wt.% Mn. In the aluminum alloy industry, manganese can be considered an alloy composition and grain structure control element — manganese remaining in solid solution can enhance the mechanical properties (e.g., strength and/or toughness) of the alloy, while manganese in particulate form (e.g., in Al)₆Mn、Al₁₂Mn₃Si₂、Al₂₀Cu₂Mn₃Forms, sometimes referred to as dispersoids), can aid in grain structure control and can also improve damage tolerance properties, such as fracture toughness. However, since Mn is defined separately in this patent application according to its own compositional limits, it is not in a "grain structure control material" for purposes of this patent applicationMaterials "(as described below).

In some embodiments, the new 7xxx aluminum alloys include a small amount of manganese. In these embodiments, the new 7xxx aluminum alloys typically include not greater than 0.04 wt.% Mn. In one embodiment, a new 7xxx aluminum alloy includes not greater than 0.03 wt.% Mn. In another embodiment, a new 7xxx aluminum alloy includes not greater than 0.02 wt.% Mn. In yet another embodiment, a new 7xxx aluminum alloy includes not greater than 0.01 wt.% Mn. In another embodiment, a new 7xxx aluminum alloy includes not greater than 0.005 wt.% Mn or less.

As noted above, the new 7xxx aluminum alloys may include one or more of Zr, Cr, V, Hf, other rare earth elements, and combinations thereof as grain structure control materials (e.g., one or more of Zr, Cr, V, Hf, and other rare earth elements each constitute 0.05-0.25 wt.%), which limits the total amount of these elements so that large primary particles are not formed in the alloy. The grain structure control material can, for example, promote a suitable grain structure (e.g., a non-recrystallized grain structure). For the purposes of this patent application, the grain structure control material contains Zr, Cr, V, Hf and other rare earth elements, but excludes Mn and Sc, to name a few. When employed, the new 7xxx aluminum alloy products typically include at least 0.05 wt.% of the grain structure control material. In one embodiment, a new 7xxx aluminum alloy product includes at least 0.07 wt.% of a grain structure control material. In another embodiment, a new 7xxx aluminum alloy product includes at least 0.09 wt.% of the grain structure control material. When employed, the new 7xxx aluminum alloy products typically include not greater than 1.0 wt.% of the grain structure control material. In one embodiment, a new 7xxx aluminum alloy product includes not greater than 0.75 wt.% of the grain structure control material. In yet another embodiment, a new 7xxx aluminum alloy product includes not greater than 0.50 wt.% of the grain structure control material. In one embodiment, the grain structure control material is selected from Zr, Cr, V, and Hf. In another embodiment, the grain structure control material is selected from Zr and Cr. In another embodiment, the grain structure control material is Zr. In another embodiment, the grain structure control material is Cr.

In one embodiment, the grain structure control material is at least chromium (Cr), and the novel 7xxx aluminum alloy products include from 0.05 to 0.25 wt.% Cr. In one embodiment, a new 7xxx aluminum alloy includes at least 0.07 wt.% Cr. In another embodiment, a new 7xxx aluminum alloy includes at least 0.10 wt.% Cr. In yet another embodiment, a new 7xxx aluminum alloy includes at least 0.12 wt.% Cr. In yet another embodiment, a new 7xxx aluminum alloy includes at least 0.14 wt.% Cr. In one embodiment, a new 7xxx aluminum alloy includes not greater than 0.24 wt.% Cr. In another embodiment, a new 7xxx aluminum alloy includes not greater than 0.22 wt.% Cr. In yet another embodiment, a new 7xxx aluminum alloy includes not greater than 0.20 wt.% Cr.

In some embodiments, the new 7xxx aluminum alloys contain small amounts of chromium (e.g., ≦ 0.04 wt.% Cr). In one embodiment, a new 7xxx aluminum alloy includes not greater than 0.03 wt.% Cr. In another embodiment, a new 7xxx aluminum alloy includes not greater than 0.02 wt.% Cr. In yet another embodiment, a new 7xxx aluminum alloy includes not greater than 0.01 wt.% Cr. In another embodiment, a new 7xxx aluminum alloy includes not greater than 0.005 wt.% Cr or less.

In one embodiment, the grain structure control material is Zr, and the new 7xxx aluminum alloy product includes from 0.05 to 0.20 wt.% Zr. In one embodiment, a new 7xxx aluminum alloy includes at least 0.06 wt.% Zr. In another embodiment, a new 7xxx aluminum alloy includes at least 0.07 wt.% Zr. In yet another embodiment, a new 7xxx aluminum alloy includes at least 0.08 wt.% Zr. In one embodiment, a new 7xxx aluminum alloy includes not greater than 0.18 wt.% Zr. In another embodiment, a new 7xxx aluminum alloy includes not greater than 0.16 wt.% Zr. In yet another embodiment, a new 7xxx aluminum alloy includes not greater than 0.15 wt.% Zr. In another embodiment, a new 7xxx aluminum alloy includes not greater than 0.14 wt.% Zr. In yet another embodiment, a new 7xxx aluminum alloy includes not greater than 0.13 wt.% Zr. In one embodiment, the grain structure control material is Zr, and the new 7xxx aluminum alloy product includes from 0.07 to 0.16 wt.% Zr. In another embodiment, the grain structure control material is Zr, and the new 7xxx aluminum alloy product includes from 0.08 to 0.15 wt.% Zr. In yet another embodiment, the grain structure control material is Zr, and the new 7xxx aluminum alloy product includes from 0.09 to 0.14 wt.% Zr. In embodiments where the grain structure control material is Zr, the novel 7xxx aluminum alloy products may contain small amounts of Cr, V, Hf and other rare earth elements (e.g., ≦ 0.04 wt.% of each of Cr, V, Hf and other rare earth elements). In one embodiment, the new 7xxx aluminum alloy product contains not greater than 0.03 wt.% of each of Cr, V, Hf, and other rare earth elements. In another embodiment, the new 7xxx aluminum alloy product contains not greater than 0.02 wt.% of each of Cr, V, Hf, and other rare earth elements. In another embodiment, the new 7xxx aluminum alloy product contains not greater than 0.01 wt.% each of Cr, V, Hf, and other rare earth elements. In another embodiment, the new 7xxx aluminum alloy product contains not greater than 0.005 wt.% each of Cr, V, Hf, and other rare earth elements.

In some embodiments, the new 7xxx aluminum alloys include a small amount of zirconium (e.g., ≦ 0.04 wt.% Zr). In one embodiment, the new 7xxx aluminum alloy product contains not greater than 0.03 wt.% Zr. In another embodiment, the new 7xxx aluminum alloy product contains not greater than 0.02 wt.% Zr. In yet another embodiment, the new 7xxx aluminum alloy product contains not greater than 0.01 wt.% Zr. In another embodiment, the new 7xxx aluminum alloy product contains not greater than 0.005 wt.% Zr or less.

In one embodiment, the grain structure control material comprises both Zr and Cr, and the novel 7xxx aluminum alloy product comprises at least 0.07 wt.% Zr and at least 0.07 wt.% Cr, with the wt.% of Zr plus the wt.% of Cr not exceeding 0.40 wt.% (i.e., wt.% Zr + wt.% Cr ≦ 0.40 wt.%). In another embodiment, the grain structure control material comprises both Zr and Cr, and the novel 7xxx aluminum alloy product comprises at least 0.07 wt.% Zr and at least 0.07 wt.% Cr, with the wt.% of Zr plus the wt.% of Cr not exceeding 0.35 wt.% (i.e., wt.% Zr + wt.% Cr ≦ 0.35 wt.%). In another embodiment, the grain structure control material comprises both Zr and Cr, and the novel 7xxx aluminum alloy product comprises at least 0.07 wt.% Zr and at least 0.07 wt.% Cr, with the wt.% of Zr plus the wt.% of Cr not exceeding 0.30 wt.% (i.e., wt.% Zr + wt.% Cr ≦ 0.30 wt.%). In another embodiment, the grain structure control material comprises both Zr and Cr, and the novel 7xxx aluminum alloy product comprises at least 0.07 wt.% Zr and at least 0.07 wt.% Cr, with the wt.% of Zr plus the wt.% of Cr not exceeding 0.25 wt.% (i.e., wt.% Zr + wt.% Cr ≦ 0.25 wt.%). In another embodiment, the grain structure control material comprises both Zr and Cr, and the novel 7xxx aluminum alloy product comprises at least 0.07 wt.% Zr and at least 0.07 wt.% Cr, with the wt.% of Zr plus the wt.% of Cr not exceeding 0.20 wt.% (i.e., wt.% Zr + wt.% Cr ≦ 0.20 wt.%). In any of these embodiments, the new 7xxx aluminum alloy product may include at least 0.09 wt.% of at least one of Zr and Cr. In any of these embodiments, the new 7xxx aluminum alloy product may include at least 0.09 wt.% of both Zr and Cr.

