Refinement the Microstructure of Al–7Si Alloy by the Addition of Cadmium


Cadmium (Cd) modified aluminium–silicon cast alloys are well known for their outstanding mechanical properties as they combine excellent strength with good ductility that is due to a modification of brittle Si in the eutectic with traces of Cd (0.2–1.0 wt%). The results showed that the Cd leads to the refinement of eutectic silicon from ~95 to 10µm. The alloys which used in this work were Al-7Si alloy with additions of 0.2, 0.6 and 1 wt% Cd as well as Al-7%Si with out Cd addition. The effect of keeping time also studied and the results indicate that the addition of 1%Cd with keeping time 3min was the best (about 10 µm).