Surface engineering to improve tribological performance of Ti–6Al–4V

A series of thermal oxidising treatments has been carried out on Ti–6Al–4V alloy at temperatures ranging from600 to 850°C to develop a new surface engineering technique for Ti–6Al–4V and other titanium alloys. Systematic characterisation of the thermal oxidation treated surface layers was performed using GDS, XRD, SEM, and nanoindentation testing. Ball on disc friction tests show that the coefficient offriction of a Ti–6Al–4V disc against an alumina ball was significantly reduced after oxidation treatment. The rolling–sliding wear resistance of Timetal 6–4 material against hardened 709M40 steel under lubricated conditions has been increased by thermal oxidation (TO) treatment to such an extent that it is even superior to that of the steel counterpart. The results also show that the electrochemical corrosion resistance in 3%NaCl solution isimproved by proper TO treatment.