As noted above, the new 7xxx aluminum alloy products may include, for example, cumulatively up to 0.15 wt.% Ti for grain refinement and/or other purposes. Grain refiners are inoculants or nuclei used to seed new grains during solidification of an alloy. An example of a grain refiner is a 9.525mm rod containing 96% aluminum, 3% titanium (Ti) and 1% boron (B), all in weight percent, where almost all of the boron is finely dispersed TiB₂The particles are present. During casting, the grain refining bar may be continuously fed at a controlled rate into the molten alloy flowing into the casting pit. The amount of grain refiner included in the alloy generally depends on the type of material used for grain refinement and the alloy manufacturing process. Examples of grain refiners include Ti and B (e.g., TiB)₂) Or a combination of carbon (TiC), although other grain refiners, such as Al-Ti master alloys, may also be used. In general, depending on the desireThe amount of grain refiner added to the alloy is in the range of 0.0003 wt% to 0.005 wt%. Furthermore, the amount of Ti added to the alloy may be up to 0.15 wt.%, depending on the product form, respectively, to increase the effectiveness of the grain refiner, and is typically in the range of 0.005 to 0.15 wt.% Ti. When Ti is included in the alloy, it is generally present in an amount of 0.01 to 0.10 wt.%. In one embodiment, the novel alloy comprises at least 0.005 wt.% Ti. In another embodiment, the novel alloy comprises at least 0.01 wt.% Ti. In yet another embodiment, the novel alloy comprises at least 0.015 wt.% Ti. In another embodiment, the novel alloy comprises at least 0.020 wt% Ti. In one embodiment, the novel alloy includes no more than 0.10 wt.% Ti. In another embodiment, the novel alloy contains no more than 0.08 wt.% Ti. In yet another embodiment, the novel alloy includes no more than 0.07 wt.% Ti. In another embodiment, the novel alloy contains no more than 0.06 wt.% Ti. In yet another embodiment, the novel alloy includes no more than 0.05 wt.% Ti. In one embodiment, the aluminum alloy includes a grain refiner, and the grain refiner is TiB₂And TiC, wherein the weight% of Ti in the alloy is 0.01 to 0.06 weight% or 0.01 to 0.03 weight%.

As noted above, the new 7xxx aluminum alloys may include up to 0.30 wt.% Fe. In one embodiment, the novel alloy comprises at least 0.01 wt.% Fe. In one embodiment, the novel alloy includes not greater than 0.25 wt.% Fe. In another embodiment, the novel alloy comprises not more than 0.20 wt.% Fe. In yet another embodiment, the novel alloy comprises not greater than 0.15 wt.% Fe. In another embodiment, the novel alloy comprises not more than 0.12 wt.% Fe. In another embodiment, the novel alloy comprises not more than 0.10 wt.% Fe. In yet another embodiment, the novel alloy comprises not more than 0.08 wt.% Fe. In another embodiment, the novel alloy comprises not more than 0.06 wt.% Fe. In yet another embodiment, the novel alloy includes not greater than 0.04 wt.% Fe. The use of 0.12 wt% or less of Fe is preferred for aerospace applications.

As noted above, the new 7xxx aluminum alloys may include up to 0.30 wt.% Si. In one embodiment, the novel alloy comprises at least 0.01 wt.% Si. In one embodiment, the novel alloy contains no more than 0.25 wt.% Si. In another embodiment, the novel alloy contains no more than 0.20 wt.% Si. In yet another embodiment, the novel alloy contains no more than 0.15 wt.% Si. In another embodiment, the novel alloy contains no more than 0.12 wt.% Si. In yet another embodiment, the novel alloy contains no more than 0.10 wt.% Si. In another embodiment, the novel alloy contains no more than 0.08 wt.% Si. In yet another embodiment, the novel alloy contains no more than 0.06 wt.% Si. In another embodiment, the novel alloy contains no more than 0.04 wt.% Si. The use of 0.10 wt% or less of Si is preferred for aerospace applications.

As noted above, new 7xxx aluminum alloys typically include no more than 0.08 wt.% Sc. Scandium may affect the grain structure of 7xxx aluminum alloys. In one embodiment, a new 7xxx aluminum alloy includes not greater than 0.05 wt.% Sc. In another embodiment, a new 7xxx aluminum alloy includes not greater than 0.03 wt.% Sc. In yet another embodiment, a new 7xxx aluminum alloy includes not greater than 0.01 wt.% Sc. In another embodiment, a new 7xxx aluminum alloy includes not greater than 0.005 wt.% Sc or less.

As noted above, the new 7xxx aluminum alloys include not greater than 0.05 wt.% Li. Lithium handling is difficult and lithium can adversely affect the properties of the 7xxx aluminum alloys. In one embodiment, a new 7xxx aluminum alloy includes not greater than 0.03 wt.% Li. In another embodiment, a new 7xxx aluminum alloy includes not greater than 0.01 wt.% Li. In yet another embodiment, a new 7xxx aluminum alloy includes not greater than 0.005 wt.% Li or less.

As noted above, the novel alloys generally comprise the recited alloy constituents, with the balance being aluminum, optional incidental elements, and impurities. As used herein, "incidental elements" means elements or materials that may optionally be added to the alloy to aid in the manufacture of the alloy in addition to the elements listed above. Examples of incidental elements include casting aids such as grain refiners and deoxidizers. The alloy may include a cumulative amount of up to 1.0 wt.% of the optional incidental elements. As one non-limiting example, one or more incidental elements may be added to the alloy during casting to reduce or limit (and in some cases eliminate) ingot cracking caused by, for example, oxide wrinkles, pits, and oxide spots. These types of incidental elements are generally referred to herein as deoxidizers. Some examples of deoxidizers include Ca, Sr, and Be. When calcium (Ca) is included in the alloy, it is typically present in an amount of up to about 0.05 wt.% or up to about 0.03 wt.%. In some embodiments, Ca is included in the alloy in an amount of about 0.001-0.03 wt%, or about 0.05 wt%, such as 0.001-0.008 wt% (or 10 to 80 ppm). Strontium (Sr) may be contained in the alloy (wholly or partially) as a substitute for Ca, and thus may be contained in the alloy in the same or similar amount as Ca. Traditionally, the addition of beryllium (Be) helped reduce the tendency of ingots to crack, but some embodiments of the alloy are substantially free of Be for environmental, health, and safety reasons. When Be is included in the alloy, it is typically present in an amount up to about 20 ppm. Incidental elements may be present in trace amounts, or may be present in substantial amounts, and may add desired or other features themselves without departing from the alloys described herein, so long as the alloys retain the desired features described herein. It is to be understood, however, that the scope of the disclosure may not be circumvented by merely adding one or more elements in an amount that does not otherwise affect the combination of properties desired and achieved herein.

The novel 7xxx aluminum alloys may contain small amounts of impurities. In one embodiment, a new 7xxx aluminum alloy includes a total of not greater than 0.15 wt.% of impurities, and wherein the 7xxx aluminum alloy includes not greater than 0.05 wt.% of each impurity. In another embodiment, a new 7xxx aluminum alloy includes a total of not greater than 0.10 wt.% of impurities, and wherein the 7xxx aluminum alloy includes not greater than 0.03 wt.% of each impurity.

