Synthesis and Characterization of Ni-P-W coating on copper substrate

Abstract

Nickel phosphorus coating is widely used in various industrial applications, due to its excellent corrosion and wear resistance properties. The coating can be further improved by the addition of various elements to form composite coatings. The primary objective of this work was to incorporate tungsten into nickel phosphorus coating by using electroless and electrolytic processes. Surface characterization of the coatings were done examined using scanning electron microscope and energy-dispersive X-ray spectroscopy. Corrosion behaviour of the coatings were evaluated using cyclic polarization and electrochemical impedance spectroscopy. Cyclic polarization was used to determine the passivation range along with re-passivation potential. Electrochemical impedance spectroscopy was used to evaluate the impedance of the coatings. The details of the results are discussed in thesis.