A Combined Experimental and Atomistic Investigation of PTFE Double Transfer Film Formation and Lubrication in Rolling Point Contacts

Abstract Solid lubricants such as polytetrafluoroethylene (PTFE) are used in rolling-element bearings (REBs) when conventional lubrication (i.e. by fluids or greases) cannot be applied owing to extreme operating conditions (e.g. high temperatures vacuum). Often a double transfer film mechanism is with cage acting lubricant reservoir resupplying the REB solid wear. An increase service life of requires better understanding processes sliding and rolling contacts. Here, we investigate effect PTFE resupply on friction formation steel/steel steel/glass contact tribometry classical molecular dynamics (MD). A ball-on-disk tribometer enhanced pin-on-disk that transfers disk. The experiment allows simultaneous situ measurement thickness white light interferometry point contact. Increasing pin load results an increased accompanied significant decrease friction. To elucidate observed mechanism, MD simulations newly developed density-functional-based, non-reactive force field for PTFE-lubricated iron oxide surfaces performed. strong adhesion chains drives formation, whilst shear-induced chain alignment within reduced reveal anti-correlation between coefficient—in agreement experiments. These investigations first step towards methods control REBs. Graphic