Preparation and tribological properties of graphene oxide doped alumina composite coatings

In this paper, nickel matrix composite coatings incorporated with graphene oxide (GO) and graphene oxide doped alumina (GO-Al2O3) particles were fabricated through electro-deposition. Given the excellent mechanical properties of GO and Al2O3, excellent anti-wear properties are expected when embedding GO-Al2O3 particles in Ni matrix. For this purpose, nano-Al2O3 particles were first grafted on GO surfaces to fabricate the GO-Al2O3 particles. The structure, composition and morphology of the GO and GO-Al2O3 were characterized by XRD, FT-IR, SEM, TEM and BSE, respectively. The results revealed that nano-Al2O3 particles were successfully doped on GO surfaces. The tribological performances of the coatings were studied under dry sliding condition. It was found that the wear rate of Ni/GO composite coating declined by 20.9% compared to pure Ni coating. The results also indicated that the Ni/GO-Al2O3 coatings with higher amount of Al2O3 content presented the lower friction coefficients and better anti-wear behaviors. The superior tribological properties of the Ni/GO-Al2O3 coating were attributed to the synergistic effects of GO and Al2O3.