Preparation and characterization of pulsed electrodeposited cobalt–graphene nanocomposite coatings

Abstract

Cobalt–graphene nanocomposite coatings possess unique mechanical and tribological properties which attract researchers to explore its potential for various industrial applications. This research work presents the investigation on cobalt–graphene nanocomposite coatings, with two different graphene compositions cobalt–graphene (0.15 and 0.45 wt%) prepared by pulsed electrodeposition from aqueous bath involving cobalt chloride, trisodium citrate, and citric acid on low carbon steel substrate. Studies on coating morphology, microhardness, tribological characteristics such as wear and corrosion for the cobalt–graphene nanocomposite coatings were reported. Cobalt–graphene (0.45 wt%) nanocomposite coating which exhibits low wear rate in all load conditions due to the self-lubricating property of graphene and cobalt–graphene (0.15 wt%) nanocomposite coating shows higher corrosion resistance due to its layered cauliflower surface morphology.

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

“…It is also inferred that the graphene-infused cobalt nanocomposite coatings performed with a lower friction coefficient than a plain cobalt coating due to graphene's self-lubricating properties. 11 In other related research, zinc-graphene composite coatings have shown that adding graphene causes crystal size reduction and changes surface morphology while providing improved anti-corrosion behaviour. 5 It is inferred that the addition of graphene oxide in the Zn matrix of the nanocomposite coating has significantly improved corrosion resistance.…”

“…These coatings involve the combination of different materials such as zinc, nickel, cobalt, tungsten, tin, graphene, CNT and many more to leverage their advantageous properties and create synergistic effects like enhancing the corrosion and wear resistance of the nanocomposite coatings. [2][3][4][5][6][7][8][9][10][11] Zinc, tungsten and graphene are among the materials that have gained significant attention for this purpose. Excellent corrosion resistance properties are known for zinc.…”

“…8 One of the most well-known methods for creating such nanocomposite coatings, which includes multiple elements such as Zn, Ni, Co, Graphene, CNT, etc., is the pulsed electro-deposition technique as it yields better mechanical, chemical, corrosion inhibition and wearresistant qualities. 10,11 An attempt is made to develop a nanocomposite coating that enhances the tribological properties of steel by harnessing the corrosion resistance of zinc, the high hardness of tungsten, and the selflubricating property of graphene. Three different combinations of coatings, namely 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.%) were applied to IS513 graded steel using the electro-deposition technique with pulsed power supply.…”

“…These coatings involve the combination of different materials such as zinc, nickel, cobalt, tungsten, tin, graphene, CNT and many more to leverage their advantageous properties and create synergistic effects like enhancing the corrosion and wear resistance of the nanocomposite coatings. 2–11…”