Morphologies and Compositions of α–Al15Fe3Si2-Type Intermetallics in Al–Si–Fe–Mn–Cr Alloys

In this paper, several Al–Si–Fe–Mn–Cr alloys were prepared, with different element contents and solidification conditions. The conventional Chinese character-shaped Al 15 (Fe,Mn) 3 Si 2 particles were detected in slowly solidified Al–12Si–2Fe–4Mn alloy, while both (Al,Si) 2 Cr and Al 15 (Fe,Cr) 3 Si 2 particles were formed in slowly solidified Al–12Si–2Fe–4Cr alloy. When the melt was solidified with high cooling speed, all of the α–Al 15 Fe 3 Si 2 -type intermetallics in Al–12Si–2Fe–4Mn, Al–12Si–2Fe–4Cr and Al–12Si–4Fe–xMn–yCr ( x + y = 4) alloys exhibit dendrite-like. It was found that the higher Mn (or Cr) addition in Al–12Si–4Fe– x Mn–yCr alloys, the higher Mn (or Cr) content in Al 15 (Fe,Mn,Cr) 3 Si 2 phase. Compared to Mn atoms, Cr atoms have a higher tendentiousness to participate in the formation of Al 15 (Fe,Mn,Cr) 3 Si 2 intermetallics.