Dresden 2017 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 109: Tribology and Structure of Surfaces: Misc.
O 109.9: Vortrag
Freitag, 24. März 2017, 12:45–13:00, WIL A317
Monitoring corrosion in nano confinement in real time using white light interferometry — •Claudia Merola1, Hsiu-Wei Cheng1, Ying-Ju Chen1, and Markus Valtiner2 — 1Max Planck Institute, Düsseldorf, Germany — 2Technische Universität Bergakademie, Freiberg, Germany
Crevice corrosion (CC) still remains one of the most difficult types of corrosion to detect and to prevent. Most often CC occurs in narrow fissures where oxygen access is poor and a stagnant electrolyte solution is present. Experimentally it is a challenge to obtain in-situ information of processes in confined geometries and to establish well defined confined situations in the first place. Here, white light interferometry has been used, for the first time, to study and monitor in situ the initial stages of the crevice corrosion process of thin layers of Nickel in different concentrations of NaCl solutions. Using Mica as a crevice former in an electrochemical surface apparatus allowed us to provide a deeper understanding of the initiation of the corrosion process. Electrochemical potential ramps were applied at different rates and different concentrations of NaCl led to different corrosion mechanism, based on a variation of the material transport mechanism into and out of the confined zones. Our results reveal that CC proceeds as a self-catalyzed pitting inside the confined zone and provides a surprising real-time view of the initial corrosion of confined surfaces, and hence may contribute to a deeper general understanding, and ultimately prevention, of localized corrosion.