Melt characteristics and solidification growth direction with respect to gravity affecting the interfacial heat transfer coefficient of chill castings

Abstract

For purposes of an accurate mathematical modeling, it is essential to establish trustworthy boundary conditions. The heat transfer that occurs at the casting/mold interface is one of these important conditions, which is a fundamental task during unsteady solidification in permanent mold casting processes. This paper presents an overview of the inverse analysis technique (IHCP) applied to the determination of interfacial heat transfer coefficients, hi, for a number of alloy solidification situations. A search algorithm is used to find the transient metal/mold interface coefficient during solidification which is reported either as a function of the casting surface temperature or time. Factors affecting hi such as the direction of gravity in relation to the growth interface, the initial melt temperature profile, the wettability of the liquid layer in contact with the mold inner surface, were individually analyzed and experimental laws for hi have been established. (C) 2009 Elsevier Ltd. All rights reserved.