Study on TIG welding performance of AM50 magnesium alloy

In order to develop the TIG welding technology suitable to AM50 magnesium alloy,the TIG welding performance of the alloy was studied.The systematic welding experiments were performed by adjusting the technological parameters.And the mechanical properties of the welding joints were experimentally determined.The results show that the welding current,welding velocity and gas feed rate significantly influence the surface forming performance and mechanical properties of the welding joints.And thus,a set of welding procedures has been obtained.The microstructural observation on the welding joints reveals that the microstructure of the weld zone is composed of α-Mg matrix and β-Al12Mg17 phase which distributes at the grain boundaries.Thus,both tensile strength and hardness of the welding joints are lower than those of the base metal.