Silicate-based Plasma Electrolytic Oxidation (PEO) coatings with incorporated CeO2 particles on AM50 magnesium alloy

Plasma Electrolytic Oxidation (PEO) coatings on AM50 were developed in electrolytes containing CeO2 particles. The effect of particle concentration in the electrolyte on the final microstructure of the coatings was studied and correlated with the corrosion behavior. CeO2 particles were incorporated into the coatings and located preferentially in pores and cracks. The process involves both uptake and reactive incorporation of CeO2 under local melting caused by microdischarges. The coating with the lower concentration of particles has the best corrosion properties as measured with EIS. Higher concentration of particles increased the defect density in the coating which has a negative effect on the corrosion resistance. [Display omitted] •PEO coatings were formed on AM50 in CeO2 particles containing electrolytes.•The addition mechanism of CeO2 involves both uptake and reactive incorporation.•High concentration of CeO2 has a negative influence on the microstructure.•Coating formed with 3gL−1 CeO2 electrolyte showed the best corrosion properties.