Multifunctional steel surface through the treatment with graphene and h-BN.

Abstract

The search for improved surface properties of engineering alloys is always a matter of interest. Herein, we introduce a surface treatment based on depositing a non-continuous layer of two-dimensional (2D) nanomaterials via a simple and scalable method. 2D nanosheets of hexagonal boron nitride (h-BN) and graphene nanoplatelets (GNP) were sprayed on mild steel, followed by mild heat treatment. The nanosheets are strongly attached to the surfaces and even diffused to submicron under the surface, as proved by various analytical techniques. The mechanical, tribological and corrosion evaluations show significant simultaneous enhancement in a set of surface properties. From the friction tests with sliding steel-steel tribo-pairs under dry conditions, the graphene treatment decreases the friction coefficient and wear area by 21% and 31%, respectively. Interestingly, it is revealed that under dry and lubricated conditions, graphene-doped h-BN exhibits outstanding anti-wear properties synergistically compared to stand-alone 2D materials. The possible wear mechanism is investigated and found to be based on the formation of a tribofilm.