| AVS 59th Annual International Symposium and Exhibition | |
| Tribology Focus Topic | Tuesday Sessions |
| Session TR-TuA |
| Session: | Molecular Origins of Friction and Wear |
| Presenter: | A.A. Pitenis, University of Florida |
| Authors: | A.A. Pitenis, University of Florida B.A. Krick, University of Florida J.J. Ewin, University of Florida W.G. Sawyer, University of Florida |
| Correspondent: | Click to Email |
Polytetrafluoroethylene (PTFE) is an excellent candidate material for solid lubrication applications due to its low friction coefficient and chemical inertness; however, its use is limited due to its high wear rate. Unfilled PTFE is known to suffer from subsurface crack propagation and subsequent delamination during sliding. To combat this high wear mode, fillers of various sizes have been added to a PTFE matrix to increase the wear resistance by typically one or two orders of magnitude by fracture toughening and load support mechanisms. Nanocomposites are the state of the art in ultra-low wear performance in fluoropolymer systems; polymer blends have been shown to achieve nearly zero wear with wear rates below 1 x 10^-8 mm^3/Nm. These low wear rates are consistently accompanied by visually distinct tribofilms at the interface of the bulk material and counterface. Experiments suggest that a combination of mechanical and tribochemical mechanisms are responsible for the development of these tribofilms and consequent ultra-low wear behavior.