Abstract: An A-rated, aluminum alloy suitable for machining, said alloy consisting essentially of: about 4-5.75 wt. % copper, about 0.2-0.9 wt. % bismuth, about 0.12-1.0 wt. % tin, the ratio of bismuth to tin ranging from about 0.8:1 to 5:1, up to about 0.7 wt. % iron, up to about 0.4 wt. % silicon, up to about 0.3 wt. % zinc, the balance aluminum, incidental elements and impurities. On a preferred basis, this alloy contains about 4.4-5.0 wt. % copper, about 0.4-0.75 wt. % bismuth, about 0.2-0.5 wt. % tin, the ratio of bismuth to tin ranging from about 1:1 to 3:1, about 0.2 wt. % or less iron and about 0.2 wt. % or less silicon. The alloy is substantially lead-free, cadmium-free and thallium-free. There is further disclosed an improved method for making screw machine stock or wire, rod and bar product from this alloy by casting, preheating, extruding, solution heat treating, cold finishing and aging the same.

Abstract: There is disclosed an improved memory disk stock comprised of an alloy composition which includes: about 1-11 wt. % magnesium, preferably between about 2-7 wt. % Mg; up to about 0.3 wt. % zirconium preferably about 0.02-0.25 wt. % Zr; up to about 0.2 wt. % iron, up to about 0.2 wt. % silicon, and about 0.02-0.2 wt. % of a dispersoid-forming element selected from scandium, erbium, thulium, lutetium, ytterbium, hafnium and yttrium, the balance aluminum and incidental elements and impurities. With preferably about 0.05-0.15 wt. % of scandium added to such compositions, these disk stocks exhibit significant room temperature yield strength increases over the same compositions without any scandium added.

Abstract: There is disclosed an improved memory disk stock comprised of an alloy composition which includes: about 1-11 wt. % magnesium, preferably between about 2-7 wt. % Mg; up to about 0.3 wt. % zirconium, preferably about 0.02-0.25 wt. % Zr; up to about 0.2 wt. % iron, up to about 0.2 wt. % silicon, and about 0.05-1 wt. % of a dispersoid-forming element selected from scandium, erbium, thulium, lutetium, ytterbium, hafnium and yttrium, the balance aluminum and incidental elements and impurities. With preferably about 0.1-0.45 wt. % of scandium added to such compositions, these disk stocks exhibit a two- to three-fold increase in strength over the same compositions without any scandium added. They result in magnetic media recording devices having improved temperature resistance with average yield strengths of 30 ksi or more. There is also claimed an improved method for making such memory disk devices.

Abstract: An A-rated aluminum alloy suitable for machining, said alloy consisting essentially of: about 0.15-1.0 wt. % copper, about 1.01-1.5 wt. % tin, about 0.65-1.35 wt. % magnesium, about 0.4-1.1 wt. % silicon, about 0.00 2-0.35 wt. % manganese, up to about 0.5 wt. % iron, up to about 0.15 wt. % chromium and up to about 0.15 wt. % titanium, the remainder substantially aluminum. On a preferred basis, this alloy contains about 0.51-0.75 wt. % copper, about 1.1-1.3 wt. % tin, about 0.7-0.9 wt. % magnesium and about 0.45-0.75 wt. % silicon. The alloy is substantially free of lead, bismuth, nickel, zirconium and cadmium. There is further disclosed an improved method for making screw machine stock or wire, rod and bar product from this alloy by casting, preheating, extruding, solution heat treating, cold finishing and thermally processing the aforementioned alloy composition.