SKM 2023 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 9: Topical Session: Fundamentals of Fracture – Interface Fracture

MM 9.4: Vortrag

Montag, 27. März 2023, 17:00–17:15, SCH A 216

The heterogeneous nature of grain boundary segregation and embrittlement — •Remi Dingreville — Sandia National Laboratories, Albuquerque NM, USA

Nanostructured materials are inherently unstable due to the high density of non-equilibrium defects that provide a substantial driving force for exaggerated or unexpected evolution. Departing from most mesoscale models for grain boundaries (GB), there is a clear recognition that GB properties, especially GB embrittlement and GB fracture, are not single-valued for a given material, but widely disparate depending on the configuration of the particular boundary and its neighboring grain. Taking this one step further, both GB character and GB defects control the GB embrittlement and fracture in response to mechanical, thermal, and irradiation stimuli. Each different type of stimuli perturb the GB character in distinctly different processes: e.g. stress causes elastic mismatch that tilts the energy barrier whereas strain drives specific dislocation content into the GB; non-implanting irradiation on the other hand creates local thermal spikes and atomic shuffling. In this presentation, I will discuss these effects on GB segregation and GB fracture properties from both a theoretical and atomistic perspectives.

Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy National Nuclear Security Administration under contract DE-NA0003525.