Effect of Fe and Mn Content on the Microstructures and Tensile Behaviour of AlSi7Cu3 Alloy: Thermal Analysis and Tensile Tests

The present study was performed on two AlSi7Cu3 alloys with different Fe and Mn contents (standard alloy and high-Fe/Mn alloy). The evolution of microstructures during solidification of the standard AlSi7Cu3 alloy was investigated by thermal analysis and interrupted quenching test. The effect of Fe and Mn content on the solidification reaction and sequence were studied. The results show that increasing the Fe and Mn content changes the precipitation sequence of the iron-intermetallic α-Al 15 (Fe,Mn) 3 Si 2 and β-Al 5 FeSi, leading to the precipitation of α + β phases at a higher temperature. Microstructural characterizations were also performed on the fully solidified alloys to study the effect of Fe and Mn content on the microstructure of AlSi7Cu3 alloy. Fe and Mn were found to promote the formation of Fe-intermetallics. With the increase of Fe/Mn content, Fe-intermetallics increased in both size and amount, while more small pores (Feret diameter