Bio-tribological properties of UHMWPE against surface modified titanium alloy

In order to improve the tribological properties of UHMWPE sliding against Ti6Al4V alloy, three different methods were applied to modified the alloys surface, namely two-step plasma immersion ion implantation, thermal oxidation (TO) and laser surface texturing (LST). Structure and wettability of surface modified titanium alloy were investigated. Friction and wear properties of UHMWPE sliding against modified alloys were tested by a pin-on-disc tribometer under distilled water and bovine serum respectively. The results showed that a graded titanium oxide–titanium nitride film and a titanium oxide film formed separately after being treated by ion implantation and TO, thus contributing to the improvement of wettability of alloy surfaces. The friction coefficients of modified Ti6Al4V alloys decreased obviously, especially for the TO-treated one, which reached as low as 0.015. The wear rate of UHMWPE was reduced and the lowest wear rate was obtained when sliding against the ion implanted one. Almost no notable wear features presented on the titanium alloy treated by ion implantation.

► Ti6Al4V alloys were modified by two-step ion implantation, TO and LST.
► New layers formed on the alloys and increased the wettability.
► The friction coefficients decreased obviously when sliding against modified alloys.
► The lowest wear factor of UHMWPE was obtained when sliding against ion implanted alloy.
► Almost no wear trace was visible on ion implanted alloys.