The Occurrence of Humping in Welding with Highest Beam Qualities

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The availability of lasers with highest beam qualities at laser powers of 1 kW (such as single-mode fibre laser, which nowadays come close to the theoretical limits) provides a unique tool to investigate welding process phenomena in a wide range of potential applications from welding with penetrations of some 50 "m to penetrations of some mm. Thus covering the field of micro welding as well as of macro welding, scalability of welding processes as well as size effects associated with the underlying physical phenomena may be of significance. In this paper, the humping effect will be given a closer look, as this periodic melt pool instability is an important limitation to possible welding speeds both in the micro and the macro range. Based on experimental investigations with a single-mode fibre laser (YLR-1000, laser power 1 kW, BPP < 0.4 mm*mrad), a model based on a modification of Rayleigh’s considerations on the stability of an inviscid incompressible fluid which is freely suspended in space and maintained only by surface tension is developed and discussed. It is shown that, within the scope of the investigations, humping to a large extent can be explained by Rayleigh’s theory, permitting to neglect the influence of three-dimensional melt flow.

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Edited by:

F. Micari, M. Geiger, J. Duflou, B. Shirvani, R. Clarke, R. Di Lorenzo and L. Fratini

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731-743

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C. Thomy et al., "The Occurrence of Humping in Welding with Highest Beam Qualities", Key Engineering Materials, Vol. 344, pp. 731-743, 2007

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July 2007

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[1] Albright, C.; Chiang, S.: High-Speed Laser Welding Discontinuities. In: Journal of Laser Applications, Fall 1988, 18-24.

[2] Miyamoto, I.; Park, S. J.; Ooie, T.: Precision microwelding of thin metal foil with single-mode fibre laser. In: Proc. 4th International Symposium on Laser Precision Microfabrication, Proc. SPIE, Vol. 5063, 2003, 297-302.

DOI: https://doi.org/10.1117/12.541155

[3] Miyamoto, I.; Park, S. J.; Ooie, T.: Ultrafinie-Keyhole Welding Process Using Single-Mode Fibre Laser. In: Proc. ICALEO, 2003, LMP Section A, 203-211.

[4] Miyamoto, I.; Park, S. J.; Ooie, T.: High. speed microwelding by single-mode fibre laser. In: Proce. LANE 2004, 55-66.

[5] Rayleigh, J. W. Strutt, Baron: The theory of sound, Vol. 2. , 2nd ed. London: Macmillan 1896, 343-375.

[6] Chandrasekhar, S.: Hydrodynamic and hydromagnetic stability. Oxford Clarendon Press 1961, 515-576.

[7] Bradstreet, B.J.: Effect of Surface Tension and Metal Flow on Weld Bead Formation. In: Welding Journal, Welding Research Supplement, July 1968, 314s-322s.

[8] Tsukamoto, S.; Irie, H.; Inagaki, M.; Hashimoto, T.: Effect of Focal Position on Humping Bead Formation in Electron beam Welding. In: Trans. National Research Institute for Metals, Vol. 25, 2 (1983), 8-13.

[9] Gratzke, U.; Kapadia, P.D.; Dowden, J.; Kroos, J.; Simon, G.: Theoretical approach to the humping phenomenon in welding processes. In: J. Phys. D: Appl. Phys. 25 (1992), 1640-1647.

DOI: https://doi.org/10.1088/0022-3727/25/11/012

[10] Beck, M.; Berger, P.; Dausinger, F.; Hügel, H.: Aspects of keyhole / melt interaction in high speed laser welding. In: Proc. 8 th Int. Symp. On Gas Flow and Chemical Lasers, 1990, Proc. SPIE, Vol. 1397, 769-774.

[11] Beck, M.: Modellierung des Lasertiefschweißens. Stuttgart: Teubner (1996).

[12] Fuhrich, T.: Marangoni-Effekt beim Laserstrahltiefschweißen von Stahl. München: Utz (2005).

[13] Landau, L.D. and Lifshitz, E.M.: Fluid Mechanics. Osford: Pergamon 1975, 6.

[14] Lancaster, J.F.: Metallurgy of Welding, 5 th Ed. London: Chapman & Hall 1993, 14.

[15] Sievers, E.R.: Schmelzbadinstabilitäten beim Elektronenstrahlschweißen von Grobblechen. In: Schweißen und Schneiden 58 (2006), 6, 288-295.

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