Effects of tool design and welding parameters on the properties of dissimilar magnesium/aluminium friction stir welded lap joints

Friction stir welded lap joints between dissimilar WE43 magnesium and AA2024-T3 clad aluminium alloys were performed using various welding conditions including tool geometry, rotation and travel speeds. The microstructural features were analyzed by metallographic examination. Intermetallic phases were detected in the weld zone. Different microstructures were observed in the stir zone which can be attributed to using different travel and rotation speeds. Hook features and other imperfections were identified in the joints. The tool design as well as welding conditions that permitted to minimize these defects were established.