EP2971213B1

EP2971213B1 - Improved aluminum-magnesium-lithium alloys, and methods for producing the same

Info

Publication number: EP2971213B1
Application number: EP14775660.5A
Authority: EP
Inventors: Francine BOVARD; Roberto J. Rioja; Ralph R. Sawtell; Dirk C. Mooy
Original assignee: Arconic Inc
Current assignee: Howmet Aerospace Inc
Priority date: 2013-03-14
Filing date: 2014-03-11
Publication date: 2019-01-16
Anticipated expiration: 2034-03-11
Also published as: CN105143492B; CA2901879C; RU2015143481A; WO2014159324A1; CA2901879A1; EP2971213A4; EP2971213A1; RU2665655C2; RU2015143481A3; CN105143492A; IL240665A0; US20150376740A1

Description

BACKGROUND

Aluminum alloys are useful in a variety of applications. However, improving one property of an aluminum alloy without degrading another property is elusive. For example, it is difficult to increase the strength of an alloy without decreasing the toughness of an alloy. Other properties of interest for aluminum alloys include corrosion resistance and fatigue resistance, to name two.
GB 2 146 353 discloses alloys consisting essentially of, by weight, 1.0 to 8.0 of Mg, 0.05 to 1.0 % of Li, at least one element selected from the group consisting of 0.05 to 0.20% of Ti, 0.05 to 0,40% of Cr, 0.05 to 0.30% of Zr, 0.05 to 0.35% of V, 0.05 to 0.30% of W and 0.05 to 2.0% of Mn, and the balance being aluminum and incidental impurities. Further, Bi in the range of 0.05 to 0.50 wt.% may be contained in said alloy.

