Aluminum Company of America

Rebecca K Wyss

T David Burleigh

Gary P Tarcy

Paul B Schultz

James T Staley

Warren H Hunt, Jr

Lynette M Angers

Thomas M Gavasto

David B Reiser

David A Lukasak

The present invention is directed to a method employing wet chemistry techniques of treating wrought aluminum alloys in order to quickly and efficiently separate the alloys into their alloy families and major constituent members by separation by surface color of the treated alloys.

Chemical treatment of aluminum alloys to enable alloy separation

A method for making a light metal-rare earth metal alloy comprises adding a pellet to a substantially flux-free bath of molten light metal, said pellet including a mixture of rare earth metal-containing compound and one or more light metal powders. On a preferred basis, such mixtures comprise scandium oxide, up to about 10 wt. % aluminum powder and a substantial majority of magnesium powder, all of which are substantially similar in median particle size. This mixture is preferably compacted under a pressure of about 7 kpsi or more, then added to a bath of molten magnesium or molten aluminum to make magnesium-scandium, magnesium-aluminum-scandium, or aluminum-magnesium-scandium alloys therefrom. There is further disclosed a method for making an alloy containing about 7-12 wt. % lithium, about 2-7 wt. % aluminum, about 0.4-2 wt. % scandium, up to about 2 wt. % zinc and up to about 1 wt. % manganese, the balance magnesium and impurities.

Method for making a light metal-rare earth metal alloy

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

A method of improving strength in aluminum alloys. The method involves solution heat treating an aluminum alloy product, quenching the alloy product, warm working the alloy product without a pre-aging step, and aging the alloy product at 250.degree.-400.degree. F. (121.degree.-204.degree. C.). The method may be used on forgings, to impart T8-type hardness to alloys that previously could only obtain such hardness levels in non-forging applications, such as by using stretch/cold working techniques.

Method for increasing the strength of aluminum alloy products through

A dual-phase magnesium-based alloy consisting essentially of about 7-12% lithium, about 2-6% aluminum, about 0.1-2% rare earth metal, preferably scandium, up to about 2% zinc and up to about 1% manganese. The alloy exhibits improved combinations of strength, formability and/or corrosion resistance. There is also disclosed a composite matrix whose metal phase consists essentially of the aforementioned composition.

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Plum Boro, PA, United States of America

Rebecca K Wyss