Numerical simulation of solidification of aluminum alloy castings
Additional Document Info
A brief review on the important considerations involved in numerical simulation of the solidification is given. This is followed by presentation of governing equations and finite element formulation for a transient, nonlinear solidification problem in two dimensional axisymmetric space with convective heat transfer boundary. The nonlinearity between the enthalpy and temperature is handled using first-step Newton procedure. The enthalpy, temperature and fraction solid are calculated at all the nodes during each time step. The fraction solid is calculated using the classical lever rule, Scheil equation and Brody-Flemings model. Modeling results are presented for the solidification of pure aluminum, two eutectic alloys (Al-12.6% Si and Al-33.2% Cu) and three hypoeutectic alloys (Al-12.6% Si and Al-33.2% Cu). The numerical solution is found to agree with the experiment. In the course of these treatments some of the numerical solution features of handling the conditions of severe discontinuity and convective boundary on the nature of the solution are also presented.