In one embodiment, the new 7xxx aluminum alloys are 7085 alloys (as defined by the aluminum association tea Sheets document, described below) that are modified to include 0.05 to 1.0 wt.% Ag, as any of the silver limits/ranges described above. The teachings of this paragraph are also applicable to other 7x85 alloys, such as 7185.

In one embodiment, the new 7xxx aluminum alloys are 7065 alloys (as defined by the aluminum association tea Sheets document, described below) that are modified to include 0.05 to 1.0 wt.% Ag, as any of the silver limits/ranges described above. The teachings of this paragraph are also applicable to other 7x65 alloys.

In one embodiment, the new 7xxx aluminum alloys are 7040 alloys (as defined by the aluminum association tea Sheets document, described below) that are modified to include 0.05 to 1.0 wt.% Ag, as any of the silver limits/ranges described above. The teachings of this paragraph are also applicable to other 7x40 alloys, such as 7140.

In one embodiment, the new 7xxx aluminum alloys are 7050 alloys (as defined by the aluminum association tea Sheets document, described below) that are modified to include 0.05 to 1.0 wt.% Ag, as any of the silver limits/ranges described above. The teachings of this paragraph are also applicable to other 7x50 alloys, such as 7150 and 7250.

In one embodiment, the new 7xxx aluminum alloys are 7055 alloys (as defined by the aluminum association tea Sheets document, described below) that are modified to include 0.05 to 1.0 wt.% Ag, as any of the silver limits/ranges described above. The teachings of this paragraph are also applicable to other 7x50 alloys, such as 7155 and 7255.

In one embodiment, the new 7xxx aluminum alloys are 7136 alloys (as defined by the aluminum association tea Sheets document, described below) that are modified to include 0.05 to 1.0 wt.% Ag, as any of the silver limits/ranges described above. The teachings of this paragraph are also applicable to other 7x36 alloys, such as 7036.

In one embodiment, the new 7xxx aluminum alloys are 7037 alloys (as defined by the aluminum association tea Sheets document, described below) that are modified to include 0.05 to 1.0 wt.% Ag, as any of the silver limits/ranges described above. The teachings of this paragraph are also applicable to other 7x37 alloys.

In one embodiment, the new 7xxx aluminum alloys are 7010 alloys (as defined by the aluminum association tea Sheets document, described below) that are modified to include 0.05 to 1.0 wt.% Ag, as any of the silver limits/ranges described above. The teachings of this paragraph are also applicable to other 7x10 alloys.

In one embodiment, the new 7xxx aluminum alloys are 7081 alloys (as defined by the aluminum association tea Sheets document, described below) that are modified to include 0.05 to 1.0 wt.% Ag, as any of the silver limits/ranges described above. The teachings of this paragraph are also applicable to other 7x81 alloys, such as 7181.

In one embodiment, the new 7xxx aluminum alloys are 7099 alloys (as defined by the aluminum association tea Sheets document, described below) that are modified to include 0.05 to 1.0 wt.% Ag, as any of the silver limits/ranges described above. The teachings of this paragraph are also applicable to other 7x99 alloys, such as 7199.

In one embodiment, the new 7xxx aluminum alloys are 7449 alloys (as defined by the aluminum association tea Sheets document, described below) that are modified to include 0.05 to 1.0 wt.% Ag, as any of the silver limits/ranges described above. The teachings of this paragraph are also applicable to other 7x49 alloys, such as 7049, 7149, 7249, and 7349.

In one embodiment, the new 7xxx aluminum alloys are 7075 alloys (as defined by the aluminum association tea Sheets document, described below) that are modified to include 0.05 to 1.0 wt.% Ag, as any of the silver limits/ranges described above. The teachings of this paragraph are also applicable to other 7x75 alloys, such as 7175 and 7475.

In one embodiment, the new 7xxx aluminum alloys are 7097 alloys (as defined by the aluminum association tea Sheets document, described below) that are modified to include 0.05 to 1.0 wt.% Ag, as any of the silver limits/ranges described above. The teachings of this paragraph are also applicable to other 7x97 alloys.

Product form

The novel alloys can be used in a variety of product forms including, for example, ingots or billets, wrought product forms (sheets, plates, forgings and extrusions), shape castings, additive manufacturing products, and powder metallurgy products.

In one embodiment, the new 7xxx aluminum alloys are in the form of thick wrought products. The thick wrought aluminium alloy product is a wrought product having a cross-sectional thickness of at least 12.7 mm. The wrought product may be a rolled product, a forged product, or an extruded product. In one embodiment, the thick wrought aluminum alloy product has a thickness of at least 25 mm. In another embodiment, the thick wrought aluminum alloy product has a thickness of at least 38 mm. In yet another embodiment, the thick wrought aluminum alloy product has a thickness of at least 60 mm. In another embodiment, the thick wrought aluminum alloy product has a thickness of at least 80 mm. In yet another embodiment, the thick wrought aluminum alloy product has a thickness of at least 100 mm. In another embodiment, the thick wrought aluminum alloy product has a thickness of at least 120 mm. In another embodiment, the thick wrought aluminum alloy product has a thickness of at least 140 mm. The improved properties described herein can be achieved with thick wrought products having a thickness of up to 305 mm. In one embodiment, the thick wrought aluminum alloy product has a thickness of no more than 254 mm. In another embodiment, the thick wrought aluminum alloy product has a thickness of no more than 203 mm. In yet another embodiment, the thick wrought aluminum alloy product has a thickness not exceeding 178 mm. As used in this paragraph, thickness refers to the minimum thickness of the product, meaning that portions of the product may have a thickness slightly greater than the stated minimum thickness.

Forging treatment of

The novel alloys may be prepared in wrought form by generally conventional practice and in appropriate temper, including Direct Cooling (DC) casting of the aluminum alloy into ingot form. These ingots may be further processed by hot working the product after conventional shaving, turning or stripping (if required) and homogenization, which may be done before or after shaving. The product may then be optionally cold worked and/or optionally annealed. After any cold working and any annealing (which may be performed multiple times and in any order), the product may then be solution heat treated, quenched, such as in a gas (e.g., air) or liquid (e.g., water) or both, and brought to an appropriate temperature (e.g., quenched to ambient temperature), and then naturally and/or artificially aged. Thus, in some embodiments, the product may be produced in the T4, T6, or T7 temper. In other embodiments, other T temper conditions may be used (e.g., any of T1, T2, T3, T5, T8, or T9 temper conditions). The product may also be produced/shipped in an F or W temper. In one approach, the novel wrought aluminum alloy product is in a T7X temper, such as any of T73, T74, T76, T79, or T77 temper. In one embodiment, the new wrought aluminum alloy product is in a T7X51 temper, such as any of a T7351, T7451, T7651, T7951, or T7751 temper. The temper conditions (F, W and T) are defined in ANSI H35.1 (2009).

Properties iv

The novel 7xxx aluminum alloys may realize improved combinations of at least two of strength, elongation, fracture toughness, and stress corrosion cracking resistance, among others.

a. Longitudinal (L)

In one embodiment, the new 7xxx aluminum alloy products have a thickness of at least 38mm and achieve a typical tensile yield strength (L) of at least 400MPa in the T7 temper. In another embodiment, the new 7xxx aluminum alloy product has a thickness of at least 38mm and realizes a typical tensile yield strength (L) of at least 410MPa in the T7 temper. In yet another embodiment, the new 7xxx aluminum alloy product has a thickness of at least 38mm and realizes a typical tensile yield strength (L) of at least 420MPa in the T7 temper. In another embodiment, the new 7xxx aluminum alloy product has a thickness of at least 38mm and realizes a typical tensile yield strength (L) of at least 430MPa in the T7 temper. In yet another embodiment, the new 7xxx aluminum alloy product has a thickness of at least 38mm and realizes a typical tensile yield strength (L) of at least 440MPa in the T7 temper. In another embodiment, the new 7xxx aluminum alloy product has a thickness of at least 38mm and realizes a typical tensile yield strength (L) of at least 450MPa in the T7 temper. In yet another embodiment, the new 7xxx aluminum alloy product has a thickness of at least 38mm and realizes a typical tensile yield strength (L) of at least 460MPa in the T7 temper. In another embodiment, the new 7xxx aluminum alloy product has a thickness of at least 38mm and realizes a typical tensile yield strength (L) of at least 470MPa in the T7 temper. In yet another embodiment, the new 7xxx aluminum alloy products have a thickness of at least 38mm and achieve a typical tensile yield strength (L) of at least 480MPa or greater in the T7 temper. The above strength properties may be achieved in products having a thickness of at least 60mm, or at least 80mm, or at least 100mm, at least 120mm, or at least 140mm, or higher.

