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MM: Fachverband Metall- und Materialphysik

MM 28: Computational Materials Modelling - Hydrogen in metals

MM 28.4: Vortrag

Dienstag, 17. März 2020, 15:00–15:15, IFW B

Atomistic simulations of hydrogen interactions with dislocations in bcc Fe — •Tapaswani Pradhan, Daria Smirnova, Sergei Starikov, Matous Mrovec, and Ralf Drautz — Interdisciplinary Centre for Advanced Materials Simulation (ICAMS), Ruhr-Universität Bochum, Germany

The presence of hydrogen degrades the mechanical properties of many metallic materials - the phenomenon known as hydrogen embrittlement (HE). One of the possible reasons of HE is the interaction of H with dislocations that leads to changes in dislocation cores and hence affects their intrinsic glide behavior. Atomic scale details of these interactions and especially the interplay between hydrogen diffusion and dislocation motion is still not fully understood. In this work, we investigate the interaction of H with three types of dislocations, namely, edge, mixed and screw, in body-centred cubic Fe using atomistic simulations. The simulations were carried out using two interatomic interaction models, a tight-binding-based magnetic bond order potential (BOP) and an empirical angularly dependent potential (ADP). Our study shows that H prefers to segregate to all dislocation cores but impacts more the mobility of the glissile mixed and edge dislocations whose Peierls barriers are very low. We present a detailed comparison of simulation predictions and discuss their relation to the HE phenomenon.