Effect of reduced graphene oxide (rGO) on corrosion and erosion-corrosion behaviour of electroless Ni-P coatings

Protective coatings have been gaining prominence in research related to graphene based compounds over the recent years. The present study aims to reveal the novel anti-corrosive properties of the coatings achieved by co-depositing the carbon allotropes. Electroless Ni-P-rGO coatings were successfully obtained on low carbon steel substrates by adding various concentrations of rGO particles to the conventional electroless Ni-P bath. The coated specimens were characterized for its morphology and composition corroborated by X-ray diffraction and microhardness analysis. The corrosion and erosion corrosion behaviour of the Electroless Ni-P-rGO coatings were studied using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) in 3.5 wt% sodium chloride solution. The erosion corrosion behaviour of the coatings for different concentrations of rGO particles was examined using a slurry pot tester. The addition of rGO particles had considerably improved the corrosion and erosion resistance and the best results were achieved at an optimum concentration of 50 mg/L of rGO in the bath.