Electrochemical polishing of Ti–13Nb–13Zr alloy

This work presents the results of the investigations on electropolishing of the Ti–13Nb–13Zr titanium alloy. The electropolishing was conducted in the solution containing ammonium fluoride and sulfuric acid. The influence of electropolishing process parameters on the texture (AFM, SEM) and chemical composition (EDX, XPS) of the surface layer was established. The Ti–13Nb–13Zr alloy after the electropolishing is covered with a thin layer composed mainly of titanium, niobium and zirconium oxides. Electrochemical impedance spectroscopy in 5% NaCl solution was used for the determination of the corrosion resistance of the alloy. The application of the electropolishing increases the corrosion resistance of the Ti–13Nb–13Zr alloy significantly. The increase of the corrosion resistance of the alloy is connected with the smoothing of the surface and with the formation of Ti, Nb and Zr oxides layer on the surface.