GROWTH MECHANISM OF TiO2 NANOTUBES ON THE Ti-6Al-4v SURFACE

: Present paper deals with investigation of the mechanism of TiO 2 nanotubes growth on titanium surface during anodization process. The samples were made of Ti-6Al-4V alloy. They were grinded, etched with 0,5 wt. % HF acid and anodized. The anodization was done in electrolyte containing 0,5 wt. % HF acid using DC power supply with graphite electrode as cathode. The samples were investigated by SEM, EDAX and XRD analysis. The results show that after 5h anodization the regions with nano-roughness as well as the regions with nanotubes with average internal diameter 102nm exist on the surface of the Ti-6Al-4V alloy sample. The field-enhanced oxidation and field-enhanced dissolution are the main processes for TiO 2 nanotubes formation during anodization. The surface micro-roughness influences on the processes running rate in different micro-regions determining origination of the titanium nanotubes on different stage and by different mechanism as well.