## 1 Introduction  
Aluminum 5 XXX alloys have excellent strength, weldability, and corrosion resistance and are widely used in the ship, vehicle, and plant industries [1, 2, 3]. In addition, aluminum 5 XXX alloys have higher strength than other aluminum alloys due to solid solution strengthening by magnesium, a major additive element [4]. [PERSON] [5] reported that the magnesium content added to the aluminum alloy and the mechanical properties was proportional. However, [PERSON]'s results were based on sheet materials and did not report the results of welds when arc welding was performed. [PERSON] et al. [6] performed MIG welding with a high current on aluminum 5083 alloys. The primary variable that changes the mechanical properties of a weld is the content of magnesium, and the magnesium concentration and yield strength in the weld have a linear proportional relationship. [PERSON] et al. [7] reported that, when gas metal arc (GMA) welding was performed on an aluminum 5083 alloy using a commercial filler wire (Mg 5.10 wt.%) and a filler wire manufactured with a higher magnesium content (Mg 5.98 wt.%), the strength of the weld using the filler wire with a high magnesium content was higher. However, there has been no research confirming whether the magnesium content and mechanical properties are proportional when high-current arc welding is performed using a filler wire with higher magnesium content (7 wt.% or more).  
During the arc welding of aluminum alloys, magnesium, an additive element, is vaporized by high arc heat and deteriorates the mechanical properties [8, 9, 10]. According to [PERSON] [11]'s study, when GMA welding aluminum alloys, the melting pool temperature of the deposited metal zone is reported to be 2000 K (1727 \({}^{\circ}\)C) at the center. Since the boiling point of magnesium is 1090 \({}^{\circ}\)C, the vaporization of magnesium will occur. In the study of [PERSON] [12], the volume temperature of the aluminum alloy filler wire was measured when the peak current was 335 A during GMA welding, and it was about 1700-1730 K (1427-1457 \({}^{\circ}\)C), which caused the magnesium to vaporize. Studies on the deterioration of the mechanical properties caused by the vaporization of magnesium when welding aluminum alloys have been reported in the gas tungsten arc (GTA) welding process and the laser welding process, but studies of the GMA welding process have not been reported [13; 14; 15].  
Manganese, one of the elements added to aluminum 5 XXX alloys, is used for solid solution strengthening in aluminum alloys, such as magnesium. Still, its strength per atom is higher than that of magnesium [16]. Moreover, the boiling point of manganese is 2090 \({}^{\circ}\)C, which is higher than the arc-melting pool temperature and volumetric temperature in the aforementioned studies of [PERSON] [11] and [PERSON] [12]. The effect of the manganese content on the mechanical properties in aluminum alloy arc welds has not been reported yet.  
This study investigates the effect of magnesium and manganese contents on the mechanical properties of GMA welds of aluminum alloys. Double-sided butt V-groove joint welding was performed using three types of aluminum alloy welding wires with different contents of magnesium and manganese than aluminum 5183 alloy wire. The mechanical properties of the welds were evaluated through tensile tests, bending tests, and microhardness tests. In addition, the microstructure and chemical composition were analyzed to compare changes in the welds according to their magnesium and manganese contents.