7050 Aluminium Rod

7050 Aluminium Rod is a very high strength heat-treatable aluminium-zinc-magnesium-copper alloy in bar form, containing 5.7-6.7% zinc, 2.0-2.6% copper, and 1.9-2.6% magnesium with a zirconium addition, available in As Drawn condition for smaller diameters and the T74511 temper across the broader diameter range. The T74511 temper, solution heat treated, overaged beyond peak strength, and stress-relieved by controlled stretching, provides very high strength alongside significantly better stress corrosion cracking resistance compared with T6 or T651 conditions. The zirconium addition forms Al3Zr dispersoids that suppress recrystallisation and preserve fracture toughness in thick sections, which is the critical metallurgical advantage of 7050 for primary aircraft structural applications. Good machinability is combined with poor fusion weldability, though friction welding is possible. In industry, 7050 rod is the primary material for aircraft structural bar stock where very high strength, good fracture toughness, and resistance to stress corrosion cracking must coexist in thick section: confirmed applications include aircraft bulkheads, wing skins, fuselage frames, and highly stressed structural components in commercial and military airframes. In research, it is used for fracture toughness and stress corrosion cracking evaluation in thick-section aluminium alloy bar, fatigue crack propagation studies, residual stress characterisation, and comparative investigations of overaged versus peak-aged temper behaviour in 7xxx series alloys.