Research on the tribological performance of Cr2O3 filled with bronze‐based PTFE composites

Abstract

ABSTRACTEnhancement of the wear resistance of bronze‐filled polytetrafluoroethylene (PTFE) composites has been achieved using various fillers, for example, chromic oxide (Cr2O3), molybdenum disulfide (MoS2), graphite, and nanometer aluminum oxide (n‐Al2O3), in the present study. The wear resistance was evaluated by a block‐on‐ring wear tester, and the effects of fillers on the wear resistance as well as the mechanism were investigated. The wear rate for the composite where the recipe containing 59% PTFE + 40% bronze + 1% Cr2O3 was 0.5 × 10−5 mm−3/N m and for the composite in the recipe containing 60% PTFE + 40% bronze was 4.2 × 10−5 mm−3/N m, which meant that that Cr2O3 increased the wear resistance by approximately 10 times. The differential scanning calorimetry measure analysis showed that Cr2O3 had a positive effect on the crystallization of PTFE; the crystallinity of PTFE composites increased from 45% to 52%, which exhibited improved wear resistance. Wear testing and scanning electron microscope analysis had shown that Cr2O3 had a positive effect on the formation of transfer film and keeping it stable to exhibit improved wear resistance. X‐ray photoelectron spectroscopy results also showed that Cr2O3 was effective in tribochemical reactions during sliding against stainless ring; these maybe responsible for forming transfer film and lowering wear rate of composite. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41117.