|Research on the Microstructure and Mechanical Properties ofTIG Welded Joint of LA103W Mg-Li Alloy
Xia Congcong Ma Licai Lu Chuanyang Wang Feng Tang Jiaqi
Beijing Xinfeng Aerospace Equipment Co., Ltd., Beijing 100080
|Using tungsten inert gas welding to weld LA103W magnesium lithium alloy plate with thickness of 5mm, the welding quality, microstructure, and mechanical properties of LA103W alloy were studied. The results show that surface quality of welded joint was good, and no obvious pores and cracks were found in the weld. The microstructure of welded joint consisted of α-Mg phase and β-Li phase. The β-Li phase grain in the base metal zone and the heat-affected zone was equiaxed, and a large number of fine needle and granular α-Mg phase was found in the weld zone and fusion zone. The α-Mg phase of the fusion zone is evenly distributed in the β-Li phase, and the fusion is good. The fusion zone is not prone to fracture. The tensile strength and elongation of welded joint were slightly lower than those of the base metal, which respectively reach 92.1% and 90% of the base metal. The fracture mode of welded joint was ductile-cleavage fracture, and the tensile fracture was located at the base metal zone.
|Key words: LA103W；Mg-Li alloy；microstructure；mechanical properties