In-situ tribometry for understanding the near ultralow wear of neat PTFE

K. K. Yap; M. Masen

Society of Tribologists and Lubrication Engineers (2023)

Despite the low friction, the notoriously high wear rate of polytetrafluoroethylene (PTFE) makes it unsuitable as a tribomaterial in its neat form. This contribution investigates the possibility of PTFE achieving an ultralow wear rate (< 10-6 mm3/ Nm) without the aid of fillers. Two in-situ pin-on-disc tribometry techniques, namely spatiotemporal mapping and optical microscopy, are used to study the transfer and wear mechanisms of PTFE when slid against AISI 304. Results demonstrate that a near ultralow wear rate as low as 2×10-6 mm3/Nm can be realized simply by pre-oxidizing the metal counterface. The authors are currently working on measuring the height profiles of PTFE transfer lumps in real time using in-situ digital holographic microscopy. Preliminary results show that the refractive index of these lumps is not constant, which contradicts the common practice in polymer tribology, which assumes a constant refractive index. DOI: