Investigation of the Corrosion Resistance of Ni-W/PTFE Nanocomposite Coatings in 3.5wt.% NaCl Solution

Electrodeposition of composite coatings, based on hard particles dispersed in a metallic matrix, is gaining much importance for potential engineering applications [1-3]. In this research, Ni-W/PTFE composite coatings were electrodeposited from a plating bath containing suspension of polytetrafluoroethylene (PTFE) particles. The influences of PTFE particle concentration in the plating bath on the composition of composite coatings were investigated. The surface morphology and composition of the composite coatings were characterized by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) measurements and X-ray diffraction analysis (XRD). The corrosion characteristics of Ni-W/PTFE nanocomposite coatings were investigated by using open circuit potential (EOCP), electrochemical impedance spectroscopy (EIS) and polarization techniques in 3.5 wt.%NaCl solution. The results showed that the incorporation of PTFE particles in the Ni-W matrix, increases the metallic luster, decreases the surface roughness, alters the chemical composition and significantly increases the corrosion resistance.