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MM: Fachverband Metall- und Materialphysik

MM 28: Mechanical properties

MM 28.1: Vortrag

Donnerstag, 20. März 2025, 10:15–10:30, H23

Parameterising edge dislocation trajectories in Ni-based superalloys with uncertainty quantification — •Geraldine Anis, Thomas Hudson, and Peter Brommer — University of Warwick, Coventry, United Kingdom

The extraordinary strength exhibited by Ni-based superalloys at high temperatures is attributed to the presence of nanoscale precipitates in their microstructure, which hinder dislocation motion. In our work, we study edge dislocation-precipitate interactions using Molecular Dynamics (MD) simulations with classical effective potentials. The motion of a pair of edge dislocations moving under shear between pure Face-Centred Cubic (FCC) Ni into Ni3Al with an L12 structure is simulated using MD, where Ni is used to represent an idealised γ solid solution phase and Ni3Al for the γ′ precipitate phase. The obtained trajectories are parameterised and Differential Evolution Monte Carlo (DE-MC) is used to determine parameter distributions. These distributions are then used to quantify the uncertainty in the model outputs, namely the dislocations’ positions and velocities. The present approach yields physically meaningful parameters and accordingly, offers a means of extracting quantitative information from the atomistic scale that can be used to inform larger length scale simulations of dislocations. Using DE-MC as a sampling approach also means that parameter uncertainties can be propagated through a hierarchy of multiscale models. We illustrate how such uncertainty propagation can be achieved by considering a dislocation mobility law with quantified uncertainties.

Keywords: Dislocations; Molecular dynamics; Ni-based superalloys; Surrogate modelling; Uncertainty quantification