In one embodiment, the new 7xxx aluminum alloy product has a thickness of at least 38mm and realizes an elongation (L) of at least 8.0% in a T7 temper. In another embodiment, the new 7xxx aluminum alloy product has a thickness of at least 38mm and realizes an elongation (L) of at least 9.0% in the T7 temper. In yet another embodiment, the new 7xxx aluminum alloy product has a thickness of at least 38mm and realizes an elongation (L) of at least 10.0% in the T7 temper. In another embodiment, the new 7xxx aluminum alloy product has a thickness of at least 38mm and realizes an elongation (L) of at least 11.0% in the T7 temper. In yet another embodiment, the new 7xxx aluminum alloy product has a thickness of at least 38mm and realizes an elongation (L) of at least 12.0% or more in the T7 temper. The above elongation properties may be achieved in products having a thickness of at least 60mm, or at least 80mm, or at least 100mm, at least 120mm, or at least 140mm, or higher.

b. Short transverse direction (ST)

In one embodiment, the new 7xxx aluminum alloy products have a thickness of at least 38mm and achieve a typical tensile yield Strength (ST) of at least 400MPa in the T7 temper. In another embodiment, the new 7xxx aluminum alloy product has a thickness of at least 38mm and realizes a typical tensile yield Strength (ST) of at least 410MPa in the T7 temper. In yet another embodiment, the new 7xxx aluminum alloy product has a thickness of at least 38mm and realizes a typical tensile yield Strength (ST) of at least 420MPa in the T7 temper. In another embodiment, the new 7xxx aluminum alloy product has a thickness of at least 38mm and realizes a typical tensile yield Strength (ST) of at least 430MPa in the T7 temper. In yet another embodiment, the new 7xxx aluminum alloy products have a thickness of at least 38mm and achieve a typical tensile yield Strength (ST) of at least 440MPa or greater in the T7 temper. The above strength properties may be achieved in products having a thickness of at least 60mm, or at least 80mm, or at least 100mm, at least 120mm, or at least 140mm, or higher.

In one embodiment, a novel 7xxx aluminum alloy product has a thickness of at least 38mm and realizes a plane strain (K) of at least 20MPa-sqrt-m in a T7 temper_IC) Fracture toughness (S-L). In another embodiment, a novel 7xxx aluminum alloy product has a thickness of at least 38mm and realizes a plane strain (K) of at least 21MPa-sqrt-m in a T7 temper_IC) Fracture toughness (S-L). In yet another embodiment, a new 7xxx aluminum alloy product has a thickness of at least 38mm and realizes a plane strain (K) of at least 22MPa-sqrt-m in a T7 temper_IC) Fracture toughness (S-L). In another embodiment, a novel 7xxx aluminum alloy product has a thickness of at least 38mm and realizes a plane strain (K) of at least 23MPa-sqrt-m in the T7 temper_IC) Fracture toughness (S-L). In yet another embodiment, a novel 7xxx aluminum alloy product has a thickness of at least 38mm and realizes a plane strain (K) of at least 24MPa-sqrt-m in the T7 temper_IC) Fracture toughness (S-L). In another embodiment, a novel 7xxx aluminum alloy product has a thickness of at least 38mm and realizes a in-plane strain (K) of at least 25MPa-sqrt-m or greater in the T7 temper_IC) Fracture toughness (S-L). The above fracture toughness properties may be achieved in products having a thickness of at least 60mm, or at least 80mm, or at least 100mm, at least 120mm, or at least 140mm, or higher.

In one embodiment, the new 7xxx aluminum alloy product has a thickness of at least 38mm and realizes an elongation (ST) of at least 2.0% in a T7 temper. In another embodiment, the new 7xxx aluminum alloy product has a thickness of at least 38mm and realizes an elongation (ST) of at least 3.0% in a T7 temper. In yet another embodiment, the new 7xxx aluminum alloy product has a thickness of at least 38mm and realizes an elongation (ST) of at least 4.0% in the T7 temper. In another embodiment, the new 7xxx aluminum alloy product has a thickness of at least 38mm and realizes an elongation (ST) of at least 5.0% in a T7 temper. In yet another embodiment, the new 7xxx aluminum alloy product has a thickness of at least 38mm and realizes an elongation (ST) of at least 6.0% in the T7 temper. The above elongation properties may be achieved in products having a thickness of at least 60mm, or at least 80mm, or at least 100mm, at least 120mm, or at least 140mm, or higher.

In one embodiment, the new 7xxx aluminum alloy product has a thickness of at least 38mm and passes wet-hot SCC (stress corrosion cracking) testing using a standard stress-corrosion tension test specimen ("HHSCC-G49") in accordance with ASTM G49, as defined below. To make HHSCC-G49 specimens, at least three Short Transverse (ST) samples were taken from the intermediate thickness of the final product and between W/4 and 3W/4 of the final product. The collected samples were then processed into tensile test specimens and matched to the dimensions of fig. 2 (dimensions in inches for fig. 2) according to ASTM E8. If the final product thickness is at least 2.25 inches (57.15mm), the length of the stretchable sample is 2.00 inches (50.8mm), as shown in FIG. 2. If the final product thickness is from 1.50 inches (38.1mm) to less than 2.25 inches (<50.8mm), the length of the test specimen must be at least 1.25 inches (31.75mm) and should be as close to 2.00 inches (50.8mm) as possible. Prior to testing, the tensile specimens were cleaned/degreased by washing in acetone. The tensile test specimen was then pulled taut in the short transverse direction at T/2 to 85% of its ST tensile yield strength. Prior to HHSCC-G49 testing, the ST tensile yield strength of the alloy was measured at room temperature and according to ASTM E8 and B557. The stress frame used is of the constant strain type according to ASTM G49, section 7.2.2 (see, for example, fig. 4a of ASTM G49). The tensioned sample was then placed in a controlled oven with an air relative humidity of 85% (no additives, such as chloride, added to the air) and a temperature of 70 ℃ or 90 ℃. At least three specimens must be tested. For the purposes of this patent application, an alloy passes the HHSCC-G49 test when all specimens remain intact for at least 100 days at 70 ℃. For the purposes of this patent application, when all specimens remain intact for at least 10 days at 90 ℃, then the alloy passes the HHSCC-G49 test. Failure occurs if the specimen breaks in half along the gauge length or at one specimen shoulder adjacent the gauge length. Shoulder failures are statistically equivalent to gauge length failures. In determining whether the alloy passed HHSCC-G49, thread failure was included only when it was statistically equivalent to gauge failure. If a crack occurs in the threaded end of the specimen, rather than in the gauge length, it is a thread failure. In some cases, a thread failure may not be detected until the test specimen is removed from the stressing frame. In one embodiment, the new 7xxx aluminum alloys pass the 150-day HHSCC-G49 test at 70 ℃, with all samples remaining intact for 150 days in the HHSCC-G49 test defined above. In another embodiment, the new 7xxx aluminum alloys pass the HHSCC-G49 test at 90 ℃ for 15 days, with all samples remaining intact for 15 days in the HHSCC-G49 test defined above. The above-mentioned stress corrosion cracking resistance can be achieved in products having a thickness of at least 60mm, or at least 80mm, or at least 100mm, at least 120mm, or at least 140mm, or more.

