Tribological properties of epoxy nanocomposites - III. Characteristics of transfer films

The multiple parts of this study are intended to experimentally and analytically elaborate the tribological properties of epoxy nanocomposites, reinforced by short carbon fibres (SCF), nano-TiO2 particles, polytetrafluorethylen (PTFE) powders and graphite flakes, in order to understand the role of fillers in modifying the wear behaviour of the materials. In this part, the influences of two solid lubricants, PTFE and graphite, were studied and compared. The transfer films established with two lubricants in sliding wear of epoxy nanocomposites against metallic counterparts were characterised under different sliding conditions. The morphology of transfer films was examined using scanning electronic microscopy (SEM), while their mechanical properties were investigated using micro-hardness tests. A method was proposed to determine the thickness of transfer films based on micro-indentation. The role of transfer films in dissipation of frictional heating was also studied. Epoxy nanocomposites containing both PTFE powders and graphite flakes showed a synergised effect in wear performance, especially under very severe wear conditions. (c) 2006 Elsevier B.V. All rights reserved.