The Effect of Test Parameters on Friction and Wear Performance of PTFE and PTFE Composites

The friction and wear properties of pure poly-tetra-fluoro-ethylene (PTFE), 35% carbon filled poly-tetra-fluoro-ethylene (PTFE+35%C), and 17% glass fiber-reinforced polytetra- fluoro-ethylene (PTFE+17% GFR) sliding against stainless steel under dry sliding conditions were studied by using a pin-on-disc tribometer. The effect of applied pressure and sliding speed on tribological properties of the polymer-stainless steel combination under dry sliding conditions was investigated. Tests were carried out at sliding speeds of 0.32, 0.64, 0.96, 1.0, 1.5, and 2.0 m/s and under applied pressures of 0.17, 0.34, 0.68, 1.02, 1.76, 3.53, 5.30, and 7.07 MPa. Optical microscopy was utilized to examine the worn surfaces of pure PTFE and it's composite. The results indicated that, for pure PTFE, carbon-filled PTFE and glass fiber-reinforced PTFE composites are used in this investigation; the friction coefficient decreases with the increase in applied load values. The maximum reduction in wear rate was obtained by glass fiber-reinforced PTFE composite. The specific wear rate for pure PTFE, carbon filled PTFE composite, and glass fiber-reinforced PTFE composite were in the order of 10(-13), 10(-14), and 10(-15) m(2)/N, respectively. The wear mechanism include adhesive and abrasive processes