Corrosion behavior of single- and poly-crystalline dual-phase TiAl-Ti3Al alloy in NaCl solution

作者：Wang, Dongpeng^*; Chen, Guang; Wang, Anding; Wang, Yuxin^*; Qiao, Yanxin; Liu, Zhenguang; Qi, Zhixiang; Liu, Chain Tsuan

来源：International Journal of Minerals Metallurgy and Materials, 2023, 30(4): 689-696.

DOI：10.1007/s12613-022-2513-5

• titanium alloy
• single crystal
• corrosion
• X-ray photoelectron spectroscopy

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 similar to 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.

• 单位
  南京理工大学; 东莞理工学院; 江苏科技大学