Investigation on tribological behaviour of co-deposited zinc, tungsten and graphene (ZnWG) nanocomposite coatings on low-carbon steel

Abstract

The protection of steel surfaces in industrial applications to improve their tribological behaviour using graphene-based nanocomposite coatings is a potential area for researchers to investigate. An attempt has been made to develop and compare the tribological properties of Zinc–tungsten (ZnW), Zinc–Tungsten with 0.25 wt.% of graphene (ZnWG 0.25 wt.%) and Zinc-Tungsten with 0.50 wt.% of graphene (ZnWG 0.50 wt.%) coatings on steel substrates with low-carbon content using the electroplating technique with pulse power supply. The electrolyte bath for pulsed electro-deposition was maintained as aqueous by involving zinc sulphate, sodium tungstate and citric acid. The experiments inferred that ZnWG 0.50 wt.% performed with better wear resistance due to its increased graphene content, contributing to the effective ductile load-bearing ability of the ZnW coating matrix. Grain size control and improved grain strength due to the presence of graphene in the ZnW matrix produced dislocation obstruction and displacement inhibition to create defect-free layered cauliflower morphology and contributed to ZnWG 0.50 wt.% exhibiting better corrosion resistance than the plain ZnW coating.