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MM: Fachverband Metall- und Materialphysik

MM 10: Methods in Computational Materials Modelling (methodological aspects, numerics)

MM 10.4: Vortrag

Montag, 1. April 2019, 16:30–16:45, H45

Parametrization of a bond-order potential for Ti — •Alberto Ferrari, Malte Schröder, Yury Lysogorskiy, Jutta Rogal, Matous Mrovec, and Ralf Drautz — Interdisciplinary Centre for Advanced Materials Simulation, Ruhr-Universität Bochum, 44801 Bochum, Germany

Ti alloys are attractive structural materials, featuring remarkable stiffness/weight and strength/weight ratios, exceptional corrosion resistance, good creep properties, and biocompatibility. In addition, many Ti alloys exhibit shape-memory and superelastic properties, and the recently discovered gum-metals are also based primarily on Ti. Atomic-scale studies of Ti-based metals often employ first-principles methods such as density functional theory, with maximum system sizes that are limited to a few hundreds atoms. To perform large-scale and/or finite temperature simulations, empirical potentials or machine-learning potentials are usually fitted. However, the transferability of these potentials to properties or environments not included in the training is limited. In this contribution, we present a newly developed bond-order potential (BOP) for Ti derived by coarse-graining the tight-binding approximation to the electronic structure. The BOP model shows an unprecedented transferability to various bulk as well as defective Ti structures. We demonstrate the excellent predictive power of our potential for a number of structural and thermodynamic properties that are relevant for the structural stability, phase transformations, and defect behavior in Ti-based materials.