CAFE Modeling of Segregation and Structure in Levitated Droplets

Abstract : The coupled two dimensional (2D) Cellular Automaton (CA) Finite Element (FE) model has been extended based on the recent work by Guillemot et al. [1]. Extensions concern i microsegregation at the scale of the CA cells ii macrosegregation at the scale of the FE mesh based on a remeshing technique. The model is applied to segregation taking place upon single grain nucleation and growth from the centre of a spherical domain. The simulation retrieves the prediction of Heringer et al. [2]. Application to solidification of a spherical Al-4wt%Cu droplet demonstrates its capability to deal with mass exchange by diffusion outside the grain envelope defined by the mushy zone together with back diffusion in the solid [3].