SUMMARY OF THE DISCLOSURE

Broadly, the present patent application relates to new aluminum-magnesium-lithium alloys, and methods for producing the same, as defined in claims 1 and 6.
The new aluminum-magnesium-lithium generally alloys contain 2.0 to 3.9 wt. % Mg. Magnesium may help improve strength, but too much magnesium may degrade corrosion resistance. In one embodiment, the new alloys include at least 2.25 wt. % Mg. In another embodiment, the new alloys contain at least 2.5 wt. % Mg. In yet another embodiment, the new alloys include at least 2.75 wt. % Mg. In one embodiment, the new alloys include not greater than 3.75 wt. % Mg. In another embodiment, the new alloys include not greater than 3.5 wt. % Mg. In yet another embodiment, the new alloys include not greater than 3.25 wt. % Mg.
The new aluminum-magnesium-lithium generally contain 0.1 to 1.8 wt. % Li. Lithium helps reduce density and may help improve strength, but too much lithium may reduce ductility. In one embodiment, the new alloys include at least 0.4 wt. % Li. In another embodiment, the new alloys include at least 0.6 wt. % Li. In yet another embodiment, the new alloys include at least 0.8 wt. % Li. In another embodiment, the new alloys include at least 1.0 wt. % Li. In yet another embodiment, the new alloys include at least 1.05 wt. % Li. In another embodiment, the new alloys include at least 1.10 wt. % Li. In yet another embodiment, the new alloys include at least 1.20 wt. % Li. In one embodiment, the new alloys include not greater than 1.5 wt. % Li. In another embodiment, the new alloys include not greater than 1.45 wt. % Li. In yet another embodiment, the new alloys include not greater than 1.4 wt. % Li.
The new alloys may contain up to 1.5 wt. % Cu. Copper may improve strength but increases density. In one embodiment, the new alloys contain not greater than 1.0 wt. % Cu. In another embodiment, the new alloys contain not greater than 0.9 wt. % Cu. In yet another embodiment, the new alloys contain not greater than 0.6 wt. % Cu. In another embodiment, the new alloys contain not greater than 0.5 wt. % Cu. In embodiments where copper is used, the new alloys generally contain at least 0.05 wt. % Cu. In one embodiment, the new alloys include at least 0.10 wt. % Cu. In embodiments where copper is not used, the new alloys include less than 0.05 wt. % Cu.
The new alloys may contain up to 2.0 wt. % Zn when Mg is within 2.5 - 3.9 wt.-% and Li is within 1.05 and 1.8 wt.-%. Alternatively, the new alloys generally contain 0.4 to 2.0 wt.-% Zn. Zinc may improve strength, but increases density. In one embodiment, the new alloys contain not greater than 1.5 wt. % Zn. In another embodiment, the new alloys contain not greater than 1.0 wt. % Zn. In embodiments where zinc is used, the new alloys generally contain at least 0.20 wt. % Zn. In one embodiment, the new alloys contain at least 0.4 wt. % Zn. In another embodiment, the new alloys contain at least 0.5 wt. % Zn. In embodiments where zinc is not used, the new alloys include less than 0.20 wt. % Zn.
The new alloys may contain up to 1.5 wt. % Mn. Manganese may improve strength, but increases density. In one embodiment, the new alloys contain not greater than 1.0 wt. % Mn. In another embodiment, the new alloys contain not greater than 0.9 wt. % Mn. In yet another embodiment, the new alloys contain not greater than 0.7 wt. % Mn. In embodiments where manganese is used, the new alloys generally contain at least 0.05 wt. % Mn. In one embodiment, the new alloys include at least 0.20 wt. % Mn. In embodiments where manganese is not used, the new alloys include not greater than 0.04 wt. % Mn.
The new alloys may contain up to 1.0 wt. % Ag. Silver may improve strength, but silver decreases density and is expensive. In one embodiment, the new alloys contain not greater than 0.9 wt. % Ag. In another embodiment, the new alloys contain not greater than 0.6 wt. % Ag. In embodiments where silver is used, the new alloys generally contain at least 0.05 wt. % Ag. In one embodiment, the new alloys include at least 0.20 wt. % Ag. In embodiments where silver is not used, the new alloys include not greater than 0.04 wt. % Ag.
The new alloys may contain up to 0.5 wt. % Si. Silicon may improve corrosion resistance, but may decrease fracture toughness. In one embodiment, the new alloys contain not greater than 0.35 wt. % Si. In another embodiment, the new alloys contain not greater than 0.25 wt. % Si. In embodiments where silicon is used, the new alloys generally contain at least 0.10 wt. % Si. In embodiments where silicon is not used, the new alloys include not greater than 0.09 wt. % Si.
The new alloys may optionally include at least one secondary element selected from the group consisting of Zr, Sc, Cr, Hf, V, Ti, and rare earth elements. Such elements may be used, for instance, to facilitate the appropriate grain structure in the resultant aluminum alloy product. The secondary elements may optionally be present as follows: up to 0.20 wt. % Zr, up to 0.30 wt. % Sc, up to 0.50 wt. % of Cr, up to 0.25 wt. % each of any of Hf, V, and rare earth elements, and up to 0.10 wt. % Ti. Zirconium (Zr) and/or scandium are preferred for grain structure control. When zirconium is used, it is generally included in the new aluminum alloys at 0.05 to 0.20 wt. % Zr. In one embodiment, the new aluminum alloys include 0.07 to 0.16 wt. % Zr. Scandium (Sc) may be used in addition to, or as a substitute for zirconium, and, when present, is generally included in the new aluminum alloys at 0.05 to 0.30 wt. % Sc. In one embodiment, the new aluminum alloys include 0.07 to 0.25 wt. % Sc. Chromium (Cr) may also be used in addition to, or as a substitute for zirconium, and/or scandium, and when present is generally included in the new alloys at 0.05 to 0.50 wt. % Cr. In one embodiment, the new aluminum alloys include 0.05 to 0.35 wt. % Cr. In another embodiment, the new aluminum alloys include 0.05 to 0.25 wt. % Cr. In other embodiments, any of zirconium, scandium, and/or chromium may be included in the alloy as an impurity, and in these embodiments such elements would be included in the alloy at less than 0.05 wt. %.
Hf, V and rare earth elements may be included an in an amount of up to 0.25 wt. % each of any of Hf, V, and rare earth elements (0.25 wt. % each of any rare earth element may be included). In one embodiment, the new aluminum alloys include not greater than 0.05 wt. % each of Hf, V, and rare earth elements (≤ 0.05 wt. % each of any rare earth element).
Titanium is preferred for grain refining during casting, and, when present is generally included in the new aluminum alloys at 0.005 to 0.10 wt. % Ti. In one embodiment, the new aluminum alloys include 0.01 to 0.05 wt. % Ti. In another embodiment, the aluminum alloys include 0.01 to 0.03 wt. % Ti.
The new alloys may include up to 0.35 wt. % Fe. In some embodiments, the iron content of the new aluminum alloys is not greater than 0.25 wt. % Fe, or not greater than 0.15 wt. % Fe, or not greater than 0.10 wt. % Fe, or not greater than 0.08 wt. % Fe, or not greater than 0.05 wt. % Fe, or less.
Aside from the above-listed elements, the balance (remainder) of the new aluminum alloys is generally aluminum and impurities.
Except where stated otherwise, the expression "up to" when referring to the amount of an element means that that elemental composition is optional and includes a zero amount of that particular compositional component. Unless stated otherwise, all compositional percentages are in weight percent (wt. %).
In embodiments where the aluminum alloy is solution heat treated (described below), the total amount of magnesium, lithium, copper, zinc, silicon, iron, the secondary elements and the other elements should be chosen so that the aluminum alloy can be appropriately solutionized (e.g., to promote hardening while restricting the amount of constituent particles). In one embodiment, the aluminum alloy includes an amount of alloying elements that leaves the aluminum alloy free of, or substantially free of, soluble constituent particles after solutionizing. In one embodiment, the aluminum alloy includes an amount of alloying elements that leaves the aluminum alloy with low amounts of (e.g., restricted / minimized) insoluble constituent particles after solutionizing. In other embodiments, the aluminum alloy may benefit from controlled amounts of insoluble constituent particles.
The new aluminum alloys may be processed into a variety of wrought forms, such as in rolled form (sheet, plate), as an extrusion, or as a forging, and in a variety of tempers. In this regard, new aluminum alloys may be cast (e.g., direct chill cast or continuously cast), and then worked (hot and/or cold worked) into the appropriate product form (sheet, plate, extrusion, or forging). After working, the new aluminum alloys may be processed into one of an H temper, T temper or a W temper, as defined by the Aluminum Association.
For any of the H temper, T temper or W temper products, the aluminum alloy may be hot worked, such as by rolling, extruding and/or forging. In one embodiment, the hot working temperature is maintained below the recrystallization temperature of the alloy. In one embodiment, the hot working exit temperature is not greater than 316°C (600°F). In another embodiment, the hot working exit temperature is not greater than 288°C (550°F). In yet another embodiment, the hot working exit temperature is not greater than 260°C (500°F). In another embodiment, the hot working exit temperature is not greater than 232°C (450°F). In yet another embodiment, the hot working exit temperature is not greater than 204°C (400°F).
In one embodiment, the new alloy is processed to an H temper. In these embodiments, the processing may include casting the new aluminum alloy, including any version of the aluminum alloy described above, after which the aluminum alloy is hot rolled to an intermediate gauge or final gauge. In instances where the alloy is hot rolled to an intermediate gauge, it will then be cold rolled to final gauge (e.g., cold rolled 2-25%), and then optionally stretched (e.g., 1-10%), for instance, for flatness and/or for stress relief. In instances where the alloy is hot rolled to final gauge, it may be stretched (e.g., 1-10%), for instance, for flatness and/or for stress relief.
In embodiments where the aluminum alloy is cold rolled and/or stretched, the aluminum alloy may be cooled to a temperature of not greater than 204°C (400°F) prior to the cold rolling and/or the stretching. In one embodiment, the aluminum alloy is cooled to a temperature of not greater than 121°C (250°F) prior to the cold rolling and/or the stretching. In another embodiment, the aluminum alloy is cooled to a temperature of not greater than 93°C (200°F) prior to the cold rolling and/or the stretching. In yet another embodiment, the aluminum alloy is cooled to a temperature of not greater than 66°C (150°F) prior to the cold rolling and/or the stretching. In yet another embodiment, the aluminum alloy is cooled to ambient temperature prior to the cold rolling and/or the stretching.
When producing the aluminum alloy in an H temper, it may be detrimental to anneal the product. Thus, in some H-temper embodiments, the process includes maintaining the aluminum alloy at a temperature below 204°C(400°F) between the hot rolling step and any cold rolling and/or stretching step. In one H-temper embodiment, the process includes maintaining the aluminum alloy at a temperature of net 121°C (250°F) between the hot rolling step and/or any cold rolling and/or stretching step. In another H-temper embodiment, the process includes maintaining the aluminum alloy at a temperature of net 93°C (200°F) between the hot rolling step and/or any cold rolling and/or stretching step. In yet another H-temper embodiment, the process includes maintaining the aluminum alloy at a temperature of net 66°C (150°F) between the hot rolling step and/or any cold rolling and/or stretching step. In another H-temper embodiment, the process includes maintaining the aluminum alloy at ambient temperature between the hot rolling step and/or any cold rolling and/or stretching step.
