Surface characteristics and corrosion behavior of Ti–Al–Zr alloy implanted with Al and Nb

Abstract Ti–Al–Zr alloys were implanted with Al and Nb to doses ranging from 1 × 10 17 to 1 × 10 18 ions cm −2 . The valence states of element on the sample surfaces were analyzed by X-ray photoelectron spectroscopy (XPS). Glancing angle X-ray diffraction (GAXRD) was employed on the as-implanted specimens to understand phase formation. X-ray diffraction (XRD) measurement revealed α-Ti on Al-implanted samples and (α + β)-Ti on Nb-implanted samples. The tendency was observed in increasing corrosion resistance from α- toward (α + β)-phase. In deaerated 5 M HCl, the ion-implanted Ti–Al–Zr surface containing Nb-stabilized β-phase was spontaneously passive, while Al-implanted surface displaying an active/passive behavior. In the aerated solution with pH = 10, all the implanted surfaces are passive. Enhanced reoxidation was confirmed on implanted surfaces by Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS) analysis. The corrosion in the solution with pH = 10 was governed by a predominantly TiO 2 surface film. The cathodic kinetics was seen to affect the corrosion behavior in 5 M HCl.