Role of particulate fillers in the modification of the tribological behavior of polymer composites in dry sliding

This paper discusses the role of fillers including solid lubricants (graphite and molybdenum disulfide), polytetraflouroethylene and silicon carbide on the tribological behavior of a specific polymer, Phenolic Resin. Polymeric composite material samples are manufactured by compression molding and are evaluated for their friction and wear properties. Using a pin-on-disc apparatus, dry sliding wear behavior under ambient conditions was studied which measured friction coefficient of samples. The counterface was made from hardened steel, AISI 52100. A number of experiments were performed using different filler types and weight percents including: graphite and molybdenum disulfide (10, 15 and 20%), polytetraflouroethylene (5, 10, 15 and 20%) and Silicon Carbide (5 and 10%). In silicon carbide case, two different particle sizes (5, 38) were tested as well. Results showed that addition of fillers with layer structure (graphite and MoS2) decrease the friction coefficient and wear resistance but PTFE powder improves both tribological behaviors. Ceramic filler of SiC exhibited different effect. In this case particle size affects the wear property. Large particles (of about 38) found to protect the polymer matrix better than small particles (of about 5), which partially increase the wear rate.