Fabrication of polytetrafluoroethylene-carbon nanotube composite coatings for friction and wear reduction

Polytetrafluoroethylene (PTFE) matrix with inherently low friction was prepared in the form of a coating and reinforced with carbon nanotubes (CNTs) to enhance its wear resistance. PTFE-CNT composite coatings with various CNT contents were deposited on silicon (100) substrates by spin coating followed by a heat treatment process. The effects of cooling rate during the heat treatment process on the morphology, mechanical properties as well as friction and wear behavior of the coatings were investigated under different loading conditions. It was revealed that the slow-cooled PTFE-CNT composite coating containing 1 wt% and 5 wt% CNT had the highest wear resistance with respect to the applied normal load. The overall experimental results demonstrated that, in comparison to pure PTFE coating, the friction and wear behavior of PTFE-CNT composite coatings could be improved by incorporating an optimum amount of CNT in the PTFE matrix and performing the heat treatment under a specified condition. POLYM. COMPOS., 39:E710-E722, 2018. (c) 2016 Society of Plastics Engineers