Dry friction and sliding wear of EPDM rubbers against steel as a function of carbon black content

The dry friction and sliding wear of ethylene/propylene/diene rubbers (EPDM) were studied against steel as a function of the carbon black (CB) content using various testing configurations, such as pin(steel)-on-plate(rubber) (POP) and ring(steel)-on-plate(rubber) (ROP). The EPDM rubbers were characterized using tensile, compression tests and dynamic-mechanical thermal analysis (DMTA). The coefficient of frictions (COF) and specific wear rates of the EPDMs were determined. It was found that with increasing CB content the specific wear rate was reduced. A similar tendency was found for the COF in ROP tests. Both COF and wear rates of the EPDM mixes strongly depended on the test configurations. The wear mechanisms were concluded by inspecting the worn surfaces in scanning electron microscopy (SEM) and discussed. Albeit several rubber characteristics follow the same trend as the COF and wear rate, at least for this EPDM formulation, further investigations are needed to deduce eventual correlations between them.