Microstructure of hypereutectic Mg-Si alloy with Sn, Al and Mn additions

摘要

In the present study, the microstructure of Mg-5Si alloys with tin, aluminum and manganese was investigated. The microstructure of Mg-5Si alloy consists of the primary coarse Mg_2Si phase, a-Mg solid solution and eutectic a-Mg + Mg_2Si in which the eutectic Mg_2Si phase solidifies in the form of Chinese script particles. The Mg2Sn phase and a-Mg solid solution with tin appear in the microstructure, when 7 wt.% of Sn was added to the Mg-5Si alloy. Aluminum dissolve in the a-Mg matrix and participates in the formation of Al_2Sn phase. The addition of manganese promotes the formation of Mn_5Si_3 compound.