Reheating of solid shell during twin belt-casting of an Al–Fe–Si alloy

The surface microstructure of a twin belt-cast Al–1 Si–0.65 Fe alloy has been studied. It was found that the initially formed solidified shell was reheated later in the casting process, resulting in surface homogenization and eutectic remelting. The consequence of this surface homogenization is a phase transformation of the surface and sub-surface intermetallics from β-AlFeSi to α-AlFeSi in this alloy.