Atomistic to continuum modeling of solidification microstructures

Abstract

a b s t r a c tWe summarize recent advances in modeling of solidification microstructures using computational methods that bridge atomistic to continuum scales. We first discuss progress in atomistic modeling of equilibrium and non-equilibrium solid-liquid interface properties influencing microstructure formation, as well as interface coalescence phenomena influencing the late stages of solidification. The latter is relevant in the context of hot tearing reviewed in the article by M. Rappaz in this issue. We then discuss progress to model microstructures on a continuum scale using phase-field methods. We focus on selected examples in which modeling of 3D cellular and dendritic microstructures has been directly linked to experimental observations. Finally, we discuss a recently introduced coarse-grained dendritic needle network approach to simulate the formation of well-developed dendritic microstructures. This approach reliably bridges the well-separated scales traditionally simulated by phase-field and grain structure models, hence opening new avenues for quantitative modeling of complex intra-and inter-grain dynamical interactions on a grain scale.Published by Elsevier Ltd.

Free dendritic tip growth velocities measured in Al-Ge

“…The fundamental concepts of dendritic growth are based on the description of a dendrite tip propagating freely in an undercooled melt, whereby the movement of the solid-liquid interface is controlled by latent heat and solute diffusion away from the interface [3,4]. As the aim is to bridge the scales between micro-and macromodeling [5][6][7][8], an accurate prediction of dendritic tip kinetics is mandatory, and therefore many theoretical and numerical efforts have been devoted to investigate the steady-state growth of the tip region [3,9,10].…”

In situ observation of solidification patterns in diffusive conditions

“…Front-tracking methods (sharp interface) [18], and, more frequently at present, phase-field (PF) models are of current use [8,10]. On space scales approaching casting conditions, scale-bridging models [19,20,21,22] and numerical automata (e.g. CAFE, Cellular Automaton-Finite Element [23, 24]) for polycrystal growth are progressively improved.…”

Finite Interface Dissipation Phase Field Modeling of Ni-Nb Under Additive Manufacturing Conditions

“…Numerical modeling of the solidification microstructure has been performed using various methodologies [4][5][6][7][8][9][10]. A thorough discussion on solidification microstructures and simulation methods can be found in prior works [11][12][13][14][15][16].…”