Corrosion under a porous layer: A porous electrode model and its implications for self-repair

Autor:	Murali Sankar Venkatraman, Ivan S. Cole, Bosco Emmanuel
Rok vydání:	2011
Předmět:	Materials science General Chemical Engineering Metallurgy Oxide Cathodic protection Corrosion Anode Metal chemistry.chemical_compound chemistry Electrical resistivity and conductivity visual_art Electrochemistry visual_art.visual_art_medium Composite material Porosity Layer (electronics)
Zdroj:	Electrochimica Acta. 56:8192-8203
ISSN:	0013-4686
DOI:	10.1016/j.electacta.2011.06.020
Popis:	A one-dimensional mathematical model for the corrosion of a metal surface under a porous layer (often an oxide layer) is presented using porous electrode theory. The model allows one to predict the rates of corrosion in a metallic system where oxygen reduction is the only cathodic reaction which occurs on the surfaces of both the metal and the porous oxide layer albeit at different rates. Thus the model simulates the scenario where the porous layer residing on the metal surface competes with or complements the oxygen reduction reaction happening on the metal surface. The study finds that a large thickness, low porosity, low oxide electrical conductivity, poor oxygen reduction on the porous layer, and high specific contact resistivity of the metal–oxide lead to poor spatial separation of the anodic and cathodic reactions and hence encourage self-repair. In particular the metal–oxide contact potential and the oxygen reduction rates on the oxide surface are shown to have profound implications for self-repair strategies for corrosion mitigation.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::69904373dae7ae285e9c11870d00c7f8 https://doi.org/10.1016/j.electacta.2011.06.020 Zobrazit plný text záznamu Full Text from ScienceDirect