Coarsening and refinement phenomena in dendritic solidification


Coarsening and refinement phenomena in dendritic solidification

Neumann-Heyme, H.; Eckert, K.; Beckermann, C.

Curvature-driven interface motion plays an important role in the formation of the final microstructure during dendritic solidification. Usually, such motion results in a coarser microstructure via coalescence or retraction of dendrite sidebranches \cite{ref1}. Under certain conditions, however, the microstructure can be refined due to curvature-driven pinching events that lead to dendrite fragmentation. Such pinching events are a strong function of the size and shape of the initial dendrite structure \cite{ref2}. In the present study, two- and three-dimensional phase-field simulations are performed to investigate coarsening and refinement phenomena during directional solidification of alloys. The phase-field model is solved using a finite element library that permits adaptive mesh refinement and exhibits wide parallel scalability on supercomputing facilities. A semi-implicit time integration scheme is used to allow for adaptive time stepping, which is important in particular, since curvature-driven interface motion occurs on significantly larger time scales than the initial growth. The present talk will focus on some characteristics of the applied model and physical insights that were obtained.

  • Lecture (Conference)
    5th GAMM Workshop on Phase-Field Modeling, 08.-09.02.2018, TU Dresden, Germany

Permalink: https://www.hzdr.de/publications/Publ-28804
Publ.-Id: 28804