Interface phenomena in aluminium-magnesium magnetic pulse welding

The morphology and structure of the weld interface in magnetic pulse welding of similar and dissimilar metals were investigated. The interface zone of dissimilar metal couples such as Al-Mg, was studied in comparison to Al-Al welds. It was found that intermetallic phases (IMP) of different compositions are created during welding of the Al-Mg couple by rapid solidification of a thin melted layer at the interface. According to the calculated energy balance of magnetic pulse welding (MPW), there is enough energy to melt a thin interfacial layer and create IMP. Intensive characterisation techniques were used, including the focused ion beam (FIB) method that was used to prepare a cross-section of the Al-Mg interface for TEM characterisation. It was established that the jet action plays an important role in the melting process at the bonding zone.