A MODEL OF THE INTERFACIAL HEAT TRANSFER COEFFICIENT DURING THE SOLIDIFICATION OF AN AL-SI ALLOY

摘要

A model was developed to predict the heat transfer coefficient during the unidirectional solidification of an Al-7wt.%Si alloy casting. An important feature of this model was that once the casting skin had solidified it was assumed to deform into a spherical shape. This implies that during solidification heat was transferred at the interface with the chill through a central area where the plane chill surface and the spherical casting skin were in contact, surrounded by an outer annulus where a local gap existed between the casting and the chill surfaces. The model produced values of the interfacial heat transfer coefficient which were comparable to those measured.