In some embodiments, when producing the aluminum alloy in an H temper, it may be detrimental to apply any thermal treatment to the product after any cold rolling and/or stretching step. Thus, in some embodiments, an H-temper processing method is absent of any thermal treatments after any cold rolling step and/or any stretching step. However, in other embodiments, one or more anneal steps could be used, such as before or after hot and/or cold rolling.
In some embodiments when cold rolling is used as a part of H-temper processing, the cold rolling may be restricted to so as to facilitate good strength, ductility and/or corrosion resistance. In one embodiment, the cold rolling comprises cold rolling the intermediate gauge product by 1-25%, i.e., the thickness of the intermediate gauge product is reduced by 1-25% by cold rolling. In one embodiment, the cold rolling is 2-22%, i.e., the thickness of the intermediate gauge product is reduced by 2-22% by cold rolling. In another embodiment, the cold rolling is 3-20%, i.e., the thickness of the intermediate gauge product is reduced by 3-20% by cold rolling.
In another embodiment, the new aluminum alloy is processed to a "T temper" (thermally treated). In this regard, during or after the hot working (as appropriate), the new aluminum alloys may be processed to any of a T1, T2, T3, T4, T5, T6, T7, T8 or T9 temper, as defined by the Aluminum Association. In one embodiment, the new aluminum alloys are processed to one of a T4, T6 or T7 temper, where the new aluminum alloys are solution heat treated, and then quenched, and then either naturally aged (T4) or artificially aged (T6 or T7). In one embodiment, the new aluminum alloys are processed to one of a T3 or T8 temper, where the new aluminum alloys are solution heat treated, and then quenched, and then cold worked, and then either naturally aged (T3) or artificially aged (T8). In another embodiment, the new aluminum alloy is processed to an "W temper" (solution heat treated), as defined by the Aluminum Association. In yet another embodiment, no solution heat treatment is applied after the hot working, and thus the new aluminum alloy may be processed to an "F temper" (as fabricated), as defined by the Aluminum Association. The alloys may also be processed with high cold work after the solution heat treatment and quench, e.g., 25% or more cold work, as described in commonly-owned U.S. Patent Publication No. 2012/0055590 .
The new aluminum alloys may achieve an improved combination of properties. For example, the new aluminum alloys may achieve an improved combination of strength, corrosion resistance and/or ductility, among others.
In one approach, the new aluminum alloys are in an H-temper, are hot rolled, and then stretched 1-10%, (no cold rolling step) and realize a tensile yield strength (L) of at least 241 MPa (35 ksi) (tested via ASTM E8 and B557). In one embodiment, the new aluminum alloys realize a tensile yield strength (L) of at least 248 MPa (36 ksi). In another embodiment, the new aluminum alloys realize a tensile yield strength (L) of at least 262 MPa (38 ksi). In yet another embodiment, the new aluminum alloys realize a tensile yield strength (L) of at least 276 MPa (40 ksi). In another embodiment, the new aluminum alloys realize a tensile yield strength (L) of at least 290 MPa (42 ksi). In yet another embodiment, the new aluminum alloys realize a tensile yield strength (L) of at least 303 MPa (44 ksi). In another embodiment, the new aluminum alloys realize a tensile yield strength (L) of at least 317 MPa (46 ksi). In yet another embodiment, the new aluminum alloys realize a tensile yield strength (L) of at least 331 MPa (48 ksi). In another embodiment, the new aluminum alloys realize a tensile yield strength (L) of at least 345 MPa (50 ksi). In yet another embodiment, the new aluminum alloys realize a tensile yield strength (L) of at least 352 MPa (51 ksi), or more. In these H-temper and stretching embodiments, the new aluminum alloys may realize an elongation (L) of at least 10% (tested via ASTM E8 and B557). In one embodiment, the new aluminum alloys realize an elongation (L) of at least 12%. In another embodiment, the new aluminum alloys realize an elongation (L) of at least 14%. In yet another embodiment, the new aluminum alloys realize an elongation (L) of at least 16%. In another embodiment, the new aluminum alloys realize an elongation (L) of at least 18%, or more. In these H-temper and stretching embodiments, the new aluminum alloys may realize a mass loss of not greater than 25 mg/cm² (tested in accordance with ASMT G67, and with 1 week of exposure to 100°C). In one embodiment, the new aluminum alloys realize a mass loss of not greater than 15 mg/cm². In these H-temper and stretching embodiments, the new aluminum alloys may realize an EXCO rating of at least EB (at T/10 and/or at surface, and as tested in accordance with ASMT G66, and with 1 week of exposure to 100°C). In one embodiment, the new aluminum alloys realize an EXCO rating of at least EA. In another embodiment, the new aluminum alloys realize an EXCO rating of at least PC. In yet another embodiment, the new aluminum alloys realize an EXCO rating of at least PB. In another embodiment, the new aluminum alloys realize an EXCO rating of at least PA.
In another approach, the new aluminum alloys are in an H-temper, are hot rolled, and then cold rolled 1-25% and realize a tensile yield strength (L) of at least 276 MPa (40 ksi) (tested via ASTM E8 and B557). In one embodiment, the new aluminum alloys realize a tensile yield strength (L) of at least 290 MPa (42 ksi). In another embodiment, the new aluminum alloys realize a tensile yield strength (L) of at least 303 MPa (44 ksi). In yet another embodiment, the new aluminum alloys realize a tensile yield strength (L) of at least 317 MPa (46 ksi). In another embodiment, the new aluminum alloys realize a tensile yield strength (L) of at least 331 MPa (48 ksi). In yet another embodiment, the new aluminum alloys realize a tensile yield strength (L) of at least 345 MPa (50 ksi). In another embodiment, the new aluminum alloys realize a tensile yield strength (L) of at least 358 MPa (52 ksi). In yet another embodiment, the new aluminum alloys realize a tensile yield strength (L) of at least 372 MPa (54 ksi). In another embodiment, the new aluminum alloys realize a tensile yield strength (L) of at least 386 MPa (56 ksi). In yet another embodiment, the new aluminum alloys realize a tensile yield strength (L) of at least 400 MPa (58 ksi), or more. In these H-temper and cold rolling embodiments, the new aluminum alloys may realize an elongation (L) of at least 6% (tested via ASTM E8 and B557). In one embodiment, the new aluminum alloys realize an elongation (L) of at least 8%. In another embodiment, the new aluminum alloys realize an elongation (L) of at least 10%. In yet another embodiment, the new aluminum alloys realize an elongation (L) of at least 12%. In another embodiment, the new aluminum alloys realize an elongation (L) of at least 14%, or more. In these H-temper and cold rolling embodiments, the new aluminum alloys may realize a mass loss of not greater than 25 mg/cm² (tested in accordance with ASMT G67, and with 1 week of exposure to 100°C). In these H-temper and cold rolling embodiments, the new aluminum alloys may realize a mass loss of not greater than 15 mg/cm². In these H-temper and cold rolling embodiments, the new aluminum alloys may realize an EXCO rating of at least EB (at T/10 and/or at surface, and as tested in accordance with ASMT G66, and with 1 week of exposure to 100°C). In one embodiment, the new aluminum alloys realize an EXCO rating of at least EA. In another embodiment, the new aluminum alloys realize an EXCO rating of at least PC. In yet another embodiment, the new aluminum alloys realize an EXCO rating of at least PB. In another embodiment, the new aluminum alloys realize an EXCO rating of at least PA.
In yet another approach, the new aluminum alloys are in an T-temper, and realize a tensile yield strength (L) of at least 310 MPa (45 ksi) (tested via ASTM E8 and B557). In one embodiment, the new aluminum alloys realize a tensile yield strength (L) of at least 317 MPa (46 ksi). In another embodiment, the new aluminum alloys realize a tensile yield strength (L) of at least 331 MPa (48 ksi). In yet another embodiment, the new aluminum alloys realize a tensile yield strength (L) of at least 345 MPa (50 ksi). In another embodiment, the new aluminum alloys realize a tensile yield strength (L) of at least 359 MPa (52 ksi). In yet another embodiment, the new aluminum alloys realize a tensile yield strength (L) of at least 372 MPa (54 ksi). In another embodiment, the new aluminum alloys realize a tensile yield strength (L) of at least 386 MPa (56 ksi). In yet another embodiment, the new aluminum alloys realize a tensile yield strength (L) of at least 400 MPa (58 ksi). In another embodiment, the new aluminum alloys realize a tensile yield strength (L) of at least 414 MPa (60 ksi). In yet another embodiment, the new aluminum alloys realize a tensile yield strength (L) of at least 428 MPa (62 ksi), or more. In these T-temper embodiments, new aluminum alloys may realize an elongation (L) of at least 6% (tested via ASTM E8 and B557). In one embodiment, the new aluminum alloys realize an elongation (L) of at least 8%. In another embodiment, the new aluminum alloys realize an elongation (L) of at least 10%. In yet another embodiment, the new aluminum alloys realize an elongation (L) of at least 12%. In another embodiment, the new aluminum alloys realize an elongation (L) of at least 14%, or more. In these T-temper embodiments, the new aluminum alloys may realize a mass loss of not greater than 25 mg/cm² (tested in accordance with ASMT G67, and with 1 week of exposure to 100°C). In one embodiment, the new aluminum alloys realize mass loss of not greater than 15 mg/cm². In these T-temper embodiments, the new aluminum alloys may realize an EXCO rating of at least EB (at T/10 and/or at surface, and as tested in accordance with ASMT G66, and with 1 week of exposure to 100°C). In one embodiment, the new aluminum alloys realize an EXCO rating of at least EA. In another embodiment, the new aluminum alloys realize an EXCO rating of at least PC. In yet another embodiment, the new aluminum alloys realize an EXCO rating of at least PB. In another embodiment, the new aluminum alloys realize an EXCO rating of at least PA.
The new aluminum alloys described herein may be used in a variety of applications, such as in automotive and/or aerospace applications, among others. In one embodiment, the new aluminum alloys are used in an aerospace application, such as wing skins (upper and lower) or stringers / stiffeners, fuselage skin or stringers, ribs, frames, spars, bulkheads, circumferential frames, empennage (such as horizontal and vertical stabilizers), floor beams, seat tracks, doors, and control surface components (e.g., rudders, ailerons) among others. In another embodiment, the new aluminum alloys are used in an automotive application, such as closure panels (e.g., hoods, fenders, doors, roofs, and trunk lids, among others), wheels, and critical strength applications, such as in body-in-white (e.g., pillars, reinforcements) applications, among others. In yet another embodiment, the new aluminum alloys are used in a marine application, such as for ships and boats (e.g., hulls, decks, masts, and superstructures, among others). In another embodiment, the new aluminum alloys are used in a munitions / ballistics / military application, such as in ammunition cartridges and armor, among others. Ammunition cartridges may include those used in small arms and cannons or for artillery or tank rounds. Other possible ammunition components would include sabots and fins. Artillery, fuse components are another possible application as are fins and control surfaces for precision guided bombs and missiles. Armor components could include armor plates or structural components for military vehicles.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1-12 are graphs illustrating results of Example 1.
FIGS. 13 is a graph illustrating results of Example 2.
FIGS. 14-21 are graphs illustrating results of Example 3.

