Preparation of Ni-P-GO composite coatings and its mechanical properties

Ni-P-GO composite coatings were prepared on mild steel through an electroless nickel bath with homemade graphene oxide (GO). The structure, surface morphology, and elemental composition of as-deposited coatings were characterized by scanning electron microscopy, energy-dispersive spectroscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, and atomic force microscopy (AFM). AFM results indicated that each GO sheet was approximately 5 nm thick. Mechanical properties of coatings were also evaluated by microhardness, friction, and wear tests. Results showed that GO improved the microhardness and wear resistance of the composite coatings. The optimum GO concentration for deposition of the electroless Ni-P-GO bath was 40 mg/L.