Welding in the World

, Volume 61, Issue 1, pp 197–207 | Cite as

Numerical study on thermal non-equilibrium of arc plasmas in TIG welding processes using a two-temperature model

  • K. Konishi
  • M. Shigeta
  • M. Tanaka
  • A. Murata
  • T. Murata
  • Anthony B. Murphy
Research Paper


A two-temperature (2-T) model for tungsten inert gas (TIG) welding process is developed to investigate the arc phenomena of the pure argon and helium plasmas. The model considers the energy conservations of the heavy particles and the electrons separately. Compared with the 1-T model, the 2-T model obtains the plasma shapes more similar to the arc appearances. Furthermore, the heavy particle temperature of the 2-T model shows good agreement with the experimental results. For a pure helium arc, the electron temperature is much higher than the heavy particle temperature, whereas both temperatures are almost identical for a pure argon arc. Thermal non-equilibrium of a pure helium arc is discussed in terms of the energy exchange between heavy particles and electrons. It is found that ions and atoms of a pure helium arc cannot exchange their energy sufficiently with electrons because the plasma has a small number of electrons and consequently the collision rate between plasma species is relatively low. The simulation results show that when a welding current is lower, thermal non-equilibrium of an arc plasma is stronger. In a low welding current condition, not only the pure helium arc but also the pure argon arc shows thermal non-equilibrium.

Keywords (IIW Thesaurus)

GTA welding Mathematical models Plasma Arc physics 


  1. 1.
    Lowke JJ, Kovitya P, Schmidt HP (1992) Theory of free-burning arc columns including the influence of the cathode. J Phys D Appl Phys 25(11):1600–1606CrossRefGoogle Scholar
  2. 2.
    Yamamoto K, Tanaka M, Tashiro S, Nakata K, Yamazaki K, Yamamoto E, Suzuki K, Murphy AB (2008) Numerical simulation of metal vapor behavior in arc plasma. Surf Coat Technol 202(22):5302–5305CrossRefGoogle Scholar
  3. 3.
    Lowke JJ, Morrow R, Haidar J (1997) A simplified unified theory of arcs and their electrodes. J Phys D Appl Phys 30(14):2033–2042CrossRefGoogle Scholar
  4. 4.
    Hsu KC, Etemadi K, Pfender E (1983) Study of the free-burning high-intensity argon arc. J Appl Phys 54(3):1293–1301CrossRefGoogle Scholar
  5. 5.
    Haidar J (1995) Local thermodynamic equilibrium in the cathode region of free burning arc in argon. J Phys D Appl Phys 28(12):2494–2504CrossRefGoogle Scholar
  6. 6.
    Haidar J (1997) Departures from local thermodynamic equilibrium in high-current free burning arcs in argon. J Phys D Appl Phys 30(19):2737–2743CrossRefGoogle Scholar
  7. 7.
    Snyder SC, Lassahn GD, Reynolds LD (1993) Direct evidence of departure from local thermodynamic equilibrium in a free-burning arc-discharge plasma. Phys Rev E 48(5):4124–4127CrossRefGoogle Scholar
  8. 8.
    Haidar J (1999) Non-equilibrium modelling of transferred arcs. J Phys D Appl Phys 32(3):263–272CrossRefGoogle Scholar
  9. 9.
    He-Ping L, Benilov MS (2007) Effect of a near-cathode sheath on heat transfer in high-pressure arc plasmas. J Phys D Appl Phys 40(7):2010–2017CrossRefGoogle Scholar
  10. 10.
    Konishi K, Shigeta M, Tanaka M, Murata A, Murata T, Murphy AB (2015) Reliability evaluation of Fowler-Milne method in a temperature measurement of gas tungsten arc. Q J Jpn Weld Soc 33(1):42–48CrossRefGoogle Scholar
  11. 11.
    Murphy AB, Tanaka M, Yamamoto K, Tashiro S, Sato T, Lowke JJ (2009) Modelling of thermal plasmas for arc welding: the role of the shielding gas properties and of metal vapour. J Phys D Appl Phys 42:194006CrossRefGoogle Scholar
  12. 12.
    Kalikhman LE (1967) Elements of magnetogasdynamics. W. B. Saunder Company, PhiladelphiaGoogle Scholar
  13. 13.
    Mitchner M, Kruger CH Jr (1973) Partially ionized gases, vol 8. Wiley, New YorkGoogle Scholar
  14. 14.
    Hutchinson IH (2002) Principles of plasma diagnostics. Cambridge University Press, CambridgeCrossRefGoogle Scholar
  15. 15.
    Milloy HB, Crompton RW, Rees JA, Robertson AG (1977) The momentum transfer cross section for electrons in argon in the energy range 0–4 eV. Aust J Phys 30(1):61–72CrossRefGoogle Scholar
  16. 16.
    Nesbet RK (1979) Variational calculations of accurate e-He cross sections below 19 eV. Phys Rev A 20(1):58–70CrossRefGoogle Scholar
  17. 17.
    Devoto RS (1967) Transport coefficients of partially ionized argon. Phys Fluids 10(2):354–364CrossRefGoogle Scholar
  18. 18.
    Devoto RS (1967) Simplified expressions for the transport properties of ionized monatomic gases. Phys Fluids 10(10):2105–2112CrossRefGoogle Scholar
  19. 19.
    Hoffert MI, Lien H (1967) Quasi-one-dimensional, nonequilibrium gas dynamics of partially ionized two-temperature argon. Phys Fluids 10(8):1769–1777CrossRefGoogle Scholar
  20. 20.
    Hinnov E, Hirschberg JG (1962) Electron-ion recombination in dense plasmas. Phys Rev 125(3):795–801CrossRefGoogle Scholar
  21. 21.
    The Japan Institute of Metals and Materials (1993) Metal Data Book. Maruzen, Tokyo, in JapaneseGoogle Scholar
  22. 22.
    Van Doormaal JP, Raithby GD (1984) Enhancements of the simple method for predicting incompressible fluid flow. Numer Heat Transfer 7(2):147–163Google Scholar
  23. 23.
    Yamamoto K, Tanaka M, Tashiro S, Nakata K, Yamazaki K, Yamamoto E, Suzuki K, Murphy AB (2009) Numerical analysis of metal vapor behavior with multi-diffusion system in TIG welding of stainless steel. Q J Jpn Weld Soc 27(2):4–7CrossRefGoogle Scholar
  24. 24.
    Yuan X (1999) Master’s thesis. Osaka UniversityGoogle Scholar

Copyright information

© International Institute of Welding 2016

Authors and Affiliations

  • K. Konishi
    • 1
  • M. Shigeta
    • 1
  • M. Tanaka
    • 1
  • A. Murata
    • 2
  • T. Murata
    • 2
  • Anthony B. Murphy
    • 3
  1. 1.Joining and Welding Research InstituteOsaka UniversityIbarakiJapan
  2. 2.Murata Welding Laboratory Co., Ltd.YodogawaJapan
  3. 3.CSIRO Manufacturing FlagshipLindfieldAustralia

Personalised recommendations