Microstructure and properties of vacuum electron beam welded WE43 magnesium alloy joint

This study presents the microstructure and properties of vacuum electron beam welded WE43 magnesium alloy joint. The process parameters of acceleration voltage 150 kV, electron beam current 120 mA and welding speed 35 mm/s are used for vacuum electron beam welding of WE43 rare earth magnesium alloy plate. In this study, the main compositions of the weld are α-Mg and a small amount of eutectic rare earth phase β-Mg 24 Y 5 . The mass fraction of the rare earth phase β-Mg 24 Y 5 in the weld area is more than that of the base metal. Segregation of Zr-rich particles can occur in weld zone. The average hardness of the weld is about 27% higher than that of the base metal, and the hardness near the center line of the weld is the highest. The yield strength, tensile strength and elongation of the joint are higher than that of the base metal by approximately 17%, 14% and 41%. Tensile fracture morphology of the welded joint is characterized by ductile and brittle mixed fracture. So, electron beam welding can achieve the connection of WE43 magnesium alloy plate with excellent microstructure and performance. It may be of great significance for this study to expand the application of rare earth magnesium alloy. Article Highlights The microstructure and morphology of WE43 magnesium alloy electron beam welded joints are analyzed. No defects such as oxidation and sag are found in magnesium alloy welds. The test result show, WE43 magnesium alloy electron beam welded joints possess high mechanical properties. By analyzing the tensile fracture morphology of welded joint, it is found that there are both ductile and brittle fracture.