Fabrication of a zinc-based coating with titanium dioxide on AM50 and AZ91 magnesium alloys

This study investigated the formation of zinc coatings incorporated with titanium dioxide (TiO2) on magnesium alloys designated as AM50 and AZ91. The coating process involved electrochemical zinc deposition, with and without concurrent electrophoresis of TiO2 particles in the deposited flux. Various analytical techniques were employed, including scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and electrochemical methods. The resulting zinc-TiO2 coating exhibited a titanium concentration approximately double that of the initial electrolyte. Additionally, an unexpected phase transition from rutile to anatase TiO2 was observed at room temperature. Corrosion tests revealed that while the pure zinc-coated alloys exhibited higher corrosion rates compared to their uncoated counterparts, the inclusion of TiO2 in the zinc coating slightly reduced this corrosion rate. The corrosion behavior of both the coated AM50 and AZ91 alloys differed from that of the uncoated alloys.