Corrosion protection afforded by a magnesium coating treated in cerium salt solution on steel substrate was investigated using open circuit potential, polarization curves, and electrochemical impedance spectroscopy (...Corrosion protection afforded by a magnesium coating treated in cerium salt solution on steel substrate was investigated using open circuit potential, polarization curves, and electrochemical impedance spectroscopy (EIS) in 0.005 M sodium chloride solution (NaCl). The morphology of the surface was characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). The cerium treated coating was obtained by immersion in CeCl3 solution. The results showed that the corrosion resistance of the treated magnesium coating was improved. The corrosion potential of the treated coating was found to be nobler than that of the untreated magnesium coating and the corrosion current decreased significantly. Impedance results showed that the cerium treatment increased corrosion protection. The improvement of anti-corrosion properties was attributed to the formation of cerium oxides and hydroxides that gave rise to a physical barrier effect.展开更多
Cerium conversion treatment was applied on magnesium coatings in a solution containing CeC13. The composition ot the cenum conversion layer on magnesium was investigated using X-ray photoelectron spectroscopy (XPS),...Cerium conversion treatment was applied on magnesium coatings in a solution containing CeC13. The composition ot the cenum conversion layer on magnesium was investigated using X-ray photoelectron spectroscopy (XPS), It was revealed that the composition predominately consisted of a three-valent state cerium compound with a relative abundance around 90%. Some of Ce^3+ was oxidized to Ce^4+. Electrochemical impedance spectroscopy results revealed that the total impedance of cerium-treated samples increased for a short immersion time in NaC1 solution before coating deteriorating. This deterioration was due to the coating porosity increasing and the breakdown of the conversion layer展开更多
文摘Corrosion protection afforded by a magnesium coating treated in cerium salt solution on steel substrate was investigated using open circuit potential, polarization curves, and electrochemical impedance spectroscopy (EIS) in 0.005 M sodium chloride solution (NaCl). The morphology of the surface was characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). The cerium treated coating was obtained by immersion in CeCl3 solution. The results showed that the corrosion resistance of the treated magnesium coating was improved. The corrosion potential of the treated coating was found to be nobler than that of the untreated magnesium coating and the corrosion current decreased significantly. Impedance results showed that the cerium treatment increased corrosion protection. The improvement of anti-corrosion properties was attributed to the formation of cerium oxides and hydroxides that gave rise to a physical barrier effect.
文摘Cerium conversion treatment was applied on magnesium coatings in a solution containing CeC13. The composition ot the cenum conversion layer on magnesium was investigated using X-ray photoelectron spectroscopy (XPS), It was revealed that the composition predominately consisted of a three-valent state cerium compound with a relative abundance around 90%. Some of Ce^3+ was oxidized to Ce^4+. Electrochemical impedance spectroscopy results revealed that the total impedance of cerium-treated samples increased for a short immersion time in NaC1 solution before coating deteriorating. This deterioration was due to the coating porosity increasing and the breakdown of the conversion layer