Berlin 2015 – scientific programme
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MM: Fachverband Metall- und Materialphysik
MM 15: Hydrogen in metals III: Experiments
MM 15.2: Talk
Monday, March 16, 2015, 16:15–16:30, TC 006
Hydrogen diffusivity as a measure for relative dislocation densities in palladium — •Martin Deutges1, Hans Peter Barth2, Yuzeng Chen3, Christine Borchers1, and Reiner Kirchheim1,4 — 1Institut für Materialphysik, Georg-August Universität Göttingen — 2Now at: DLR Göttingen — 3State Key Lab of Solidification Processing, Northwestern Polytechnical University, Xi’an, P.R. China — 4International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, Japan
It is well known that hydrogen affects the defect formation energy [1] which is thermodynamically described by the defactant concept [2]. The palladium-hydrogen system was chosen to analyze the effect of hydrogen on the formation of dislocations [3,4]. For this purpose palladium was loaded with different amounts of hydrogen and subsequently cold rolled. The dislocation density was quantified by measuring hydrogen diffusivity, which depends on the amount of trap sites for hydrogen. The results were compared to conventional XRD-methods [4]. After cold rolling, residual hydrogen is removed. During reloading with hydrogen the diffusion through the material is measured. The change in diffusivity allows to calculate the relative dislocation density. The presence of hydrogen during cold rolling of palladium leads to an increase of dislocation density [3].
[1] M. Deutges et al., Scripta Mater.68 (2013) 71.
[2] R. Kirchheim, Acta Mater. 55 (2007) 5129.
[3] Y.Z. Chen et al., Scripta Mater. 68 (2013) 743.
[4] M. Deutges et al., Acta Mater. 82 (2015) 266.