Cast aluminum alloy for can stock and process for producing the alloy

Abstract

An aluminum alloy strip useful for can stock having a thickness of less than or equal to about 30 mm, and containing large (Mn,Fe)Al.sub.6 intermetallics as principal intermetallic particles in said strip. The intermetallic particles have an average surface size at a surface of the strip and an average bulk size in a bulk of the strip, the average surface size being greater than the average bulk size. The strip article may be produced by supplying a molten aluminum alloy having a composition consisting, in addition to aluminum, essentially by weight of: Si between 0.05 and 0.15%; Fe between 0.3 and 0.6%; Mn between 0.6 and 1.2%; Mg between 1.1 and 1.8%; Cu between 0.2 and 0.6%; and other elements: less than or equal to 0.05% each element with a maximum of 0.2% for the total of other elements; and casting the molten alloy in a continuous caster having opposed moving mold surfaces to an as-cast thickness of less than or equal to 30 mm. The moving mold surfaces have a surface roughness of between 4 and 13 microns, substantially in the form of sharp peaks, and heat flux is extracted from the metal at a rate that results in the production of an interdendritic arm spacing of between 12 and 18 microns at the surface of said strip. The strip may then be processed to final thickness by means of rolling and annealing steps.