Experimental and Numerical Investigations of the Interaction between a Plasma Arc And a Laser

Laser-assisted plasma arc welding of stainless steel

“…Indeed, these comparatively low laser intensities are even found to be much more effective for the stabilization of the arc attachment than the high intensities of the much more focused laser beam used in a previous study, which were causing an increase in arc voltage. 23,24 These results may be regarded as additional proof of our argumentation that the arc stabilization is not caused by the laser-induced evaporation of base material. Instead, it is concluded that the molten surface region within the beam spot region does already offer preferred conditions for arc rooting.…”

“…In the case of steel welding, the use of the focused laser beam actually induced an increase in arc voltage and a slight destabilization of the arc column. 24 These experimental findings demonstrated that the often observed effect of increased process efficiency cannot be considered as a direct consequence of adequate and measurable improvements of the arc characteristics.…”

“…These results conform with the authors own experience that a high-intensity laser beam is capable of destabilizing a plasma arc during steel welding. 28,29 The simple presence of metal vapor is consequently not considered as being a consistent reason for synergistic effects in laser-arc processing. Instead, the thermal interaction between a focused laser beam and an electric arc may play a more crucial role.…”

“…[22][23][24] Initially, both heat sources were arranged in a separate order but inclined to each other in such a way that a common operation point of the arc root and the laser spot resulted. The most distinguishing feature of this set-up was the use of a highly focused single-mode fiber laser beam with a focus diameter of only 40 lm and a resultant intensity of 8 Â 10 6 W cm À2 in the case of 100 W applied laser power.…”

Influence of Welding Current and Focal Position on the Resonant Absorption of Laser Radiation in a TIG Welding Arc

“…The root of the electrical arc is also fixed to the laser beam. Thus it is possible to affect the position of the electrical arc (Schnick et al, 2012;Hermsdorf et al, 2009a). The additional energy of the laser radiation leads to an increase of metal vapor in the electrical arc which increases the amount of the metal ions (Hu, 2002).…”