Lower wing skin metal with improved damage tolerance properties

A manufacturing process for a rolled product in T351 temper, comprising:

• preparing and casting an aluminum alloy of thickness from 15 to 50 mm comprising, as a percentage by weight,
• Cu:
• 3.85-4.15,
• Mg:
• 0.95-1.25,
• Mn:
• 0.45-0.57,
• Zr:
• 0.09-0.16,
• Ti:
• 0.005-0.1,
• Fe:
• <0.070,
• Si:
• <0.060,
• with Cu+Mg 5≤5.15,
• other elements <0.05 each and less than 0.15 in total, the remainder being aluminum;
• adding a grain-refining agent of AlTiB type to obtain a rolling slab;
• optionally homogenizing said slab at a temperature from 480° C. to 510° C.;
• optionally hot rolling said homogenized slab to obtain a plate of thickness e from 15 to 50 mm;
• solution heat treating said plate at a temperature from 480 to 505° C. for a time t in hours such that t≥e/7;
• quenching said solution heat treated plate;
• cold stretching said quenched plate with a deformation of from 1.5 to 3%;
• and
• carrying out natural aging at room temperature.