Grain Refinement of the Al-Cu-Mg-Ag Alloy with Er and Sc Additions

The present work investigated the effects of additions with Sc and Er on the grain refinement in an Al-Cu-Mg-Ag alloy containing minor zirconium. The results indicated that 0.32 pct Sc addition interacted with 0.11 pct Zr and formed primary Al3(Sc,Zr) phase. It acted as the nuclei for heterogeneous nucleation of a-Al grain growth in the melt and refined the grains greatly. Additions of 0.3 pct Er resulted in an Al8Cu4Er phase formed at the grain boundary and refined mainly the dendritic substructure. There is no visible interaction of Er and Zr.