Influence of geometry and crystal structures of TiO2 nanotubes on micro Vickers hardness

We formed various TiO2 nanotube layers by anodizing Ti metal under various conditions of anodization temperature and time. By controlling these conditions, we could adjust the morphology of the TiO2 nanotubes in terms of length and wall thickness. Subsequent annealing converted the TiO2 nanotubes into crystallized nanostructures. TiO2 nanotubes of different crystalline phases had different mechanical properties. To evaluate the mechanical properties of the TiO2 nanotubes in detail, they were subjected to Vickers hardness testing. The TiO2 nanotube layers showed wide variations in hardness depending upon the anodization and annealing temperatures.