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MM: Fachverband Metall- und Materialphysik
MM 34: Hydrogen in Materials I
MM 34.2: Vortrag
Donnerstag, 12. März 2026, 16:00–16:15, SCH/A215
In situ Micromechanical Investigation of Hydrogen Embrittlement Mechanisms in Fe3%Si — •Maral Sarebanzadeh1, Svetlana Korneychuk1,2, Rolf Rolli1, Hans-Christian Schneider1, Astrid Punt1, Xufei Fang1, and Christoph kirchlechner1 — 1Institute for Applied Materials, Karlsruhe Institute of Technology, Karlsruhe, Germany — 2Insitute of Nanotechnology, Karlsruhe Institute Technology, Karlsruhe, Germany
Hydrogen embrittlement (HE) remains a critical limitation for the reliable use of hydrogen in structural applications. Among the proposed micromechanisms, hydrogen-enhanced localized plasticity (HELP) is widely discussed, suggesting that hydrogen facilitates dislocation motion and localizes deformation. However, its microstructural manifestation remains insufficiently understood and rarely observed directly. To address this, we investigate HE in Fe3%Si using in-situ micropillar compression combined with tritium charging, leveraging the advantage of probing a few dislocations in a well-defined geometry. Micropillar tests conducted before and after charging with a protium/tritium gas mixture show a strong increase in yield strength, indicating pronounced dislocation blocking rather than enhanced glide. We demonstrate that dislocations can lose mobility, with the activating stress increasing by a factor of 2-3. Transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS) investigations are being performed to identify hydrogen-containing features around dislocations and to clarify how hydrogen governs dislocation mobility in bcc materials such as Fe3%Si.
Keywords: Hydrogen Embrittlement; In-situ Micromechanical Testing; Dislocation Mobility; HELP Mechanism; Tritium Charging