ICAMS / Interdisciplinary Centre for Advanced Materials Simulation

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Long-term aging and coherency effects in γ/γ′ forming superalloys

Date: 02.08.2014
Place: Symposium on Simulation of Phase Transformation and Microstructure Evolution of Materials, Changwon, South Korea

Johannes Görler

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
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