Effect of RE on Microstructure and Electrochemical Corrosion Behavior of Arc Sprayed Zn-Al-Mg Coating
Cored wires and arc spraying technique were used to produce Zn-Al-Mg-RE alloy coatings on low carbon steel substrates. The effect of RE (where RE is Rare Earth) on the microstructure and electrochemical corrosion behavior of coatings was investigated comparing with Zn-Al-Mg coatings. With addition of RE, the Zn-Al-Mg-RE coating has denser microstructure and fewer porosity. But RE has no discernible effect on the adhesion strength between coating and substrate. The Zn-Al-Mg-RE coating has superior corrosion resistance compared to Zn-Al-Mg coating due to the formation of more compact and uniform corrosion products. The role of the RE elements appears to be associated with the self-sealing process and the refinement of the coating microstructure.
Z. X. Zhu et al., "Effect of RE on Microstructure and Electrochemical Corrosion Behavior of Arc Sprayed Zn-Al-Mg Coating", Applied Mechanics and Materials, Vols. 66-68, pp. 727-730, 2011