为获得表面形貌良好、耐蚀性能优异的无铬Zn-Al涂层,向涂层中添加了0~1.6%纳米SiO_(2)。用涂层测厚仪、表面粗糙度仪和显微硬度仪等设备对涂层的形貌、厚度、硬度、耐蚀性等进行表征,以探究纳米SiO_(2)含量对涂层性能的影响。结果表明:无铬Zn-Al涂层中加入0~1.6%纳米SiO_(2)后,所制涂层呈银灰色,表面光滑、致密、平整,粗糙度维持在1.0μm左右。随着纳米SiO_(2)含量的增加,涂层厚度在45~80μm范围内波动,并呈下降趋势;涂层硬度有了显著的提高,达到123.08 HV;涂层结合力良好,均在IO S-2级以上;纳米SiO_(2)的添加可改善涂层的耐蚀性,当添加量为1.2%时,耐蚀性最优。

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%.