Thin sheet or strip of aluminum alloy for bottle caps and wrapping foil has a thickness of less than 200 microns, is essentially free of manganese, and has increased mechanical strength

摘要

A thin sheet or strip with a thickness between 6 and 200 microns (Micro) is of an alloy with the following composition (by wt %): Si : 1.0 - 1.5; Fe : 1.0 - 1.5; Cu less than 0.2; Mn less than 0.1; other elements less than 0.05 each and less than 0.15 in total; and remainder Al. It has a resistance to rupture R m, in the annealed state, greater than 110 MPa, preferably greater than 115 MPa, for thickness greater than 9 Micro, and greater than 100 MPa for thickness between 6 and 9 Micro. An independent claim is also included for the fabrication of the thin sheet or strip, involving: production of a first strip either by semi-continuous casting followed by hot rolling, or by continuous casting optionally followed by hot rolling; cold rolling of the first strip to a final thickness with intermediate annealing at 250-350[deg]C, preferably 280-340[deg]C; and a final annealing at 200-370[deg]C.