INVESTIGATION ON WEAR BEHAVIOR OF PTFE/HA COMPOSITE FABRICATED BY HOT-PRESS SINTERING PROCESS

Polytetrafluoroethylene (PTFE) is an biocompatible engineering material. During rubbing or sliding against a hard surface, PTFE exhibits a low coefficient of friction but a high rate of wear. These unique properties of the polymer have encouraged many mechanistic and physical examinations of the processes involved in the friction and wear of this polymer. Many kinds of PTFE-based composites have been produced in order to improve the wear resistance of PTFE. In the present work, a newbiocompatible composite was fabricated by hot press sinter-bonding of PTFE /hydroxyapatite(HA). Furthermore, wear properites of this composite have been studied by computer controlled pin-on-disc type tribometer in reporting volume loss per distance. The investigation has performed in three different percentages of HA(10,20,30 Wt.%). In order to improve the bonding between HA andPTFE, and hence to increase the wear properties of the composite, effect of adding silane coupling agent was investigated. Furthermore, for simulating the environment of human body, some of the wear tests were carried out in ringer solution. Wear resistance was improved at high loads. Moreover,an optimum fraction of HA (20%. wt) was found in which the best wear resistance was achieved,especially in dry sliding. At last, the role of factors such as wear load, ringer solution and coupling agent are described with respect to their influences on the wear rates.

Keywords:

PTFE/HA composite , Silane coupling agent , Ringer solution , Wear behavior