Abstract: A method is provided for producing a high strength aluminum alloy characterized by improved resistance to exfoliation. The method comprises providing an aluminum-base alloy comprising 5.9 to 8.2 wt. % zinc, 1.5 to 4.0 wt. % magnesium, 1.5 to 3.0 wt. % copper, less than 0.001 wt. % boron not more than 0.04 wt. % chromium, and 0.5 wt. % maximum other alloying elements such as zirconium, manganese, iron, silicon and titanium, with the balance consisting of aluminum, working the alloy into a product of predetermined shape, solution heat treating the shaped product, quenching, and aging the heat treated and quenched product to a temperature of from above 270.degree. F. to 285.degree. F. for a period of from 6 to 30 hours.

Abstract: A method is provided for producing a high strength aluminum alloy characterized by improved resistance to exfoliation. The method comprises providing an aluminum-base alloy comprising 5.9 to 8.2 wt. % zinc, 1.5 to 4.0 wt. % magnesium, 1.5 to 3.0 wt. % copper, less than 0.01 wt. % boron not more than 0.04 wt. % chromium, and 0.5 wt. % maximum other alloying elements such as zirconium, manganese, iron, silicon and titanium, with the balance consisting of aluminum, working the alloy into a product of predetermined shape, solution heat treating the shaped product, quenching, and aging the heat treated and quenched product to a temperature of from above 270.degree. F. for a period of from 6 to 30 hours.