Patent ID: 8366839
Filing Date: 2013-02-05
Classification: C22C,C22F

Abstract:
1. Extruded aluminum alloy product having a density less than 2.67 g/cm 3 obtained by a method comprising: a) preparing a liquid metal bath comprising 2.45 to 2.65% by weight of Cu, 1.4 to 1.5% by weight of Li, 0.1 to 0.5% by weight of Ag, 0.1 to 1.0% by weight of Mg, 0.05 to 0.18% by weight of Zr, 0.2 to 0.6% by weight of Mn and at least one element selected from Cr, Sc, Hf or Ti, the quantity of said element being 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, remainder aluminum and inevitable impurities; b) casting an unwrought shape from said liquid metal bath; c) homogenizing said unwrought shape at a temperature from 515° C. to 525° C. such that the equivalent time for homogenization is from 5 to 20 hours, where T (in Kelvin) is the instantaneous treatment temperature, which varies with the time t (in hours), and T d) hot working and optionally cold working said unwrought shape into an extruded product; e) subjecting the product to a solution treatment and quenching; f) stretching said product with a permanent set of 1 to 5%; g) artificially aging said product by heating at 140 to 170° C. for 5 to 70 hours, wherein the toughness K