ALUMINIUM-COPPER-LITHIUM ALLOY WITH IMPROVED COMPRESSIVE STRENGTH AND TOUGHNESS

摘要

The invention relates to a process for manufacturing rolled products made of an aluminium-based alloy comprising 4.2 to 4.6% by weight of Cu, 0.8 to 1.30% by weight of Li, 0.3 to 0.8% by weight of Mg, 0.05 to 0.18% by weight of Zr, 0.05 to 0.4% by weight of Ag, 0.0 to 0.5% by weight of Mn, at most 0.20% by weight of Fe + Si, less than 0.20% by weight of Zn, at least one element chosen from Cr, Se, Hf and Ti, the amount of said element, if it is chosen, being from 0.05 to 0.3% by weight for Cr and for Se, 0.05 to 0.5% by weight for Hf and 0.01 to 0.15% by weight for Ti, the other elements being at most 0.05% by weight each and 0.15% by weight in total, the remainder being aluminium, comprising the steps of smelting, casting, homogenization, rolling with a temperature greater than 400°C, solution heat treating, quenching, tensioning between 2 and 3.5% and tempering. The invention also relates to the rolled products obtained by this process, which have a favourable compromise of properties between mechanical strength in compression and in tension and toughness. The products according to the invention are especially of use for the manufacture of upper wing skin.