To obtain chromium-free Zn-Al coatings with good surface morphology and excellent corrosion resistance,0~1.6%nano-SiO_(2) was added to the coatings.The morphology,thickness,hardness,and corrosion resistance of the coatings were characterized using equipment such as coating thickness testers,surface roughness meters,and microhardness testers to investigate the effect of nano-SiO_(2) content on the coating performance.The results show that when 0~1.6%nano-SiO_(2) is added to chromium-free Zn-Al coatings,the coatings are silver-gray color,possessing a smooth,dense,and flat surface with a roughness around 1.0μm.As the nano-SiO_(2) contents increase,the coating thickness varies within the range of 45~80μm,exhibiting a downward trend.Notably,the coating hardness is significantly enhanced,reaching a value of 123.08 HV.Additionally,the coatings have good adhesion,all of which are above IO S-2 level.Furthermore,the addition of nano SiO_(2) can boost the corrosion resistance of coatings,and it is observed that the optimal corrosion resistance is achieved when the nano-SiO_(2) addition is 1.2%.