Abstract
In the current investigation, plasma electrolytic oxidation (PEO) ceramic coatings on Al are galvanostatically synthesized at various processing stages in an alkaline silicate system. The resultant coatings are systematically surveyed in terms of the following respects: the applied voltage and surface sparking evolution over the studied course of PEO are recorded by the signal acquisition system and the real time imaging, respectively; the phase constitution, the surface morphology, polished cross section of the coated specimens, the fractured cross section and coating/substrate interface of the detached coatings are characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) assisted with energy-dispersive X-ray spectrometer (EDS), respectively. In particular, the coatings detached by an in-house developed electrochemical way disclose the coating microstructure in a new angle, which allows the cross section and the coating/substrate interface to come clearly into focus. The microstructure evolution of the oxide ceramic coatings and the correspondences among the characteristic microstructures of the free surface, the fractured cross section and the coating/substrate interface are presented and discussed. Further, based on the present PEO coating microstructure, a model of the coating growth that evolves over time is proposed.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
