Title: Effect of graphene coating on the microstructure and mechanical properties of tungsten inert gas surface melted AISI-316L steel
Authors: Tanmoy Das; Abhishek Sharma; Jinu Paul
Addresses: Department of Mechanical Engineering, Indian Institute of Technology, Kharagpur 721302, West Bengal, India ' Department of Mechanical Engineering, Indian Institute of Technology, Kharagpur 721302, West Bengal, India ' Department of Mechanical Engineering, National Institute of Technology, Calicut 673601, Kerala, India
Abstract: In this study, stainless steel substrates were coated with a graphene layer by a drop coating method. The surface of these graphene-coated samples was then modified using tungsten inert gas (TIG) surface melting technique. Phase changes, microstructure, microhardness, and wear properties of as-received (unprocessed), TIG surface-melted and graphene-coated TIG surface-melted specimens were inspected. Due to the inclusion of graphene, surface melting steered the creation of thick layers of iron-carbide (FeC) particles. The hardness of the graphene-coated melted layer depicted a high value of 420 HV, while the maximum hardness of the as-received surface melted layer was only 260 HV. Peak shifts observed in Raman spectroscopy depicts the disorderness developed in the graphene incorporated on the substrate. There is a reduction of ~14% in the specific wear rate with the incorporation of graphene coating due to its self-lubricating nature. As an outcome, as-received surface melted steel samples displayed relatively higher wear rates compared to those of surface melted graphene-coated specimens. The formation of a thin graphene tribolayer led to the reduction of the wear in the graphene-coated samples. Delamination, grooves, abrasive wear were observed on the as-received surface melted specimens where a very rough surface was obtained against the graphene-coated one.
Keywords: graphene; tungsten inert gas; TIG; surface melting; hardness; wear resistance.
International Journal of Materials and Product Technology, 2021 Vol.62 No.1/2/3, pp.30 - 48
Received: 02 Jan 2020
Accepted: 07 Jul 2020
Published online: 21 May 2021 *