Wear Behavior of PTFE–Hydroxyapatite Composite Fabricated by Hot-Press Sintering Process

In the present work, a new biocompatible composite was fabricated by hot-press sinter-bonding of polytetrafluoroethylene (PTFE)–hydroxyapatite composite. Furthermore, the wear properties of this composite were studied by computer-controlled pin-on-disk type tribometer in reporting volume loss per distance. The investigation was performed in three different fractions of hydroxyapatite (10, 20 and 30 wt%). In order to improve the bonding between hydroxyapatite and PTFE, and thus to increase the wear properties of the composite, the effect of adding silane-coupling agent was investigated. Furthermore, to simulate the environment of human body, some of the wear tests were carried out in the ringer’s solution. It was found that the wear resistance is improved at high load. Moreover, an optimum fraction of hydroxyapatite (20 wt%) was found in which the best wear resistance is achieved, especially at dry sliding condition. At last, the roles of the factors such as wear load, ringer’s solution, and silane-coupling agent are described with respect to their influences on the Lancaster wear coefficient.