Patent ID: 6423164
Filing Date: 2002-07-23
Classification: C22F

Abstract:
A method of producing an aluminum alloy sheet product comprising:casting an aluminum alloy to provide a slab said aluminum alloy, by weight percent, consisting essentially of 0.60 to 1.1 Si, 0.40 max. Fe, 0.50 to 0.9 Cu, 0.10 to 0.45 Mn 0.5 to 1.0 Mg, 0.10 max Cr, 0.15 max Zn; homogenizing the slab; hot rolling the slab in a hot mill to provide an intermediate gauge product, the hot rolling process being controlled so that the temperature of a slab upon entering the hot mill is sufficiently high to maintain solute in solid solution and so that the slab is rolled to provide an intermediate gauge product exiting the hot rolling step at a temperature between about 500 Â° F. (260Â° C.) and 600Â° F. (316Â° C.); cold rolling the intermediate gauge product to a final gauge product; said intermediate product being subjected to one of: annealing at a temperature of between 700Â° F. (371 Â° C.) and 900Â° F. (482 Â° C.) prior to cold rolling to the final gauge product, and cold rolling to provide a second intermediate gauge sheet product, annealing of said second intermediate gauge product between 600Â° F. (316Â° C.) and 900Â° F. (482Â° C.), and cold rolling of said annealed second intermediate gauge product to the final gauge product; and solution heat treating and quenching the final gauge product to provide an aluminum alloy sheet product, the method providing an aluminum alloy sheet product that, when subsequently strained, has a minimum of ridging lines formed on a surface thereof.