This study investigates the effect of ultrasonic-assisted interval time on the microstructure and electrochemical corrosion properties of Watts-type nickel coatings prepared by electrodeposition. To address challenges such as coarse grains and porosity caused by concentration polarization during traditional direct current plating, ultrasonic intervals of varying durations were introduced. The surface morphology, crystallographic orientation, grain size, and corrosion resistance were analyzed using scanning electron microscopy, X-ray diffraction, and electrochemical techniques. Results reveal that continuous ultrasound and short-interval pulsing promote (220) texture and yield finer grains, with sample #3 exhibiting the strongest (220) orientation and smallest grain size. Longer intervals shift the preferred orientation to (200), enhance coating compactness and improve thermodynamic stability (higher open-circuit potential), but do not necessarily result in better corrosion resistance. Notably, sample #1 demonstrated the lowest corrosion current density and a balanced polarization resistance, indicating the best overall electrochemical protection. This study highlights the importance of ultrasonic interval tuning to balance structural and electrochemical properties in functional nickel coatings.
Jiao et al. (Sun,) studied this question.