Effects of different welding process on the electronic temperature of plasma and weld shape during laser-MIG hybrid welding of A7N01P-T4 aluminum alloy

In this paper, the authors investigated on the spectral characteristics of A7N01P-T4 aluminum alloy in MIG, laser, and laser-MIG hybrid welding; calculated the electronic temperature of the welding plasma; and analyzed the difference of three kinds of welding processes with the weld shape. The influence of the oxide film on the spectral characteristics and weld shape of the laser-MIG plasma was investigated. The authors made further research of different welding parameters (laser power, wire feeding speed, and shielding gas flow) on the spectral characteristics of laser-MIG plasma and the weld shape, and then explained the relationship between the plasma and the weld shape. The results are indicated: when the laser power increased from 1 to 4 kW, the spectral intensity, electronic temperature, weld penetration, and weld width increased. When the wire feeding speed increased from 9 to 18 m/min, the spectral intensity, the electronic temperature, weld penetration, and weld width increased. When the shielding gas flow increased from 20 to 40 l/min, the plasma temperature, the penetration depth, and weld width increased. When the protective gas flow increased from 40 to 50 l/min, the electronic temperature, weld penetration, and weld width all decreased, but the argon spectrum intensity and the number of argon atom both increased. In the absence of oxide film, the laser-MIG plasma temperature, the weld penetration, and weld width increased.