Electrodeposition of Ni–ZrO2 composite coatings and evaluation of particle distribution and corrosion resistance

Abstract

The Ni–ZrO2 composite coatings were prepared by conventional electrodeposition method in Watts bath containing different amounts of ZrO2 to be codeposited. Pure Ni coating was also prepared as a comparison. The distribution and amount of the particles in the coatings were studied using an optical microscope, SEM, EDX, microhardness instrument and XRD. The results showed that with increasing ZrO2 concentration in the bath up to 90 g L−1, particle content in the coating increases. If concentration of ZrO2 surpasses 90 g L−1, ZrO2 content in the coating decreases, and distribution of the particles in the coating becomes non-uniform. Evaluation of corrosion behaviour showed that with increasing ZrO2 content in the coating, the corrosion potential shifted towards noble and positive values, and the corrosion resistance increased. The results revealed that the electroplated sample in the bath containing 90 g L−1 ZrO2 has the maximum particle content and the best corrosion resistance.