Effects of sonication on anticorrosive and mechanical properties of electrodeposited Ni-Zn-TiO2 nanocomposite coatings

Ni-Zn-TiO2 nanocomposite coating was fabricated using the electrodeposition process with the aid of ultrasonic vibration (0, 108, 135, 162 and 216 W cm− 2 ultrasonic power densities) on mild steel disks. The properties of the nanocomposite film were investigated using scanning electron microscopy (SEM), energy dispersive X-ray (EDX), EDX-mapping, Vickers microhardness test, Tafel polarization test and electrochemical impedance spectroscopy (EIS). The results revealed a significant improvement of anticorrosive properties and hardness of the nanocomposite coatings compared to Ni-Zn alloy coating. Ecorr became more positive and changed from − 0.921 V for Ni-Zn alloy coating to − 0.789 V for Ni-Zn-TiO2 nanocomposite coating. Icorr decreased from 1.25 × 10− 5 A cm− 2 for Ni-Zn alloy coating to 3.46 × 10− 6 A cm− 2 for Ni-Zn-TiO2 nanocomposite coating. On the other hand, hardness increased from 253 HV for Ni-Zn alloy coating to 876 HV for Ni-Zn-TiO2 nanocomposite coating. The improvements were related not just to the content of nano-TiO2 in the coatings but also to surface homogeneity and nanoparticles uniform dispersion in the matrix of the coating.