Investigation of the Tribological Behavior of TiAl6V4 for Bio-application.

Titanium alloys are encouraging materials as bone implantations in medical operations due to their interesting performances. However, wear debris engendered by wear was found to be the biggest handicap in terms of implant longevity. On the other hand, the biological environment has been considered to impact the tribological response. In this context, this work investigated the effect of the lubrication on the tribological response of the TiAl6V4/TiAl6V4 couple using a pin-on-disk tribometer. Thus, four various bio-lubricants were used: the physiological solution (NaCl 0.9%), nigella and sesame natural oils and Hyalgan® (sodium hyaluronate) used for the treatment of osteoarthritis (OA). The results displayed an enhancement in the friction and wear behaviors of the TiAl6V4/TiAl6V4 pair in the presence of natural oils. The analyses of the chemical structure of natural oils in terms of the unsaturations number (UN) suggest the existence of a dependency between the oil chemical structure and the wear resistance. The wear mechanism of the titanium alloys is governed by the continuous wear process of the formed and re-formed thin oxide layer on the metallic surface. It is found that the change of wear mechanism with the use of oils is mainly linked to their structure. In fact, natural oils have the ability to generate a dense lubricating layer on the metallic surface which will reduce wear. [ABSTRACT FROM AUTHOR]