Aluminum alloy products having improved property combinations and method for artificially aging same

US7678205B2 · kind B2 · utility

Assignee

• ALCOA INC. · US

Inventors

• Dhruba J. Chakrabarti · Export, US
• John Liu · Murrysville, US
• Jay Goodman · Murrysville, US
• Gregory B. Venema · Bettendorf, US
• Ralph R. Sawtell · Monroeville, US
• Cynthia M. Krist · Bettendorf, US
• Robert W. Westerlund · Bettendorf, US

Key dates

• Filing date: Nov 28, 2005
• Grant date: Mar 16, 2010
• Expiry date: Nov 28, 2025

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C22C21/10
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

Aluminum 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.