Effect of Scanning Mode on Microstructure and Mechanical Properties of 2198 Al-Li Alloy Joint Fabricated by Electron Beam Welding [电子束扫描波形对铝锂合金显微组织及力学性能的影响]

作者：Zhang Z.; Wang S.^*; Ke L.; Li J.

来源：Rare Metal Materials and Engineering, 2018, 47(7): 2245-2251.

• Aluminum-lithium alloy
• Electron beam welding
• Mechanical property
• Weld formation

Vacuum electron beam welding of 2198-T8 aluminum lithium alloy sheet with a thickness of 1.8 mm was carried out. The influence of different scanning modes on weld formation and joint mechanical properties was investigated, as well as the microstructure and mechanical properties of the welding joint under the optimal welding process. The results show that when the working distance is 300 mm, the acceleration voltage (U) is 60 kV, the focusing current (If) is 498 mA, the welding speed (V) is 1200 mm/min, and the electron beam (Ib) is 6.8 mA, the welding joint without the addition of scanning are formed well without macro porosity defects. According to the comparison of welding with scanning modes under the same parameters, we derive that the hardness values and tensile strength of the welding joint are improved when adding triangle wave scanning in the process of welding. The average tensile strength of welded joint is 326.5 MPa, the fracture strength of the joint is 71.5% of that of the base metal, and the elongation is up to 86.8% of the base metal elongation. The weld fusion zone is the weakest in the weld zone.

• 单位
  南昌航空大学