INFLUENCE OF SURFACE TOPOGRAPHY ON THE TRIBOLOGICAL BEHAVIOUR OF SELF-LUBRICATING IRON BASED COMPOSITES

摘要

1. The presence of nodules + pores induced increased surface roughness. 2. Increasing precursor content and, as a consequence, the number of turbostratic 2D graphite nodules, reduced average friction coefficients. 3. Friction coefficient is strongly influenced by surface finish. 4. The unpolished specimens exhibited significantly lower wear rates compared to the polished samples. The counter bodies presented much higher wear rates when sliding against the polished surfaces, being this even more significant for the reference alloy. 5. Besides significantly reducing the surface roughness, polishing also affected the availability of solid lubricant reservoirs in the active sliding interface. 6. The presence of 2D turbostratic graphite nodules affected the surface topography of the samples and had a great influence on the dynamics of the formation of protective tribolayers, and consequently on wear mechanisms.