Regensburg 2025 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 9: Poster

MM 9.36: Poster

Monday, March 17, 2025, 18:30–20:30, P1

Unveiling the Origin of the Yield Stress Anomaly in L12 Intermetallics via Atomistic Approaches — •Xiang Xu, Xi Zhang, and Blazej Grabowski — University of Stuttgart, Stuttgart, Germany

We present an approach to studying the yield stress anomaly (YSA) in L12 intermetallics by bridging the electronic scale with large-scale molecular dynamics simulations, using machine-learning-based interatomic potentials. An ab initio database of temperature-dependent Gibbs energy for relevant planar defects in L12 Ni3Al was developed, covering the full temperature range of the YSA. Machine-learning interatomic potentials for Ni3Al, trained through a physically informed active-learning scheme, achieved accuracy comparable to DFT data and successfully modeled key dislocation behaviors in million-atom models. These MD results enabled the development of a phenomenological model that effectively explains YSA characteristics, offering new insights into the high-temperature performance of L12-strengthened high-entropy alloys.

Keywords: Ni-based Superalloys; Yield stress anomaly; dislocation cross-slip; machine-learning interatomic potentials; multiscale simulations