Abstract
AZ61 magnesium alloy plate with 4mm thickness was butt welded using a high voltage electron beam welder. Effects of both welding speed and post weld heat treatment on the microstructure and mechanical properties of electron beam welded joints were investigated. The arcing phenomenon tended to appear with welding speed is under 250mm/min. Independent of the welding speed, the remarkably fine crystal grains were observed in the fusion zone, though after post weld heat treatment those were become coarse. The tensile strength of the welded joints showed almost same value as that of the base metal regardless of the welding speed. The elongation of as welded joints was inferior to that of the base metal. But it increased with after post weld heat treatment. The highest elongation could be obtained with T6 heat treated welded joints.
