Development of ZnO incorporated composite Ni–ZnO–P alloy coating

The process of electroless nickel phosphorus (EN) plating has become an inevitable technology in various industrial fields due to its excellent corrosion and wear resistance characters. Incorporation of Zn in EN plate has great impact on the chemical composition and properties of the plate. This paper focuses on significant improvement of the plate by incorporation with ZnO as a composite in the EN plate. In the present study, ZnO was selected for the composite plating by virtue of its properties like semiconductivity (band gap of 3.37 eV), piezoelectric property and biocompatibility. ZnO incorporated plate was obtained using a standard EN bath dispersed with ZnO. The plate was evaluated based on the results of porosity test, hardness and thickness measurements, OCP measurements and polarization studies. The composite plate corresponding to 0.50 g/l of ZnO in the bath showed excellent mechanical as well as electrochemical characteristics. The effect of incorporation of ZnO and the influence of its concentration on the plating characteristics are briefly discussed in this paper.