Corrosion Behavior of Zinc under the Combined Layer of Electrolyte

Abstract:

By constructing a novel electrochemical cell, the corrosion behavior of pure zinc under the combined layer of 3 wt% sodium chloride electrolyte consisting of an open layer connected with a confined one was studied. The results show that a galvanic corrosion cell is formed once the zinc being covered by the combined layer of electrolyte, where the zinc under the open layer (named as open-Zn) plays as the cathode but the zinc under the confined layer (named as confined-Zn) as the anode, therefore the latter presents the higher corrosion rate. Furthermore, because ions transfer between the open layer and confined layer become difficult, the hydrolysis of excessive zinc ions in the confined electrolyte results the acidification of electrolyte and thus also accelerates the corrosion of confined-Zn. The critical thickness for corrosion of zinc under the combined layer is 105 μm where corrosion rate for both of the open-Zn and confined-Zn reach the maximum.

• Periodical: Advanced Materials Research (Volumes 616-618)
• Pages: 1063-1067
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.616-618.1063
• Online since: December 2012
• Authors: Bai Gang An, Hai Feng Sun, Li Xiang Li
• Keywords: Combined Layer of Electrolyte, Corrosion, Galvanic Effect, Zinc

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DOI: 10.1016/j.electacta.2006.12.088