Aluminum alloy products and artificial aging method

Abstract From the Canadian patent

Alluminum alloy products, such as plate forgings and extrusions, suitable for use in making aerospace structural components like integral wing spars ribs , and webs, comprises about: 6 to 10 wt.%Zn; 1.2 to 1.9 wt.% Mg; 1.2 to 2.2 wt.% Cu, with Mg (Cu+0.3); and 0.05 to 0.4 wt. % Zr the balance Al, incidental , elements and impurities. Preferably the alloy contains about 6.9 to 8.5 wt.% Zn; 1.2 to 1.7 wt.% Mg; 1.3 to 2 wt.% Cu. This alloy provides improved combinations of strength and fracture toughness in thick gauges. When artificially aged per the three stage method of preferred embodiments this , alloy also achieves superior SCC performance including under seacoast , conditions.