Modified cellular automaton model for the prediction of dendritic growth with melt convection

Abstract

A modified cellular automaton (MCA) coupled with a momentum and species transport model has been developed in order to predict the evolution of dendritic morphology during solidification of alloys in the presence of melt convection. In the present model, the cellular automaton algorithm for dendritic growth is incorporated with the transport model, for calculating fluid flow and mass transfer by both convention and diffusion. The MCA model takes into account the effects of the constitutional undercooling and the curvature undercooling on the equilibrium interface temperature. It also considers the preferred growth orientation of crystals and solute redistribution during solidification. In the transport model, which is coupled with cellular automaton approach, the SIMPLE scheme is employed to solve the governing equations of momentum and species transfers. The present model was applied to model solutal dendritic growth of an Al-3mass%Cu alloy in a forced flow. The simulations reproduced the typical asymmetric growth features of convective dendrites with various preferred orientations. The effects of inlet flow velocity on the solute redistribution and the growth velocity of a dendritic tip were quantitatively investigated.

Solidification microstructures and solid-state parallels: Recent developments, future directions

“…Phase-field models have been developed [223][224][225] and widely used to simulate solidification in the presence of fluid flow [226][227][228][229][230][231][232][233][234][235][236]. Other methods, such as the sharp-interface tracking technique [237][238][239], lattice Boltzmann models [240][241][242][243], cellular automaton techniques [244][245][246] and Monte Carlo simulations [247], have also become available.…”

Probabilistic Modelling of Microstructural Evolution in Zr Based Bulk Metallic Glass Matrix Composites during Solidification in Additive Manufacturing

“…In present study, which is continuation of author's previous work [2], a probabilistic model of nucleation and growth [9] [10] is developed to supplement deterministic model to describe this phenomena in these alloys without recurrence to experimentation. Much research has been carried out previously on modelling and simulation of solidification phenomena in various processes employing cellular automata or modified cellular automata combined with finite element such as modified additive manufacturing (HDMR [11], LAMP [12] on 316L SS [10], two dimensional CAFE [13], cladding [14] [15]), selective laser melting (SLM) using CAFE [14] [15] [16] [17], CAPF, CAFVM [18] and modified CAFE [19] but none has been conducted on the use of cellular automata method on bulk metallic glasses or their composites. On modelling and simulation of bulk metallic glasses themselves; only two studies have been reported [20] [21] but again they are not aimed at explaining microstructure evolution.…”

A Model for Initial Spherical Growth during Equiaxed Solidification

“…Thus, the fundamentals of crystal growth kinetics attract numerous research interests [1][2][3][4][5][6][7][8][9] but the understanding of equiaxed crystal growth is inadequate because of the complexity of the process. Basically, the processing of crystal growth relies only on the undercooling, AT, in the liquid, which is given as AT = AT, + AT r + AT C + AT k (1) where AT, , AT r , AT C and AT k are the thermal, curvature, constitutional and kinetic undercooling, respectively.…”