Heat treatable L12 aluminum alloys

A heat treatable aluminum alloy comprising:

• about 1.0 to about 8.0 weight percent copper;
• about 0.2 to about 4.0 weight percent magnesium;
• about 0.5 to about 3.0 weight percent lithium;
• at least one first element selected from the group consisting of about 0.1 to about 0.5 weight percent scandium, about 0.1 to about 6.0 weight percent erbium, about 0.1 to about 10.0 weight percent thulium, about 0.1 to about 15.0 weight percent ytterbium, and about 0.1 to about 12.0 weight percent lutetium;
• at least one second element selected from the group consisting of about 0.1 to about 4.0 weight percent gadolinium, about 0.1 to about 4.0 weight percent yttrium, about 0.05 to about 1.0 weight percent zirconium, about 0.05 to about 2.0 weight percent titanium, about 0.05 to about 2.0 weight percent hafnium, and about 0.05 to about 1.0 weight percent niobium;
• and
• the balance substantially aluminum;
• wherein the alloy is formed by a process selected from the group consisting of casting, deformation processing or rapid solidification processing, followed by heat treating by a solution anneal at a temperature of about 800° F. (426° C.) to about 1100° F. (593° C.) for about 30 minutes to four hours, followed by quenching, and is thereafter aged at a temperature of about 200° F. (93° C.) to about 600° F. (316° C.) for about two to forty-eight hours.