Anchored graphene nanosheet films towards high performance solid lubricants

Abstract

Graphene nanosheet films with improved durability and load capability are highly desired to realize the engineering application of graphene as solid lubricants. Here, we report a general approach to fabricate anchored graphene nanosheet films (A-GNSF), which is based on the selective electrochemical dissolution of graphene-containing metal matrix composites. A-GNSF are composing of many anchored graphene nanosheets, whose parts of basal plane expose on the graphene-containing metal matrix composite's surface while other parts of their basal plane anchor into the composite. The microstructure evolution of the A-GNSF as a function of the duration of selective electrochemical dissolution and the graphene content in composites is investigated and is correlated with their tribological performance. The mechanism on reduction of friction and wear for A-GNSF is also discussed. The results show the unique architecture of the A-GNSF greatly contributes to the rapid formation and the stability of the in-situ developed graphene sliding against graphene lubricating interface. As a consequent, A-GNSF show a friction coefficient as low as 0.14, excellent wear resistance and long lifetime under a contact pressure that is up to 0.88 GPa. Keywords: Graphene, Durability, Load capability, Tribolayer, Transfer layer