Effects of Heat Transfer Model between Cast and Mold and Constitutive Law in Solidification Simulation coupled with Thermal Contraction Analysis

Abstract

  The heat transfer coefficient between cast and mold may have a strong influence on the solidification process. It is, therefore, important to correctly evaluate the heat transfer coefficient, by considering all factors relevant for its evolution, such as mold coating, air-gap formation, contact pressure, and thermomechanical behavior of the cast. In the present paper, the simulation of the solidification process coupled with the analysis of the thermal contraction of the cast is carried out with the aid of the finite element software V-Shrink, developed under the VCAD System Research Program. The results obtained confirm that proper evaluation of the heat transfer coefficient has a major effect on the temperature history, and consequently on the distribution of the local solidification times, and on the prediction of shrinkage porosity. Furthermore, the simulation results point out the considerable role played by the constitutive modeling of the cast material on the development of air gaps and hence on the heat transfer between the cast and mold.