Effect of roll-separating force on as-cast material characteristics of an Al–Mn–Mg aluminum alloy produced via twin-roll casting technique

OpenAlex English

The aim of the present study is to investigate the influence of roll-separating force (RSF) on the through-thickness uniformity of microstructural features and crystallographic texture in an Al–Mn–Mg aluminum alloy as-cast strip produced by the twin-roll casting (TRC) technique. Results indicate that the strip fabricated with a higher RSF exhibits a non-uniform distribution of intermetallic particles, accompanied by a heterogeneous grain structure across its thickness. The near-surface region experiences significant shearing, characterised by a crystallographic texture of {001}⟨110⟩ (rotated-cube) on the surface. However, a lower RSF results in a cellular-dendritic microstructure that remains consistent throughout the cross-section. It also leads to a relatively random crystallographic texture and a reduction in the overall strength of the strip, while enhancing elongation. In both strips, intermetallic particles in the near-surface region and quarter-plane predominantly consist of Al, Fe, Si and Mn elements, identified as α-Al (Fe, Mn)Si. However, the concentrations of these elements in the intermetallic particles are higher and more uniform in the strip fabricated with a lower RSF. The through-thickness homogeneity observed in both the microstructure and microchemistry under a lower RSF indicates a more uniform and slower cooling rate throughout the thickness of the strip.