A thermomechanical model for the analysis of light alloy solidification in a composite mould

A coupled thermomechanical model to simulate light alloy solidification problems in permanent composite moulds is presented. This model is based on a general isotropic thermoelasto-plasticity theory and considers the different thermomechanical behaviours of each component of the mould as well as those of the solidifying material during its evolution from liquid to solid. To this end, plastic evolution equations, a phase-change variable and a specific free energy function are proposed in order to derive temperature-dependent material constitutive laws. The corresponding finite element formulation and the staggered scheme used to solve the coupled nonlinear system of equations are also presented. Finally, the temperature and displacement predictions of the model are validated with laboratory measurements obtained during an experimental trial. (C) 1999 Elsevier Science Ltd. All rights reserved