Electrodeposition and Corrosion Resistance Properties of Co-W/PCTFE Nanocomposite Coatings

The present work deals with the process of electrochemical deposition of cobalt–tungsten /polychlorotrifluoroethylene (Co-W-PCTFE) nanocomposite coatings in the tartrate bath and electrochemical corrosion behavior in 3.5 wt.% NaCl solution. Surface morphology and composition of the composite coatings are characterized by energy dispersive X-ray (EDX), scanning electron microscopy (SEM). Corrosion behavior of coatings is carried out applying opencircuit potential (OCP) measurements, electrochemical impedance spectroscopy (EIS) and polarization techniques in 3.5 wt.% NaCl solution. The study reveals reduce in corrosion current density, important substitute in corrosion potential towards the positive direction with the incorporation of PCTFE particles in the Co-W matrix. Therefore, the significant improvement in corrosion resistance observed for Co-W-PCTFE nanocomposite coatings (7.587kΩ cm2) compared to Co-W (2.325kΩcm2). The results of SEM images indicated to changing morphology of alloys coatings in the presence of PCTFE particle sizes from micrometric to nanometeric sizes. The EDX analyzes confirmed the forming of Co-W-PCTFE nanocomposite coatings.