Effects of electromagnetic stirring on microstructure of Bi-containing hypereutectic Al-Si alloy were observed by OM （optical microscope） and SEM （scanning electron microscope）

and effect mechanism of electromagnetic stirring and Bi phase was analyzed. The results show that primary Si phase is greatly decreased in the presence of a little fine bulky phase

and acicular eutectic Si phase is increased with the occurrence of primary α-Al dendrite phase in electromagnetic stirred Bi-containing hypereutectic Al-Si alloy. With increasing in stirring velocity

morphology of eutectic Si phase is transformed from coarse acicular structure to fine acicular one to coarse acicular one. Meanwhile

segregation of Bi in the alloy can be obviously improved by electromagnetic stirring. With increasing in stirring velocity

distribution morphology of the Bi in the alloy is converted from bulky structure to short-rod one to spherical one to fine spherical one

tending to uniform distribution.