Structural and sliding wear properties of Ag/Graphene/WC hybrid nanocomposites produced by electroless co-deposition

Abstract

The main objective of this work has been the deposition of hybrid silver/WC/Graphene nanocomposites and characterization of their tribological behaviors. Graphene as a conductive solid lubricant additive was introduced into Ag matrix from the electrolytes in which submicron WC particles and Graphene nanosheets were suspended. The main purpose for two different reinforcements is to improve both wear and friction properties. The friction and wear behaviors of Ag/WC/Graphene coatings on the metal substrates against M50 steel ball were tested under dry sliding wear conditions. Comprehensive characterizations were performed using Scanning Electron Microscopy, X-Ray Diffraction analysis, Raman spectroscopy and 3D profilometry facilities. Tribological test results have revealed that even small amounts of Graphene addition are able to drastically improve the antifriction and antiwear properties of hybrid nano Ag matrix composites. A possible explanation for these results is that the co-deposition of Graphene not only provides an enhanced effect for nanocomposites to produce better wear resistance, but also forms a local protective layer on the contact surfaces to reduce the friction. The investigation shown that hybrid reinforcements of sub-micron WC and Graphene hold great potential applications as effective load bearing and solid lubrication for Ag matrix composites and possibly for similar alloys. (C) 2015 Elsevier B.V. All rights reserved.