Preparation and properties of ceramic coatings by cathode plasma electrolytic deposition on titanium alloy

The ceramic composite coatings consisting of Al2O3 bond-coat (70-90 μm) and La2Zr2O7 top-coat (300-330 μm) were prepared by two-step cathode plasma electrolytic deposition (CPED) on titanium alloy. Compared with single La2Zr2O7 coating, the bonding strength of the composite coatings was improved by 40%, owing to the anchor-bond of Al2O3 coating and La2Zr2O7 coating. High temperature cyclic oxidation at 700 °C was adopted to investigate the high temperature corrosion resistance of the La2Zr2O7 coating and the composite coatings. The results revealed the composite coatings possessed the best high-temperature oxidation and spallation resistance. Deposition processes of La2Zr2O7 coating and Al2O3/La2Zr2O7 composite coatings were illustrated through current density-time curves.