Graphene coatings to enhance tribological performance of steel

Friction and wear affect machine reliability, efficiency and safety, increasing the maintenance and operating costs. A reduction of the coefficient of friction (CoF) of sliding parts would increase the machine efficiency, while a reduction of wear damage would allow higher reliability and safety. The aim of this work is to investigate the application of graphene to reduce the CoF and wear damage in mechanical components made of steel. In this work, graphene has been applied on C40 steel samples using two coating procedures based on chemical vapor deposition technique: direct growth graphene (DG) and transferred graphene coating (TGC). Tribological performance has been evaluated, by means of ball on disk tests, in terms of CoF and worn volume. Results obtained with no coated samples with have been compared to those obtained with coated ones. Results show that the proposed graphene coatings enhance tribological performance of C40 steel, in particular results show that DG sample has better wear strength, while TGC sampled are better to reduces CoF.