Solidification of aluminum-copper B206 alloys with iron and silicon additions

Solidification of B206 aluminum alloys with additions of iron and silicon was studied to investigate their combined effect on the formation and precipitation of intermetallics, particularly Fe-rich phases. Iron is precipitated mainly by either β(CuFe) or α(MnFe) phases, or both depending of the iron and silicon content, as well as the cooling rate. It was found that in alloys having up to 0.3 wt pct Fe, the precipitation of β(CuFe) phase can be largely suppressed if the ratio Si/Fe is close to 1 and the cooling rate is moderately high. The low mobility of the large facets of the β(CuFe) platelets is likely the cause limiting the amount of this phase, especially when the iron atoms have the possibility to be captured by another phase, in this case, the α(MnFe) phase