Simulated Ni transport in the molten pool of wire feed laser beam welding: (a) without electromagnetic stirring, (b) with electromagnetic stirring
Source: BAM Division Welding Technology
The high-power laser beam welding is one of the most promising metal joining techniques in modern manufacturing industries. The introduction of electromagnetic stirring to laser beam welding can bring further beneficial effects e.g. element homogenization and grain refinement. However, the underlying physics has not been fully explored due to the absence of quantitative data of heat and mass transfer in the molten pool. Thus, the optimization of the welding parameter combination is still very challenging.
The objective of this study is to obtain a quantitative insight into the physical phenomena during the electromagnetic stirring enhanced wire feed laser beam welding. The influence of the induced Lorentz force on the thermo-fluid flow and element transport is studied numerically and experimentally. A three-dimensional transient heat transfer and fluid flow model coupled with dynamic keyhole, magnetic induction and element transport is developed for the first time. It is shown that the Lorentz force produced by an oscillating magnetic field and its induced eddy current shows an important influence on the thermo-fluid flow and the keyhole stability. The additional elements from the filler wire are significantly homogenized because of the enhanced forward and downward flow. The model can provide quite accurate prediction of the welding process and final element distribution. It has been well verified by the experimental fusion line, high-speed images of the molten pool and EDX measurement. This work may give some fundamental guidelines for the parameter optimization of electromagnetically assisted laser beam welding.
Numerical and experimental investigation of thermo-fluid flow and element transport in electromagnetic stirring enhanced wire feed laser beam welding
Xiangmeng Meng, Antoni Artinov, Marcel Bachmann, Michael Rethmeier
published in International Journal of Heat and Mass Transfer, Vol. 144, page 118663 et seq.
BAM Division Welding Technology