High fracture toughness aluminum-copper-lithium sheet or light-gauge plate suitable for use in a fuselage panel
AssigneeAlcan Rhenalu
InventorBernard Bes
Life of this patent
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Abstract
A low density aluminum based alloy useful in aircraft structure for fuselage sheet or light-gauge plate applications which has high strength, high fracture toughness and high corrosion resistance, comprising 2.7 to 3.4 weight percent Cu, 0.8 to 1.4 weight percent Li, 0.1 to 0.8 weight percent Ag, 0.2 to 0.6 weight percent Mg and a grain refiner such as Zr, Mn, Cr, Sc, Hf, Ti or a combination thereof, the amount of which being 0.05 to 0.13 wt. % for Zr, 0.1 to 0.8 wt. % for Mn, 0.05 to 0.3 wt. % for Cr and Sc, 0.05 to 0.5 wt. % for Hf and 0.05 to 0.15 wt. % for Ti. The amount of Cu and Li preferably corresponds to the formula Cu(wt. %)+5/3 Li(wt. %)<5.2.
Claims38
A method for producing an aluminum alloy sheet or a light-gauge plate having high fracture toughness and strength, said method comprising:
- a) casting an ingot comprising 2.7 to 3.4 wt. % Cu, 0.8 to 1.4 wt. % Li, 0.1 to 0.8 wt. % Ag, 0.2 to 0.6 wt. % Mg and at least one grain refiner selected from the group consisting of 0.05 to 0.13 wt. % Zr, 0.05 to 0.8 wt. % Mn, 0.05 to 0.3 wt. % Cr, 0.05 to 0.3 wt % Sc, 0.05 to 0.5 wt. % Hf and 0.05 to 0.15 wt. % Ti,
- remainder aluminum and unavoidable impurities,
- with the additional proviso that the amount of Cu and Li is such that
- Cu(wt. %)+5/3 Li(wt. %)<5.2;
- b) homogenizing said ingot at 490-530° C. for a duration from 5 and 60 hours;
- c) rolling said ingot to a sheet or a light-gauge plate with a final thickness from 0.8 to 12 mm;
- d) solution heat treating and quenching said sheet or light-gauge plate;
- e) stretching said sheet or light-gauge plate with a permanent set from 1 to 5%;
- f) aging said sheet or light-gauge plate by heating at 140-170° C. for 5 to 30 hours.
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 3.0 to 3.4 wt. % Cu, 0.8 to 1.2 wt. % Li, 0.2 to 0.5 wt. % Ag, 0.2 to 0.6 wt. % Mg and at least one grain refiner selected from the group consisting of 0.09 to 0.13 wt. % Zr, 0.05 to 0.8 wt. % Mn, 0.05 to 0.3 wt. % Cr 0.05 to 0.3 wt % Sc, 0.05 to 0.5 wt. % Hf and 0.05 to 0.15 wt. % Ti,
- remainder aluminum and unavoidable impurities,
- with the additional proviso that the amount of Cu and Li is such that
- Cu(wt. %)+5/3 Li(wt. %)<5.0;
- b) homogenizing said ingot at 490-530° C. for a duration from 5 to 60 hours;
- c) rolling said ingot to a 2 to 9 mm final gauge sheet or light-gauge plate;
- d) solution heat treating said sheet or light-gauge plate at a temperature from 490 to 530° C. for a duration from 15 minutes to 2 hours, followed by quenching;
- e) stretching said sheet or light-gauge plate with a permanent set from 2.5 to 4%;
- f) aging said sheet or light-gauge plate by heating at 140-155° C. for 10 to 30 hours.
A method for producing an aluminum alloy sheet or a light-gauge plate having high fracture toughness and strength, said method comprising:
- a) casting an ingot comprising 2.7 to 3.4 wt. % Cu, 0.8 to 1.4 wt. % Li, 0.1 to 0.8 wt. % Ag, 0.2 to 0.6 wt. % Mg, 0.05 to 0.13 wt. % Zr, 0.02 to 0.3 wt % Sc and optionally 0.05 to 0.8 wt. % Mn, 0.05 to 0.3 wt. % Cr, 0.05 to 0.5 wt. % Hf and 0.01 to 0.15 wt. % Ti,
- remainder aluminum and unavoidable impurities,
- with the additional proviso that the amount of Cu and Li is such that
- Cu(wt. %)+5/3 Li(wt. %)<5.2;
- b) homogenizing said ingot at 490-530° C. for a duration from 5 to 60 hours;
- c) rolling said ingot to a sheet or a light-gauge plate with a final thickness from 0.8 to 12 mm;
- d) solution heat treating and quenching said sheet or light-gauge plate;
- e) stretching said sheet or light-gauge plate with a permanent set from 1 to 5%;
- f) aging said sheet or light-gauge plate by heating at 140-170° C. for 5 to 30 hours.
A rolled, forged and/or extruded aluminum alloy comprising 2.7 to 3.4 wt. % Cu, 0.8 to 1.4 wt. % Li, 0.1 to 0.8 wt. % Ag, 0.2 to 0.6 wt. Mg and at least one grain refiner selected from the group consisting of 0.05 to 0.13 wt. % Zr, 0.05 to 0.8 wt. % Mn, 0.05 to 0.3 wt. % Cr, 0.05 to 0.3 wt % Sc, 0.05 to 0.5 wt. % Hf and 0.05 to 0.15 wt. % Ti,
- remainder aluminum and unavoidable impurities,
- with the additional proviso that the amount of Cu and Li is such that
- Cu(wt. %)+5/3 Li(wt. %)<5.2.
Dependencies are inferred from the claim text.