ALUMINUM-COPPER-LITHIUM ALLOY THIN SHEETS WITH IMPROVED TOUGHNESS, AND PROCESS FOR MANUFACTURING AN ALUMINUM-COPPER-LITHIUM ALLOY THIN SHEET

摘要

The invention relates to a process for manufacturing a thin sheet made of an aluminum-based alloy comprising, in percent by weight, 2.2 to 2.7% Cu,1.3 to 1.6% Li, less than 0.1% Ag, 0.2 to 0.5% Mg, 0.1 to 0.5% Mn, 0.01 to 0.15% Ti, less than 0.3% Zn, no more than 0.1% Fe and no more than 0.1% Si, and inevitable impurities at a content of no more than 0.05% by weight each and 0.15% by weight in total, the remainder being aluminum, wherein, in particular, the hot-rolling input temperature is between 400°C and 460°C and the hot-rolling output temperature is less than 300°C, the mean heating rate during the solution heat treatment is at least approximately 17°C/min between 300°C et 400°C, and the tempering conditions such as the 0.2% offset yield strength in the transverse direction Rp0.2(TL) ranges from 350 to 380 MPa. The sheets according to the invention have advantageous mechanical properties and are used in particular for manufacturing aircraft fuselage panels.