Electrodeposition, Characterization, and Corrosion Stability of Nanostructured Anodic Oxides on New Ti-15Zr-5Nb Alloy Surface

الملخص EN

A new Ti-15Zr-5Nb alloy with suitable microstructure and mechanical properties was processed by galvanostatic anodization in 0.3 M H3PO4 solution and a continuous nanostructured layer of protective TiO2 oxide was electrodeposited.

The obtained anatase oxide layer has a nanotubes-like porosity (SEM observations) and contains significant amount of phosphorus in phosphotitanate compound embedded in the oxide lattice (Raman, FT-IR, SEM, and EDX analysis).

This layer composition can stimulate the formation of the bone and its porosity can offer a good scaffold for bone cell adhesion.

The electrochemical behaviour, corrosion stability, and variations of the open circuit potentials, Eoc, and corresponding open circuit potential gradients, ΔEoc, for 1500 soaking hours in Ringer solutions of 3.21, 7.58, and 8.91 pH values were studied.

The anodized layer was more resistant, stable (from EIS spectra), and was formed from an inner barrier insulating layer that assures the very good alloy corrosion resistance and an outer porous layer that provides the good conditions for cell development.

The nanostructured alloy has higher corrosion stability, namely, a more reduced quantity of ions released and a lower toxicity than that of the bare one.

The monitoring of Eoc and ΔEoc showed the enhancement and stabilizing of the long-term passive state of the anodized alloy and, respectively, no possibility at galvanic corrosion.