Corrosion resistance of the layer-by-layer assembled multilayers on Mg alloy: Effects of covalent cross-linking

•Polyelectrolyte multilayers on Mg alloys could be cross-linked by glutaraldehyde.•Imine bonds were formed between glutaraldehyde and poly (allylamine hydrochloride).•The cross-linked multilayers exhibited enhanced anticorrosion effects for Mg alloy. Mg alloys coated with layer-by-layer assembled multilayers always suffered from rapid degradation. In this research, the cross-linked multilayers consisted of CeO2 nanoparticles on Mg alloys were successfully prepared and glutaraldehyde was selected as the cross-linker. The improved corrosion protection of the resulting coatings assessed by tafel plots, electrochemical impedance spectroscopy and immersion test was attributed to the cross-linkages together with the corrosion inhibition effects of the CeO2 nanoparticles.