High fracture toughness aluminum-copper-lithium sheet or light-gauge plates suitable for fuselage panels
OwnerBernard Bes, Herve Ribes +2inventors
InventorsBernard Bes, Herve Ribes, Christophe Sigli, Timothy Warner
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Abstract
An aluminum alloy comprising 2.1 to 2.8 wt. % Cu, 1.1 to 1.7 wt. % Li, 0.1 to 0.8 wt. % Ag, 0.2 to 0.6 wt. % Mg, 0.2 to 0.6 wt. % Mn, a content of Fe and Si less or equal to 0.1 wt. % each, and a content of unavoidable impurities less than or equal to 0.05 wt. % each and 0.15 wt. % total, and the alloy being substantially zirconium free.
Claims29
An aluminum alloy comprising 2.1 to 2.8 wt. % Cu, 1.1 to 1.7 wt. % Li, 0.1 to 0.8 wt. % Ag, 0.2 to 0.6 wt. % Mg, 0.2 to 0.6 wt. % Mn, a content of Fe and Si less or equal to 0.1 wt. % each, and a content of unavoidable impurities less than or equal to 0.05 wt. % each and 0.15 wt. % total, and the alloy being substantially zirconium free.
A method for producing an aluminum alloy sheet or light gauge plate having high fracture toughness and strength, said method comprising:
- (a) casting an ingot comprising 2.1 to 2.8 wt. % Cu, 1.1 to 1.7 wt. % Li, 0.1 to 0.8 wt. % Ag, 0.2 to 0.6 wt. % Mg, and 0.2 to 0.6 wt. % Mn, a content of Fe and Si less than or equal to 0.1 wt. % each, and a content of unavoidable impurities less than or equal to 0.05 wt. % each and 0.15 wt. % total, and wherein said alloy is substantially zirconium free,
- (b) homogenizing said ingot at 480-520° C. for about 5 to about 60 hours,
- (c) hot rolling said ingot to a slab, with an hot rolling initial temperature of about 450° C. to about 490° C. and optionally cold rolling said slabs,
- (d) solution heat treating said slabs at about 480° C. to about 520° C. for about 15 min. to about 4 hours,
- (e) quenching said slabs,
- (f) stretching said slabs with a permanent set from about 1 to about 5%,
- (g) aging said slab by heating at about 140° C. to about 170° C. for about 5 to about 80 hours.
A substantially Zr free AlLi alloy comprising Cu from 2.1-2.8, Ag from 0.1-0.8 and Mn from 0.2-0.6 such that wherein said alloy is formed into a sheet or light gauge plate, said sheet or light gauge plate has improved fracture toughness:
- Δaeff(max), in the T-L direction of at least 60 mm and for which no intergranular corrosion is observed under a test according to ASTM G110.
A substantially Zr free AlLi alloy comprising Cu from 2.1-2.8, Ag from 0.1-0.8 and Mn from 0.2-0.6, such that when said alloy is formed into a sheet or light gauge plate, said sheet or light gauge plate has improved properties as compared to a sheet or plate formed of AA2098 such that:
- the density of said sheet or plate is at least 2% lower than an AA2098 sheet or plate and,
- Δaeff(max), in the T-L direction thereof is at least 50% higher than said AA2098 sheet or plate, and
- the ratio (TYS (L)−TYS (45°))/ TYS (L) thereof is at least 40% lower than said AA2098 sheet or plate
Dependencies are inferred from the claim text.