Patent ID: 6322646
Filing Date: 2001-11-27
Classification: C22C,C22F

Abstract:
A method for making a superplastically formable, aluminum-based sheet product having greater than about 250% elongation at a strain rate of about 0.0001-0.003/sec and a temperature between about 950-1135.degree. F., said method comprising the steps of:(a) providing a hot rolled plate or slab made from an aluminum alloy containing: about 2.7-3.8 wt. % magnesium, at least one dispersoid-forming element selected from the group consisting of: up to about 1.6 wt. % manganese, up to about 0.2 wt. % zirconium, and up to about 0.3 w. % chromium; at least one nucleation-enhancing, recrystallization element selected from: about 0.11-1.0 wt. % silicon, up to about 1.5 wt. % copper, and combinations thereof, the balance incidental elements and impurities;(b) solution heat treating the plate or slab at one or more temperatures between about 950-1135.degree. F.; and(c) quenching the plate or slab at a drastic cooling rate prior to subsequent cold rolling to form said sheet product.