Dendrite remelting during arc oscillation welding of magnesium alloys: a phase-field study

Based on two-dimensional phase-filed simulations, we demonstrated how the solidification morphologies evolved during gas-tungsten arc welding of Mg-4.0 wt% Al magnesium alloy with transverse arc oscillation. Results showed that reheating caused by arc oscillation can cause dendrite fragmentation by remelting/pinch-off of sidebranches. Furthermore, the effects of arc oscillation frequency on the solidification morphologies during welding were investigated. We found that the oscillation frequency can significantly alter the reheating time duration during cooling, affect the sidebranches' pinching behavior, and influence the formation of the dendrite fragments. Results from this research are consistent with previous experimental results.

Automated summary

Based on two-dimensional phase-field simulations, this study demonstrated the evolution of solidification morphologies during gas-tungsten arc welding of Mg-4.0 wt% Al magnesium alloy with transverse arc oscillation. It was found that the reheating caused by arc oscillation can result in dendrite fragmentation, and the oscillation frequency can significantly affect the solidification morphologies during welding.