Background: The properties like high strength to weight ratio and superior corrosion resistance made Ti-6Al-4V as one on the most sorted alloy among titanium alloys for the manufacturing of orthopedic and other implants. Despite these characteristics, it is accompanied by disadvantages like lower wear resistance, release of metal ions due to degradation of passive oxide layer present on the alloys causing allergic reaction to patients. This limits their application to non-articulating joints and long-term stability of the simplant is uncertain. Surface modifi-cation through different techniques is considered as viable solution to overcome the above limitations.Method: Surface modification in the present study is carried out using thermal oxidation technique. Titanium dioxide (TiO2) layers were synthesized over the surface of Ti-6Al-4V substrate using thermal oxidation technique. The polished Ti-6Al-4V substrates were subjected to oxidation for 24 h at a temperature of 650 degrees C in a muffle furnace. The specimens are then brought to room temperature using furnace cooling, air cooling and oil cooling. The resultant oxide layers were characterized for surface morphology, oxide layer thickness, crystalline phase, chemical composition, wettability, surface texture, hardness, and adhesion strength.Results: The sample subjected to oil cooling had least Sa of 0.107 mu m and highest contact angle of 118.64 +/- 2.53 degrees leading to hydrophobicity. The furnace and air-cooled samples had similar Sa of 0.135 mu m and 0.134 mu m leading to contact angles of 78.28 +/- 1.56 degrees and 84.11 +/- 1.51 degrees which are hydrophilic in nature. The surface of the oil -cooled samples is dominated by TiO2 when compared to other oxides. The adhesion strength of the oxide layers developed was investigated by using single point progressive scratch test. The influence of surface texture, chemical nature on hydrophilicity and adhesion strength were examined.
