Kinetics of Phase Transformations
The project group ‘Kinetics of Phase Transitions’ aims at an understanding of the dynamical processes that are essential for transformations in various materials. From a mesoscopic perspective, such descriptions demand in particular the knowledge of interfacial properties and kinetic coefficients, which then enter into modelling approaches that investigate the front motion in non-equilibrium situations and nucleation.
Atomistic representation of a model interface structure.
The growth of precipitates in shape memory alloys is such an example and highlighted in more detail below. On the atomic scale, the dynamics of the individual atoms as well as the concerted motion of clusters is pursued. Linking these very different aspects demands not only to bridge the vast gap of length-and timescales between atomistic and continuum simulations, but also to extract the appropriate information from the large number of degrees of freedom in atomistic simulations for the thermodynamics-based mesoscale models. Therefore, within the project group, methods have been developed to detect phases and structures in the bulk and at interfaces. The long term goal is to establish a contact between microscopic and mesoscopic approaches, for a unified and closed description of phase transformation kinetics starting from ab-initio approaches.
The project group has close ties to the research group Mesoscale Simulations at the Max-Planck Institute for Iron Research in Düsseldorf. Scientific exchange concerns mainly the two MPIE projects „Heterogeneous nucleation and microstructure formation“ and „Modelling of pine-tree nanowires“.