Degradation of Micro-Arc Oxidation Coatings on the Surface of Magnesium Alloy under NaCl Droplet

Abstract:

With scanning Kelvin probe and microscopy technique, the degradation process of the micro-arc oxidation (MAO) treated magnesium alloy was investigated under a 3% NaCl droplet. Because of the unique two-layer structure of the MAO specimen, the droplet penetrated in and spread through the external loose layer during the initial several minutes. Subsequently, with the increase of time, only a thin layer of electrolyte was left on the surface of the MAO specimen. During the entire corrosion process, the potential exhibited a valley type distribution, only the width of potential valley increased with time. Based on above observations, a model was proposed for describing the contamination mechanism of MAO treated magnesium alloy under droplet.

• Periodical: Key Engineering Materials (Volumes 480-481)
• Pages: 437-442
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.480-481.437
• Online since: June 2011
• Authors: Yan Hua Wang, Yuan Yuan Liu
• Keywords: Droplet, Kelvin Probe, Magnesium Alloy, Micro-Arc Oxidation (MAO), Potential

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