TA18钛合金板材焊接工艺对比研究

Comparative Study on Welding Process of TA18 Titanium Alloy Sheet

研究了直流钨极氩弧焊(直流TIG)、脉冲钨极氩弧焊(脉冲TIG)和激光焊接3种不同焊接工艺对TA18钛合金焊接接头宏观形貌、显微组织和力学性能的影响。结果表明,与直流TIG焊接工艺相比,脉冲TIG焊接工艺的高频脉冲促使电弧能量集中,整体的焊接热输入减小,焊缝宽度降低;激光焊接工艺可显著降低焊接接头宽度,与直流TIG焊接工艺相比,焊接接头宽度减少约69.5%。TA18钛合金激光焊接接头显微组织主要为网篮状排列的针状马氏体α′相及少量块状相变α相,且针状马氏体α′相更加细小。此外,激光焊接接头具有更高的显微硬度,但弯曲性能相对较低。

The effects of three different welding processes,direct-current tungsten inert gas welding(DC TIG),pulsed tungsten inert gas welding(pulsed TIG)and laser welding on the macroscopic morphology,microstructure and mechanical properties of TA18 titanium alloy welded joints were studied.The results show that compared with the DC TIG welding process,the high frequency pulse of pulsed TIG can promote the concentration of arc energy,decrease the overall welding heat input and weld width.Meanwhile,laser welding process can significantly reduce the welded joint width,and the width can be reduced by 69.5%compared with DC TIG welding process.The microstructure of laser welded joint is mainly consisting of acicular martensiteα′phase arranged in basket shape and a small amount of massive transformationαphase,and acicular martensiteα′phase is finer.Laser welded joint has higher microhardness than TIG welded joint,however,the bending properties of laser welded joint is lower than TIG welded joint.