Long-term atmospheric corrosion properties of thermally sprayed Zn, Al and Zn-Al coatings exposed in a coastal area

The long-term atmospheric corrosion properties of thermally sprayed Zn, Al and Zn-Al coatings have been evaluated using an electrochemical impedance measurement and several analytical techniques. All the thermal-sprayed specimens with 100 mu m coating thickness have protected the steel substrates. In case of the Zn-Al coating, the red rust was not observed regardless of the coating thickness. The corrosion products were identified by the XRD analysis. Preferential dissolution of zinc was observed on the Zn-Al coating by EPMA analysis. The electrochemical impedance results provided an insight about the surface structures of each thermally sprayed coating. Crown Copyright (C) 2013 Published by Elsevier Ltd. All rights reserved.