Tribologically modified surfaces on elastomeric materials

As the result of tribological loading, the properties of the surface of elastomeric materials will alter. This effect has been observed using SEM and EDS analysis of the tread of a used car tyre, where differences in structure between the substrate and the area near the surface were found. To study the effects of tribological loading on the surface properties of elastomers in a more reproducible manner, a pin-on-disk tribometer was employed, using EPDM disks and spherical pins made of 100Cr6 steel. In the tribologically loaded area, a modification of the surface with a thickness ranging between 4 and 8 µm was observed, whilst in the unloaded area such a surface modification was not observed. The mechanical and tribological properties of the modified and unmodified surfaces were analysed using micro-indentations and friction experiments on a nano-tribometer, showing a reduction of the stiffness of the tribo-modified surface as well as altered time-dependent behaviour and a 60% reduction in the coefficient of friction when sliding against steel.