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MM: Fachverband Metall- und Materialphysik
MM 21: Phase Transformations II
MM 21.3: Vortrag
Mittwoch, 11. März 2026, 10:45–11:00, SCH/A215
Mechanism of structure formation during electrochemical dealloying — •Gideon Henkelmann1 and Jörg Weissmüller1,2 — 1Institute of Materials Physics and Technology, Hamburg University of Technology, Germany — 2Institute of Hydrogen Technology, Helmholtz-Zentrum Hereon, Geesthacht, Germany
During electrochemical dealloying of a solid solution, atoms of the more noble species rearrange by surface diffusion to form a connected nanoporous structure with a characteristic length scale. Details of the underlying nanoscale self-organization process, specifically the criteria that select this characteristic length scale, remain to be understood. Here, we study this issue by kinetic Monte Carlo simulations. While previous studies started out with corroding a planar single-crystal surface, our approach starts by forming an internal cavity and follows the evolution of the surface of the growing void. This allows us to focus on passivation or bifurcation of the corrosion front in a realistic scenario with curved and rough surfaces. We find that passivation is governed by simple geometric criteria related to the enrichment of the more noble species on the pore surface. Furthermore, the variation of the resulting structure size with the overpotential may be rationalized by a Gibbs-Thomson-type scaling law.
Keywords: nanoporous metals; dealloying