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Tribological characterization of nanoparticle filled PTFE: Wear-induced crystallinity increase and filler accumulation

2021; Budapest University of Technology and Economics; Volume: 15; Issue: 10 Linguagem: Inglês

10.3144/expresspolymlett.2021.78

1788-618X

Levente Ferenc Tóth, Gábor Szebényi, Jacob Sukumaran, Patrick De Baets,

Fiber-reinforced polymer composites

The present research aims to clarify the friction and wear behavior, the transfer layer formation, and the wear mechanism of mono-filled polytetrafluoroethylene (PTFE).A well-known limitation of PTFE is the low wear resistance, which can be surpassed with the use of micro-or nanoparticles.The applied fillers were graphene, alumina (Al 2 O 3 ), boehmite alumina (BA80), and hydrotalcite (MG70).The samples were produced by room temperature pressing -free sintering method.All specimens were tested with a pin-on-disc tribo-tester in dry contact condition against 42CrMo4 steel disc counterface with 3 MPa contact pressure and 0.1 mm/s sliding speed.PTFE filled with 4 wt% Al 2 O 3 achieved the highest wear resistance; the increase was more than two orders of magnitude compared to the neat PTFE.This improvement comes from the protective transfer layer formation due to the Al 2 O 3 and the iron-oxide accumulation on the polymer contact surface.Significant wear-induced crystallinity was also registered, which originated from the mechanical chain scission of the PTFE molecular chains during the wear process.