| Plasma electrolytic oxidation (PEO) is an emerging environmentally friendly process, which can be used to form thick, hard coatings on aluminum alloys. In this study, PEO coatings were produced on two Al alloys, Al6061 and Al319, using a DC power mode. The effects of the process parameters, including the electrolyte concentration, treatment time and current density, on the formation and properties of the PEO coatings were systematically investigated and analyzed. Cyclic potentiodynamic polarization measurements were conducted to evaluate the corrosion properties of the samples. The polarization resistance of the PEO coatings in a 3.5wt.% NaCl solution were determined and compared with the corresponding anodized coatings.;The corrosion performances of several metallic materials (304 stainless steel, cast iron 2500, and Al6061 and Al319 alloys) in ethanol-gasoline alternative fuels were investigated. PEO coatings on both the Al6061 and Al319 alloys provided enhanced polarization resistances in the alternative fuel environments. |
