Synthesis and recent advances in tribological applications of graphene

Graphene is one of the most emerging material in the field of nanotechnology, and it is gaining a tremendous amount of research interest in recent years. Apart from its unique electronic, electrical, mechanical, and thermal properties, graphene also possesses lower wear rate and friction coefficient. The superior tribological properties of graphene have attracted many researchers to synthesize self-lubricating nanocomposite materials that can have several applications in the automobile, aerospace, and marine industries. Graphene is also proven a competitive nanomaterial as an additive in the lubricant oil because of stable suspension and improved anti-wear properties of the component. This article aims to present the review of the advancement in the field of graphene synthesis; tribological properties of graphene; the role of graphene as reinforcement in polymer-matrix, metal-matrix, and ceramic-matrix nanocomposites; and also graphene as an additive in lubricant oil. The results reveal that addition of graphene to the composites can lead to decrease both wear rate and coefficient of friction for all three class of materials. Moreover, when graphene used as a lubricant additive, it improves the load carrying capacity of lubricant oil along with decreased friction and wear. Performance of graphene-reinforced composites and graphene suspended lubricants depend on various tribological and materials parameters which are discussed in this article. The limitation of present knowledge and future research scope are also highlighted.