Abstract: The present invention is directed to an ultra-thick high strength aluminum alloy, comprising 7.5 to 8.4 wt. % Zn, 1.6 to 2.3 wt. % Mg, 1.4 to 2.1 wt. % Cu, and 0.05 to 0.15 wt. % Zr. This alloy can be fabricated to produce 2-10 inch thick plate, extrusion or forging products, and is especially suitable for aerospace structural components, especially large commercial airplane wing structure applications. The aluminum product has a minimum yield strength of [75 ksi?0.8×(thickness in inch?3.94 inch)] in LT direction and [76 ksi?0.8×(thickness in inch?3.94 inch)] in L direction for more than 2 inch thick product in T7651 temper. Besides strength, product provides necessary damage tolerance performance as well as corrosion resistance performance suitable for aerospace application.

Abstract: High strength aluminum alloys based on the Al—Zn—Mg—Cu alloy system preferably include high levels of zinc and copper, but modest levels of magnesium, to provide increased tensile strength without sacrificing toughness. Preferred ranges of the elements include by weight, 8.5-10.5% Zn, 1.4-1.85 % Mg, 2.25-3.0% Cu and at least one element from the group Zr, V, or Hf not exceeding about 0.5%, the balance substantially aluminum and incidental impurities. In addition, small amounts of scandium (0.05-0.30%) are also preferably employed to prevent recrystalization. During formation of the alloys, homogenization, solution heat treating and artificial aging processes are preferably employed.

Abstract: High strength aluminum alloys based on the Al—Zn—Mg—Cu alloy system preferably include high levels of zinc and copper to provide increased tensile strength without sacrificing toughness. In addition, small amounts of scandium are also preferably employed to prevent recrystalization. Preferred ranges of the elements include by weight, 8.5-11.0% Zn, 1.8-2.4% Mg, 1.8-2.6% Cu, 0.05-0.30% Sc and at least one element from the group Zr, V, or Hf not exceeding about 0.5%, the balance substantially aluminum and incidental impurities. During formation of the alloys, a homogenization process is preferably employed after alloy ingot casting in which a slow rate of temperature increase is employed as the alloy is heated as near as possible to its melting temperature. For the last 20-30 F below the melting temperature, the rate of increase is limited to 20 F/hr. or less to minimize the amount of low melting point eutectic phases and thereby further enhance fracture toughness of the alloy.