Influence of Nb addition on the corrosion behavior of a Ti60Zr10Si15Ta15 alloy in PBS solution

Abstract

The Ti60 Zr10Si15Ta15‐xNbx (x = 0, 3, 7, 11 at.%) alloys were casted by an arc melting method, and the Ti60Zr10Si15Ta15 ribbon was prepared by the single roll melt‐spinning method. The identifications of the microstructure of the Ti alloys were carried out by X‐ray diffraction (XRD) instruments. The effects of the Nb addition on the corrosion behavior of the Ti60 Zr10Si15Ta15‐xNbx (x = 0, 3, 7, 11 at.%) alloys in phosphate buffer solution (PBS) were investigated using electrochemical polarization and electrochemical impedance spectroscopy (EIS) tests. It was found that the microstructure of the as‐cast Ti60 Zr10Si15Ta15‐xNbx (x = 0, 3, 7, 11 at.%) alloys mainly contained β phase, and the as‐spun Ti60 Zr10Si15Ta15 ribbon shows amorphous structure. The crystalline Ti60 Zr10Si15Ta15‐xNbx (x = 0, 3, 7, 11 at.%) alloys and amorphous ribbon all exhibited the passivation characterization with the formation of a stable passive film on their surfaces during the immersion in PBS solution. For the Ti60Zr10Si15Ta15‐xNbx (x = 0, 3, 7, 11 at.%) alloys, the addition of Nb decreased the passive current density, thus the corrosion resistance increased with the Nb content increasing from 0 to 11 at.%. But the as‐spun amorphous Ti60Zr10Si15Ta15 ribbon exhibited the lowest passive current density, which indicated the better corrosion resistance in comparison with the as‐cast Ti60Zr10Si15Ta15‐xNbx (x = 0, 3, 7, 11 at.%) alloys.