Anodic oxidation of Ti–13Nb–13Zr alloy in silicate solutions

Investigations on the surface modification of Ti–13Nb–13Zr alloy by anodic oxidation are reported here. The oxidation process was carried out in a solution containing K2SiO3 and KOH. The anodising was conducted at voltages of 100, 200 and 400 V. The morphology, chemical composition, and phase composition of the treated Ti–13Nb–13Zr alloy were investigated using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). It was found that the morphology of the samples surface did not change during the alloy oxidation at 100 and 200 V. It was observed that during the anodic process under sparking discharge conditions, the simultaneous incorporation of silicon in the forming oxide layer occurs. An application of 400 V led to the incorporation of silicon into the formed oxide layer and significant modification of the surface morphology. The formed coatings are typical of the plasma electrolytic oxidation process, and they include a considerable amount of incorporated silicon, which is present as SiO2.