Seminars and Events

Atomistic simulations of dislocation-interface interactions in the γ/γ’ microstructure in Ni-based superalloys

Date/Time: 16.09.2014. 10:10 a.m.
Place: Ruhr-Universität Bochum, Bochum, Germany

Juan Wang, Department of Materials Science and Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen

The interaction of dislocations in the channels with the γ' precipitates is a main factor for the superior strength of Ni-based superalloys even at high temperatures. Here we report on a detailed study of screw and 60° dislocations interacting with a planar γ/γ'-interphase boundary in a quasi-two dimensional set-up. Static calculations as well as molecular dynamic calculations were performed to determine the critical penetration stress and to study the interaction of the channel dislocations with the misfit dislocation network. In addition, the interaction of dislocations with a curved interphase boundary was studied in a fully 3D set-up modeling an experimental microstructure obtained by 3D Atom Probe Tomography. The results of the simulations are discussed in the framework of a multiscale modeling approach to study the mechanical behavior and stability of Ni-based superalloys.

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