Ni-TiO2 nanocomposite coating with high resistance to corrosion and wear

Ni-TiO2 nanocomposite coatings with various contents of TiO2 nanoparticles were prepared by electrodeposition in a Ni plating bath containing TiO2 nanoparticles to be codeposited. The influences of the TiO2 nanoparticle concentration in the plating bath, the current density and the stirring rate on the composition of nanocomposite coatings were investigated. The composition of coatings was studied by using energy dispersive X-ray system (EDX). The wear behavior of the pure Ni and Ni-TiO2 nanocomposite coatings were evaluated by a pin-on-disc tribometer. The corrosion performance of coatings in 0.5M NaCl, 1M NaOH and 1M HNO3 as corrosive solutions was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy methods (EIS). The microhardness and wear resistance of the nanocomposite coatings increase with increasing of TiO2 nanoparticle content in the coating. With increasing of TiO2 nanoparticle content in the coating, the polarization resistance increases, the corrosion current decreases and the corrosion potential shifts to more positive values.