Effects of rare earth cerium addition on the synthesis and corrosion resistance of electroless Ni–PTFE–P coating

Abstract

AbstractElectroless Ni–PTFE–P coatings have been successfully deposited on the surface of mild steel shaft from plating baths containing various concentrations of rare earth metal cerium (RE Ce). Surface morphology, Ce fraction, and thickness of the coatings were characterized by scanning electron microscope, inductively coupled plasma optical emission spectrometry, and reflection optical microscope, respectively. Salt spray test was used to determine the corrosion resistance of the coating. Results revealed that structure, compactness, and deposition rate of the Ni–PTFE–P coatings were increased significantly by addition of a small amount of RE Ce (10–20 ppm) to the plating bath. Electroless Ni–PTFE–P coating deposited from plating baths with 20 ppm Ce shows the highest corrosion resistance, owing to its high compactness and thickness. Deposition rate and corrosion resistance of the Ni–PTFE–P coating were deteriorated greatly as concentration of RE Ce in the plating baths exceeds 100 ppm.