Effects of content and morphology of iron phase in eutectic Al-Si alloy have been investigated by optical microscope（OM）

universal material testing machine and XRD（X-ray diffusion）.The composition and microstructure of iron phase and the distribution of iron element in the alloy have been observed by SEM and energy spectrum analysis.The experimental results reveal that with the increase of Fe content

the tensile strength and elongation of the alloy are decreased gradually

in which the tensile strength and elongation are sharply descended with about 1% Fe content.The tensile strength of the alloy containing high Fe content can be improved by 180% with adding Mn to a given Fe/Mn ratio

which is contributed to the transformation of needle-like Fe phase from bulky and Chinese script Fe phase.