Investigation On The Friction And Wear Properties Of Carbon Material Filled PTFE Composites

PTFE has many excellent properties such as self-lubrication, low frication, chemistry stabilization and thermal stabilization but its wear resistance is very low , to improve the wear resistance of PTFE have been down by means of adding fillers to it, In this paper, PTFE and PTFE composite with graphite, carbon fiber and carbon tube with various ratios respectively have been obtained by compression molding experiment. Study was made to question above problem. The dry sliding wear properties of PTFE composites filled with carbon material were tested on the model MM-200 tester.Under the condition of dry friction, a systematic study has been done on the weight loss and the friction coefficient of composites and the relations between the load, the content and the diameter and fillers. Scanning Electron Microscopy(SEM) was employed to examine the worn surfaces.The results show that an increase of the load led to decrease of wear resistance, friction coefficient decrease. With the increase of content, the wear resistance of PTFE composites upgrade and best wear-resistance was obtained with 7% soft carbon and carbon fiber, 10% hard carbon. The friction coefficient of PTFE composites increase slightly. When the content is same, the carbon black exhibited better performance than carbon nano-tube, hard carbon, carbon fiber, soft fiber and graphite. It was also found that the composites with nano-graphite exhibited better wear resistance than with usual filler, but carbon black, nano- filler is poor.The wear mechanism changes with the change of the wear system parameters, such as the properties, content and load. Adhesive wear serious when load increase. The adhesive wear is the main abrasion mechanism when the content of filling is low. With the increase the content of filler, the wear mechanism transit from adhesive wear to abrasion wear. The composite filled with graphite, the main abrasion mechanism is cutting, with carbon black and carbon nano-tube is adhesive, the wear mechanism for the composite with carbon fiber , hard carbon and soft carbon is adhesive wear and cutting .With the increase of filling ,the hardness of composite is increase, carbon tubes is the...