This paper evaluated the protection effect of the cerium conversion coatings on the SiCp/5A06 Al composite and the 5A06 Al alloy.Electrochemical impedance spectroscopy(EIS) was employed to examine the variation of the...This paper evaluated the protection effect of the cerium conversion coatings on the SiCp/5A06 Al composite and the 5A06 Al alloy.Electrochemical impedance spectroscopy(EIS) was employed to examine the variation of the electrochemical variables of the samples treated and immersed in 3.5% NaCl solution at 35 °C for 1 h,which showed the enhancement of charge transfer resistance(Rt) and coating film resistance(Rc),i.e.,the corrosion resistance of the conversion coated samples was improved.The best protection ef...展开更多
This article studies the effects of the CeCl3 concentrations in conversion solutions with and without addition of NaCl, pH-values of conversion solution, drying temperature, time and temperature of immersion on the Ce...This article studies the effects of the CeCl3 concentrations in conversion solutions with and without addition of NaCl, pH-values of conversion solution, drying temperature, time and temperature of immersion on the Ce-conversion coatings for corrosion protection of the SiCp/5A06 Al-MMC and 5A06 Al-alloy in the 3.5% NaCl aqueous solution at room temperature. Potentiodynamic polarization tests reveal that the Ce-conversion treatment could markedly improve the pitting corrosion resistance of the composite and the matrix alloy in chloride containing environment. The best corrosion resistance effects are obtained for the samples treatment in 1% CeCl3.7H2O/3.5% NaCl solution at 45℃ for 60 min, followed by drying at 100 ℃ for 30 min. Examinations by means of scanning electron microscopy （SEM）, energy dispersion spectroscopy （EDS） and X-ray photoelectron spectroscopy （XPS） indicate that this behavior is due to the precipitation of Ce-oxides/hydroxides on the cathodic intermetallics and the Al-oxide film on the rest of the metal matrix.展开更多
基金supported by Higher Education Commission of Pakistan
文摘This paper evaluated the protection effect of the cerium conversion coatings on the SiCp/5A06 Al composite and the 5A06 Al alloy.Electrochemical impedance spectroscopy(EIS) was employed to examine the variation of the electrochemical variables of the samples treated and immersed in 3.5% NaCl solution at 35 °C for 1 h,which showed the enhancement of charge transfer resistance(Rt) and coating film resistance(Rc),i.e.,the corrosion resistance of the conversion coated samples was improved.The best protection ef...
文摘This article studies the effects of the CeCl3 concentrations in conversion solutions with and without addition of NaCl, pH-values of conversion solution, drying temperature, time and temperature of immersion on the Ce-conversion coatings for corrosion protection of the SiCp/5A06 Al-MMC and 5A06 Al-alloy in the 3.5% NaCl aqueous solution at room temperature. Potentiodynamic polarization tests reveal that the Ce-conversion treatment could markedly improve the pitting corrosion resistance of the composite and the matrix alloy in chloride containing environment. The best corrosion resistance effects are obtained for the samples treatment in 1% CeCl3.7H2O/3.5% NaCl solution at 45℃ for 60 min, followed by drying at 100 ℃ for 30 min. Examinations by means of scanning electron microscopy （SEM）, energy dispersion spectroscopy （EDS） and X-ray photoelectron spectroscopy （XPS） indicate that this behavior is due to the precipitation of Ce-oxides/hydroxides on the cathodic intermetallics and the Al-oxide film on the rest of the metal matrix.
