Effect of voltage and duty cycle on microstructure and corrosion resistance of ZrO₂ coating by cathode plasma electrolytic deposition

Power parameters are of importance to determine the microstructure and property of coatings deposited by cathode plasma electrolytic deposition (CPED). In the present study, the effect of power parameters including voltage and duty cycle on the microstructure and anti-corrosion property of zirconia (ZrO₂) CPED-coatings was investigated. The results suggested that the as-deposited coatings consisted of t-ZrO₂ and m-ZrO₂, while the content of t-ZrO₂ exceeded 50 %. The content of t-ZrO₂ increased with the increase of voltage and decreased with the increase of duty cycle, reaching a maximum of 89.9 %. In addition, as the voltage and duty cycle increased, the porosity of the coating increased from 3.7 % to 15.5 %. Due to the high t-ZrO₂ content, high thickness and relatively dense structure, the coatings deposited at 250 V had a superior corrosion resistance in 3.5 wt% NaCl solution. This work will provide a guideline for tailoring high performance ZrO₂ CPED-coatings.