Aluminum-Lithium Alloy 1441 as a Promising Material for Fuselage

A comprehensive study of the suitability of sheets of alloy 1441 of the Al – Cu – Mg – Li system for the production of long-life airplane fuselages is described. The alloy has been used in the Be 103 boatplane airframe and is tested for use in the new business-class airplane of the A. N. Tupolev Aircraft Scientific-and-Engineering Company (ANTK). Sheets of alloy 1441 including thin ones with a thickness of 0.5 mm are manufactured by cold coil rolling. As compared to traditional deformable alloys of the Al – Cu – Mg system, alloy 1441 has a diminished density and an elevated modulus of elasticity at a comparable level of strength. Researchers in Russia (GP GNTs VIAM) and in the USA (LaRC, NASA) studied the tensile mechanical properties, the fracture toughness, the impact toughness, the fatigue resistance, and the growth rate of fatigue crack in sheets fabricated from alloy 1441. Researchers of the A. N. Tupolev ANTK fabricated fuselage panels with sheathing from alloy 1441 and stringers from high-strength aluminum alloy V95. The panels were tested in the ANTK and in the LaRC by the method of internal pressure by pulse-cycle simulation of the surface conditions of the airplane.