Place: Symposium on Simulation of Phase Transformation and Microstructure Evolution of Materials, Changwon, South Korea
Superalloys are of technological importance since they exhibit superior properties at elevated temperatures. Ni-base superalloys possess the unusual microstructure composed of thin γ-phase channels combined with dominant γ′-phase precipitates. In this study, dislocation induced strains at the interface are used to describe coherent and semi-coherent interfaces. We find, that there is a driving force which prevents precipitate coalescence. Moreover, the presented study shows that in contrast to coherent interfaces, semi-coherent interfaces significantly reduce repulsive stresses in the gamma-channels and promote precipitate coalescence. This knowledge is then used in a phase field simulation to investigate the microstructure evolution during long term aging of Ni-base superalloys.
Supporting information:Görler_KIMS Symposium abstract.pdf