Dresden 2017 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 37: Topical session: Data driven materials design - defect engineering

MM 37.4: Talk

Wednesday, March 22, 2017, 11:15–11:30, BAR 205

Environmental tight-binding modelling of structural defects in metals — •Eunan J. McEniry, Tilmann Hickel, and Jörg Neugebauer — Max-Planck-Institut für Eisenforschung GmbH, Düsseldorf, Germany

The modelling of structural defects in metallic systems, such as phase boundaries and dislocations, involves a complex interplay between the chemical composition and the local atomic coordination. Specific challenges include the role of incoherency, the preferential segregation of light elements such as carbon and hydrogen to such defects, and the need to efficiently describe the interactions of compositionally complex systems. While the chemical complexity can be described accurately within density functional theory approaches, the computational cost becomes prohibitive when studying, for example, hydrogen segregation to incoherent phase boundaries between a host matrix and a precipitate.

The environmental tight-binding approach offers a rigorous and computationally efficient framework in which high-throughput atomistic simulations of multi-component systems can be performed, which retains the full quantum-mechanical nature of the problem. The development of potentials derived from this approach will be illustrated, demonstrating the flexibility and speed of the method. As an example, the energetics and diffusion behaviour of hydrogen at the incoherent phase boundary between α-Fe and TiN will be presented.