采用双侧同步填丝激光焊接的方法获得Ti-6Al-4V 合金T 型接头，研究激光焊接参数对焊接缺陷如未熔合、气孔等的影响。试验结果表明：未熔合缺陷的产生由激光功率、焊接速度、激光入射角度及入射位置等参数所决定，足够大的焊接热输入(较高的激光功率，较小的焊接速度)，较小的激光入射角度以及较高的激光辐照位置可以避免出现未熔合缺陷。激光功率一定时，出现未熔合缺陷的焊缝在焊接过程中，熔池上方等离子体/金属蒸气喷发量多于无此类缺陷的焊缝。不同焊接参数下T 型接头焊缝中的气孔缺陷具有典型的小孔型气孔特征，激光功率一定的情况下，较高的焊接速度有利于减少此类气孔。

The T-joints of Ti-6Al-4V alloy are fabricated by double-sided synchronized laser beam welding with the homologous filler wire. The influence of the welding conditions on weld defects such as lack of fusion and porosity are investigated. Results show that the lack of fusion defects are determined by the laser power, welding speed, laser incident angle and position. With larger enough welding heat input (higher laser power, and slower welding speed), the lower laser incident angle and higher laser incident position are required to avoid the lack of fusion defects. The quantity of plasma/metal vapor above the molten pool for weld seam with the lack of fusion defects is larger than that of the weld seam without the defects under a certain laser power. The porosity defects in the welded T-joints are mainly the type of keyhole porosity defects under different welding conditions, and the higher welding speed is helpful to decrease the porosity defects under a certain laser power.