Study on Microstructure of In-situ Mg_2Si Reinforced Hypoeutectic Al-Si Alloy Composite

By means of optical micrograph,the microstructure of in-situ Mg2Si reinforced hypoeutectic Al-8%Si alloy composite was studied.The results show that,the microstructure of eutectic Mg2Si in the composite with 6%Mg is coarse chinese characters-like shape and dendritic shape.While the content of magnesium is 2%,the number of eutectic Mg2Si in the composite with 2% Mg decreases,the microstructure of eutectic Mg2Si is particle shape and dendritic shape.The microstructures of eutectic Mg2Si in the composite with 4% Mg is fibrilliform and dendritic shape,which is the optimum microstructure of in-situ Mg2Si reinforced hypoeutectic Al-8%Si alloy composite.