Micro- and macrodefects in thin sheet twin-roll cast aluminum alloys

Twin-roll casting has been used to produce thin sheet (1–4mm thick) in aluminum alloys. The micro- and macrodefects found in the thin sheet material have been investigated. The defects include surface defects (surface bleeds), internal defects (such as channel segregates and deformation segregates), inhomogeneity of grain and secondary arm spacing (banding), and macroscopic buckling. This paper describes the experimental observations and relates their occurrence to the operating conditions. Mechanisms are proposed to explain the different defects that are formed.