Abstract: An aluminum alloy product for use as a damage tolerant product for aerospace applications, including fuselage skin stock. The aluminum alloy composition contains about 3-7 wt % magnesium, about 0.03-0.2 wt % zirconium, about 0.2-1.2 wt % manganese, up to 0.15 wt % silicon and about 0.05-0.5 wt % of a dispersoid-forming element selected from the group consisting of: scandium, erbium, yttrium, gadolinium, holmium and hafnium, the balance being aluminum and incidental elements and impurities.

Abstract: A method of producing a sheet product and improved products having improved levels of toughness and fatigue crack growth resistance at good strength levels. The method comprises providing an aluminum base alloy containing 4 to 4.5% Cu, 1.2 to 1.5% Mg, 0.4 to 0.6% Mn, 0.12% max. Fe, 0.1% max. Si, the remainder aluminum, incidental elements and impurities and hot rolling the alloy, heating the alloy to above 910.degree. F. and additionally hot rolling it in a range of about 600.degree. to 900.degree. F., solution heat treating, preferably for a time of less than about 15 minutes at a solution heat treating temperature, and rapidly cooling and naturally aging. The invention products have very good combinations of strength together with high fracture toughness or low fatigue crack growth rate, or both, making them well suited for aerospace applications such as fuselage skin. The products preferably include a corrosion protecting cladding of aluminum or aluminum alloy.

Abstract: Disclosed is an aluminum base alloy suitable for forming into a wrought product having improved combinations of strength, corrosion resistance and fracture toughness. The alloy is comprised of 0.2 to 5.0 wt. % Li, 0.05 to 6.0 wt. % Mg, at least 2.45 wt. % Cu, 0.01 to 0.16 wt. % Zr, 0.05 to 12 wt. % Zn, 0.5 wt. % max. Fe, 0.5 wt. % max. Si, the balance aluminum and incidental impurities.

Abstract: A method for thermally treating an article made from an aluminum alloy having a first temperature at which solute atoms cluster to yield nuclei for the formation and growth of strengthening precipitates, and a second higher temperature at which the strengthening precipitates dissolve. The method comprises: heating the article to allow substantially all soluble alloy components to enter into solution; rapidly cooling the article in a quenching medium; and precipitation hardening the article by aging at or below the first temperature for a few hours to several months; then aging above the first temperature and below the second temperature until desired strength is achieved. A method for imparting improved combinations of strength and fracture toughness to a solution heat treated-article which includes an aluminum-lithium alloy is also disclosed. This method comprises aging the article at one or more temperatures at or below a first temperature of about 93.degree. C. (200.degree. F.

Abstract: Disclosed is a method of making aluminum base alloy flat rolled product substantially free of Luder's lines after stretching, the method comprising the steps of providing a body of a lithium-containing aluminum base alloy and working the body to produce a flat rolled product prior to solution heat treating and quenching. The flat rolled product is preaged for a time and temperature which does not substantially affect mechanical properties but which permits stretching the flat rolled product without formation of Luder's lines. Thereafter, the preage flat rolled product is stretched and aged to a condition having a substantially stable level of mechanical properties.