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: Composite materials having improved fracture toughness are formed by dispersing ductile inclusions in a less ductile matrix. The matrices may be formed from metals, such as high-strength aluminum alloys or ceramics. Bonding should be present between the inclusions and the matrix so that cracks in the composite material must pass through the inclusions.

Abstract: Disclosed is a metal alloy product having increased resistance to fatigue crack growth and having coarse grains distributed in a fine grain structure, the coarse grains having a different alloy composition from the fine grain structure.

Abstract: A weldable aluminum base alloy product is disclosed which is characterized by high strength, including high resistance to ballistic penetration and resistance to stress-corrosion cracking. The alloy consists essentially of from above 5 wt. % to 7 wt. % copper, 0 to 0.8 wt. % manganese, 0.1 wt. % titanium, 0 to 0.25 wt. % vanadium, 0 to 0.25 wt. % zirconium and 0.10 to 0.30 wt. % magnesium with the balance consisting essentially of aluminum. The alloy is cold worked a minimum amount equivalent to 6% stretching at room temperature after solution heat treatment and quenching, preferably by stretching. The alloy is then aged, after cold working, for at least 2 hours at a temperature of at least 121.degree. C. (250.degree. F.).

Abstract: A weldable aluminum base alloy product is disclosed which is characterized by high strength, including high resistance to ballistic penetration and resistance to stress-corrosion cracking. The alloy consists essentially of from above 5 wt. % to 7 wt. % copper, 0 to 0.8 wt. % manganese, 0.1 wt. % titanium, 0 to 0.25 wt. % vanadium, 0 to 0.25 wt. % zirconium and 0.10 to 0.30 wt. % magnesium with the balance consisting essentially of aluminum. The alloy is cold worked a minimum amount equivalent to 6% stretching at room temperature after solution heat treatment and quenching, preferably by stretching. The alloy is then aged, after cold working, for at least 2 hours at a temperature of at least 121.degree. C. (250.degree. F.).