中文摘要：

针对钛合金激光自熔焊对毛坯和装夹精度要求高,焊接后表面存在凹陷、咬边、不饱满等问题,对1 mm厚TC4钛合金进行激光填丝焊试验,研究了焊丝送入条件、离焦量和送丝速度对焊缝成形质量的影响,并优选工艺参数,分析了焊接接头的显微组织、硬度和拉伸强度。结果表明在工艺参数为离焦量＋2 mm、激光功率800 W、焊接速度20mm/s、送丝速度25 mm/s、送丝角度50°、丝光间距0 mm时进行激光填丝焊,焊缝表面未出现凹陷、不饱满等缺陷,且焊缝微观组织致密。焊接接头的平均抗拉强度为1287 MPa,大约是基材的1.32倍,比激光自熔焊提高了20.96%左右。

英文摘要：

In view of high accuraly requirements of blank and clamping and some welding defects （like sag, surface undercut underfill and so on） tending to occur in the process of autogenously laser welding, the laser filler wire welding tests for TC4 titanium alloy sheet with lmm thickness were carried out to investigate the influence of wire feeding condition, defoeusing and wire feeding speed on weld forming quality. The microstructure, microhardness and tensile strength of welded joint were also investigated through choosing optimized process parameters. The results show that adapting some reasonable technology parameters can efficiently improve the weld forming quality （like sag, surface undercut, and density）, and the best process parameters of laser filler wire welding for TC4 titanium alloy are obtained： defocus 2 ram, laser power 800W, welding speed 20 mm/s, filler wire effding speed 25 ram/s, filler wire feeding angle 50°, and mercerizing spacing 0 ram. The average tensile strength of the welded joint with filler wire is 1287 MPa, which is 1.32 times of substmte and 20.96% higher than the joint with autogenously laser welding.