Regensburg 2022 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 18: Poster Session 2

MM 18.18: Poster

Dienstag, 6. September 2022, 17:30–20:00, P2

High-Pressure Torsion Deformed Magnesium: Microstructure Evolution and Hydrogen Diffusion — •Sabine Schlabach^1,2,3, Bingyu Wu¹, Giorgia Guardi¹, Stefan Wagner¹, Julia Ivanisenko^2,3, and Astrid Pundt¹ — ¹Karlsruhe Institute of Technology, Institute for Applied Materials, Karlsruhe, Germany — ²Karlsruhe Institute of Technology, Institute of Nanotechnology, Karlsruhe, Germany — ³Karlsruhe Institute of Technology, Karlsruhe Nano Micro Facility, Karlsruhe, Germany

Magnesium (Mg) is one of the materials considered as a solid state storage material for Hydrogen (H) as it is capable of storing up to 7.6 wt.% of H while forming magnesium hydride (MgH₂). However, the volume diffusion rate of H in MgH₂ is low, and thus the sorption rate of H is rather slow. As grain boundaries are suggested as fast diffusion paths, an increasing volume fraction of grain boundaries by reducing the grain size is aimed. Starting from polycrystalline bulk Mg, this can be done, e.g., by high-pressure torsion, one method of severe plastic deformation. The deformation induced microstructure evolution is investigated by using electron backscatter diffraction depending on different process parameters like imposed pressure and number of revolutions. Special attention is taken on local misorientations as a measure of dislocation density and their possible influence on H-diffusion. The related H loading capability of the deformed Mg samples is tested at room temperature utilizing gas volumetry. In a first step, H-diffusion in the α-Mg phase is assessed as model system. Thus, the maximum H concentration is kept below the solid solution limit.