A study on the friction and wear behavior of polytetrafluoroethylene filled with potassium titanate whiskers

The friction and wear behavior of polytetrafluoroethylene (PTFE) filled with potassium titanate whiskers (PTW) was studied. It is shown that the friction coefficient of PTW/PTFE composites decreases with the increase of PTW content and with 20 wt% PTW content, the best wear resistance occurs, which is over 1000 times larger than that of pure PTFE. The crystallization of the composite was measured by differential scanning calorimeter (DSC). It reveals that PTW has the ability of inducing heterogeneous nucleation. The degree of crystallization increases initially up to 35 wt% PTW content and then it decreases slightly afterwards. At 35 wt% PTW, the composite has the highest degree of crystallization which is 37% higher than that of pure PTFE. The relationship between the degree of crystallization and the wear behavior was also analyzed which reveals the effect of PTW on PTFE. It is also manifested that the increase of crystallization improves the wear property. Finally, the image of abrasive dust and the worn surface were investigated by optical microscope and SEM, respectively. These observations show that the PTW has the ability to reduce wear by preventing the destruction of PTFE's strap-like structure. (c) 2006 Elsevier B.V. All rights reserved.