As-cast morphology of iron-intermetallics in Al-Si foundry alloys

The “as-cast” three-dimensional morphologies of α-Al15(Fe, Mn)3Si2 and β-Al5FeSi intermetallics were investigated by serial sectioning. Large β-Al5FeSi intermetallics were observed to grow around pre-existing dendrite arms. The α-Al15(Fe, Mn)3Si2 intermetallic particle was observed to have a central polyhedral particle and an external highly convoluted three-dimensional structure.