Characterization of Thermally Oxidized Ti6Al7Nb Alloy for Biological Applications

Wear and biological performances of a thermally oxidized Ti6Al7Nb alloy were investigated. Thermal oxidation (TO) performed at 600 degrees C for 60 h in air formed a 0.6 mu m thick and relatively rough (having an average surface roughness of 1.1 mu m) oxide layer (OL) on the surface. The OL was identified as the rutile form of TiO2 and there was an oxygen diffusion zone (ODZ) with an average thickness of 5 mu m just beneath it. The applied TO process resulted in more than ten-fold increase in wear resistance in a simulated body fluid (SBF) solution. Additionally, the biological performance was also enhanced as revealed by SBF immersion and cell culture tests.