Growth Mechanism and Corrosion Behavior of Ceramic Coatings on CP-Ti Produced by Plasma Electrolytic Oxidation
Ceramic coatings were prepared in situ on commercial pure Ti(CP-Ti) by Plasma Electrolytic Oxidation(PEO) technology in an environmental-friendly solution. The voltage–time responses were recorded during different PEO processes. For short treatment times, the formation processes of ceramic coatings follow a linear kinetics, while for longer times the kinetics departs from the linear behavior. The surficial morphology and composition of the coatings was studies by X-ray diffraction(XRD) and scanning electron microscopy (SEM). The acted electrochemical method was used to evaluate the corrosion of the coated samples in 1moll-1 NaOH solution. The potentiodynamic polarization curves of coated titanium samples and the untreated metal substrate show that the PEO coated titanium samples possess much higher corrosion potential and lower corrosion current than uncoated aluminum alloy. It is noticed that the passive current density of the samples decreased from 10-4A/cm2, for the titanium, to 10-7 A/cm2, for PEO coated titanium sample.
Zhengyi Jiang, Xianghua Liu and Jinglong Bu
P. Y. Guo et al., "Growth Mechanism and Corrosion Behavior of Ceramic Coatings on CP-Ti Produced by Plasma Electrolytic Oxidation", Advanced Materials Research, Vols. 154-155, pp. 896-901, 2011