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Cr2O3-based ceramic composite coatings with a NiCr intermediate layer adding nano TiO2 particles were synthesized by Air plasma spraying(APS)followed further seal treatment.The coating samples were characterized by X-ray diffractions(XRD),scanning electron microscope(SEM).The corrosion behavior of coating was measured by weight loss in three solutions(HCl,NaOH,and NaCl).The relationships between the microstructure,corrosion behavior,and the content of TiO2 in coatings were investigated.When the content of TiO2 was relative high,the coating was composed of(Cr0.88Ti0.12)2O3 and Cr2O3 phase.Before sealing,the coating weight decreased all long in three kinds of solutions.However,after sealing treatment the coating weight decreased early but increased later,changed periodically as so.Polarization curve and electrochemical impedance spectroscopy(EIS) were performed to study the corrosion mechanism.The results showed that like organic coating,the corrosion of ceramic coating included three stages,in which the weight of samples decreased or increased corresponding to different physical and physical or chemical processes.The salt spray test showed the Cr2O3-based ceramic composite coating had an excellent decay resistance in marine environment.
Cr2O3-based ceramic composite coatings with a NiCr intermediate layer adding nano TiO2 particles were synthesized by Air plasma spraying (APS) followed further seal treatment. The coating samples were characterized by X-ray diffractions (XRD), scanning electron microscope (SEM). The relationships between the microstructure, the corrosion behavior, and the content of TiO2 in coatings were investigated. When the content of TiO2 was relative high, the coating was composed of (Cr0.88Ti0.12) 2O3 and Cr2O3 phase. Before sealing, the coating weight decreased all long in three kinds of solutions. After sealing treatment the coating weight decreased early but increased later, changed periodically as so .Polarization curve and electrochemical impedance spectroscopy (EIS) were performed to study the corrosion mechanism. The results showed that like organic coating, the corrosion of ceramic coating included three st ages, in which the weight of samples decreased or increased corresponding to different physical and physical or chemical processes. The salt spray test showed the Cr2O3-based ceramic composite coating had an excellent decay resistance in marine environment.