Modelling of Equiaxed Microstructure Formation in Solidifying Two-Component Alloys

Abstract

The paper deals with a numerical modelling of equiaxed microstructure formation during the solidification of two-component alloys, poured into metal forms. The basic enthalpy formulation was applied to model the solidification. The formulation allows the characteristic dimensions of computed microstructure in thermal calculations to take into account. The so-called indirect model of solidification (solid phase growth), which allows the modelling of all possible solidification courses, from equilibrium to non-equilibrium solidification, was used to model the equiaxed microstructure formation. This model was worked out from an approximate solution of the diffusion equation of solute in a single grain. The equiaxed grain size was dependent on the average velocity of cooling at the moment when the liquid metal reached the temperature of the beginning of solidification. The above simulation was performed using the NuscaScomputer program, which has been developed at the Technical University of Czestochowa.