DETAILED DESCRIPTION

Example 1

Twelve book mold ingots were produced, the compositions of which are provided in Table 1, below (all values in weight percent).

Table 1 - Example 1 Alloy Compositions (alloys marked with * are outside of the claims)

Alloy	Mg	Li	Cu	Zn
1^*	2.89	0.00	0	0
2^*	2.80	0.21	0	0
3^*	2.90	0.87	0	0
4	2.80	1.20	0	0
5	2.70	1.60	0	0
6^*	5.03	0.00	0	0
7^*	4.75	0.23	0	0
8^*	4.75	0.87	0	0
9^*	4.55	1.20	0	0
10^*	5.55	0.85	0	0
11^*	5.04	0.00	0.19	0.54
12^*	4.50	0.86	0.18	0.46

Unless otherwise indicated, all alloys contained the listed elements, from 0.10 to 0.13 wt. % Zr, 0.60 wt. % Mn, not more than 0.04 wt. % Fe, not more than 0.03 wt. % Si, 0.02 wt. % Ti, the balance being aluminum and other elements, where the other elements did not exceed more than 0.05 wt. % each, and not more than 0.15 wt. % total of the other elements.

The alloys were cast as approximately 73.025 mm (2.875 inch) (ST) x 120.65 mm (4.75 inch) (LT) x 431.8 mm (17 inch) (L) ingots that were scalped (machined) to about 50.8 mm (2 inches) thick. Alloys 10-12 were then homogenized. Each ingot was then hot rolled to a gauge of about 6.35 mm (0.25 inch). The finish hot rolling temperature varied as shown below (the starting hot rolling temperature was about 454 °C (850°F)). Part of these hot rolled pieces were then cold rolled to a gauge of about 4.763 mm (0.1875 inch) (about a 25% reduction in thickness). For Alloys 1-5, other parts of the hot rolled pieces were stretched about 2% for flatness. The mechanical properties of the as hot rolled (HR), the as cold rolled materials (CR) and hot rolled and 2% stretched material (HR-2%S) were then tested, the results of which are provided in Tables 2-4, below. Strength and elongation properties were measured in accordance with ASTM E8 and B557 -- all test values relative to the longitudinal (L) direction, unless otherwise indicated.

