Abstract: An aluminum alloy shaped casting includes about 6.3 wt. % to 9 wt. % silicon, about 0.05 wt. % to 0.4 wt. % magnesium, no more than about 0.8 wt. % manganese, no more than 0.5 wt. % copper, no more than about 1 wt. % zinc, no more than about 0.2 wt. % iron, no more than about 0.2 wt. % titanium, and no more than about 0.04 wt. % strontium, the aluminum alloy shaped casting receiving a T5 heat treatment.

Abstract: An improved Al—Si—Mg—Mn casting alloy that consists essentially of: about 6.0-9.0 wt. % silicon, about 0.2-0.8 wt. % magnesium, about 0.1-1.2 wt. % manganese, less than about 0.15 wt. % iron, less than about 0.3 wt. % titanium and less than about 0.04 wt. % strontium, the balance aluminum. Preferrably, this casting alloy is substantially copper-free, chromium-free and beryllium-free.

Abstract: A method for preventing oxidation of molten aluminum alloy and magnesium alloy surfaces, the method comprising providing a molten aluminum alloy or magnesium alloy having a molten aluminum or magnesium alloy surface; covering the molten aluminum or magnesium alloy surface with an initial layer of petroleum coke, the initial layer of petroleum coke having an initial layer thickness of about 0.75 inches; oxidizing a portion of the initial layer of petroleum coke to form a working layer of petroleum coke covering the molten metal surface, the working layer of coke having a working layer thickness of about 0.5 inches, and a layer of carbon dioxide immediately adjacent to and contiguous with the working layer of petroleum coke; and adding additional petroleum coke to the working layer of petroleum coke to maintain the working layer thickness at about 0.5 inches.

Abstract: An improved Al—Si—Mg—Mn casting alloy that consists essentially of: about 6.0-9.0 wt. % silicon, about 0.2-0.8 wt. % magnesium, about 0.1-1.2 wt. % manganese, less than about 0.15 wt. % iron, less than about 0.3 wt. % titanium and less than about 0.04 wt. % strontium, the balance aluminum.