Evaluation of the corrosion resistance of an epoxy-polyamide coating containing different ratios of micaceous iron oxide/Al pigments

The corrosion resistance of an epoxy coating reinforced with different ratios of MIO/Al pigments was studied. The coatings properties were investigated by an electrochemical impedance spectroscopy (EIS), salt spray test, cathodic disbonding and a scanning electron microscope (SEM). The corrosion resistance of the epoxy coating was improved using MIO (micaceous iron oxide) and Al pigments. The corrosion resistance of the purely Al pigmented coating was considerably greater than the purely MIO pigmented coating. The cathodic disbonded area of coating was decreased using MIO and Al pigments. The decrease in disbonded area was more pronounced in the presence of Al particles.

Research highlights
► The corrosion resistance of the coating was improved using MIO and Al pigments.
► The greatest coating corrosion resistance was observed at MIO/Al ratio of 10/90.
► The cathodic disbonded area of the coating was decreased using MIO and Al particles.
► The lowest disbonded area was observed at MIO/Al ratio of 10/90.
► Al particles had high capability of reacting with the OH− ions.