Regensburg 2019 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 8: Topical session (Symposium MM): High entropy and compositionally complex alloys

MM 8.1: Topical Talk

Montag, 1. April 2019, 15:45–16:15, H43

First principles modeling of high entropy alloys — •Levente Vitos — Royal Institute of Technology KTH, Stockholm, Sweden

Thanks to impressive developments within Density Functional Theory (DFT), electronic structure solvers and computational power during the last few decades, modern materials research receives increasing support from first-principles modeling. Such approach gives fundamental understanding, offers efficient pre-screening against various degrees of freedom and provides information where experimental assessments are not feasible. Today the ab initio theory aided materials assay finds its way in almost all areas of advanced materials design and characterization.

Due to the complexity of the problem, DFT modeling was practically missing within the field of High Entropy Alloys (HEAs) for almost one decade after their discovery. Starting from early 2010s, we made a series of attempts to fill this gap and extend the scope of ab initio modeling to HEAs. In the present contribution, I will briefly overview the pioneering applications of alloy theory in the case of magnetic and refractory HEAs, and point out the main known and hidden challenges associated with such efforts. I will present our recent theoretical predictions for the mechanical and magnetic properties of existing and hypothetical HEAs. Special emphasis will be places on the plastic deformation mechanism in HEAs with close packed crystal structure and the role of intrinsic energy barriers in the competing deformation mechanisms.