A 2-PHASE FINITE ELEMENT MODEL TO STUDY CONCURRENT FLUID FLOW AND SOLID DEFORMATION OCCURRING IN MUSHY ZONES DURING THE SOLIDIFICATION OF METALLIC ALLOYS

摘要

As an approach towards a better modelling of solidification problems, we present the basic assumptions and implementation of a thermo-mechanical two-phase model that considers the solidifying alloy as a binary mixture made of a liquid and a solid phase. Macroscopic mass and momentum balances are obtained considering that, at the microscopic level, the liquid is Newtonian whereas the solid is a power law fluid. Assuming local thermal equilibrium, a single equation for the conservation of the mixture energy is then written. The numerical implementation in a 2D finite element code is then detailed. Lastly, some examples of isothermal simulations of academic tests and application examples are discussed. They particularly enlighten the ability of the formulation to describe the mixture evolution over the whole solidification interval.