Determination of transient interfacial heat transfer coefficients in chill mold castings

The present work focuses on the determination of transient mold-environment and metal-mold heat transfer coefficients during solidification. The method uses the expedient of comparing theoretical and experimental thermal profiles and can be applied both to pure metals and metallic alloys. A solidification model based on the finite difference technique has been used to provide the theoretical results. The experiments were carried out by positioning the thermocouples in both metal and mold. The comparison between experimental and theoretical results is made by an automatic search of the best fitting among theoretical and experimental cooling curves simultaneously in metal and in mold. This has permitted the evaluation of the variation of heat transfer coefficients along the solidification process in unsteady state unidirectional heat flow of AI-Cu and Sn-Pb alloys, as well as the analysis of the effects of the material and the thickness of the mold and melt superheat. (C) 2001 Elsevier Science B.V. All rights reserved.3194167117418