Preparation and Properties of Ni-P-SnO₂ Composite Coating

The nanometer composite coating of Ni-P-SnO2 was prepared on carbon steel substrate by double pulse electrodeposition technology. The deposition rate, microhardness and surface morphology were considered as selection standard to get the optimal technological conditions for preparing Ni-P-SnO2 nanometer composite coating: 2 g/L nanometer SnO2, current density of 2 A/dm2, plating liquid temperature of 60 ℃, plating time of 30 min, duty cycle of 20%~30%, frequency of 100~150 Hz. The surface morphology and phase structure of Ni-P-SnO2 composite coating were characterized by SEM and XRD; the electrochemical behavior of the coating was tested by electrochemical method. The results showed that the nanocomposite coating surface was intact, no obvious defects, nanometer SnO2 was uniformly distributed in the Ni-P plating layer, the corrosion resistance was not as good as Ni-P coating, but the inhibition efficiency was also up to 90%.