Surface Characteristics of Nanotube Formed Ti–25Nb–xZr Alloys.

The purpose of this study was to investigate surface characteristics of nanotube formed Ti–25Nb–xZr alloys. Ti–25Nb–xZr ternary alloys with 0–15 wt% Zr were manufactured in a vacuum arcmelting furnace. Ingots of the alloys were homogenized in an Ar atmosphere at 1000 °C for 12 h, followed by quenching in ice water. Nanotube layers were formed by an electrochemical method in 1 M H₃PO₄ and 0.8 wt% NaF at 30 V for 1 h. As the Zr content of the Ti–25Nb–xZr Alloys increased, the crystals transformed from a needle-like to equiaxed structure. Two nanotube sizes were obtained on the Ti–25Nb–xZr alloys. As the Zr content was increased, the diameters of the larger tubes decreased, whereas those of the smaller tubes increased. However, increased Zr content in the Ti–25Nb–xZr alloys had little effect on wettability.