Phase-field simulation of microstructure evolution during solidification, heat treatment and under service conditions
The project examines the evolution of microstructure in single crystal Ni-base superalloys upon solidification, heat treatment and high temperature applications by means of phase-field simulations. The mutual influence of the material constitution and the thermo-mechanical conditions is considered. In the simulation of directional solidification, the focus of research is on the primary arm selection in technical, multicomponent alloys and casting defects criteria (false grain formation, porosity). The results serve as input data for the simulation of the solution and annealing precipitation. A second focus of the work lies in the simulation of raft formation under operating conditions. Here we again consider alloy constitution and consistent thermo-mechanical loading conditions. In addition to composition-dependent elastic constants, in particular, a reliable model description is needed for the thermally activated creep in order to investigate the influence of diffusive and plastic material transport on the raft formation.
C5 addresses the formation and evolution of γ-γ′ microstructures in Ni-base superalloys. A large scale three-dimensional phase field simulation of γ′-phase precipitation and coarsening is performed. The microstructure evolution during different heat treatment cycles and under service conditions are numerically simulated with our in-house open-source software OpenPhase which is based on a multi-phase field multi-component model [Steinbach et al., 1996; Steinbach, 2009].
It is carried out and funded in the framework of the SFB/TR103 "Superalloy Single Crystals.