Modification effect of Er on hypoeutectic Al-8Si alloy

The modification effect of Er on hypoeutectic Al-8Si alloy was investigated by KH-2200 optical microscope, JXA-8800R electron probe microanalysis (EPMA) and CMT5105 electromechanical universal testing machine. The results show that the eutectic silicon is modified from a coarse flake-like to refined plate-like structure and the tensile properties are improved. With the additional level of Er up to 0.5%, the tensile strength of the Al-8Si alloy is increased by 24%. The Al8Si-0.5Er alloy has a ductile fractured surface, while the unmodified Al-8Si alloy possesses a brittle fractured surface.