The Evolution of Extruded Products for Use in Aerospace

The progression of upper wing product improvements achieved through the development of alloys that include 7075-(T651 & T7651), 7150-(T6151 &

T7751) and 7x55-(T7751 & T7951) is reviewed.  The most current advancements include aluminum-lithium plate and extruded products that can attain strength equivalent to that of 7055-T7751 with higher modulus, similar fracture toughness and improved fatigue, fatigue crack growth and corrosion performance. The state of development of a new class of high strength Al-Li alloys is reviewed in detail. The improved fatigue performance of these products is highlighted.  Trade studies showing the benefit in terms of weight savings and durability using advanced products and advanced design considerations are discussed.