TearSim: A 2D simulator for two-phase mechanics during DC casting of aluminium

This work presents a new axisymmetric 2D model, TearSim, for the simulation of DC casting of aluminium, with emphasis on modelling the flow, the stresses and the strains in the two-phase mushy zone. The model is intended to serve as a starting point for establishing new hot tearing criteria, based on the mechanical quantities resulting from the simulation. Two equations are solved in the model: the mixture equilibrium equation for the thermally induced deformations coupled with the non-linear Poisson equation for the liquid pressure, which describes liquid flow in the mushy zone using Darcy's law. For the rheology of the mushy zone, constitutive equations modelling the semi-solid material as a viscoplastic porous medium saturated with liquid are applied. This paper describes the numerical implementation of the TearSim simulator based on a FEM technique. Some validation examples are presented, as well as some preliminary results of DC casting simulations.