Department Atomistic Modelling and Simulation
Master Thesis: Atomistic simulations of heterogeneous nucleation during solidifcation in nickel (Dr. Jutta Rogal, Dr. Grisell Diaz Leines)
Nickel alloys are an important example of high-temperature materials used for turbine blades in jet engines and gas turbines. Despite their importance little is known about the atomistic processes during solidification, especially for the initial nucleation of the solid phase within the melt. Molecular dynamics simulations provide an atomistic picture of solidification, but the modelling of the initial nucleation is hampered by the extended timescales of the process. In this project we will employ advanced computational methods like transition path sampling (TPS) to investigate nucleation during solidification in nickel on the atomistic level. Recently we have employed TPS to investigate homogeneous nucleation in nickel. Here the task is to extend our study to investigate important aspects of heterogeneous nucleation at defects in nickel. The analysis of the transition path ensemble provides information about the structures, shapes and critical sizes of the nuclei, as well as free energies and rate constants. These results can be directly compared to homogeneous nucleation during solid-liquid transformations in nickel.
Interdisciplinary Centre for Advanced Materials Simulation (ICAMS)
Ruhr University Bochum
44780 Bochum, Germany