ON THE THERMO-MECHANICAL MODELING OF THE COHERENT MUSHY ZONE DURING SOLIDIFICATION PROCESSES

摘要

This paper addresses the modeling of the thermo-mechanical behavior of the mush below the coherency temperature where the solidified dendrites agglomerate and form a continuous skeleton. A continuum-mechanical model based on the theory of porous media is introduced to describe the deformation and solidification phenomena in casting processes. The model is based on two constituents which are incompressible on the microscale, namely an elasto-viscoplastic solid skeleton and a viscous pore fluid. The balance equations are formulated on the macroscale and the exchange of mass, momentum and energy between the constituents is quantified. Restrictions and dependencies for the constitutive equations describing the exchange terms and the material laws are deduced from the entropy inequality. Moreover, it is a non-isothermal model by taking into account thermal deformations and achieving a direct coupling to the thermal solidification analysis.