【摘要】 以焊前不对铝合金板材做任何处理为前提,采用扩散冷却板条CO2激光系统,开展对1420铝锂合金的双光束激光焊接焊缝气孔控制的实验研究。实验结果表明:在激光表面扫描焊时,表面氧化膜对焊缝中气孔的影响大大高于背面氧化膜;但是,在激光对接焊时,焊缝气孔对背面氧化膜的敏感性和焊缝背面成形有直接的关系。经过实验得出了优化的焊接工艺以达到降低气孔率、提高焊缝质量的目的。还进行了1420铝锂合金的对接焊焊接接头拉伸强度实验。数据显示:选用优化的对接焊工艺,焊接接头的平均拉伸强度可达336.1MPa,为母材的87.5﹪。更多还原

【Abstract】 As a precondition of laser welding,the plate of Al-Li alloy wasn′ t treated before welding.A DC035 CW CO2 laser,in the TEM00 mode,with output up to 3 500 W,was employed to experimentally study the porosity control of 1420 Al-Li alloy by dual-beam laser welding.The experimental results show that the influence from the surface oxide film on the porosity in weld is deeper than that from the backside one when the laser welding is in the form of beam on the surface of plate.However,welding porosity has a distinct connection with the sensibility of backside oxide film and the backside formation in the weld when the butt joint laser welding is carried out.The optimized laser welding techniques were achieved experimentally to decrease the porosity in weld and increase the weld qualities.The tensile strength of welded joints of butt joint laser welding was experimentally tested too.The data indicate that the average tensile strength of the joints could reach up to 336.1 MPa,which is equal to 87.5﹪ of the substrate alloy.更多还原