Abstract: An aluminum based alloy having a composition within the following ranges, all of the ranges being in weight percent: lithium 2.0 to 2.8, magnesium 0.4 to 1.0, copper 2.0 to 3.0, manganese 0.7 to 1.2, zirconium up to 0.2 and the balance aluminum, save for incidental impurities and up to 2.0 in total of one or more grain controlling elements to provide microstructural optimization and control.

Abstract: An aluminum based alloy having a composition within the following ranges, all of the ranges being in weight percent: lithium 2.0 to 2.8, magnesium 0.4 to 1.0, copper 2.0 to 3.0, manganese 0.7 to 1.2, zirconium up to 0.2 and the balance aluminum, save for incidental impurities and up to 2.0 in total of one or more grain controlling elements to provide microstructural optimization and control.

Abstract: A magnesium-free aluminum alloy suitable for use as the matrix alloy in a metal matrix composite material is disclosed which overcomes the drawback of the rapid natural ageing response exhibited by prior art alloys. This facilitates greater flexibility in manufacturing with metal matrix composites because of the improvement in fabricability. The alloy composite comprises 1 to 50% by weight of reinforcing material embedded in a matrix alloy having the following composition in proportions by weight: copper 4-6%, aluminum the balance, save for incidental impurities, and further comprising one of the grain refining additives from the group comprising zirconium, manganese or chromium in an amount up to 0.5% by weight.

Abstract: The stiffness of materials formed from aluminum alloy sheets laminated with layers of long aligned fibers embedded in a matrix of resin material is enhanced by reinforcing the aluminum alloy component with ceramic particles or whiskers. Use of stiff fibers such as carbon, aramid, alumina, silicon carbide or mixtures of these enables the stiffness of the fiber/resin component to be matched to that of the metal/ceramic component. This results in good fatigue crack growth resistance in the finished laminate, even for short crack lengths. In a preferred laminate, the metal/ceramic component is formed with a matrix of aluminum-lithium alloy. Such alloys are inherently stiffer than alloys without lithium, with the result that the increased stiffness obtained from ceramic reinforcement is enhanced stiff further.

Abstract: Artificially aged aluminum-lithium alloys are given an auxiliary heat treatment at or after completion of ageing to improve short-transverse properties, particularly fracture toughness. The auxiliary heat treatment comprises heating the material steadily to a reversion temperature above the ageing temperature by at least 20.degree. C. but not higher than 250.degree. C., retaining the material briefly at temperature then cooling to room temperature. Typically the treatment involves heating to a reversion temperature in the range 190.degree.-230.degree. C. with a hold at this temperature of around 5 minutes. Boosted properties decay with extended exposure to temperatures of 60.degree. C. and above but may be restored by reimposition of the auxiliary heat treatment.

Abstract: Aluminum alloys having compositions within the ranges (in Wt %) 0.2 to 3 lithium -0 to 4 magnesium -0.4 to 5 zinc -0 to 2 copper -0 to 0.2 zirconium -0 to 0.5 manganese -0 to 0.5 nickel -0 to 0.4 chromium-balance aluminum. The alloys are precipitation hardenable and exhibit a range of properties, according to heat treatment, which made them suitable for engineering applications where light weight and high strength are necessary.

Abstract: Aluminium alloys having compositions within the ranges (in wt %) 2 to 2.8 lithium--0.4 to 1 magnesium--1 to 1.5 copper--0 to 0.2 zirconium--0 to 0.5 manganese--0 to 0.5 nickel--0 to 0.5 chromium--balance aluminium. The alloys are precipitation hardenable and exhibit a range of properties, according to heat treatment, which make them suitable for engineering applications where light weight and high strength are required.