Zn-Ni-Al2O3 nano-composite coatings were electroplated by our newly developed sol-enhanced electroplating method. In order to obtain the optimal chemical composition, corrosion resistance and mechanical properties, a systematic study of Zn-Ni-x-Al2O3 coatings with different sol concentrations (where xis the sol-doping concentration from 0 to 20 ml/l) has been conducted. It was found that the Ni content, phase structure, surface morphology, mechanical properties and corrosion resistance of the nano-composite coatings were strongly affected by the sol concentration. The mechanical properties and corrosion resistance of sol-enhanced nano-composite coating were significantly improved compared to Zn-Ni alloy coatings. The microhardness of the sol-enhanced Zn-Ni-6 ml/l Al2O3 coating was similar to 312 HV100 compared to similar to 237 HV100 of Zn-Ni coating. Meanwhile, the wear resistance has also been improved remarkably. (C) 2015 Elsevier B.V. All rights reserved.