The Role of PTFE Lubricant Additives in Enhancing Rolling Contact Fatigue Life

ABSTRACTRolling contact fatigue (RCF) is the default mode of failure observed in Hertzian rolling contact elements, such as bearings. Experimentally, the current study examines the influence of the existence of solid lubricant dispersed in liquid base lubricant on RCF life. Polytetrafluoroethylene (PTFE), a solid lubricant additive, is selected for this purpose, and the RCF performance of varying percentages of PTFE (0.1–2.5 wt%) on the base lubricant has been examined. RCF tests were carried out on a two‐disc on‐cylinder test rig under pure rolling conditions within the mixed lubrication regime. The RCF life was enhanced for every concentration of PTFE‐added lubricant composition. The base lubricant containing 2 wt% PTFE concentration exhibits the highest improvement in mean and L10 RCF life, yielding a 2.3‐fold increase in improvement over the base lubricant. The excellent RCF performance is attributed to the decreased wear rate, PTFE particle adsorption and tribo‐chemical film formation, and there is a decreased likelihood of metal‐to‐metal contact and a delayed onset of micropitting.