Development of Structural Plate for Aircraft Internal Structure

A significant weight of "thick" aluminum plate products is used in the manufacture of an aircraft's internal structure in applications such as ribs, spars, frames, bulkheads, etc. With the recent launch of more fuel efficient and primarily metallic single aisle aircraft but also the introduction of composite-intensive twin-aisle aircraft, a number of opportunities exist for upgrading alloys developed more than 30 years ago with a new generation of Al-based products. These include 7xxx aluminum thick plate products (7085, C85T) that show significant improvements in both strength and toughness along with Al-Li products (C77W, C14U) that show high strength, low density and very high corrosion resistance with significantly improved toughness over previous generation products. Property improvements are reviewed in terms of metallurgical enablers, such as lower quench sensitivity, along with predicted structural gains (weight savings, lower maintenance) for typical applications. Development status and timelines for commercialization are also presented.