Abstract: Disclosed is a method of producing a forged and rolled Al-Zn-Cu-Mg alloy plate product having improved fatigue properties in the long transverse direction. The method comprises providing a body of an Al-Zn-Cu-Mg alloy, working said body by a forging operation to reduce its thickness in a C direction by at least 30% and rolling or working the forged body to provide a forged and rolled plate product having improved fatigue properties in the long transverse direction.

Abstract: The present invention provides a method for improving aluminum alloy plate product properties by delaying final stretching of the plate product. During processing of the product, a time interval or intentional delay is provided between the final cold rolling step and the final stretching step. By delaying the final stretching procedure, an aluminum alloy plate product is provided with an improved fracture toughness without significant decrease in strength values. The method of intentionally delaying final stretching is particularly adapted for 2000 series aluminum alloys.

Abstract: The invention provides a method for heat treating aluminum-base alloys. The method increases stress corrosion resistance after heating of the alloy to temperatures between 100.degree. C. and 150.degree. C. A dispersion strengthened aluminum-base alloy containing lithium and magnesium is shaped to form an object of substantially final form. The dispersion strengthened aluminum-base alloy is heated to a temperature between 160.degree. C. and 250.degree. C. for at least 3 hours. The heat treated object has increased stress corrosion resistance after exposure to temperatures between 100.degree. C. and 150.degree. C.

Abstract: The present invention provides a method of producing a hardened aluminum alloy sheet having superior thermal stability, the method comprising the steps of: homogenizing an ingot of an aluminum alloy consisting essentially of, in weight percentage, 3.0 to 6.0% Mg and 0.4 to 0.8% Mn, with the balance being Al and incidental impurities; hot rolling the homogenized ingot to a sheet; cold rolling the hot-rolled sheet at a rolling reduction of at least 20%; intermediate heat treating the cold-rolled sheet at 200.degree. to 250.degree. C. for one hour or more; and final cold rolling the intermediate heat-treated sheet at a reduction of at least 50%. In this process, the aluminum ingot may further contain from 0.05 to 0.4% Cu with or without 0.05 to 0.5% Si, 0.1 to 0.5% Fe, 0.01 to 0.05% Ti and 0.0001 to 0.0010% B. Further, the above homogenizing and hot rolling steps may be replaced by the steps of homogenizing, hot rolling to a sheet thickness of 2 to 6 mm, cold rolling and annealing for recrystallization.

Abstract: A hypereutectic aluminum-silicon casting alloy having a refined primary silicon particle size and a modified silicon phase in the eutectic. The aluminum base alloy includes from 19% to 30% by weight of silicon and also contains 0.005% to 0.06% by weight of phosphorus, and 0.15% to 1.15% by weight of titanium. On cooling from solution temperature, the phosphorus serves as an active nucleant for the primary silicon phase, while at a lower temperature, a titanium-aluminum intermetallic compound is formed that is sheathed by the pseudoprimary .alpha.-aluminum and the sheathed particles act as a nucleant to modify the acicular silicon phase in the eutectic. The resulting alloy has primary silicon refinement coupled with eutectic silicon modification.

Abstract: The present invention provides a process for making high strength, high ductility, low density rapidly solidified aluminum-base alloys, consisting essentially of the formula Al.sub.bal Zr.sub.a Li.sub.b X.sub.c, wherein X is at least one element selected from the group consisting of Cu, Mg, Si, Sc, Ti, U, Hf, Be, Cr, V, Mn, Fe, Co and Ni, "a" ranges from about 0.2-0.6 wt %, "b" ranges from about 2.5-5 wt %, "c" ranges from about 0-5 wt % and the balance is aluminum. The alloy is given multiple aging treatments after being solutionized. The microstructure of the alloy is characterized by the precipitation of a composite phase in the aluminum matrix thereof.

Abstract: A rapidly solidified aluminum base lithium containing alloy is subjected to at least one overaging treatment and a plurality of rolling passes. Upon completion of the process, the alloy is comprised of grains having an ultrafine grain size. A predominant number of the grains have grain boundaries pinned by the precipitation of Al.sub.3 Zr phase. The alloy has an elongation greater than 500% at temperature above about 500.degree. C. and a strain rate above about 4.times.10.sup.-2 /s.