Fe2+对镁合金电化学磷化改性研究

Study on Electrochemical Phosphating Modification of Magnesium Alloy by Fe2+

采用FeSO4对电化学磷化膜进行改性,以提高AZ91D镁合金的耐腐蚀性能。通过电化学曲线、X射线衍射仪(XRD)、激光共聚焦显微镜(LSCM)和扫描电子显微镜(SEM)研究了FeSO4添加量对电化学磷化膜表面形貌和耐蚀性的影响。结果表明,磷化液中加入FeSO4后,磷化膜主要组成为Fe4(P2O7)3、Zn3(PO4)2和Mn3(PO4)2。当FeSO4加入量为0.3g/L时,电化学磷化膜腐蚀电位为-1.512V,自腐蚀电流密度为2.346×10^-5A/cm^2,极化电阻为1626.3Ω/cm^2,耐腐蚀性能最好。

The electrochemical phosphating film was modified by FeSO4 in order to improve the corrosion resistance of AZ91D magnesium alloy. The effects of FeSO4 on the surface morphology and corrosion resistance were investigated by electrochemical curves,X-ray diffraction(XRD),laser confocal microscopy(LSCM)and scanning electron microscopy(SEM). The results showed that the main components of the electrochemical phosphating film were Fe4 (P2O7)3,Zn3 (PO4)2 ,Mn3 (PO4)2 after adding FeSO4 to the phosphating solution. When the additive amount of FeSO4 was 0.3 g/L,the film showed the best corrosion resistance,and the corrosion potential was -1.512 V,the self-corrosion current density was 2.346×10^-5 A/cm^2,the polarization resistance was 1626.3 Ω/cm^2.