Table 2 - Mechanical Properties of Hot Rolled (HR) Alloys

Alloy	*Hot Rolling Finish Temp. (°C) ((°F))**	TYS (MPa) ((ksi))**	UTS (MPa) ((ksi))**	Elong. (%)
1	500-550	25.2	35.8	28.4
1	400-450	28.7	38.3	26.1
2	500-550	24.3	37.9	24.9
3	400-450	32.5	46.2	15.2
4	400-450	35.0	48.5	12.9
5	400-450	35.7	53.0	11.8
6	400-450	35.0	50.0	24.1
6	500-550	32.4	49.7	23.2
7	400-450	36.8	53.2	17.0
8	500-550	31.5	51.8	23.5
9	400-450	38.3	55.8	19.1
10	400-450	39.0	57.5	18.9
11	400-450	40.4	56.5	17.5
12	400-450	39.1	56.8	16.4

* 0 °C = 32°F ** 1 ksi = 6.8948 MPa

Table 3 - Mechanical Properties of HR + 25% CR Alloys

Alloy	*Hot Rolling Finish Temp. (°C) ((°F))**	TYS (MPa) ((ksi))**	UTS (MPa) ((ksi))**	Elong. (%)
1	500-550	37.6	41.9	14.1
1	400-450	41.4	43.7	10.7
2	500-550	39.0	42.6	13.5
3	400-450	48.8	50.4	7.2
4	400-450	51.5	53.2	5.7
5	400-450	55.1	57.7	5.0
6	400-450	51.2	57.9	11.6
6	500-550	48.9	57.4	12.2
7	400-450	53.3	60.5	8.0
8	500-550	51.0	59.0	11.0
9	400-450	56.2	64.4	7.7
10	400-450	60.4	67.1	8.8
11	400-450	56.5	63.7	8.5
12	400-450	59.3	66.4	6.8

* 0 °C = 32°F ** 1 ksi = 6.8948 MPa

Table 4 - Mechanical Properties of HR + 2% Stretch Alloys

Alloy	*Hot Rolling Finish Temp. (°C) ((°F))**	TYS (MPa) ((ksi))**	UTS (MPa) ((ksi))**	Elong. (%)
1	500-550	27.4	35.5	24.3
1	400-450	30.7	37.8	23.9
2	500-550	31.8	38.4	22.5
3	400-450	39.8	44.9	15.4
4	400-450	43.4	47.9	12.6
5	400-450	48.8	53.2	10.3
* 0 °C = 32°F ** 1 ksi = 6.8948 MPa

As shown in FIGS. 1-3, lower hot rolling exit temperatures resulted in better properties. As shown in FIGS. 4-5, the cold rolled alloys generally realize better strength than the hot-rolled only alloys. As shown in FIGS. 6-7, the hot rolled alloys without cold rolling generally realized good ductility at all lithium levels. As shown in FIGS. 8-9, higher levels of magnesium and lithium generally result in higher strengths.

The HR only alloys and the HR + 25% CR alloys were also tested for corrosion resistance in accordance with ASTM G66 (exfoliation resistance) and G67 (mass loss). Specifically, the alloys were tested for corrosion resistance before and after exposure to a temperature of about 100°C for about 1 week. Alloys 1-5 that were hot rolled and then stretched 2% were also tested for corrosion resistance in accordance with ASTM G67 (mass loss). The corrosion resistance results are shown in Tables 5-7, below.

Table 5 - Corrosion Resistance Results - Hot Rolled (HR) Alloys

Alloy	*Hot Rolling Finish Temp. (°C) ((°F))**	Before Thermal Exposure			After Thermal Exposure
Alloy	*Hot Rolling Finish Temp. (°C) ((°F))**	G67 Mass Loss (mg/cm² )	G66 Ratin g @ T/10	G66 Rating @ Surfac e	G67 Mass Loss (mg/cm²)	G66 Rating @ T/10	G66 Rating @ Surface
1	500-550	1.11	PB	PB	1.75	PB	PB
1	400-450	1.47	PB	PB	1.90	PB	PB
2	500-550	1.26	PB	PB	1.79	PB	PB
3	400-450	1.38	PA	PA	3.06	PB	PB
4	400-450	1.21	PB	PB	2.99	PB	PB
5	400-450	1.64	PB	PB	2.48	EA	PB
6	400-450	1.74	PB	PB	40.05	EA	EC
6	500-550	1.90	PB	PB	49.23	EA	EC
6	400-450	1.30	PB	PB	49.17	PB	PB
7	400-450	1.65	PB	PB	31.11	EB	ED
7	400-450	1.66	PB	PB	33.68	EB	EB
8	500-550	2.36	PB	PB	55.61	EB	EB
9	400-450	3.55	EA	EA	33.18	EC	ED
9	400-450	2.31	PB	PB	29.68	PB	PB
10	400-450	7.70	PB	PB	46.20	EB	EC
10	400-450	6.84	PB	PB	73.16	EA	EA
11	400-450	2.00	EC	EC	13.73	EC	EC
11	400-450	1.72	EC	EC	15.72	EC	EC
12	400-450	2.20	EC	EC	14.98	EC	EC
12	400-450	2.31	EC	EC	17.77	ED	ED

* 0 °C = 32°F

Table 6 - Corrosion Resistance Results - HR + 25% CR Alloys

Alloy	*Hot Rolling Finish Temp. (°C) ((°F))**	Before Thermal Exposure			After Thermal Exposure
Alloy	*Hot Rolling Finish Temp. (°C) ((°F))**	G67 Mass Loss (mg/cm²)	G66 Rating @ T/10	G66 Rating @ Surface	G67 Mass Loss (mg/cm²)	G66 Rating @ T/10	G66 Rating @ Surface
1	500-550	1.16	PA	PA	1.49	PA	PA
1	400-450	1.55	PA	PA	1.68	PA	PA
2	500-550	1.33	PB	PB	2.03	PA	PA
3	400-450	1.26	PA	PA	4.58	EA	EA
4	400-450	1.25	PB	PB	4.20	EA	EA
5	400-450	1.37	PA	PA	2.29	PA	PA
6	400-450	1.48	PB	PB	38.29	ED	ED
6	500-550	1.34	PA	PA	53.10	ED	ED
6	400-450	1.37	PA	PA	56.63	EA	EA
7	400-450	1.49	PB	PB	36.46	ED	ED
7	400-450	1.76	PA	PA	35.72	ED	ED
8	500-550	2.08	PB	PB	54.86	ED	ED
9	400-450	2.70	EA	EA	33.47	ED	ED
9	400-450	2.08	PA	PA	44.44	ED	ED
10	400-450	5.01	PB	EA	43.08	ED	ED
10	400-450	4.11	PA	PA	68.24	ED	ED
11	400-450	1.77	EC	EC	29.55	ED	ED
11	400-450	1.63	EC	EC	30.67	ED	ED
12	400-450	2.31	EC	EC	26.13	ED	ED
12	400-450	2.25	EC	EC	28.01	ED	ED

