Effect of power supply on the deposition of Zn on a steel substrate using cathodic plasma electrolysis

Cathodic plasma electrolysis (CPE) has been used as an environmentally-friendly process to deposit metal coating on metal substrate. In this work, a coating of zinc was deposited via CPE on a low carbon steel wire using direct current (DC) and square wave pulsed current (SWPC) power. The experimental results showed that application of continuous DC power did not produce zinc deposition, but a dense coating of zinc was easily applied to the substrate with the application of SWPC power at 120 V, 4000 Hz and an 80% duty cycle. The resulting coating was porous with some imperfections on the surface, but the morphology and quality of the coating could be controlled by adjusting the parameters of the SWPC power. Increasing both the duty cycle and frequency of the power resulted in a lower deposition rate, but the coating was denser. The steel wire surface was cleaned using plasma generated in the CPE process and the Zn coating was found to accumulate during the rise in the power pulse. A linear regression model was established to describe the relationship between coating thickness and power parameters.