Evaluation of TiO2 Nanoparticles Concentration and Applied Current Density Role in Determination of Microstructural, Mechanical, and Corrosion Properties of Ni-Co Alloy Coatings

The goal of the present investigation is to evaluate the influences of plating parameters such as TiO2 nanoparticles concentration in the plating bath and applied current density on the microstructure-related and mechanical properties as well as corrosion behavior of Ni-Co coatings. The coatings were fabricated by different current densities and TiO2 nanoparticles concentration over the range 2-8 A dm(-2) and 0-30 g/L, respectively. Results demonstrate that the incorporation of TiO2 nanoparticles into the plating bath coupled with the change in current density can deeply affect the microstructure-related, mechanical properties as well as corrosion resistance of Ni-Co coatings. According to the results, Ni-Co-20 g/L TiO2 coatings electroplated at current density of 4 A dm(-2) shows the superior properties. The synergistic effects of higher Co amount coupled with the higher volume fraction of TiO2 throughout the microstructure of the coating is responsible for the above-mentioned improvements.