High strength aluminum base alloy

An aluminum base alloy suitable for forming in semi-solid condition into a member having improved strength, the member having a globular microstructure contained in a lower melting eutectic matrix, the member having a tensile strength in the range of 45 to 65 ksi and a yield strength in the range of 40 to 55 ksi in solution heat treated and aged condition, the alloy comprised of 3.5 to 5.5 wt. % Si, 3.6 to 5 wt. % Cu, 0.3 to 1 wt. % Mg, max. 0.25 wt. % Fe, max. 0.1 wt. % Mn, max. 0.25 wt. % Zn, and max. 0.25 wt. % Ti, the balance comprised of aluminum, incidental elements and impurities, the member having a maximum grain size less than 150 μm.

An aluminum base alloy suitable for forming in semi-solid condition into a member having improved strength, the member having a globular microstructure contained in a lower melting eutectic matrix, the member having a tensile strength in the range of 45 to 65 ksi and a yield strength in the range of 40 to 55 ksi in solution heat treated and aged condition, the alloy comprised of 3.5 to 4.9 wt. % Si, 3.7 to 4.8 wt. % Cu, 0.3 to 1 wt. % Mg, max. 0.25 wt. % Fe, max. 0.1 wt. % Mn, max. 0.25 wt. % Zn, and max. 0.25 wt. % Ti, the balance comprised of aluminum, incidental elements and impurities, the member having a maximum grain size less than 150 μm.

An aluminum base alloy consisting essentially of 3.5 to 4.9 wt. % Si, 3.7 to 4.8 wt. % Cu, 0.3 to 1 wt. % Mg, max. 0.25 wt. % Fe, max. 0.1 wt. % Mn, max. 0.25 wt. % Zn, and max. 0.25 wt. % Ti, the balance comprised of aluminum, incidental elements and impurities.

An aluminum base alloy consisting essentially of 3.5 to 4.9 wt. % Si, 3.6 to 5 wt. % Cu, 0.3 to 1 wt. % Mg, max. 0.25 wt. % Fe, max. 0.1 wt. % Mn, max. 0.25 wt. % Zn, and max. 0.25 wt. % Ti, the balance comprised of aluminum, incidental elements and impurities.

An improved aluminum alloy member formed from semi-solid aluminum alloy, the member having a globular microstructure contained in a lower melting eutectic matrix and having a maximum grain size of less than 150 μm and having a tensile strength in the range of 45 to 65 ksi and a yield strength of 40 to 55 ksi in solution heat treated and aged condition, the alloy for said member comprised of 3.5 to less than 5 wt. % Si, 3.6 to 5 wt. % Cu, 0.3 to 1 wt. % Mg, max. 0.25 wt. % Fe, max. 0.1 wt. % Mn, max. 0.25 wt. % Zn, and max. 0.25 wt. % Ti, the balance aluminum, incidental elements and impurities.

An improved aluminum alloy formed member having a globular microstructure contained in a lower melting eutectic matrix having a maximum grain size less than 125 μm and having a tensile strength in the range of 45 to 65 ksi and a yield strength in the range of 40 to 55 ksi after solution heat treating in a temperature range of 800 ° to 1000° F. for 0.1 to 12 hours, cold water quenching and aging for 1 to 24 hours in a temperature range of 200° to 400° F., the member comprised of 3.5 to 4.9 wt. % Si, 3.7 to 4.8 wt. % Cu, 0.3 to 1 wt. % Mg, max. 0.25 wt. % Fe, max. 0.1 wt. % Mn, max. 0.25 wt. % Zn, and max. 0.25 wt. % Ti, the balance aluminum, incidental elements and impurities.