Studies on the effect of welding current in laser-plasma arc hybrid welding of an Al-Li alloy

The effect of welding current on welding quality was studied in laser-plasma arc hybrid welding of 1420 Al-Li alloy using both experimental and numerical modeling methods. Results show that the weld pools are all hybrid welding type under welding current of 40-80A, both length and width of the weld pool increase approximately linearly with the increasing of welding currents. Increasing welding current can significantly reduce the porosity in the welds. Increasing the welding current will increase the stay time of liquid weld pool and hence allow the pores grow and move out of weld pools more easily. The porosity in weld is therefore decreased significantly. This paper is beneficial for the process optimization and quality improvement of the hybrid welding of Al-Li alloy.