Abstract: Tungsten inert gas weld was carried out on super-light magnesium-lithium alloy plates with a thickness of 2 mm, using
argon gas as a protecting atmosphere. The microstructure and mechanical properties of the welded joints were investigated. The
results indicate that the microstructure in the fusion zone is fine, and the microstructure in the heat-affected zone is coarser than the
parent metal. The tensile strength of the welded joint is about 84% that of the parent metal. The fracture occurs in a mixed type of
toughness and brittleness in the heat-affected zone. During the welding process, aluminum and cerium are enriched at grain
boundaries in the fusion zone.