Hardness and Friction Coefficient Analysis of Electrochemically Anodized Ti-6Al-4V

Electrochemical anodization was performed for surface modification of Ti-6Al-4V, using an HCl-based electrolyte. The effect of increasing the electrode spacing of the electrochemical cell by 1, 2, and 2.5 cm on the hardness and COF was investigated. Using a 0.5 M solution of HCl and glycerol in different percentages (85, 90, and 95 %), a voltage of 30 V and a time of 5 minutes. The results revealed the growth of nanotubular structures, which contribute to the increase in hardness, obtaining a maximum of 7.1 GPa for the anodized samples and the reduction of COF to a minimum of 0.5. While the heat-treated samples increased their microhardness up to 10.25 GPa.