Berlin 2018 – scientific programme
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MM: Fachverband Metall- und Materialphysik
MM 27: Poster Session I
MM 27.11: Poster
Tuesday, March 13, 2018, 18:30–19:45, Poster E
Hydrogen Diffusion in α-Magnesium: Further Investigations into the Influence of Grain Boundaries — •Felix Jung1, Magnus Hamm1, Jakub Čížek2, and Astrid Pundt1 — 1Institute of Materials Physics, Georg-August-Universität Göttingen, Germany — 2Department of Low-Temperature Physics, Charles University, Prague, Czech Republic
In this work we measure the room temperature diffusion coefficient of hydrogen in the α-magnesium-hydrogen system by using gas volumetry. To explore the dependency of the diffusion coefficient on the volume fraction of grain boundaries, the sample grain size is varied. Grain boundary (DGB) diffusion conventionally differs from bulk diffusion (DV). For substitutional solvents in metals, DGB is several orders of magnitude higher than DV, for interstitial solvents it can be either lower or higher, depending on the solvent concentration [1, 2, 3]. Bulk magnesium samples subjected to various degrees of severe plastic deformation are characterized using optical and electron microscopy. Purity and microstructure of the samples are investigated by EDX and EBSD measurements. The grain size distribution is examined by an automated analysis of backscatter SEM images. Details of this method are presented. Financial support provided by the Deutsche Forschungsgemeinschaft via the projects PU131/9-2 and PU131/10-1 is gratefully acknowledged.
[1] Kaur and Gust, Ziegler Press Stuttgart (1989)
[2] Mütschele et al., Scr. Metall. 21, 135-140 and 1101-1104 (1987)
[3] Uchida et al., Acta Mater. 85, 279-289 (2015)