Patent ID: 7604704
Filing Date: 2009-10-20
Classification: B64C,B64G,C22C,C22F

Abstract:
1. A method of producing a balanced Al—Cu—Mg—Si alloy having a high toughness, good strength levels and an improved fatigue crack growth resistance, comprising the steps of: a) casting an ingot consisting of the following composition (in weight percent): the balance essentially aluminum and incidental elements and impurities, which are at most 0.05% per element, 0.15% total, wherein the ingot is cast by semi-continuous direct chill (DC) casting, b) homogenizing and/or pre-heating the ingot after the casting step, c) hot rolling the homogenized and/or pre-heated ingot and optionally cold rolling into a rolled product, d) solution heat treating the hot rolled product, e) quenching the solution heat treated product, f) stretching the quenched product, and g) naturally ageing the stretched, rolled and heat-treated product.