Investigation of the tribological behavior of Ni-W-TİO2 coatings produced by ultrasonic assisted electrodeposition coating technique

Keywords: ultrasonic–assisted electrodeposition, elevated temperature wear, nanohardness corrosion resistance Ni–W–TiO2 co–depositions were produced by pulse electrodeposition under ultrasonic conditions. The influences of ultrasonic powers and concentration of TiO2 on the surface morphology, surface roughness, nanomechanical, anti-corrosion, high–temperature wear, and friction behavior of the Ni–W co–depositions were systematically investigated and discussed with X-ray diffraction, Field emission scanning electron microscope, X–ray Energy–Dispersive Spectrometry, electrochemical measurements (potentiodynamic polarization and electrochemical impedance spectroscopy) and tribological test (ball–on–disc wear testing). The results indicate that increasing TiO2 particle concentration and ultrasonic power significantly refined the microstructure and reduced crystallite size of the coatings, and improve the tribology and electrochemical properties of Ni(W) coating. The optimum electrodeposition condition for Ni–W co-deposition was achieved at TiO2 concentration of 20 g/L and ultrasonic power of 50 W, resulting in a coating with the lowest wear rate (8.4×10−6 for room temperature and 7.2×10−6 mm3/Nm for 300 °C), minimum corrosion rate (0.0014 gr), excellent nanomechanical properties (hardness of ~8 GPa and elastic modulus of ~209 GPa), maximum TiO2 incorporation rate (24.4 wt. % TiO2) among all investigated coatings.