Patent ID: 6074498
Filing Date: 2000-06-13
Classification: C22C,C22F

Abstract:
A method for preparing an aluminum-copper-lithium-scandium alloy article, comprising:a) providing an aluminum alloy comprising, in weight percent, about 2.6% to about 3.3% Cu; about 2.0% to about 2.4% Li; about 0.05 to about 0.14% Sc, balance aluminum and incidental impurities;b) solution treating said alloy at a temperature and for a time sufficient to form a solid solution followed by rapidly cooling said article such that precipitation of second phases in said alloy is prevented to form a quenched alloy;c) subjecting said quenched alloy to a first aging step at a temperature of from about 120.degree. C. to about 140.degree. C. for a time of from about 8 to about 30 hours to form an aged alloy;d) subjecting said aged alloy to a second aging step at a temperature of from about 150.degree. C. to about 170.degree. C. for a time of from 10 to about 20 hours to form a dual aged alloy, wherein the alloy, following step (d), exhibits a difference between tensile yield strength at 0.2% elongation and ultimate tensile strength which is greater than that of an identical alloy subjected to single step aging at 130.degree. C. for 8-12 hours.