In one embodiment, the new 7xxx aluminum alloy product has a thickness of at least 38mm and passes a stress corrosion cracking test ("SCC alternate immersion test") performed according to ASTM G47 under alternate immersion exposure conditions according to ASTM G44 using a standard stress-corrosion tension specimen conforming to ASTM G49. For the purposes of this patent application, when all samples remained intact for 20 days in the SCC alternate immersion test conducted under a net stress of 172MPa in the ST direction, then the new 7xxx aluminum alloys passed the SCC alternate immersion test with a test environment of 3.5% NaCl, requiring a minimum of five (5) samples to be tested. In one embodiment, the new 7xxx aluminum alloys pass the SCC alternate immersion test as defined above for 30 days. In another embodiment, the new 7xxx aluminum alloys pass the SCC alternate immersion test for 20 days, as defined above, but at a net stress of 241 MPa. In yet another embodiment, the new 7xxx aluminum alloys pass the SCC alternate immersion test for 30 days, as defined above, but at a net stress of 241 MPa. The above-mentioned stress corrosion cracking resistance can be achieved in products having a thickness of at least 60mm, or at least 80mm, or at least 100mm, at least 120mm, or at least 140mm, or more.

In one embodiment, the new 7xxx aluminum alloy product has a thickness of at least 38mm and passes the wet thermal SCC (stress corrosion cracking) test as defined below in accordance with ASTM G168 ("HHSCC-G168"). For the purposes of this patent application, when (a) the stress intensity factor is given to not exceed 10-⁷A crack growth rate in mm/s, and (b) a K value of at least 13MPa-sqrt-m (MPa v m) is achieved, the novel 7xxx aluminum alloys pass the HHSCC-G168 test. The HHSCC-G168 test was performed at T/2 and with S-L coupons at 70 ℃ and 85% relative humidity. In one embodiment, no greater than 10-⁷The K value achieved at a crack growth rate of mm/s is at least 14 MPa-sqrt-m. In another embodiment, at no greater than 10-⁷The K value achieved at a crack growth rate of mm/s is at least 15 MPa-sqrt-m. In yet another embodiment, at no greater than 10-⁷The K value achieved at a crack growth rate of mm/s is at least 16 MPa-sqrt-m. In another embodiment, at no greater than 10-⁷The K value achieved at a crack growth rate of mm/s is at least 17 MPa-sqrt-m. In yet another embodiment, at no greater than 10-⁷The K value achieved at a crack growth rate of mm/s is at least 18MPa-sqrt-m or higher. The above-mentioned stress corrosion cracking resistance can be achieved in products having a thickness of at least 60mm, or at least 80mm, or at least 100mm, at least 120mm, or at least 140mm, or more.

In one embodiment, the new 7xxx aluminum alloys pass at least two of the SCC tests defined above (i.e., at least two of (a) the HHSCC-G49 test as defined above, (b) the SCC replacement immersion test as defined above, and (c) the SCC hh-G168 test as defined above). In another embodiment, the new 7xxx aluminum alloys pass all of the SCC tests defined above.

While the above L and ST properties are generally referred to as thick sheet products, similar properties can be achieved in thick wrought products and thick extruded products. Furthermore, many of the above properties can also be achieved in combination, as shown by the examples below.

v. definition

Unless otherwise indicated, the following definitions apply to the present application:

the "7 xxx Aluminum Alloys" are Aluminum Alloy compositions having zinc as the major alloying element according to the Aluminum association definition provided in "International Alloy Designations and Chemical Composition Limits for Wurough Aluminum and Wurough Aluminum Alloys" (2015), also known as "Manual Sheets". For purposes of this patent application, the 7xxx aluminum alloy compositions may be used in non-wrought products, such as shape castings, ingot/billets, and additive manufactured products, among others.

"wrought aluminum alloy products" means aluminum alloy products that undergo hot working after casting, and includes rolled products (sheets or plates), forged products, and extruded products.

By "wrought aluminum alloy product" is meant a wrought aluminum alloy product that undergoes die forging or hand forging.

By "solution heat treatment" is meant exposing the aluminum alloy to elevated temperatures for the purpose of placing solutes in solid solution.

"Hot working" means working the aluminum alloy product at an elevated temperature, typically at least 250 ° F.

"Cold working" means working the aluminum alloy product at a temperature not considered a hot working temperature, typically below about 250 ° F (e.g., at ambient temperature).

By "artificial aging" is meant exposing the aluminum alloy to elevated temperatures for the purpose of precipitating solutes. Artificial aging may be performed in one or more steps, which may include changing the temperature and/or exposure time.

Strength and elongation were measured according to ASTM E8 and B557.

As used herein, a "typical longitudinal (L) tensile yield strength" or TYS (L) is determined according to ASTM B557-10 and by measuring the Tensile Yield Strength (TYS) in the longitudinal direction (L) at the T/4 position of material from at least three different batches, each of which is tested on at least two parallel samples, resulting in a total of at least 6 different measured sample values, typically TYS (L) being an average of at least 6 different measured sample values. Typical elongation (L) is measured during the longitudinal tensile test.

As used herein, a "typical longitudinal (ST) tensile yield strength" or TYS (ST) is determined according to ASTM B557-10 and by measuring the Tensile Yield Strength (TYS) in the short transverse direction (ST) of material from at least three different batches, each of which is tested on at least two parallel samples, resulting in a total of at least 6 different measured sample values, typically TYS (ST) being an average of at least 6 different measured sample values. A short transverse tensile sample is taken so that the midpoint of the gauge cross-section coincides with the panel mid-thickness plane. Typical elongation (ST) is measured during short transverse tensile testing.

As used herein, "typical plane strain fracture toughness (K)_IC) (L-T) "determined by measuring the plane strain fracture toughness (K) in the L-T direction of materials from at least three different batches using C (T) specimens as per ASTM E399-12, measured at the T/2 location for a sheet having a thickness of at most 4.0 inches, measured at the T/4 location for a sheet having a thickness greater than 4.0 inches, where" W "is 4.0 inches, for a product having a thickness of at least 2.0 inches, where" B "is 2.0 inches, and for a product having a thickness less than 2.0 inches, where" B "is 1.5 inches, testing at least two parallel specimens per batch to give a total of at least 6 different measured specimen values, typically the plane strain fracture toughness (K)_IC) (L-T) is at least 6 different effective Ks_ICThe average of the sample values is measured.

As used herein, "typical plane strain fracture toughness (K)_IC) (S-L) "is determined by measuring the in-plane strain fracture toughness in the S-L direction at the T/2 position of materials from at least three different batches using the C (T) specimens according to ASTM E399-12, wherein" W "and" B "are in accordance with the following table, and each batch is tested on at least two parallel specimens, yielding a total of at least 6 different measured specimen values, typically the in-plane strain fracture toughness (K)_IC) (S-L) is at least 6 different effective Ks_ICThe average of the sample values is measured.

S-L sample parameters

As used herein, "additive Manufacturing" means "a method of joining materials to manufacture an article according to 3D model data, typically layer-by-layer Manufacturing, as opposed to subtractive Manufacturing methods," as defined in ASTM F2792-12a entitled "Standard Terminology for additive Manufacturing Technologies". Non-limiting examples of additive manufacturing processes that may be used to manufacture aluminum alloy products include, for example, Direct Metal Laser Sintering (DMLS), Selective Laser Melting (SLM), Selective Laser Sintering (SLS), and Electron Beam Melting (EBM), among others. Any suitable feedstock made from the novel 7xxx aluminum alloys described above may be used, including one or more powders, one or more wires, one or more sheets, and combinations thereof. In some embodiments, the additive manufacturing feedstock consists of one or more powders comprising the novel 7xxx aluminum alloys. Wood shavings are a type of particle. In some embodiments, the additive manufacturing feedstock consists of one or more wires comprising the novel 7xxx aluminum alloys. A ribbon is one type of wire. In some embodiments, the additive manufacturing feedstock consists of one or more sheets comprising the novel 7xxx aluminum alloys. Foil is one type of sheet material.

These and other aspects, advantages, and novel features of this novel technology are set forth in part in the description that follows, and in part will become apparent to those skilled in the art upon examination of the following description and drawings, or may be learned by practice of one or more embodiments of the technology provided by this disclosure.

The drawings constitute a part of this specification and include illustrative embodiments of the present disclosure and illustrate various objects and features thereof. Additionally, any measurements, specifications, etc. shown in the various figures are intended to be illustrative, and not limiting. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.

