|Cite this article as:|
|Dongpeng Wang, Guang Chen, Anding Wang, Yuxin Wang, Yanxin Qiao, Zhenguang Liu, Zhixiang Qi, and Chain Tsuan Liu, Corrosion behavior of single- and poly-crystalline dual-phase TiAl-Ti3Al alloy in NaCl solution, Int. J. Miner. Metall. Mater.,(2022). https://doi.org/10.1007/s12613-022-2513-5|
To clarify the correlation of single-crystalline structure with corrosion performance in high-strength TiAl alloys, electrochemical and surface characterization was performed by comparing Ti-45Al-8Nb dual-phase single crystals with their polycrystalline counterparts in NaCl solution. Polarization curves show a lower corrosion rate and a higher pitting potential of ~280 mV for the dual-phase single crystals. Electrochemical impedance spectroscopy and potentiostatic polarization plots revealed a higher impedance of the charge transfer through the compact passive film. Surface composition analysis indicated a compact film with more content of Nb, as twice as that in the film on the polycrystals. Our results reflect that the dual-phase Ti-45Al-8Nb single crystals possess a higher corrosion resistance in NaCl solution, compared with their polycrystalline counterpart, arising from a more homogeneous microstructure and composition distribution.