Investigation of iron containing intermetallics in AlSi12 alloy with w (Mn/Fe) = 0.99

The precipitation of iron-rich intermetallic phases in AlSi12 alloy with manganese/iron weight ratio w (Mn/Fe) = 0.99 was investigated. Calculation of solidification sequence under equilibrium conditions, obtained using Computer Aided Thermodynamic Diagram Calculation, comprehended precipitation of α-Al15(FeMn)3Si2 and β-Al5FeSi. However, the microstructural investigations performed using light and electron microscopy indicated the lack of β- Al5FeSi in needle-like morphology. The intermetallic phases in Chinese script, transitional and polyhedral morphology were found, respectively. The results of Energy Dispersive Spectroscopy showed the minimum difference in the chemical composition between the intermetallic phases in Chinese script and polyhedral morphology due to high w (Mn/Fe) weight ratio.