Surface morphology and electrochemical behaviour of Ti-48Al-2Cr-2Nb alloy in low-concentration salt solution


Electrochemical machining (ECM) is becoming increasingly important for the efficient machining of parts with a large machining area. This is an addition challenge for ECM because of the very high machining current. To overcome this difficulty, a direct and effective strategy is to adopt the machining mode that uses a low-concentration electrolyte with a low current density. The purpose of this study is to reveal the electrochemical behaviour and surface morphology in low-concentration electrolyte. The polarization behavior of Ti-48Al-2Cr-2Nb is measured by linear sweep voltammetry and cyclic voltammetry curves. The ηω-j curves demonstrate the special dissolution behaviour of Ti-48Al-2Cr-2Nb at low current densities. The surface morphology, surface quality, and dissolution mechanism are analysed in three low-concentration electrolytes at different current densities after the ECM dissolution experiments. The results demonstrate that Ti-48Al-2Cr-2Nb exhibits three unique dissolution morphologies in the three solutions, and we found that the γ-TiAl phase dissolves faster than the α2-Ti3Al phase. These results also show that 1% NaCl solution is more suitable for Ti-48Al-2Cr-2Nb in ECM compared with the other two solutions, considering its good surface quality, low breakdown potential, and high material removal rate. Later, the dissolution process of the sample in 1% NaCl solution at different corrosion times is revealed. Moreover, a dissolution model is proposed for the electrochemical dissolution behaviour of Ti-48Al-2Cr-2Nb in 1% NaCl solution.

This is a preview of subscription content, access via your institution.


  1. 1

    Rajurkar K P, Zhu D, McGeough J A, et al. New developments in electro-chemical machining. CIRP Ann, 1999, 48: 567–579

    Article  Google Scholar 

  2. 2

    Xu Z, Xu Q, Zhu D, et al. A high efficiency electrochemical machining method of blisk channels. CIRP Ann, 2013, 62: 187–190

    Article  Google Scholar 

  3. 3

    Xu Z, Wang Y. Electrochemical machining of complex components of aero-engines: Developments, trends, and technological advances. Chin J Aeronaut, 2019, doi: 10.1016/j.cja.2019.09.016

    Google Scholar 

  4. 4

    Klocke F, Klink A, Veselovac D, et al. Turbomachinery component manufacture by application of electrochemical, electro-physical and photonic processes. CIRP Ann, 2014, 63: 703–726

    Article  Google Scholar 

  5. 5

    Fang X, Qu N, Zhang Y, et al. Improvement of hole exit accuracy in electrochemical drilling by applying a potential difference between an auxiliary electrode and the anode. J Mater Process Tech, 2014, 214: 556–564

    Article  Google Scholar 

  6. 6

    Gu Z, Zhu D, Xue T, et al. Investigation on flow field in electrochemical trepanning of aero engine diffuser. Int J Adv Manuf Technol, 2017, 89: 877–884

    Article  Google Scholar 

  7. 7

    Guo P, Lin X, Li J, et al. Electrochemical behavior of Inconel 718 fabricated by laser solid forming on different sections. Corrosion Sci, 2018, 132: 79–89

    Article  Google Scholar 

  8. 8

    Guo P, Lin X, Xu J, et al. Electrochemical removal of different phases from laser solid formed Inconel 718. J Electrochem Soc, 2017, 164: E151–E157

    Article  Google Scholar 

  9. 9

    Wang D, Zhu Z, Wang N, et al. Investigation of the electrochemical dissolution behavior of Inconel 718 and 304 stainless steel at low current density in NaNO3 solution. Electrochim Acta, 2015, 156: 301–307

    Article  Google Scholar 

  10. 10

    Ge Y, Zhu Z, Wang D. Electrochemical dissolution behavior of the nickel-based cast superalloy K423A in NaNO3 solution. Electrochim Acta, 2017, 253: 379–389

    Article  Google Scholar 

  11. 11

    Xu Z, Chen X, Zhou Z, et al. Electrochemical machining of hightemperature titanium alloy Ti60. Procedia CIRP, 2016, 42: 125–130

