A study on welding mode transition by electrical detection of laser-induced plasma at varying energy levels
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The transition between heat conduction and deep penetration laser welding is investigated by the electrical detection of laser-induced plasma with an electrical passive probe. A further improved physical model based on plasma sheath effect is established to clarify the mechanism of plasma electrical signal. Different electrical signals are detected at varying levels of laser input energy and analyzed in the time and frequency domains. The amplitudes and the fluctuation frequency of the collected signals are demonstrated to be effective in reflecting the electron temperature and the plasma oscillation features respectively. These assessments are identical with the experimental results obtained by a high-speed camera. Combined with the signal characteristics and the weld profiles at different laser powers, the critical state and laser power density of mode transition are discussed and identified by an analytic calculation model.
KeywordsLaser welding Mode transition Electrical detection Plasma
This work is supported by the National Natural Science Foundation of China (Grant No. 51875403).
- 3.Zhang Y, Li LJ, Zhang G(2005) Experimental study on plasma inside the keyhole in deep penetration laser welding. Proc. SPIE, Lasers in Material Processing and Manufacturing II 5629Google Scholar
- 21.Mrňa L, Martin S, Rerucha S, Jedlicka P (2016) Autocorrelation analysis of plasma plume light emissions in deep penetration laser welding of steel. J Laser Appl 29(1):0122009Google Scholar
- 22.Sibillano T, Ancona A, Rizzi D, Saludes RS, Rodríguez NJ, Konuk, AR, Aarts R, Huis in’t Veld AJ (2010) Study on the correlation between plasma electron temperature and penetration depth in laser welding processes. Phys Proc5:429–439Google Scholar
- 23.Bellan PM (2008) Fundamentals of plasma physics. Cambridge University PressGoogle Scholar
- 24.Bekefi G (1976) Principles of laser plasmas. Wiley, New YorkGoogle Scholar
- 26.Richard D (1993) Plasma physics: an introductory course. Cambridge University PressGoogle Scholar
- 27.Ambrosy G, Avilov V, Berger P, Huegel H(2007) Laser induced plasma as a source for an intensive current to produce electromagnetic forces in the weld pool. 16th International Symposium on Gas Flow 6346Google Scholar
- 34.National Institute of Standards and Technology Database https://physics.nist.gov/PhysRefData/ASD/levels_form.html
- 41.Pang SY, Shao XY, Li W, Chen X, Gong SL (2016) Dynamic characteristics and mechanisms of compressible metallic vapor plume behaviors in transient keyhole during deep penetration fiber laser welding. Appl Phys A Mater Sci Process 22(7):122–702Google Scholar