Effect of Counter-Surface Texturing on the Tribological Behaviour of Virgin and Glass-Filled PTFE Sliding Against Grey Cast Iron

In this research study, effect of laser surface texturing on the tribological performance of composite of polytetrafluoroethylene with 25 wt.% glass fibre against grey cast iron. Dimples (50 µm diameter) were ablated on GCI with dimple pitches of 100 µm and 150 µm. Friction and wear tests were conducted on a pin-on-disc tribometer under ambient conditions. Specific wear rate of both PTFE and its composite generally decreased with increasing sliding distance for all GCI surfaces, whether textured or untextured. The coefficient of friction (COF) followed a similar trend for PTFE but increased for 25 wt.% glass fibre/PTFE on textured GCI surfaces. Compared to untextured GCI, PTFE exhibited a 14.2-16.7% reduction in COF and specific wear rate when sliding against GCI with a 150 µm dimple pitch. For 25 wt.% glass fibre/PTFE, LST increased friction but significantly reduced specific wear rate by 66.6-73.2%.Increasing the dimple pitch from 100 µm to 150 µm further decreased COF and wear. FESEM micrographs of textured GCI surfaces post-sliding against PTFE revealed polymer debris deposition, forming transfer films that contributed to friction and wear reduction. These findings highlight the potential of LST in enhancing the tribological performance of PTFE-based materials, particularly in optimizing wear resistance and friction control through surface texturing.