US Patent 7993474 Aircraft structural member made of an Al-Cu-Mg alloy

The invention relates to a work-hardened product, particularly a rolled, extruded or forged product, made of an alloy with the following composition (% by weight): Cu 3.8-4.3; Mg 1.25-1.45; Mn 0.2-0.5; Zn 0.4-1.3; Fe<0.15; Si<0.15; Zr≦0.05; Ag<0.01, other elements <0.05 each and <0.15 total, remainder Al, treated by dissolution, quenching and cold strain-hardening, with a permanent deformation of between 0.5% and 15%, and preferably between 1.5% and 3.5%. Cold strain-hardening can be achieved by controlled tension and/or cold transformation, for example rolling, die forging or drawing. This cladded metal plate type product is a suitable element to be used as aircraft fuselage skin.