an aluminum alloy of the alcu type containing cadmium and manganese exhibits an optimum combination of strength , toughness and corrosion resistance . the alloy contains 4 . 0 to 5 . 0 % copper , 0 . 1 to 0 . 2 % cadmium and 0 . 2 to 1 . 0 % manganese . the alloy is suitable for the production of high strength , tough and corrosion resistant extrusion products .