A Model for Equiaxed Eutectic Solidification with Melt Convection and Solid-Phase Transport

Abstract

This paper presents a method to track microstructural evolution during eutectic solidification using a coupled fluid flow—mass transport model. The continuum formulations were used to describe the macroscopic transports of mass, energy, and momentum, associated with the microstructural evolution, for two-phase systems. It was assumed that the liquid flow is driven by thermal and solutal buoyancy, as well as solidification contraction. The eutectic cell (grain) of cast iron was assumed to have a spherical morphology. The microstructural model includes the gray-to-white eutectic transition and the influence of microsegregation on the eutectic temperature. A continuous nucleation law was used in calculation. Rules for grain movement have been developed to track the nucleation, growth and movement of grains because of melt convection. Three test cases are discussed to demonstrate the influence of melt convection and solid phase transport on microstructure evolution for eutectic cast iron.