AZ31 magnesium alloy sheet was welded by MIG.Effects of process parameters on droplet transfer

jointing formation

microstructure and properties of the joint were analyzed.The results reveal that with increasing in current

the voltage in the range of one volt is gradually reduced

and the droplet is evolved into globular transferring into the projected transferring to the spray transferring successively

and droplet size is correspondingly reduced.In addition

arc height is reduced with widening the width.With the current more than 180 A

welding joint exhibits desirable.With the current increase and the voltage decrease

bead width

penetration depth and reinforcement are increased with decrease of the aspect ratio.Grain size in welding joint is much smaller than that of heat-affected zone.With the linear energy increase

the grain size in welding joint and heat affected zone are increased

however

the hardness is decreased.