Investigation of mechanical and wear properties of Ni-Cerium oxide nanocomposite coatings

Recently, Ni-Cerium oxide nanocomposite coatings are of great interest and have been successfully used in many applications such as: high oxidation and corrosion resistance films, catalytic and magnetic. Many of these applications require high wear resistance. In this research, the nano-indentation and nano-scratch techniques were used to evaluate the wear properties of Ni-CeO2 nanocomposite coatings. It can be seen from the results that the molar ratio of Ce/Ni in the deposition bath has an important role on the tribological properties of the coatings. It was observed that, by increasing the molar ratio of Ce/Ni from 0 to 0.001 and 0.01, the percent of cerium oxide in the coating increase. The increase in ceria percent in the coating makes an increase in elastic modulus and hardness of the coating and causes decrease in friction coefficient of the coating. Also, by increasing the molar ratio of Ce/Ni from 0.01 to 0.1 and 0.2, the friction coefficient and scratch resistance of the coating, owing to formation of cracks in the coatings, increase and decrease, respectively. So, high scratch and wear resistance coating was formed when the amount of molar ratio of Ce/Ni was 0.01.