Phase-field simulation of morphology evolution during eutectic solidification

In dieser Arbeit werden mögliche Strukturbildungsmechanismen bei der Erstarrung von eutektischen Schmelzen, anhand der beiden Systeme Platin-Kohlenstoff (Pt-C) und Magnesium-Aluminium (Mg-Al), unter Anwendung der Phasenfeldmethode untersucht. Dazu wird unter Abgleich von experimentellen Ergebnissen das Phasenfeld-Framework angepasst und erweitert und so realistische Mikrostrukturen reproduziert die qualitativ und quantitativ vergleichbar mit den experimentellen Mikrostrukturen sind. So wird unter anderem der Einfluss der Kühlrate auf das entstehende Gefüge beider Systeme simuliert. Die Simulationen, zusammen mit den unterstützenden Experimenten, lassen auf die Sequenz und Position der Keimbildungsprozesse in eutektischen interdendritischen Kanälen in Mg-Al Legierungen schließen. Damit wird ein Beitrag zum Verständnis der Erstarrung dieser wichtigen Leichtbauwerkstoffe geleistet

Parallel multiphase field simulations with OpenPhase

The open-source software project OpenPhase allows the three-dimensional simulation of microstructural evolution using the multiphase field method.The core modules of OpenPhase and their implementation as well as their parallelization for a distributed-memory setting are presented. Especially communication and load-balancing strategies are discussed. Synchronization points are avoided by an increased halo-size, i.e. additional layers of ghost cells, which allow multiple stencil operations without data exchange. Load-balancing is considered via graph-partitioning and sub-domain decomposition. Results are presented for performance benchmarks as well as fora variety of applications, e.g. grain growth in polycrystalline materials, including a large number of phase fields as well as Mg-Al alloy solidification

Full-field simulation of solidification and forming of polycrystals

The phase-field method has emerged as the method of choice for simulation of microstructure evolution and phase-transformations in material science. It has wide applications in solidification and solid state transformations in general. Recently, the method has been generalized to treat large deformation and damage in solids. A through process full-field simulation will be presented starting from solidification and ending with the evolution of damage during large deformation. Aspects of numerical discretization, efficient numerical integration and massive parallelization will be discussed

Full-field simulation of solidification and forming of polycrystals

The phase-field method has emerged as the method of choice for simulation of microstructure evolution and phase-transformations in material science. It has wide applications in solidification and solid state transformations in general. Recently, the method has been generalized to treat large deformation and damage in solids. A through process full-field simulation will be presented starting from solidification and ending with the evolution of damage during large deformation. Aspects of numerical discretization, efficient numerical integration and massive parallelization will be discussed