Aluminum-Copper-Lithium Alloy With Improved Mechanical Strength and Toughness

A process for producing an extruded, rolled and/or forged aluminum alloy-based product, comprising:

• a) producing an aluminum-based liquid metal bath comprising 3.0 to 3.9% by weight Cu, 0.8 to 1.3% by weight Li, 0.6 to 1.0% by weight Mg, 0.05 à 0.18% by weight Zr, 0.0 to 0.5% by weight Ag, 0.0 to 0.5% by weight Mn, at most 0.20% by weight Fe+Si, at most 0.15% by weight Zn, at least one element selected from the group consisting of Cr, Sc, Hf and Ti, the amount of said element, if selected, being from 0.05 to 0.3% by weight for Cr and for Sc, 0.05 to 0.5% by weight for Hf and 0.01 to 0.15% by weight for Ti, the other elements at most 0.05% by weight each, and 0.15% by weight in total, remainder aluminum;
• b) casting a raw product from said liquid metal bath;
• c) homogenizing said raw product at a temperature of from 450° C. to 550° for a period of from 5 to 60 hours;
• d) hot and optionally cold working said raw product into an extruded, rolled and/or forged product;
• e) solution treating said product at from 490 to 530° C. for 15 min to 8 hours and quenching;
• f) stretching said product in a controlled manner with a permanent set of 1 to 6%;
• g) aging said product, comprising heating at a temperature of from 130 to 170° C. for 5 to 100 hours so as to obtain a yield strength close to peak.