Effect of Oscillation Modes on Microstructure and Properties of WE43 Rare‐Earth Magnesium Alloy Welded Joints

The oscillating laser welding of 2 mm‐thick WE43 rare‐earth magnesium alloy is carried out with different modes. The oscillating laser modes mainly include nonoscillating, square, circular, figure‐of‐eight, and spiral oscillation. The effects of oscillating laser welding mode on the macroscopic morphology, microstructure, molten pool flow, and mechanical properties of WE43 welded joints are investigated. The macroforming and microstructure of welded joints with the spiral oscillation mode are the best. The spiral oscillation laser welding can achieve the conditions of heat conduction welding mode and turbulent flow of molten pool, and effectively inhibits the formation of keyholes and the appearance of biting defects. Because of its fine and uniform microstructure, the tensile strength of the welded joint reaches 230.3 MPa, which is 92.1% of the tensile strength of the base material. The research has enriched the theory of rare‐earth magnesium alloy oscillation welding to a certain extent and provides the theoretical data of rare‐earth magnesium alloy WE43 oscillation laser welding.