Tribological properties of Ti-based alloys in a simulated bone–implant interface with Ringer’s solution at fretting contacts

The wear properties of oxidized and non-oxidized gamma-TiAl (a potential biomaterial) as well as Ti–6Al–4V and CP-Ti disks were studied and characterized by means of standard wear tests using a custom made bone pin arrangement. The Ti-based disks were oxidized in air at 500 and 800 °C for one hour. The tribological properties of the oxides formed over the disks were studied using a linear reciprocating wear testing machine under both dry and simulated biological conditions using Ringer’s solution. Loss of metal oxide and coefficient of friction values were determined from wear testing. From the results, abrasion and adhesion were the primary wear mechanisms in each of the three alloy–bone pairs. Specifically, the oxide formed on gamma-TiAl possessed the highest COF and wear resistance of the three materials which were studied. Also, as expected, bone wears down faster than the Ti-based metal oxide.

Research highlights
► Oxidized gamma titanium aluminide surfaces show high COF values against bone pins.
► Abrasion appears to be dominant mechanism in wear of oxidized Ti alloy surfaces.
► Oxide removal is greater in lubricated medium.
► Oxidized gamma titanium aluminide shows excellent wear reistance to bone.