The corrosion behavior and anti-corrosion mechanism of the Zn-Ni-Al2O3 composite coating were investigated by SEM, EDS and XPS. The results indicate that the corrosion type of the Zn-Ni-Al2O3 coatings in neutral 5 wt.% NaCl solution is uniform corrosion. The presence of compact and uniformly dispersed nano alumina particles substantially inhibits the corrosion of Zn-Ni-Al2O3 composite coatings. In the initial corrosion stage, the corrosive products of Zn-Ni matrix form a compact ZnCl2·4Zn(OH)2 layer. With the development of corrosion, some nano alumina particles are embedded and form a Ni enrichment layer. In Ni enrichment layer, Ni presents as Ni and NiO.
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