Electrodeposited nickel–graphene nanocomposite coating: influence of graphene nanoplatelet size on wear and corrosion resistance

Abstract

In this paper, we broaden our previous work, which investigated the influence of graphene nanoplatelets (GNPs) size on microstructure and hardness of composite coatings, to determine the effect of GNP size on wear-resistance and anti-corrosion property of GNP-reinforced nickel coating (Ni/GNPs). The experimental results indicated that the small GNP material size could enhance the wear resistance for nickel composite coating with the wear rate of 13.2 × 10–4 mm3/Nm, the wear depth of 17.69 µm. Meanwhile, the anti-corrosion property is enhanced significantly, this is shown via the low corrosion current density (Icorr value of 1.16 × 10–7 A/cm2) and the high corrosion potential (Ecorr value of − 0.1661 V). In addition, the mass lost in salt fog testing is low with the weight of 12.3 mg, which decreased down to ~ 55.27% compared to pristine Ni coating. These results are attributed to the uniform distribution of the small GNP size inside Ni matrix as well as the grain refinement effect of composite coating when using the small GNP size.