Microstructure and mechanical properties of Al–Cu–Mg alloy tube fabricated by friction stir welding and tube spinning

A large-diameter thin-walled aluminum alloy tube was produced by friction stir welding combined with spinning, and the tube’s microstructure and mechanical properties were investigated. The microstructural heterogeneity of the friction stir welded joint is significantly improved by severe plastic deformation, which results in the generation of a fine-grained structure and uniform distribution of second-phase particles in the weld and base material. The weld region of the tube shows similar microstructure and mechanical properties to that in base material.