Electrochemical behavior of novel Ti-Al-Mo-Zr alloys in fluorine-containing solution

Novel titanium alloys Ti-5Al-2Mo-1V-1Zr-1Cr-1Nb (Ti-1) and Ti-5Al-2Mo-2V-2Zr-2Cr-1Nb (Ti-2) were systematically investigated in terms of their microstructural evolution under different heat treatments in both neutral and acidic fluoride-containing environments. The microstructures were characterized using Electron Backscatter Diffraction (EBSD), while corrosion resistance was evaluated through a series of electrochemical tests and X-ray photoelectron spectroscopy (XPS). The results demonstrated that water quenching specimens exhibited finer grains, higher dislocation densities, and stronger crystallographic textures, which facilitated the formation of uniform passive films and improved corrosion resistance. F - ions significantly damaged the passive films, causing rapid dissolution and intensifying corrosion reactions. Electrochemical noise (EN) analysis combined with the Hilbert-Huang Transform (HHT), revealed high-frequency and high-amplitude transients. These transients reflected the multi-stage localized corrosion processes, such as film rupture and pit initiation. These findings provide valuable insights into the study of titanium alloy design and monitoring electrochemical behavior in extreme environments.