Patent ID: 7883590

Claim:
A method of forming a heat treatable aluminum alloy, the method comprising: (a) forming a melt consisting of: 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; (b) solidifying the melt to form a solid body; and (c) heat treating the solid body.