Aluminum Company of America

Brian A Cheney

Roberto J Rioja

Edward L Colvin

Asuri K Vasudevan

Jeffrey J Witters

Disclosed is a method of making lithium-containing aluminum base alloy extrusion having at least a section thereof having a low aspect ratio, the extrusions having improved properties in sections thereof having the low aspect ratio. The method comprises providing a body of a lithium-containing aluminum alloy, extruding a low aspect ratio extrusion section, the aspect ratio being in the range of 1 to 2.5, and maintaining the body in a temperature range of 400.degree. to 1000.degree. F. and at least a 4:1 extrusion reduction during said extrusion step, the extrusion section having tensile yield strength of at least 60 ksi and having an ultimate yield strength of at least 4.5 ksi greater than the tensile yield strength.

Low aspect ratio lithium-containing aluminum extrusions

A method for thermally treating an article made from an aluminum alloy having a first temperature at which solute atoms cluster to yield nuclei for the formation and growth of strengthening precipitates, and a second higher temperature at which the strengthening precipitates dissolve. The method comprises: heating the article to allow substantially all soluble alloy components to enter into solution; rapidly cooling the article in a quenching medium; and precipitation hardening the article by aging at or below the first temperature for a few hours to several months; then aging above the first temperature and below the second temperature until desired strength is achieved. A method for imparting improved combinations of strength and fracture toughness to a solution heat treated-article which includes an aluminum-lithium alloy is also disclosed. This method comprises aging the article at one or more temperatures at or below a first temperature of about 93.degree. C. (200.degree. F.) for a few hours to several months; and further aging the article at one or more temperatures above the first temperature and below a second temperature of about 219.degree. C. (425.degree. F.) for at least about 30 minutes.

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Bettendorf, IA, United States of America

Brian A Cheney