Print Email Facebook Twitter Corrosion Mechanism of Microporous Nickel-Chromium Coatings Title Corrosion Mechanism of Microporous Nickel-Chromium Coatings: Part II. SECM Study Monitoring Cu2+and Oxygen Reduction Author Ganborena, Larraitz (IK4-CIDETEC Research Centre) Gonzalez Garcia, Y. (TU Delft Team Yaiza Gonzalez Garcia) Özkaya, Berkem (Atotech Deutschland GmbH) García, Marta (Maier Technology Centre (MTC)) García-Lecina, Eva (IK4-CIDETEC Research Centre) Vega, Jesús Manuel (IK4-CIDETEC Research Centre) Date 2022 Abstract The corrosion mechanism of microporous nickel-chromium multilayer coatings was studied at localised scale by Scanning Electrochemical Microscopy (SECM) after exposure to an aggressive electrolyte (chloride-based one at pH 3.1 containing cupric ions). The open circuit potential was initially monitored during 22 h, followed by a detailed characterisation using Glow Discharge-Optical Emission Spectroscopy and Field Emission Scanning Electron Microscope. Interestingly, Cu deposition occurs over the surface of the microporous nickel layer, and it is located on spots where micro-discontinuities (i.e., cracks and pores) of the outermost Cr layer are present. The application of different operation modes of the SECM (i.e., redox competition and surface generation/tip collection) not only reveals such copper deposits (which were identified after monitoring their catalytic capabilities for oxygen reduction reaction) but also confirms the stepwise reduction of Cu2+ to Cu (via intermediate species of Cu+) during the corrosion process. The impact of metallic copper particles in the local pH due to their catalytic activity could also explain why the microporous nickel layer is not corroded after exposure to such electrolyte. To reference this document use: http://resolver.tudelft.nl/uuid:0da0bbd8-db2b-4fa6-bd8e-c9fb4e497207 DOI https://doi.org/10.1149/1945-7111/ac554a Embargo date 2023-07-01 ISSN 0013-4651 Source Electrochemical Society. Journal, 169 (2) Bibliographical note Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public. Part of collection Institutional Repository Document type journal article Rights © 2022 Larraitz Ganborena, Y. Gonzalez Garcia, Berkem Özkaya, Marta García, Eva García-Lecina, Jesús Manuel Vega Files PDF Ganborena_2022_J._Electro ... 021509.pdf 1.37 MB Close viewer /islandora/object/uuid:0da0bbd8-db2b-4fa6-bd8e-c9fb4e497207/datastream/OBJ/view