Effect of KI on the Corrosion Resistance of Ni-P Electroless Plating Coating

摘要

To improve the corrosion resistance of Ni-P electroless coating, the KI was added in the electroless solution. The surface micrograph was observed using scanning electron microscopy (SEM), and the corrosion resistance of Ni-P coatings in 3.5%NaCl solution was examined by polarization curves and electrochemical impedance spectroscopy (EIS). The experimental results showed that KI reduced the amount of defects and the size of crystal grain of Ni-P coating, and the surface of Ni-P coating became more homogenous, smoother and compact by KI. In addition, the phosphorus content of Ni-P coating was increased by KI. These factors increased the ability to corrosion protection of Ni-P coating.