Deposition and corrosion investigation of cerium based conversion coatings on aluminum alloy

The purpose of this paper was to investigate corrosion protection، electrochemical response and surface morphology of cerium oxide conversion coating deposited on Al7075-T6 by a spontaneous dip immersion process after different surface treatments. Coatings were deposited by immersing the alloy panel in an aqueous solution of CeCl3 and glycerin. Corrosion behaviors of coatings were monitored in 3. 5 wt% NaCl solution at room temperature. It was found that activation of the panel using alkaline etching and then de-smutted in H2SO4 increased corrosion resistance. Analysis of the surface morphology of the coatings showed that the coatings stored at room temperature in laboratory air for 24 h، exhibited fewer visible cracks and the inhibition efficiency 97. 66% was obtained.