* 0 °C = 32°F

Table 7 - Corrosion Resistance Results - Hot Rolled (HR) + 2% Stretch Alloys

Alloy	*Hot Rolling Finish Temp. (°C) ((°F))**	Before Thermal Exposure	After Thermal Exposure
Alloy	*Hot Rolling Finish Temp. (°C) ((°F))**	G67 Mass Loss (mg/cm²)
1	500-550	1.59	2.09
1	400-450	1.33	1.92
2	500-550	1.31	2.04
3	400-450	1.29	3.62
4	400-450	1.28	4.50
5	400-450	1.41	2.36
* 0 °C = 32°F

As shown in FIG. 10, all alloys realize low (good) mass loss prior to thermal exposure realizing less than 15 mg/cm² mass loss during the ASTM G67 test. However, after thermal exposure, the about 3 wt. % Mg alloys realize low mass loss, but many of Alloys 6-12 with magnesium realize high mass loss (See, FIG. 11). FIG. 12 illustrates mass loss as a function of lithium for high magnesium alloys. As shown above, the higher magnesium alloys also realize worse exfoliation resistance.

Example 2 (not according to the claims)

Fourteen book mold ingots were produced, the compositions of which are provided in Table 8, below (all values in weight percent).

Table 8 - Example 2 Alloy Compositions

Alloy	Mg	Li	Zn	Cu	Ag
13	4.42	2.01	0.96	0.35	0.24
14	4.33	2.09	1.87	0.35	0.23
15	4.53	2.13	0.97	0.95	0.24
16	4.48	2.18	1.92	0.95	0.24
17	4.41	2.03	0.97	0.35	0.65
18	4.38	2.04	1.90	0.36	0.65
19	4.41	2.06	0.98	0.95	0.66
20	4.36	2.12	1.89	0.89	0.62
21	4.37	2.08	1.44	0.65	0.44
22	4.31	2.22	2.82	0.64	0.43
23	4.43	2.16	1.44	1.85	0.45
24	4.45	2.18	1.48	0.68	0.91
25	4.45	2.06	1.45	0.67	0.45
26	4.40	2.13	1.45	0.67	0.44

Unless otherwise indicated, all alloys contained the listed elements, from about 0.10 to 0.012 wt. % Zr, not more than about 0.03 wt. % Fe, not more than 0.04 wt. % Si, about 0.02 wt. % Mn, about 0.02 wt. % Ti, the balance being aluminum and other elements, where the other elements did not exceed more than 0.05 wt. % each, and not more than 0.15 wt. % total of the other elements. Alloy 25 contained about 0.24 wt. % Si. Alloy 26 contained about 0.87 wt. % Si.

The alloys were cast as approximately 73.025 mm (2.875 inch) (ST) x 120.65 mm (4.75 inch) (LT) x 431.8 mm (17 inch) (L) ingots that were scalped to about 50.8 mm (2 inches) thick, and then homogenized. After homogenization, each ingot was hot rolled to a gauge of about 6.35 mm (0.25 inch), and then cold rolled about 25% (reduced in thickness by 25%) to a final gauge of about 4.763 mm (0.1875 inch). Tensile yield strength and corrosion resistance properties were then tested, the results of which are provided in Tables 9a-9b, below. Tensile yield strength properties were measured in accordance with ASTM E8 and B557 -- all test values relative to the longitudinal (L) direction, unless otherwise indicated. Corrosion resistance was tested in accordance with ASTM G66 (exfoliation resistance) and G67 (mass loss) -- the alloys were tested for corrosion resistance before and after exposure to a temperature of about 100°C for about 1 week.

Table 9a - Mechanical Properties of Example 2 Alloys

Alloy	*TYS (MPa) ((ksi))**	*UTS (MPa) ((ksi))**	Elong. (%)
13	59.2	66.0	6.4
14	60.1	65.7	3.9
15	55.6	62.1	5.2
16	57.3	62.0	5.2
17	64.3	68.9	3.7
18	59.4	64.2	4.5
19	54.2	59.5	5.9
20	52.9	59.4	4.6
21	55.7	61.8	7.1
22	55.3	60.2	4.8
23	53.2	59.3	6.1
24	55.9	60.6	3.5
25	56.0	60.2	5.5
26	53.6	58.1	4.6

* 1 ksi = 6.8948 MPa

Table 9b - Corrosion Resistance Properties of Example 2 Alloys

Alloy	Before Thermal Exposure			After Thermal Exposure
Alloy	G67 Mass Loss (mg/cm²)	G66 Rating @ T/10	G66 Rating @ Surface	G67 Mass Loss (mg/cm²)	G66 Rating @ T/10	G66 Rating @ Surface
13	1.64	PC	PB	21.66	ED	ED
14	2.26	PC	PB	25.62	ED	ED
15	2.43	PC	PA	23.36	ED	ED
16	2.48	PC	PC	28.80	ED	ED
17	2.14	PC	PC	31.19	ED	ED
18	2.72	PC	PB	32.85	ED	ED
19	3.71	PC	PA	23.99	ED	EC
20	2.99	PC	EC	34.99	ED	ED
21	2.48	PC	PC	29.38	ED	ED
22	3.31	PC	PC	43.34	ED	ED
23	4.09	PC	PC	32.86	ED	ED
24	3.41	PC	PA	28.25	ED	EC
25	2.40	PC	PA	25.59	ED	ED
26	3.41	PC	PA	17.45	PC	EC

As shown in FIG. 13, the strongest alloy contained about 1.0 wt. % Zn, 0.35 wt. % Cu and 0.65 wt. % Ag. In low silver alloys (∼ 0.25 wt. % Ag), increasing copper from about 0.35 to 0.95 wt. % and/or increasing zinc did appear to benefit strength. In medium silver alloys (∼ 0.45 wt. % Ag), increasing copper from about 0.65 to 1.85 wt. % decreased strength, and increasing zinc from about 1.45 to 2.82 wt. % had little effect on strength. In moderately-high silver alloys (∼ 0.65 wt. % Ag), increasing copper from about 0.35 to about 0.90 wt. % decreased strength, and increasing zinc also decreased strength. Increasing silver from about 0.45 to 0.91 wt. % did not appear to materially affect strength. Increasing silicon from about 0.04 wt. % to 0.24 wt. % also did not appear to materially affect strength. Increasing silicon to about 0.89 wt. %, however, did affect strength.
Regarding ductility, all of the alloys have somewhat low elongation, indicating that less than 25% cold work may be required to achieve better ductility.
Regarding corrosion resistance, most of the alloys did not pass the mass loss test, all achieving a mass loss of more than 15 mg/cm², and often a mass loss of more than 25 mg/cm². Increasing the silicon level did appear to help with mass loss.

