针对3 mm厚的Ti75钛合金, 采用10 kW的连续光纤激光器对材料进行搭接试验, 研究不同工艺参数对焊缝成形的影响规律。通过调节两板间的预留间隙、激光功率、焊接速度以及离焦量来分析焊缝的氧化程度、下塌量、气孔状况和抗拉强度。最后基于焊缝的氧化程度、下榻量、气孔状况和抗拉强度评价焊接接头质量。结果表明, 搭接间隙在0.1～0.15 mm, 激光功率在3 000～3 100 W、焊接速度在0.04～0.045 m/s, 离焦量在-1～1 mm的工艺参数下, 试件氧化程度较低且焊缝成形连续美观, 气孔率较低, 此时的抗拉强度保持在720 MPa以上。通过调整激光功率、焊接速度和离焦量等激光焊工艺参数, 可以对焊缝成形进行有效控制, 提高焊接接头质量。

For Ti75 titanium alloy with a thickness of 3 mm, a 10 kW continuous fiber laser was used to conduct the lap test on the material, and the influence of different process parameters on the weld formation was studied.By adjusting the reserved gap, laser power, welding speed and defocusing amount between the two plates, the oxidation degree of the weld, the lower collapse, the porosity and the tensile strength were analyzed.Finally, the quality of the welded joint was evaluated based on the oxidation degree, the number of beds, the porosity status and the tensile strength of the weld.The results showed that the lapping gap was 0.10~0.15 mm, the laser power was 3 000~3 100 W, the welding speed was 0.040~0.045 m/s, the defocus was -1~1 mm, the oxidation degree of the specimen was low, the weld was continuous and beautiful, the porosity was low, and the tensile strength remained above 720 MPa.By adjusting the laser power, welding speed, defocus and other parameters of laser welding process, the weld formation can be effectively controlled and the quality of welded joints can be improved.