Role of surface texture and roughness parameters on friction and transfer film formation when UHMWPE sliding against steel

Understanding friction between material pairs is very crucial when utilizing the materials in various applications, including mechanical and biological systems. In the present investigation, tribological properties, such as coefficient of friction (COF) and transfer film formation, were investigated by varying surface texture and roughness features during sliding of Ultra High Molecular Weight Polyethylene (UHMWPE) pins against steel plates using an inclined pin-on-plate sliding tester. The roughness of the textures was quantified using optical profilometer. Scanning Electron Microscope was utilized to characterize the fracture features on the pin surface and transfer film formation on the plate surface. Results showed that the COF is significantly depend on surface texture when compared to surface roughness (Ra) of the harder steel material. The transfer film formation is found to depend on the COF. Detailed analysis of friction components, namely adhesion and hysteresis, demonstrated that the effect of surface texture on the COF and transfer film formation was attributed to the variation of the hysteresis friction component. The variations in hysteresis friction with surface texture is attributed to the nature of constraints imposed by the surface textures at the asperity level during sliding conditions.