Among those benefits and improvements that have been disclosed, other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings. Detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely illustrative of the invention that may be embodied in various forms. Additionally, each of the examples given in connection with the various embodiments of the invention are intended to be illustrative, and not restrictive.

Throughout the specification and claims, the following terms take the meanings explicitly associated herein, unless the context clearly dictates otherwise. As used herein, the phrases "in one embodiment" and "in some embodiments" do not necessarily refer to the same embodiment (although they may). Additionally, as used herein, the phrases "in another embodiment" and "in some other embodiments" do not necessarily refer to a different embodiment (although they may). Thus, various embodiments of the invention may be readily combined without departing from the scope or spirit of the invention.

Furthermore, as used herein, the term "or" is an inclusive "or" operator, and is equivalent to the term "and/or," unless the context clearly dictates otherwise. Unless the context clearly dictates otherwise, the term "based on" is not exclusive and allows for being based on other factors not described. Further, throughout this specification, the meaning of "a," "an," and "the" includes plural referents unless the context clearly dictates otherwise. The meaning of "in.

While various embodiments of the present invention have been described, it is to be understood that these embodiments are illustrative and not restrictive, and that various modifications may become apparent to those skilled in the art. Further, the various steps may be performed in any desired order, and any applicable steps may be added and/or eliminated, unless the context clearly requires otherwise.

Drawings

FIG. 1 is a graph illustrating the hot wet Stress Corrosion Cracking (SCC) G168 performance of the alloy of example 1.

FIG. 2 is a graphic representation of a tensile specimen used to test HHSCC-G49 resistance properties.

FIG. 3 is a graph illustrating the hot wet Stress Corrosion Cracking (SCC) G168 performance of the alloy of example 2.

Detailed Description

Example 1

Casting a plurality of 7xxx aluminum alloy compositions into rectangular ingots having a thickness of 2.875 inches: the new inventive alloy with silver and two conventional 7050 alloys and two conventional 7085 alloys. The composition of the alloys is provided in table 1 below.

TABLE 1 composition of alloy of example 1 (% by weight)

Each alloy contains 0.02-0.03 wt% Ti as incidental element; for each alloy, none of the impurities exceeded 0.05 wt.%, and the total amount of impurities did not exceed 0.15 wt.%.

After casting, the ingot was homogenized, shaved, and then hot rolled into a slab. The final gauge of the plate was about 1.125 inches (28.575 mm). The plate was then planarized, then solution heat treated, and then quenched in 195 ° f water. The 195 ° f water quench simulates the quenching conditions for thick plates (e.g., plates with a final gauge thickness of about 8-12 inches). After quenching, the plates were stretched and then artificially aged to a T7 temper. The mechanical properties of the panels were then evaluated. Strength and elongation properties were measured according to ASTM B557 and E8. Fracture toughness properties were measured according to ASTM E399. The results are provided in tables 2-3 below.

TABLE 2 longitudinal Properties

TABLE 3 short transverse Properties

As shown, the newly invented alloy achieves improved strength, elongation and fracture toughness compared to conventional alloys.

The alloys were also tested for corrosion resistance. Specifically, S-L oriented Double Cantilever Beam (DCB) specimens were tested according to ASTM G168 to measure the Stress Corrosion Cracking (SCC) resistance of each alloy. The temperature during the SCC test was 70 ℃ and the Relative Humidity (RH) was 85%. The test was repeated twice for each alloy. Fig. 1 shows the results. For comparison purposes, data for conventional factory produced 7050 and 7085 sheet products are also provided in fig. 1. As a baseline, the C-ring specimens were also placed in the test to measure the onset of stress corrosion cracking SCC based on time to failure at 60% TYS in 70 ℃ and 85% RH. After 87 days of testing, there was no failure in any of the compositions.

The DCB curves for the 7085 and 7050 book-type die alloys were consistent with those for factory-produced 7085-T7451(152mm) and 7050-T7451(100mm) slabs. However, for the present alloy (7085+ Ag), the crack growth rate is much lower and the threshold stress intensity (K) is much lower_ISCC) Much higher. Thus, the present alloys achieve improved strength, elongation, toughness, and SCC resistance compared to conventional alloys.

Example 2

Seven additional 7xxx aluminum alloys were cast into ingots (6 inches thick (152.4mm)) having the compositions shown in table 4 below.

Table 4-composition of alloy of example 2 (% by weight). -%.)

Each alloy contains 0.02-0.03 wt% Ti as incidental element; for each alloy, none of the impurities exceeded 0.05 wt.%, and the total amount of impurities did not exceed 0.15 wt.%.

Alloys 3 and 5 also contained about 0.25 wt.% Mn.

After being scraped and homogenized, the ingot was hot rolled to a final gauge of about 1.75 inches (44.45 mm). The alloy is then solution heat treated and then quenched in hot water (190F./87.8℃), which simulates a sheet about 8-12 inches (20.32-30.48cm) thick. After quenching, the plates were stretched and then artificially aged to various versions of the T7 temper. The mechanical properties of the panels were then evaluated. Strength and elongation properties were measured according to ASTM B557 and E8. Fracture toughness properties were measured according to ASTM E399. The results are provided in tables 5-6 below. (the term "alloy type __ - __" below indicates the alloy number as per Table 4 above, followed by the aging conditions for that alloy. for example, alloy 1-1 means alloy 1 as shown in Table 4 above, aged as usual 1.)

TABLE 5 short transverse Properties

*＝K_QValue of

TABLE 6 longitudinal Properties

*＝K_QValue of

Various example 2 alloys were also subjected to the hot humid SCC (stress corrosion cracking) ASTM G49 test ("HHSCC-G49") as defined in the summary section above, but some of the test specimens were tested at 90 ℃ instead of 70 ℃. The results are shown in tables 7 to 8 below. As described above in the summary section, for purposes of this patent application, an alloy passes the HHSCC-G49 test when all specimens remain intact for at least 100 days at 70 ℃ and passes the HHSCC-G49 test when all specimens remain intact for at least 10 days at 90 ℃.

TABLE 7-70 deg.C (85% TYS, 85% RH) HHSCC-G49 test results

T (#) indicates that the indicated sample did not fail after the specified number of test days, e.g., "T (42)" indicates that the sample did not fail after 42 days of testing.

TABLE 8-90 deg.C (85% TYS, 85% RH) HHSCC-G49 test results

T (#) indicates that the indicated sample did not fail after the specified number of test days, e.g., "T (7)" indicates that the sample did not fail after 7 days of testing.

Various example 2 alloys were also tested for Stress Corrosion Cracking (SCC) resistance according to ASTM G44 (3.5% NaCl, alternate immersion) and the results are shown in table 9 below.

Table 9-ASTM G44 results

"OK 90" means that the sample passed the final inspection after 90 days of testing according to ASTM G47.

Various example 2 alloys were also tested according to ASTM G168 of example 1. Fig. 3 shows the results. For comparison purposes, data for a conventional 7085 sheet product (factory produced) is also provided in fig. 3. Similar to the results of example 1, the alloy with silver achieved a much lower crack growth rate and a much higher threshold stress intensity (K)_ISCC)。

The above results for example 2 show that the novel 7xxx + Ag alloys achieve an improved combination of at least two of strength, ductility, fracture toughness, and corrosion resistance.

While various embodiments of the present disclosure have been described in detail, it is apparent that modifications and adaptations of those embodiments will occur to those skilled in the art. However, it is to be expressly understood that such modifications and adaptations are within the spirit and scope of the present disclosure.

