High strength al-cu-li-zn-mg alloys

Abstract

Aluminum-base alloys containing Cu, Li, Zn and Mg are disclosed which possess highly desirable properties, such as relatively low density, high modulus, high strength/ductility combinations, strong natural aging response with and without prior cold work, and high artificially aged strength with and without prior cold work. In addition, the alloys possess good weldability, cryogenic properties, and elevated temperature properties. The alloys may comprise from about 3.5 to about 7 weight percent Cu, from about 0.1 to about 1.8 eight percent Li, from about 0.01 to about 4 weight percent Zn, from about 0.05 to about 3 weight percent Mg, from about 0.01 to about 2 weight percent grain refiner selected from Zr, Cr, Mn, Ti, Hf, V, Nb, B and TiB.sub.2, and the balance Al along with incidental impurities. Preferred alloys comprise from about 3.5 to 6.5 weight percent Cu, from about 0.5 to 1.8 weight percent Li, from about 0.3 to 2 weight percent Zn, from about 0.1 to 1.5 weight percent Mg, from about 0.05 to 0.5 weight percent grain refiner, and the balance Al and incidental impurities. Additional elements selected from Ge, Sn, Cd, In, Be, Sr, Sc, Y, and Ca may be included in the present alloys.