Did You try the electrodeposition method?

Thin coating of TiO2 (a few nanometers) on titanium substrates, there is always - it is formed automatically and almost instantly on contact with the titanium air at normal temperatures. Only through this natural titanium coating exhibits high corrosion resistance. When heated titanium TiO2 layer becomes thicker (up to tens of micrometers at 500-600 ° C). This thick, porous coating bounces off the substrate, so above 600 ° C is rapidly oxidized titanium.