Wear Debris Mobility, Aligned Surface Roughness, and the Low Wear Behavior of Filled Polytetrafluoroethylene

• Published in: Tribology letters 2015-10, Vol.60 (1), p.1-8, Article 2
• Main Authors: Harris, Kathryn L., Curry, John F., Pitenis, Angela A., Rowe, Kyle G., Sidebottom, Mark A., Sawyer, W. Gregory, Krick, Brandon A.
• Format: Article
• Language: English
• Subjects: Alignment; Alumina; Aluminum oxide; Chemistry and Materials Science; Composite materials; Corrosion and Coatings; Debris; Materials Science; Matrix composite; Morphology; Nanotechnology; Original Paper; Physical Chemistry; Polymer composite; Polymer matrix composites; Polymers; Polytetrafluoroethylene; Polytetrafluoroethylenes; Protective coatings; PTFE; Reciprocating sliding; Sliding; Sliding direction; Surface morphology; Surface roughness; Surfaces and Interfaces; Theoretical and Applied Mechanics; Thin Films; Third body; Transfer film; Tribo-chemistry; Tribochemistry; Tribological systems; Tribology; Wear; Wear of materials; Wear particles; Wear rate
• ISSN: 1023-8883; 1573-2711; 1573-2711
• DOI: 10.1007/s11249-015-0581-7

PTFE/α-alumina composites are well known to exhibit very low wear rates compared to unfilled PTFE and various other PTFE-matrix composites. The improved wear life of these composites is attributed in part to the formation of a uniform protective transfer film on the metal countersurface. It is postulated that the retention of transferred material and the recirculation of third bodies between the transfer film and running surface of the polymer composite are necessary for the maintenance of low wear within this tribological system. The accumulation of these third bodies was observed in reciprocating sliding tests on countersamples prescribed with aligned roughness. Wear performance of the polymer composite was tested as a function of the between the sliding direction and the aligned roughness of the countersample, ranging from parallel to perpendicular to the sliding direction. The wear rate of roughness oriented with the sliding direction was 300 times higher than roughness perpendicular to the sliding direction, revealing the importance of surface morphology and third body retention.