Abstract
Summary: Wear behavior correlations with morphology have been established from polytetrafluoroethylene (PTFE) drawn at 200, 327, and 375βΒ°C with draw ratio about 4. The friction coefficient and wear rate for PTFE drawn at 327βΒ°C are lower and the wear rate is lower than that of undrawn PTFE by about 30%. The structures of samples were characterized by scanning electron microscope (SEM), DSC, and wide angle Xβray diffraction (WAXD). Results indicate that the debris morphologies of samples are different. The differences in the tribological behavior of undrawn and drawn samples were attributed to the improvement of the degree of the crystalline, fibrillation, and orderliness by drawing, especially, for PTFE drawn at 327βΒ°C. The orderliness of molecular arrangement along the drawn direction is also higher for PTFE drawn at 327βΒ°C than those of PTFE drawn at 200 and 375βΒ°C, respectively. Therefore, the intensity of covalent bond along drawn direction is higher. The shear resistance and the deformability of the material are greatly improved and the size of the wear breakage unit decreases, which results in a good tribological property for PTFE drawn at 327βΒ°C.
SEM morphology of fractured surface perpendicular to the draw direction for PTFE drawn at 327βΒ°C.
magnified imageSEM morphology of fractured surface perpendicular to the draw direction for PTFE drawn at 327βΒ°C.