    Article  Google Scholar 

  12. 12

    Wang Y, Xu Z, Zhang A. Electrochemical dissolution behavior of Ti-45Al-2Mn-2Nb+0.8 vol% TiB2 XD alloy in NaCl and NaNO3 solutions. Corrosion Sci, 2019, 157: 357–369

    Article  Google Scholar 

  13. 13

    Wang Y, Xu Z, Zhang A. Comparison of the electrochemical dissolution behavior of extruded and casted Ti-48Al-2Cr-2Nb alloys in NaNO3 solution. J Electrochem Soc, 2019, 166: E347–E357

    Article  Google Scholar 

  14. 14

    Sharman A R C, Aspinwall D K, Dewes R C, et al. The effects of machined workpiece surface integrity on the fatigue life of γ-titanium aluminide. Int J Machine Tools Manuf, 2001, 41: 1681–1685

    Article  Google Scholar 

  15. 15

    Liu J, Zhu D, Zhao L, et al. Experimental investigation on electrochemical machining of γ-TiAl intermetallic. Procedia CIRP, 2015, 35: 20–24

    Article  Google Scholar 

  16. 16

    Klocke F, Herrig T, Zeis M, et al. Experimental research on the electrochemical machinability of selected γ-TiAl alloys for the manufacture of future aero engine components. Procedia CIRP, 2015, 35: 50–54

    Article  Google Scholar 

  17. 17

    Wang Y, Xu Z, Zhang A. Anodic characteristics and electrochemical machining of two typical γ-TiAl alloys and its quantitative dissolution model in NaNO3 solution. Electrochim Acta, 2020, 331: 135429

    Article  Google Scholar 

  18. 18

    Kothari K, Radhakrishnan R, Wereley N M. Advances in gamma titanium aluminides and their manufacturing techniques. Prog Aerosp Sci, 2012, 55: 1–16

    Article  Google Scholar 

  19. 19

    Aspinwall D K, Dewes R C, Mantle A L. The machining of γ-TiAl intermetallic alloys. CIRP Ann, 2005, 54: 99–104

    Article  Google Scholar 

  20. 20

    Klocke F, Settineri L, Lung D, et al. High performance cutting of gamma titanium aluminides: Influence of lubricoolant strategy on tool wear and surface integrity. Wear, 2013, 302: 1136–1144

    Article  Google Scholar 

  21. 21

    Hood R, Aspinwall D K, Soo S L, et al. Workpiece surface integrity when slot milling γ-TiAl intermetallic alloy. CIRP Ann, 2014, 63: 53–56

    Article  Google Scholar 

  22. 22

    Bewlay B P, Weimer M, Kelly T, et al. The science, technology, and implementation of TiAl alloys in commercial aircraft engines. MRS Proc, 2013, 1516: 49–58

    Article  Google Scholar 

  23. 23

    Ittah R, Amsellem E, Itzhak D. Pitting corrosion evaluation of titanium in NH4Br solutions by electrochemical methods. Int J Electrochem Sci, 2014, 9: 633–643

    Google Scholar 

  24. 24

    Klocke F, Zeis M, Klink A, et al. Experimental research on the electrochemical machining of modern titanium- and nickel-based alloys for aero engine components. Procedia CIRP, 2013, 6: 368–372

    Article  Google Scholar 

Download references

Author information



Corresponding author

Correspondence to ZhengYang Xu.

Additional information

This work was supported by the National Natural Science Foundation of China (Grant No. 91960204), the Natural Science Foundation for Distinguished Young Scholars of Jiangsu Province (Grant No. BK20170031), and the Fundamental Research Funds for the Central Universities (Grant No. NE2014104).

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Wang, Y., Xu, Z., Zhang, A. et al. Surface morphology and electrochemical behaviour of Ti-48Al-2Cr-2Nb alloy in low-concentration salt solution. Sci. China Technol. Sci. 64, 283–296 (2021).

Download citation


  • electrochemical machining
  • γ-TiAl alloy
  • low-concentration salt solution
  • surface morphology
  • electrochemical behaviour