Fabrication and Tribological Behavior of Ni-ZrO₂ Nanocomposite Coatings Prepared by Electrodeposition in Ultrasonic Field

Ni-ZrO₂ nanocomposite coatings were fabricated by electrodeposition from a modified Watt’s type electrolyte containing ZrO₂ nanoparticles, where an ultrasonic field was imposed during electrodeposition process. The weight percent of ZrO₂ in coatings and the surface morphology of coatings were examined. The microhardness and tribological properties of Ni-ZrO₂ nanocomposite coatings and pure Ni coating were investigated. The results show that ultrasonic agitation can greatly affect the microstructure and the tribological behavior of Ni-ZrO₂ nanocomposite coatings. The Ni-ZrO₂ nanocomposite coatings record variable ZrO₂ contents and surface morphologies by modifying ZrO₂ concentration in electrolyte and ultrasonic parameters. The Ni-ZrO₂ nanocomposite coating fabricated with ultrasonic agitation exhibits finer grains and more compact structure compared to pure Ni coating and the Ni-ZrO₂ nanocomposite coating fabricated without ultrasonic agitation. The dispersed ZrO₂ nanoparticles in coatings and ultrasonic agitation during electrodeposition synthetically contribute to the grain refinement of the coatings. Therefore, the Ni-ZrO₂ nanocomposite coating by ultrasonic electrodeposition exhibits high microhardness and excellent tribological behavior. In general, the improvement in friction and wear properties of Ni-ZrO₂ nanocomposite coatings can be attributed to the homogeneously dispersed ZrO₂ nanoparticles and the finer-grained structure.