Effect of Current Density on Microstructure, Mechanical, and Corrosion Behavior of Ni-P-TiO₂ Composite Coating

Coatings are extensively applied in various industries due to their notable hardness, corrosion resistance, and superior mechanical and chemical properties. One method to enhance their wear resistance is the incorporation of oxide particles, such as TiO₂. In this work, a Ni-P-TiO₂ composite coating was synthesized through electroplating, and the influence of current density during electrodeposition on the microstructure and tribological properties was examined. Coating morphology was investigated using scanning electron microscopy (SEM), while phase composition and crystallite size were determined by X-ray diffraction (XRD) analysis. The microhardness of the samples was measured using a Vickers microhardness apparatus. A pin-on-disc test was employed to evaluate the wear resistance of coated and uncoated samples. Furthermore, corrosion behavior was assessed through potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) measurements in a ۳.۵% NaCl solution. Results demonstrated that lowering the current density leads to finer crystallites, decreased microhardness, and reduced wear resistance. Potentiodynamic polarization and EIS tests revealed that increasing the electroplating current density diminishes the corrosion resistance of the coatings.

کلیدواژه ها:

Electroplating ، Ni-P-TiO۲ Coating ، Wear resistance ، corrosion