Influence of SiO2/MoS2/graphite content on the wear properties of PTFE composites under natural seawater lubrication

Abstract

The polytetrafluroethylene (PTFE) mixed with different particles, such as SiO2, MoS2, and graphite, were prepared by using cold briquetting and hot sintering technologies. In order to investigate the influence of different mixture ratios of particles on the wear properties of PTFE composite under natural seawater lubrication, 10 different samples were designed through orthogonal test table and evaluated using an MMU-5 G wear tester. For comparison, the wear experiments of pure PTFE were also carried out under the same conditions. Moreover, the 3D profiles and depth variations of wear scars of PTFE composites were observed by a laser scanning confocal microscope. Results showed that the addition of SiO2, MoS2, and graphite can greatly improve the wear resistance of PTFE under seawater lubrication. In particular, 10% SiO2, 15% MoS2, and 15% graphite filled with PTFE composite possesses the best wear resistance. And a synergistic effect is found for the combination of SiO2, MoS2, graphite, and seawater, which effectively prevents the slipping of PTFE from matrix, increases the adhesion resistance, decreases the friction energy, further results in lower wear rate and little damage on the surface of the PTFE composites.