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

US8524014B2 · 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: Jul 7, 2011
• Grant date: Sep 3, 2013
• Expiry date: Jul 7, 2031

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 3-stage method of preferred embodiments, this alloy also achieves superior SCC performance, including under seacoast conditions.