Dresden 2017 – scientific programme
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MM: Fachverband Metall- und Materialphysik
MM 14: Topical session: Interface-Controlled Microstructures: Mechanical Properties and Mechano-Chemical Coupling - Electro- and mechno-chemical coupling
MM 14.6: Talk
Monday, March 20, 2017, 17:00–17:15, BAR 205
Size effects on hydrogen electrosorption in nanoporous Pd-Cu alloys — •Shan Shi1,2, Jürgen Markmann1,2, and Jörg Weissmüller1,2 — 1Institut für Werkstoffforschung, Werkstoffmechanik, Helmholtz-Zentrum Geesthacht, Geesthacht — 2Institut für Werkstoffphysik und -technologie, Technische Universität Hamburg-Harburg, Hamburg
Nanoporous (np) metals made by electrochemical dealloying exhibit a three dimensional metal network with high specific surface area, which couples the entire material behaviour to surface effects and specifically to electrocapillary effects that induce stress in the network. Electrochemical hydrogen electrosorption into bulk and surface of np-palladium-copper (np-PdCu) alloys results in reversible macroscopic expansion/contraction which can be monitored by in-situ dilatometry. This has been demonstrated to be an actuation mechanism and will be used to study the thermodynamics of the Pd-Cu-H system. Here, we fabricated mm-sized homogeneous monolithic np-PdCu samples by electrochemical dealloying. By thermal annealing after the synthesis, the characteristic ligament size was adjusted between 10 nm and 300 nm. Then we explored the influence of ligament size on both actuation performances (response time and strain amplitude) and thermodynamics (hydrogen solubility and hysteresis).