Evolution of microstructures and mechanical properties of AZ31 magnesium alloy weldment with TIG and Pulsed TIG process

Magnesium alloys are very attractive materials owing to their properties of low density, high specific strength and stiffness, good castability, and weldability. AZ31 magnesium alloys in terms of weldability has better situation than the other, so it has more applications than other magnesium alloys. In this study, TIG and pulsed TIG welding method was used to welding the AZ31 alloy and finally microstructure and mechanical properties of welds with metallography, scanning electron microscopy (SEM), tensile test were examined. The results showed that the heat input affected the size of grains that are leading to changes in mechanical properties. Sample was welded with TIG welding with minimum current has maximum strength among the samples both pulsed TIG welding and TIG method. It is observed that with increasing frequency in TIG welding, strength is reduced. Despite the same IP and IB, higher frequency has created a stronger welding. Also increases the frequency leads to more fine-grained samples, resulting in increased strength.