Electrodeposition and characterization of electroplated Ni/Graphene composite coatings

Abstract Pure nickel and composite nickel coatings were produced by using a Watts bath containing 0.1g/L Graphene platelets - GnPs in presence or absence of the surfactant Sodium Dodecyl Sulfate under both direct current-DC and pulse current-PC conditions. The surface morphology, crystallographic orientation, and micro-hardness as well as the wear mechanism of the produced coatings under dry sliding conditions were investigated. The results have shown that the presence of additive in the electrolytic bath led to a more uniform distribution of Graphene platelets in the nickel metal matrix. The simultaneous presence of additive in combination with the imposition of high pulse current frequency is accompanied by the predominance of a mixed Ni crystalline orientation [110 + 111], while for all composites an enhancement of the crystalline orientation through (111) axis was revealed. The presence of Graphene platelets increases the micro-hardness values of the coatings and enhances the wear resistance compared to pure nickel coatings produced under the same electrolytic conditions.