Claims (65)

1. A 7xxx aluminum alloy comprising: 0.05 to 1.0 wt% Ag; 1.2 to 2.6 wt% Cu; 1.3 to 2.5% by weight of Mg; 5.5 to 9.0% by weight of Zn; up to 0.60% by weight of Mn; up to 1.0% by weight of at least one grain structure control material, wherein the at least one grain structure control material is selected from the group consisting of Zr, Cr, V, Hf, other rare earth elements, and combinations thereof, up to 0.30 wt% Fe; up to 0.30% by weight of Si; up to 0.15% by weight of Ti; not more than 0.08% by weight of Sc; not more than 0.05% by weight of Li; The balance is aluminum, optional incidental elements and impurities. 2. The 7xxx aluminum alloy of claim 1, wherein the 7xxx aluminum alloy comprises at least 5.75 wt% Zn, or at least 6.0 wt% Zn, or at least 6.25 wt% Zn, or at least 6.5 wt% Zn , or at least 6.75 wt% Zn, or at least 7.0 wt% Zn. 3. The 7xxx aluminum alloy of any preceding claim, wherein the 7xxx aluminum alloy comprises no more than 8.75 wt% Zn, or no more than 8.5 wt% Zn, or no more than 8.25 wt% Zn, Either no more than 8.0 wt% Zn, or no more than 7.75 wt% Zn, or no more than 7.5 wt% Zn, or no more than 7.25 wt% Zn. 4. The 7xxx aluminum alloy of claim 1, wherein the 7xxx aluminum alloy comprises no more than 7.0 wt. % Zn, or no more than 6.75 wt. % Zn, or no more than 6.5 wt. % Zn. 5. The 7xxx aluminum alloy of any preceding claim, wherein the 7xxx aluminum alloy comprises no more than 2.3 wt% Cu, or no more than 2.2 wt% Cu, or no more than 2.1 wt% Cu, Either no more than 2.0 wt% Cu, or no more than 1.9 wt% Cu, or no more than 1.8 wt% Cu. 6. The 7xxx aluminum alloy of any preceding claim, wherein the 7xxx aluminum alloy comprises at least 1.3 wt % Cu, or at least 1.4 wt % Cu, or at least 1.5 wt % Cu, or at least 1.6 wt % Cu wt % Cu, or at least 1.7 wt % Cu, or at least 1.8 wt % Cu. 7. The 7xxx aluminum alloy of any preceding claim, wherein the 7xxx aluminum alloy comprises no more than 2.2 wt% Mg, or no more than 2.1 wt% Mg, or no more than 2.0 wt% Mg, or no more than 1.9 wt% Mg, or no more than 1.8 wt% Mg, or no more than 1.7 wt% Mg, or no more than 1.65 wt% Mg. 8. The 7xxx aluminum alloy of any preceding claim, wherein the 7xxx aluminum alloy comprises at least 1.4 wt% Mg, or at least 1.45 wt% Mg. 9. The 7xxx aluminum alloy of any preceding claim, wherein the combined amount of copper and magnesium is at least 3.0 wt% (ie, (wt% of Cu) + (wt% of Mg) > 3.0 wt%) , or at least 3.25 wt%, or at least 3.5 wt%, or at least 3.75 wt%, or at least 4.0 wt%. 10. The 7xxx aluminum alloy of any preceding claim, wherein the 7xxx aluminum alloy comprises at least 0.06 wt % Ag, or at least 0.07 wt % Ag, or at least 0.08 wt % Ag, or at least 0.09 wt % Ag wt% Ag, at least 0.10 wt% Ag, or at least 0.15 wt% Ag, or at least 0.2 wt% Ag, or at least 0.225 wt% Ag, or at least 0.25 wt% Ag. 11. The 7xxx aluminum alloy of any preceding claim, wherein the 7xxx aluminum alloy comprises no more than 0.7 wt% Ag, or no more than 0.5 wt% Ag, or no more than 0.4 wt% Ag, Either up to 0.35 wt% Ag, or up to 0.3 wt% Ag. 12. The 7xxx aluminum alloy of any preceding claim, wherein the 7xxx aluminum alloy comprises at least 0.05 wt. % Mn, or at least 0.10 wt. % Mn, or at least 0.15 wt. % Mn, or at least 0.20 wt. wt % Mn, or at least 0.25 wt % Mn. 13. The 7xxx aluminum alloy of any preceding claim, wherein the 7xxx aluminum alloy comprises no more than 0.55 wt% Mn, or no more than 0.50 wt% Mn, or no more than 0.45 wt% Mn, or up to 0.40 wt% Mn. 14. The 7xxx aluminum alloy of any one of claims 1-11, wherein the 7xxx aluminum alloy comprises no more than 0.04 wt% Mn, or no more than 0.03 wt% Mn, or no more than 0.02 wt% Mn Mn, or up to 0.01 wt% Mn. 15. The 7xxx aluminum alloy of any preceding claim, wherein the at least one grain structure control material is at least chromium, and wherein the 7xxx aluminum alloy comprises at least 0.05 wt% Cr, or at least 0.10 wt % Cr, or at least 0.12 wt % Cr, or at least 0.14 wt % Cr. 16. The 7xxx aluminum alloy of claim 15, wherein the 7xxx aluminum alloy comprises no more than 0.24 wt. % Cr, or no more than 0.22 wt. % Cr, or no more than 0.20 wt. % Cr. 17. The 7xxx aluminum alloy of any one of claims 1-14, wherein the 7xxx aluminum alloy comprises no more than 0.04 wt % Cr, or no more than 0.03 wt % Cr, or no more than 0.02 wt % Cr Cr, or up to 0.01 wt% Cr. 18. The 7xxx aluminum alloy of any preceding claim, wherein the 7xxx aluminum alloy comprises no more than 0.25 wt % Fe, or no more than 0.20 wt % Fe, or no more than 0.15 wt % Fe, Either up to 0.12 wt% Fe, or up to 0.10 wt% Fe, or up to 0.08 wt% Fe, or up to 0.06 wt% Fe, or up to 0.04 wt% Fe. 19. The 7xxx aluminum alloy of any preceding claim, wherein the 7xxx aluminum alloy comprises no more than 0.25 wt % Si, or no more than 0.20 wt % Si, or no more than 0.15 wt % Si, Or no more than 0.12 wt% Si, or no more than 0.10 wt% Si, or no more than 0.08 wt% Si, or no more than 0.06 wt% Si, or no more than 0.04 wt% Si. 20. The 7xxx aluminum alloy of any preceding claim, wherein the 7xxx aluminum alloy comprises at least 0.005 wt % Ti, or at least 0.010 wt % Ti, or at least 0.015 wt % Ti, or at least 0.020 wt% Ti. 21. The 7xxx aluminum alloy of any preceding claim, wherein the 7xxx aluminum alloy comprises no more than 0.10 wt % Ti, or no more than 0.08 wt % Ti, or no more than 0.07 wt % Ti, Either up to 0.06 wt% Ti, or up to 0.05 wt% Ti. 22. The 7xxx aluminum alloy of any preceding claim, wherein the grain structure controlling material is at least Zr, and wherein the alloy comprises 0.05 to 0.20 wt % Zr. 23. The 7xxx aluminum alloy of claim 22, wherein the 7xxx aluminum alloy comprises at least 0.06 wt % Zr, or at least 0.07 wt % Zr, or at least 0.08 wt % Zr. 24. The 7xxx aluminum alloy of any one of claims 22-23, wherein the 7xxx aluminum alloy comprises no more than 0.18 wt % Zr, or no more than 0.16 wt % Zr, or no more than 0.15 wt % Zr Zr, or up to 0.14 wt % Zr, or up to 0.13 wt % Zr. 25. The 7xxx aluminum alloy of any one of claims 1-21, wherein the 7xxx aluminum alloy comprises no more than 0.04 wt % Zr, or no more than 0.03 wt % Zr, or no more than 0.01 wt % Zr Zr, or up to 0.005 wt% Zr. 26. The 7xxx aluminum alloy of any preceding claim, wherein the 7xxx aluminum alloy comprises no more than 0.05 wt % Sc, or no more than 0.03 wt % Sc, or no more than 0.01 wt % Sc, or up to 0.005 wt% Sc. 27. The 7xxx aluminum alloy of any preceding claim, wherein the 7xxx aluminum alloy comprises no more than 0.03 wt % Li, or no more than 0.01 wt % Li, or no more than 0.005 wt % Li. 28. A 7x85 aluminum alloy comprising 0.05 to 1.0 wt% Ag. 29. A 7x65 aluminum alloy comprising 0.05 to 1.0 wt% Ag. 30. A 7x40 aluminum alloy comprising 0.05 to 1.0 wt% Ag. 31. A 7x50 aluminum alloy comprising 0.05 to 1.0 wt% Ag. 32. A 7x55 aluminum alloy comprising 0.05 to 1.0 wt % Ag. 33. A 7x36 aluminum alloy comprising 0.05 to 1.0 wt % Ag. 34. A 7x37 aluminum alloy comprising 0.05 to 1.0 wt% Ag. 35. A 7x10 aluminum alloy comprising 0.05 to 1.0 wt% Ag. 36. A 7x81 aluminum alloy comprising 0.05 to 1.0 wt % Ag. 37. A 7x99 aluminum alloy comprising 0.05 to 1.0 wt% Ag. 38. A 7x49 aluminum alloy comprising 0.05 to 1.0 wt % Ag. 39. A 7x75 aluminum alloy comprising 0.05 to 1.0 wt % Ag. 40. A 7x97 aluminum alloy comprising 0.05 to 1.0 wt % Ag. 41. The 7xxx aluminum alloy of any one of claims 28-40, wherein the 7xxx aluminum alloy comprises at least 0.06 wt % Ag, or at least 0.07 wt % Ag, or at least 0.08 wt % Ag, or At least 0.09 wt% Ag, at least 0.10 wt% Ag, or at least 0.15 wt% Ag, or at least 0.2 wt% Ag, or at least 0.225 wt% Ag, or at least 0.25 wt% Ag. 42. The 7xxx aluminum alloy of any one of claims 28-40, wherein the 7xxx aluminum alloy comprises no more than 0.7 wt % Ag, or no more than 0.5 wt % Ag, or no more than 0.4 wt % Ag Ag, or no more than 0.35 wt% Ag, or no more than 0.3 wt% Ag. 43. A wrought aluminium alloy product made from a 7xxx aluminium alloy according to any preceding claim. 