Nanotube Formation on Ti-15Zr-4Nb-4Ta by Anodic Oxidation

Abstract

Surface morphology and composition of anodized Ti-15Zr-4Nb-4Ta alloys with nanotube were examined by using X-ray diffractometry and analytical scanning electron microscopy. The Ti alloy consisted of α and β phases. Anodizing to form nanotube on the Ti alloy was carried out using electrolyte of 0.2 wt.% NH4F and 2 Vol.% H2O in ethylene glycol under different potential at from 30 to 60V. SEM observation showed that nanotubes were vertically aligned on surface of the Ti alloy. Inner diameter of these nanotubes varied from 45 to 127 nm with increasing applied potential to the specimen from 30 to 60 V. Surface of the Ti alloy with nanotube was ragged due to the difference in dissolution rate of the internal structure of α and β phases.