Properties of PTFE Composites Modified with Surface Treated SiC Fiber

SiC short fiber(as-received and treated with couple agent) strengthened polytetrafluoroethylene(PTFE) composites were prepared through mixing and cold pressing.The mechanical,friction and wear properties of the composites were tested.The effects of the surface treatment on the performance of the composites were investigated.The fracture surfaces by tensile stress were observed by using a scanning electron microscope(SEM).The strengthen mechanism for the composites was proposed.The results indicated that the tensile strength,impact strength,and friction and wear properties of the composites with surface treated SiC fiber are higher than those with as-received SiC fiber.SEM observation of fracture surfaces showed that poor bonding interface with gaps between untreated SiC fiber and the PTFE matrix is responsible for the lower performances of the corresponding composites.The couple agent surface treated SiC fiber has a strong adhesion with PTFE so that less SiC fiber were pull out during tensile process.