Influence of Cr addition on microstructure evolution and corrosion behavior of the Ti[sbnd]Zr alloys

The microstructure and corrosion behavior of novel Ti-Zr-Cr alloys were investigated. All Ti-Zr-Cr alloys were consisted of α and (TiZr)Cr2 phase, and the results of EDS indicated that a certain amount of Ti were dissolved in ZrCr2 phase. The detailed XPS analysis were conducted to investigate the chemical composition of the passive film, and revealing the existence of protective TiO2, ZrO2 and Cr2O3 as well as a tiny amount of and Ti(OH)4, Zr(OH)4 and Cr(OH)3. The results of AFM and contact angle test indicated that the roughness and hydrophilicity of the surface of the examined Ti-Zr-Cr alloys decreases with the addition of Cr. Potentiodynamic polarization and EIS analysis indicated that the addition of Cr enhanced the corrosion resistance owing to the formation of protective passivation film. The semi-conductive properties of the passive film were evaluated by means of Mott-Schottky curves, and the result showed that the passive film was tend to be more dense and less defective with the increasing content of Cr. The results of the present study suggest that the addition of Cr may be one of extremely effective ways to enhance the corrosion resistance of the Ti50Zr50 alloy. © 2021 Elsevier Inc.