Effect of cooling rate on the solidification behaviour of Al-Fe-Si alloys

The effect of cooling rate on the: solidification microstructure: of an Al- Fe-Si alloy is investigated Samples were solidified with cooling rates betw een 0.04 and 3.5 K s(-1). The microstructures are characterised in terms of eutectic volume fraction, dendrite arm spacing and size and shape of secon dary phases. Eutectic volume fraction and dendrite arm spacing were also ca lculated using a microsegregation model. Predicted data are found to be in good agreement with the experimental observations. Further, the role of mic rosegregation on phase selection is discussed with reference to earlier stu dies on phase selection in these alloys. The concentration of the liquid at the onset of eutectic solidification is correlated with the selection of t he secondary phases in the eutectic. (C) 2000 Elsevier Science S.A. All rig hts reserved.