In order to optimize the laser-MIG hybrid welding process of thick aluminum alloy and improve the welding efficiency

the effects of laser and arc energy ratio coefficient η(P

L

/P

MIG

) on the weld formation and welded joint structure were analyzed under the two modes of fixed laser power and fixed arc power

respectively. The results indicate that in the fixed laser power mode

the weld penetration and penetration width are decreased

and the aspect ratio of the weld has little change with the increase of η. In the fixed arc power mode

the weld penetration

melting width and the aspect ratio are all increased with the increase of η. The laser heat source has a certain influence on the weld penetration depth and width

while the arc heat source mainly affects the weld penetration width. In the fixed laser power mode

the weld porosity is decreased with the increase of η

which is inverse in the fixed arc power mode. In the fixed arc power mode

Mg content in the laser action area of the weld is decreased

while Zn content is increased with the increase of η. The 12 mm thick plate A7 N01 aluminum alloy butt bottom welding and cover welding were carried out using the process parameters of η=1.5 and η=0.25

and weld joint is well formed

where the tensile strength of the joint reaches 78.95% of the base material.