Influence of Ce and Mn addition on α-Fe morphology in recycled Al-Si alloy ingots

The influence of Ce or Ce and Mn combined additions on the morphology of α-Fe phases in recycled Al-Si alloys was experimentally investigated by microstructure observation and room temperature tensile testing. It is found that Ce modifies the morphology of α-Fe phase from the large Chinese script-like into the individual and fine nodular shape. A combined addition of Ce and Mn results in the promotion of primary α-Fe formation, and their size increases considerably with the increase in Ce content. The mechanism of the above morphological changes was discussed in accordance with the nucleation and growth of α-Fe phase during solidification.