Example 3

Twenty-three book mold ingots were produced, the compositions of which are provided in Table 9, below (all values in weight percent).

Table 10 - Example 1 Alloy Compositions (alloys marked with* are outside of the claims)

Alloy	Mg	Li	Mn	Cu	Zn
27^*	2.2	1.1	0.55	0.05	--
28	2.5	1.0	0.58	--	--
29	3.3	1.0	0.54	--	--
30	3.5	1.1	0.56	--	--
31^*	4.1	1.1	0.57	--	--
32	2.9	1.1	0.54	--	--
33	3.1	1.0	0.29	--	--
34	3.2	1.1	--	0.01	--
35	3.0	1.0	1.10	--	--
36	3.0	1.0	1.60	--	--
37	3.0	1.0	0.56	--	0.10
38	3.0	1.1	0.56	--	0.24
39	2.9	1.1	0.57	--	0.51
40	3.0	1.1	0.56	--	0.97
41	3.0	1.1	0.56	--	1.90
42	2.9	1.0	0.57	0.14	0.02
43	3.1	1.1	0.56	0.29	-
44	2.9	1.1	0.56	0.48	--
45	3.1	1.0	0.56	0.25	0.50
46	2.8	1.1	0.56	--	--
47	2.94	--	0.54	--	--
48^*	2.9	0.50	0.57	--	--
49^*	2.8	1.00	0.57	--	--
50	2.9	1.60	0.57	--	--

Unless otherwise indicated, all alloys contained the listed elements, from about 0.10 to 0.14 wt. % Zr, not more than about 0.04 wt. % Fe, not more than 0.08 wt. % Si, the balance being aluminum and other elements, where the other elements did not exceed more than 0.05 wt. % each, and not more than 0.15 wt. % total of the other elements. Alloy 46 contained about 0.09 wt. % Zr, about 0.10 wt. % Fe and about 0.14 wt. % Si.

The alloys were cast as 73.025 mm (2.875 inch) (ST) x 120.65 mm (4.75 inch) (LT) x 431.8 mm (17 inch) (L) ingots that were scalped to 50.8 mm (2 inches) thick and then homogenized. After homogenization, each ingot was hot rolled to a gauge of about 6.35 mm (0.25 inch) (Alloy 36 could not be rolled due to too much manganese). Part of these hot rolled pieces were then cold rolled to a gauge of about 4.763 mm (0.1875 inch) (about 25% reduction in thickness). Other parts of the hot rolled pieces were stretched about 2% for flatness. The mechanical properties and corrosion resistance properties of the hot rolled and cold rolled materials were then tested, the results of which are provided in Tables 11-14, below. Strength and elongation properties were measured in accordance with ASTM E8 and B557 -- all test values relative to the longitudinal (L) direction, unless otherwise indicated. Corrosion resistance was tested in accordance with ASTM G67 (mass loss) -- the alloys were tested for corrosion resistance before and after exposure to a temperature of about 100°C for about 1 week.

Table 11 - Mechanical Properties of Hot Rolled + 2% Stretch Alloys

Alloy	*TYS (MPa ((ksi))**	*UTS (MPa) ((ksi))**	Elong. (%)
27	38.3	41.3	13.5
28	38.1	42.6	15.0
29	45.5	15.0	15.0
30	40.3	46.7	15.5
31	40.7	47.4	14.5
32	39.1	43.6	14.0
33	37.3	41.3	16.0
34	35.7	40.5	16.0
35	42.6	47.9	13.0
37	39.4	44.7	15.5
38	39.4	44.9	15.5
39	39.7	45.0	15.0
40	39.9	45.5	15.5
41	42.6	49.3	15.0
42	41.7	46.3	15.0
43	44.9	50.4	13.0
44	49.4	53.3	10.0
45	42.5	48.4	15.0
46	40.1	44.8	15.5
47	37.0	41.0	18.5
48	38.0	42.7	15.0
49	40.3	44.7	15.5
50	44.5	49.9	14.0

* 1 ksi = 6.8948 MPa

Table 12 - Mechanical Properties of Hot Rolled + Cold Rolled Alloys

Alloy	*TYS (MPa) ((ksi))**	*UTS (MPa) ((ksi))**	Elong. (%)
27	45.5	46.7	7.0
28	47.4	49.1	8.5
29	45.3	53.6	8.0
30	51.4	55.7	8.0
31	52.2	57.2	9.0
32	51.3	52.2	8.0
33	46.9	49.4	10.0
34	43.0	45.4	9.5
35	51.9	56.7	6.0
37	48.5	52.0	9.0
38	49.2	52.8	8.0
39	49.0	52.4	8.0
40	49.6	53.4	8.0
41	48.5	56.0	7.5
42	44.5	53.3	8.0
43	55.9	56.9	8.0
44	57.5	59.7	7.5
45	52.7	55.0	8.5
46	50.5	51.7	7.0
47	43.7	47.1	10.5
48	45.2	48.4	8.5
49	48.9	51.2	8.5
50	57.9	59.6	7.5

* 1 ksi = 6.8948 MPa

Table 13 - Corrosion Resistance Results - Hot Rolled (HR) Alloys

Alloy	Before Thermal Exposure	After Thermal Exposure
Alloy	G67 Mass Loss (mg/cm²)
27	1.29	1.57
28	1.25	2.48
29	1.32	8.96
30	1.66	17.2
31	1.59	30.23
32	1.28	5.34
33	1.37	6.29
34	1.51	9.68
35	1.49	8.12
37	1.62	11.8
38	1.73	10.39
39	1.53	2.9
40	1.72	2.52
41	1.87	2.61
42	1.18	3.5
43	1.17	3.41
44	1.5	3.51
45	1.29	3.3
46	1.77	6.68
47	1.46	2.24
48	1.72	3.28
49	1.47	6.71
50	1.73	3.97

