Influence of process parameters on growth behaviour and properties of coatings obtained by plasma electrolytic oxidation (PEO) on AA 6061

Plasma electrolytic oxidation coating is obtained on AA6061 alloy using positive uni-polar pulsed DC in a sodium silicate-based electrolyte. The effect of process parameters such as solution concentration, process time, average current density, pulse frequency and positive on-time is investigated systematically and the corresponding voltage–time response is correlated with the coating growth rate. Surface morphology of the coatings is studied...