An epoxy/polyamide coating was reinforced with various loadings of aluminum particles. The coatings were applied on steel panels. The corrosion resistance, cathodic delamination, and surface morphology of the coatings were studied by electrochemical impedance spectroscopy (EIS) (3.5 wt% sodium chloride [NaCl]), a sacrificial Mg anode, optical microscopy, and x-ray diffraction (XRD) techniques, respectively. Results showed that aluminum particles improved corrosion resistance of the epoxy coating significantly. The rate of cathodic delamination of the coating was reduced in the presence of the particles noticeably. The corrosion protection mechanism of the coating was changed using low and high loadings of the particles. The aluminum particles showed active/passive behaviors against the corrosive electrolyte depending on exposure times. The lamellar aluminum particles improved barrier properties of the coating and behaved as a sacrificial pigment at long immersion times. This pigment reduced cathodic activity of the substrate by an aluminum oxide layer formation.

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