Aluminum Company of America

James T Staley

Ralph R Sawtell

John Liu

Roberto J Rioja

Melvin H Brown

Gary H Bray

Dhruba J Chakrabarti

Stephen F Baumann

Philip E Bretz

Warren H Hunt, Jr

Craig L Jensen

Rebecca K Wyss

Lynette M Angers

Sootae Lee

David B Reiser

David A Lukasak

Shelly M Miyasato

Rolled plate products up to 6 inches thick or more and other products in an aluminum alloy consisting essentially of about 5.2 to 6.8% zinc, 1.7 to 2.4% copper, 1.6 to 2% magnesium, 0.03 to 0.3% zirconium, balance substantially aluminum and incidental elements and impurities, are useful in making structural members for commercial airplanes especially by machining or shaping such members from the plate. Such members include lower wing skins and wing spars and other members. The plate is made by operations comprising homogenization, hot rolling, solution heat treatment, stretching and artificial aging. Alternatively, the plate is shaped after stretching, which may include machining, and is then artificially aged.

Aluminum alloy products suited for commercial jet aircraft wing members

An alloy product having improved combinations of strength, density, toughness and corrosion resistance, said alloy product consisting essentially of about 7.6 to 8.4% zinc, about 1.8 to 2.2% magnesium, about 2 to 2.6% copper and at least one element selected from zirconium, vanadium and hafnium present in a total amount not exceeding about 0.5%, preferably about 0.05 to 0.25% zirconium, the balance aluminum and incidential elements and impurities. The alloy product, suitable for aerospace applications, exhibits high yield strength, at least about 10% greater yield strength than its 7X50-T6 counterpart, with good toughness and corrosion resistance properties typically comparable to or better than those of its 7X50-T76 counterpart. Upper wing members made from this alloy typically have a yield strength over 84 ksi, good fracture toughness and an EXCO exfoliation resistance level of 'EC' or better, typically 'EB'.

Aluminum alloy product having improved combinations of properties

An aluminum base alloy suitable for forming into a wrought product having improved combinations of strength and fracture toughness is disclosed. The product is comprised of 0.2 to 3.0 wt. % Li, 0.1 to 3 wt. % Mg, 0.2 to 3 wt. % Cu, 5.1 to 12 wt. % Zn, 0.5 wt. % max. Fe, 0.5 wt. % max. Si, at least one of the elements selected from the group Cr, V, Hf, Mn, Ti, Ag, In and Zr, with Cr, V, Ti and Zr in the range of 0.01 to 0.2 wt. %; Hf and Mn up to 0.6 wt. % each, Ag in the range of 0.05 to 1 wt. % and in the range of 0.01 to 0.5 wt. %, the balance aluminum and incidental impurities.

Aluminum-lithium alloys having high zinc

Superplastic forming of aluminum work stock is improved by including therein about 0.05% to about 10% or 15% scandium together with up to 0.2 or 0.25% zirconium. In preferred practices, soluble elements such as magnesium are also included in the aluminum alloy. One or more of the elements from the group of scandium, yttrium, gadolinium, holminum, dysprosium, erbium, ytterbium, lutetium, and terbium, may be included in addition to or in lieu of scandium. Heat treatable aluminum alloys such as 7XXX alloys and 2XXX alloys can be made superplastic by including scandium and zirconium to provide very high strength in superplastically formed products.

Superplastic aluminum products and alloys

There is disclosed a method for producing an aluminum alloy product and the resulting product having improved combinations of strength and corrosion resistance. The method includes providing an alloy consisting essentially of about 6-16% zinc, about 1.5-4.5% magnesium, about 1-3% cooper, one or more elements selected from zirconium, chromium, manganese, titanium, vanadium and hafnium, the total of said elements not exceeding about 1%, the balance aluminum and incidental impurities. The alloy is then solution heat treated; precipitation hardened to increase its strength to a level exceeding the as-solution heat treated strength level by at least about 30% of the difference between as-solution heat treated strength and peak strength; subjected to treatment at a sufficient temperature or temperatures for improving its corrosion resistance properties; and again precipitation hardened to raise its yield strength and produce a high strength, highly corrosion resistant alloy product.

Aluminum alloy product having improved combinations of strength and

Aluminum base 7000 series alloys can have improved tensile properties when, after heat treatment and subsequent quenching, they are subjected to a three-step aging process comprising a first aging step at 190.degree.-230.degree. F., a second aging step at over 230.degree. F. and a third aging step at 315.degree.-380.degree. F. The improved process is particularly effective in improving the tensile properties of slowly quenched materials such as large extrusions or forgings.

Aging process for 7000 series aluminum base alloys

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Murrysville, PA, United States of America

James T Staley