Patent ID: 8840737

Claim:
A plate comprising an aluminum alloy, wherein the aluminum alloy consists essentially of 6.8-8.5 wt. % Zn, 1.75-2.3 wt. % Cu, 1.5-1.84 wt. % Mg, and up to 0.25 wt. % of at least one of Zr, Hf, Sc, Mn, and V, the balance being aluminum, incidental elements and impurities; wherein the plate has a thickness of not greater than 2.00 inches; wherein the plate has strength-to-toughness relationship that satisfies the expression: FT_LT≧−4.0*(TYS_L)+453; wherein the plate has a TYS_L of at least 80 ksi; wherein the plate has a FT_LT of at least 100 ksi√inch; wherein TYS_L is the L tensile yield strength of the plate in ksi as measured in accordance with ASTM Standard E8 and ASTM B557; wherein FT_LT is the L-T plane stress fracture toughness (K app ) of the plate in ksi√inch as measured in accordance with ASTM Standard E561 and B646 on a center-cracked aluminum alloy specimen taken from the T/2 location of the plate, wherein the specimen has a width of 16 inches, a thickness of 0.25 inch and a initial fatigue pre-crack length of 4 inches.