Perspectives of Application of Fiber Metal Laminate Materials Based on Aluminum Alloys in Aircraft Design

Abstract

Alcoa has developed Al-Li Alloy 2099, also designated C460, for use in aerospace and high strength applications requiring low density, high stiffness, superior damage tolerance, excellent corrosion resistance and weldability. Li additions increase the strength and modulus of Al alloys while lowering their density. Alloy 2099 extrusions are available in two tempers from 0.050 to 3.00 inch (1.2 to 76 mm) thicknesses. Alloy 2099-T83 has high strength and excellent corrosion resistance with moderate fracture toughness. Alloy 2099-T8E67 has somewhat lower strength, but very high fracture toughness and excellent fatigue crack growth resistance. Alloy 2099 is also available in T3-and T4-type and O tempers that meet stringent requirements of forming applications. Alloy 2099 extrusions can replace 2xxx, 6xxx, and 7xxx aluminum alloys in applications such as statically and dynamically loaded fuselage structures, lower wing stringers, and stiffness dominated designs. Alloy 2099 extrusions have exhibited very good machining, forming, fastening, and surface finishing behavior in production facilities.