Effect of Fe on grain refining of pure aluminum refined by Al5TiB master alloy

High pure aluminum and commercial pure aluminum were refined by Al5TiB master alloy, respectively. Experimental results show 0.2 wt.% Al5TiB master alloy can refine commercial pure aluminum effectively, but has no contribution to the refining of high pure aluminum and 1 wt.% Al5TiB master alloy also can refine high pure aluminum effectively. SEM observation indicates that in situ FeAl3 rod phase was found on grain boundary. According to experimental findings, the effect of Fe includes promoting nucleation of primary α-Al and forming FeAl3 rods which can act as pinning effect on grain boundary to hinder growth of α-Al grain.