Table 14 - Corrosion Resistance Results - Hot Rolled (HR) + 25% CR Alloys

Alloy	Before Thermal Exposure	After Thermal Exposure
Alloy	G67 Mass Loss (mg/cm²)
27	1.28	1.81
28	1.2	2.79
29	1.35	11.26
30	1.63	18.2
31	1.72	32.45
32	1.31	8.77
33	1.3	9.97
34	1.25	10.23
35	1.76	14.96
37	1.64	12.88
38	1.72	12.22
39	1.55	4.11
40	1.63	3.14
41	1.92	2.67
42	1.22	5.17
43	1.31	5.96
44	1.46	4.91
45	1.28	5.13
46	1.82	9.32
47	1.46	2.57
48	1.57	4.58
49	1.59	11.51
50	1.63	3.97

As shown in FIGS. 14-18, increasing levels of Mg, Li, Mn and Cu resulted in increased strength. Increasing zinc may increase strength in hot rolled only alloys. However, as shown in FIG. 19, poor corrosion resistance is realized in alloys having more than about 4.0 wt. % Mg, indicating that the alloys should include not greater than 3.9 wt. % Mg for good corrosion resistance. As shown in FIG. 20, higher levels of copper tend to improve corrosion. As shown in FIG. 21, higher levels of zinc (e.g., at or above 0.4 wt. % Zn) also tend to improve corrosion resistance. Manganese above about 1.0 wt. % tends to degrade corrosion resistance.

Claims

A method comprising:
(a) casting an aluminum alloy consisting of:
2.0 - 3.9 wt. % Mg;

0.1 - 1.8 wt. % Li;

up to 1.5 wt. % Cu;
(A) 0.4 to 2.0 wt. % Zn, or alternatively

(B) up to 2.0 wt. % Zn, when Mg is within 2.5 - 3.9 wt. % and Li is within 1.05 and 1.8 wt. %;

up to 1.0 wt. % Ag;

up to 1.5 wt. % Mn;

up to 0.5 wt. % Si;

up to 0.35 wt. % Fe;

optionally at least one secondary element selected from the group consisting of Zr, Sc, Cr, Mn, Hf, V, Ti, and rare earth elements, and in the following amounts:
up to 0.20 wt. % Zr;

up to 0.30 wt. % Sc;

up to 0.50 wt. % Cr;

up to 1.0 wt. % Mn;

up to 0.25 wt. % each of any of Hf, V, and rare earth elements;

up to 0.10 wt. % Ti; and

the balance being aluminum and impurities;

and either
(b1) after the casting step (a), hot rolling the aluminum alloy into an intermediate product;

(c1) after the hot rolling step (b1), cooling the intermediate product to a temperature of not greater than 204°C (400°F);

(d1) after the cooling step (c1), cold rolling the intermediate product to final gauge, wherein the cold rolling reduces the thickness of the intermediate product by from 1% to 25%;

(e1) maintaining the aluminum alloy at a temperature of not greater than 204°C (400°F) between the cooling step (c1) and the cold rolling step (d1);
or
(b2) after the casting, hot rolling the aluminum alloy to final gauge;

(c2) after the hot rolling step (b2), cooling the aluminum alloy to a temperature of not greater than 204°C (400°F);

(d2) after the cooling step (c2), stretching the aluminum alloy 1% to 10%;

(e2) maintaining the aluminum alloy at a temperature of not greater than 400°F between the cooling step (c2) and the stretching step (d2).
The method of claim 1, wherein the cooling step (c1) comprises cooling the intermediate product to a temperature of not greater than 121°C (250°F), preferably not greater than 93°C (200°F), preferably not greater than 66°C (150°F), preferably to ambient temperature, and wherein the maintaining step (e) comprises maintaining the aluminum alloy at a temperature of not greater than 121°C (250°F), preferably not greater than 93°C (200°F), preferably not greater than 66°C (150°F), preferably at ambient temperature, between the cooling step (c1) and the cold rolling step (d1).
The method of any of claims 1 - 2, comprising:
after the cold rolling step (d1), solution heat treating and then quenching the aluminum alloy.
The method of claim 3, comprising:
after the solution heat treating and then quenching step, artificially aging the aluminum alloy.
The method of any of claims 1 - 2, wherein the method is absent of any thermal treatments after the cold rolling step (d1).
An aluminum alloy consisting of:
2.0 - 3.9 wt. % Mg;

0.1 - 1.8 wt. % Li;
(A) 0.4 to 2.0 wt.% Zn , or alternatively

(B) up to 2.0 wt. % Zn, when Mg is within 2.5 - 3.9 wt.% and Li is within 1.05 and 1.8 wt.%, up to 1.5 wt. % Cu;

up to 1.0 wt. % Ag;

up to 1.5 wt. % Mn;

up to 0.5 wt. % Si;

up to 0.35 wt. % Fe;

optionally at least one secondary element selected from the group consisting of Zr, Sc, Cr, Mn, Hf, V, Ti, and rare earth elements, and in the following amounts:
up to 0.20 wt. % Zr;

up to 0.30 wt. % Sc;

up to 0.50 wt. % Cr;

up to 1.0 wt. % Mn;

up to 0.25 wt. % each of any of Hf, V, and rare earth elements; and

up to 0.10 wt. % Ti; and

the balance being aluminum and impurities.
The aluminum alloy of claim 6, wherein the aluminum alloy includes 0.4 to 2.0 wt. % Zn and from 2.25 wt. % Mg to 3.9 wt. % Mg, preferably from 2.5 wt. % Mg to 3.9 wt. % Mg, preferably from 2.5 wt. % Mg to 3.5 wt. % Mg.
The aluminum alloy of any of claims 6-7, wherein the aluminum alloy includes 0.4 to 2.0 wt. % Zn and from 0.4 wt. % Li to 1.5 wt. % Li, preferably from 0.8 wt. % Li to 1.45 wt. % Li, preferably from 1.2 wt. % Li to 1.4 wt. % Li.
The aluminum alloy of any of claims 6-8, wherein the aluminum alloy includes from 0.4 wt. % Zn to 1.5 wt. % Zn.
The aluminum alloy of claim 6, wherein the aluminum alloy includes from 0.5 wt. % Zn to 1.0 wt. % Zn.
The aluminum alloy of any of claims 6 or 10, wherein the aluminum alloy includes 2.5 - 3.9 wt. % Mg, 1.05 - 1.8 wt. % Li and not greater than 1.0 wt. % Cu, preferably not greater than 0.9 wt. % Cu, preferably not greater than 0.5 wt. % Cu.
The aluminum alloy of any of claims 6, 10 or 11, wherein the aluminum alloy includes 2.5 - 3.9 wt. % Mg, 1.05 - 1.8 wt. % Li and at least 0.10 wt. % Cu.