Microstructural and thermodynamic investigations on friction stir welded Mg/Al-joints

With friction stir welding it is possible to join light metals in the solid state. However joints between dissimilar metals are a special challenge. At the Institute of Materials Science and Engineering of the University of Kaiserslautern the friction stir weldability of magnesium–aluminium-joints was investigated. For the realization of high strength joints between these materials the knowledge of the developing microstructure in the welding zone is of especially high interest. Therefore, light microscopic and scanning electron microscopic investigations were carried out and the results compared with phase diagrams and phase fractions for the bonding zone which were calculated at Institute of Metallurgy of the University of Clausthal.