Fabrication and mechanical properties of anodized zirconium dioxide nanotubular arrays

A series of highly ordered ZrO2 nanotubular arrays with different thickness was synthesized by changing the anodization voltage or anodization period. The thickness of the nanotubular arrays depended on the anodization voltage and anodization period. Openings of the tubular structure were only slightly affected by the anodization voltage. Microindentation tests demonstrated that the apparent Young's modulus, ratio of elastic energy to the total deformation energy and hardness decreased as the thickness of the nanotubular array films increased due to densification and collapse of longer nanotubes under external force. Resistance of nanotubular arrays to sliding wear was evaluated in different cultures. Wear loss, which was proportional to the width of the wear track, significantly decreased in water compared with that in air. The pH values of solutions slightly affected the width of the wear track of the ZrO2 nanotubular arrays. The results showed that wear loss of the ZrO2 nanotubular arrays and friction force on the ZrO2 nanotubular arrays decreased with increasing pH from 2.5 to 13.