44. The wrought aluminum alloy product of claim 43, wherein the wrought aluminum alloy product has a thickness of at least 12.7 mm. 45. The wrought aluminum alloy product of claim 43, wherein the wrought aluminum alloy product has a thickness of at least 25 mm, or at least 38 mm, or at least 60 mm, or at least 80 mm, or at least 100 mm, or at least 120 mm, or At least 140mm. 46. The wrought aluminum alloy product of any one of claims 44-45, wherein the wrought aluminum alloy product has a thickness of no more than 305 mm, or no more than 254 mm, or no more than 203 mm, or no more than 178 mm. 47. The wrought aluminum alloy product of any one of claims 44-46, wherein the wrought aluminum alloy product achieves a tensile yield strength (L) of at least 400 MPa in the T7 tempered condition, or at T7 Achieve a tensile yield strength (L) of at least 410 MPa in the tempered condition, or at least 420 MPa in the T7 tempered condition, or at least 430 MPa in the T7 tempered condition (L), or a tensile yield strength (L) of at least 440 MPa in the T7 tempered condition, or a tensile yield strength (L) of at least 450 MPa in the T7 tempered condition, or at least 450 MPa in the T7 tempered condition A tensile yield strength (L) of at least 460 MPa, or a tensile yield strength (L) of at least 470 MPa in the T7 tempered condition, or a tensile yield strength (L) of at least 480 MPa in the T7 tempered condition. 48. The wrought aluminum alloy product of any one of claims 44-47, wherein the wrought aluminum alloy product achieves an elongation (L) of at least 8.0% in the T7 tempered condition, or at T7 At least 9.0% elongation (L) in the tempered condition, or at least 10.0% elongation (L) in the T7 tempered condition, or at least 9.0% elongation in the T7 tempered condition (L), or at least 11.0% elongation (L) in the T7 tempered condition, or at least 12.0% elongation (L) in the T7 tempered condition. 49. The wrought aluminum alloy product of any one of claims 44-48, wherein the wrought aluminum alloy product achieves a typical tensile yield strength (ST) of at least 400 MPa in the T7 tempered condition, or at A typical tensile yield strength (ST) of at least 410 MPa in the T7 tempered condition, or a typical tensile yield strength (ST) of at least 420 MPa in the T7 tempered condition, or at least 430 MPa in the T7 tempered condition Tensile yield strength (ST), or achieve a typical tensile yield strength (ST) of at least 440 MPa in the T7 tempered condition. 50. The wrought aluminum alloy product of any one of claims 44-49, wherein the wrought aluminum alloy product achieves a plane strain ( _KIC ) fracture of at least 20 MPa-sqrt-m in the T7 tempered condition Toughness (SL), or at least 21 MPa-sqrt-m in plane strain (K _IC ) fracture toughness (SL) in the T7 tempered condition, or at least 22 MPa-sqrt-m in the T7 tempered condition Strain (K _IC ) fracture toughness (SL), or at least 23 MPa-sqrt-m plane strain (K _IC ) fracture toughness (SL) in the T7 tempered condition, or at least 24 MPa in the T7 tempered condition - plane strain (KIC) fracture toughness (SL) in sqrt-m, or at least 25 MPa-sqrt-m in plane strain ( _KIC ) fracture _toughness (SL) achieved in the T7 tempered condition. 51. The wrought aluminum alloy product of any one of claims 44-50, wherein the wrought aluminum alloy product achieves an elongation (ST) of at least 2.0% in the T7 tempered condition, or at T7 Achieve at least 3.0% elongation (ST) in the tempered condition, or at least 4.0% elongation (ST) in the T7 tempered condition, or at least 5.0% elongation in the T7 tempered condition (ST), or achieve at least 6.0% elongation (ST) in the T7 tempered condition. 52. The wrought aluminum alloy product of any one of claims 44-51, wherein the wrought aluminum alloy product passes the HHSCC-G49 test for 100 days at 70°C or 10 days at 90°C. 53. The wrought aluminum alloy product of any one of claims 44-52, wherein the wrought aluminum alloy product passes the HHSCC-G49 test for 150 days at 70°C or 15 days at 90°C. 54. The wrought aluminum alloy product of any one of claims 44-53, wherein the wrought aluminum alloy product passes the SCC Alternate Immersion Test at 172 MPa net stress (ST) for 20 days. 55. The wrought aluminum alloy product of any one of claims 44-54, wherein the wrought aluminum alloy product passes the SCC Alternate Immersion Test at 172 MPa net stress (ST) for 30 days. 56. The wrought aluminum alloy product of any one of claims 44-55, wherein the wrought aluminum alloy product passes the SCC Alternate Immersion Test at 20 days and 241 MPa net stress (ST). 57. The wrought aluminum alloy product of any one of claims 44-56, wherein the wrought aluminum alloy product passes the SCC Alternate Immersion Test at 241 MPa net stress (ST) for 30 days. 58. The wrought aluminum alloy product of any one of claims 44-57, wherein the wrought aluminum alloy product passes HHSCC-G168, wherein the stress intensity factor gives no more than ^10-7 mm/ s, and wherein the achieved K value is at least 13 MPa-sqrt-m (MPa√m). 59. The wrought aluminum alloy product of claim 58, wherein the realized K value is at least 14 MPa-sqrt-m, or wherein the realized K value is at least 15 MPa-sqrt-m, or wherein the realized K value is at least 15 MPa-sqrt-m The value is at least 16 MPa-sqrt-m, or wherein the achieved K value is at least 17 MPa-sqrt-m, or wherein the achieved K value is at least 18 MPa-sqrt-m. 60. The wrought aluminum alloy product of any one of claims 44-59, wherein the wrought aluminum alloy product is one of a sheet product, an extruded product, or a forged product. 61. The wrought aluminum alloy product of any one of claims 43, wherein the wrought aluminum alloy product is a sheet product. 62. An additively manufactured product made from the 7xxx aluminum alloy of any one of claims 1-42. 63. An additive manufacturing feedstock made from the 7xxx aluminum alloy of any one of claims 1-42. 64. A shape cast product made from the 7xxx aluminum alloy of any of claims 1-42. 65. An ingot or billet made from the 7xxx aluminum alloy of any one of claims 1-42.

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