Light Magnesium Constructions For Transportation Applications.

Manufacturing of transportation vehicles as handicapped scooter, other small vehicles or light constructions often require the use of hybrid combination of wrought and cast alloys. Welding technology still remains the conventional joining process of hybrid alloys such as die-cast tube profile to forged rigid part. Hence, the motivation of the current study was to select an appropriate welding method, which resulted in suitable mechanical properties of the hybrid, based on mechanical/metallurgical characterization accompanied by acoustic emission (AE) monitoring.The program was initiated by selecting hybrid consist of high-pressure die-cast AM50 and forged AZ31B Mg alloys, and by choosing' electron beam welding (EBW) and gas tungsten arc welding (GTAW). Preliminary work was performed in order to obtain the optimal welding parameters, which was supported mainly by non-destructive tests.From microstructure and mechanical point of view, it was found that the EBW method is the favorable joining process, resulted in reliable mechanical response, even though the ductility property is still low, compare to the base alloys. This behavior was related to fine inter-granular micro cracking existing mainly at the welding tip vicinity, which may be originated by the existence of the brittle beta phase at the grain boundaries. The partially success of the current study encourage us, in continuing such activity, which will open wide range use of hybrid light-magnesium in transportation applications.