Effect of additional side shielding on the wire arc additive manufacturing of AZ31 magnesium alloy

Magnesium (Mg) alloys have a low density among the structural metals, but it is hard to be plastically deformed due to their crystallographic nature. Wire arc additive manufacturing (WAAM) could be one of the alternative processes to fabricate the Mg products for various industrial applications. Nonetheless, it is used in limited industrial fields due to challenging issues such as low commercial availability of wire, high oxygen affinity, explosive and flammable hazard, and typical defects of WAAM like distortion and side collapse, grain coarsening, etc. In this research, it was tried to find out the better way to fabricate the WAAM of AZ31 alloy. An additional Ar gas side shielding was given during the WAAM process, and compared with the conventional shielding method. It was observed that the global shielding affects the microstructural evolution of the WAAM product, and influences the mechanical property in a positive way.