Wearing Research of Modified PTFE Materials in Water Pump Bearing

Two kinds of polytetrafluoroethylene (PTFE) composites PTFE/GF/Gr (sample 1) and PTFE/GF/Gr/Cu (sample 2) were prepared by mixed molding method. X-ray diffraction results show that sample 2 is crystal structure, while sample 1 is amorphous/crystal structure. They were processed into the bearing bushes, which were installed on the water pump bearing to study the influence of different structures on friction properties by rotating bearing. Experimental results reveal that the wearing rate of sample 2 is much higher than that of sample 1. From the optical microscope and SEM analysis of the worn surface, it indicates that the wearing mechanism of sample 1 with amorphous structure is adhesive wearing, while that of sample 2 is abrasive and fatigue wearing mechanism. Our results indicate that the PTFE composition with amorphous matrix can be used to sliding bearings because of its ideal self-lubricating properties.