Research On Arc-Assisted TA2 Thin Plate Laser Welding Process And Joint Performance

Titanium and titanium alloys are widely used in aerospace,seawater desalination,Biomedical and other fields due to their high specific strength and excellent weather resistance.As a new and efficient welding method,arc-assisted laser welding has corresponding research and application cases in the field of aluminum alloy,magnesium alloy,steel and other materials.Using arc-assisted laser welding to weld titanium and titanium alloy thin plates or thin-walled tubes has great advantages in terms of welding efficiency,joint performance,and cost.In this paper,arc-assisted laser welding is used to perform welding experiments on industrial pure titanium TA2.The effects of welding process parameters on the welding process,weld seam shape and corrosion resistance are studied.Based on this,the laser-arc theory is combined with high-speed photography to analyze the laser-arc coupling mechanism,which provides a certain process specification and theoretical basis for the promotion and application of arc-assisted laser welding in titanium and titanium alloys.The process experiment results show that the different heat source modes of arc-assisted laser welding have different process characteristics.When the laser is leading,the welding process is stable and there are fewer welding defects.When the TIG arc is leading,the heat source has a better penetration ability and it has a better ability to penetrate plates Gap tolerance is better.Regardless of whether the laser is leading or the TIG arc is leading,the heat source spacing has a great effect on the penetration depth and the front fusion width.Observation of the dynamic behavior of the arc and the molten pool through high-speed photography shows that the TIG arc will be attracted by the laser.When the TIG arc is leading,the arc will heat the metal surface,which will increase the energy utilization rate of the composite heat source of the base material and produce mutually enhanced Synergy.When the laser is leading,a molten pool will be formed.The TIG arc will repair the molten pool formed by the laser,thereby reducing the occurrence of welding defects.And whether the laser is leading or the TIG arc is leading,the plume above the laser will decrease as the heat source distance decreases,further improving the laser's energy efficiency.The results of kinetic potential polarization curve and electrochemical impedance spectroscopy experiments show that the base metal and weld have good corrosion resistance in 3.5% Na Cl solution.And two electrochemical tests show that the corrosion resistance of the weld is better than the base metal.At the same time,there is no significant difference in the corrosion resistance of the weld under different welding process parameters.Finally,based on the research of arc-assisted laser welding,field welding was performed on 0.7mm and 0.5mm thick titanium pipes.The results show that the arc-assisted laser welding technology can achieve high-speed welding of industrial pure titanium TA2 titanium pipes The mechanical properties of the welded pipe,flaring and flattening tests all meet national standards,and the corrosion resistance is good.