Effects of the welding process on fiber laser welding of 1.2mm 2A97T3 Al-Li alloy are studied through a lot experiments. The results show that with the increase of the welding heat input

the welding bead width and the backtop width ratio will be improved. Moreover

the variation of the back side bead width is significant

while the top side bead width has small changes. Too much heat input will lead to decrease of welding bead width due to the collapse of welding seam. The welding process parameters will be much more narrow when laser power and welding speed increasing. Under the condition of the same welding linear energy

welding forming of high speed is better. The hardness of laser thermal conducting welding is obviously higher than that of laser deep penetration welding.