CHARACTERIZATION AND SURFACE ANALYSIS ON ELECTROLESS NI-P COATING PROCESS ON EN – 8 STEEL

Electroless Nickel (EN) is the major evolving surface coating technique employed in industries today. Various physical characteristics of EN coatings such as hardness, wear resistance, coating uniformity and corrosion resistance makes this coating as a choice for many engineering applications. The major advantages of EN coatings are uniform coating thickness, improved wear and corrosion resistance, hardness, ability to deposit on surface activated non conductors etc. Typical anionic surfactant and various passive chemical additives and nano additives such as ZnO, Al2O3 were added to the EN bath. In this project, Sodium Lauryl Sulphate (SLS) surfactant along with nano additives such as ZnO, Al2O3 were added to the EN bath. The effect of surfactant along with nano additives on surface properties such as surface roughness, microhardness and microstructure of electroless nickel-phosphorus (ENi-P) coating was investigated. The surface roughness of the coated specimens was measured using stylus instrument, microhardness was measured using vicker’s hardness tester, microstructure was studied using Scanning Electron Microscope (SEM) and wear test was measured using Pin on disc machine. The result obtained from the above tests clearly indicates that the surfactant and passive additives improves the surface finish, microhardness, microstructure and wear rate of ENi-P coatings significantly. The complete experimental details, their results and analysis are reported in this project.