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采用扫描电镜和电化学工作站、盐雾实验研究了铜离子对钢铁磷化膜表面形貌、生成机制、防腐蚀性能的影响。结果表明:未加入铜离子时,磷化膜由片状的ZPO(Zn3(PO4)2.4H2O)组成;加入铜离子后,磷化膜由花瓣状的ZPO和团簇状的CuO组成。未加入铜离子时,磷化膜中ZPO的生成机制为由花瓣状至片状;加入铜离子后,磷化膜中ZPO的生成机制为由片状至花瓣状。铜离子对磷化膜的影响存在一个临界浓度6～8 g/L。在临界浓度下,随着磷化液中Cu2+的增多,磷化膜的耐腐蚀性能逐步提高;当磷化液中Cu2+的浓度超过临界浓度后,Cu2+会阻碍ZPO的形成,并且耐腐蚀性能下降。
The effects of copper ions on the surface morphology, formation mechanism and corrosion resistance of steel phosphating coatings were investigated by scanning electron microscopy and electrochemical workstation, salt spray experiments. The results showed that the phosphating film consisted of flaky ZPO (Zn3 (PO4) 2.4H2O) without adding copper ions. After adding copper ions, the phosphating film consisted of petal-shaped ZPO and cluster-like CuO. When copper ions were not added, the formation mechanism of ZPO in the phosphating film was from petaloid to flaky. When copper ion was added, the formation mechanism of ZPO in the phosphating film was from flake to petal. The effect of copper ions on phosphate film has a critical concentration of 6 ~ 8 g / L. At the critical concentration, with the increase of Cu2 + in the phosphating solution, the corrosion resistance of the phosphate coating gradually increases. When the concentration of Cu2 + in the phosphating solution exceeds the critical concentration, Cu2 + will hinder the formation of ZPO and the corrosion resistance will decrease .