Observation of Stability and Cleaning Action in AC-GTA under like Mars atmosphere

In 2010, Barack Obama, the former president of the United States, announced sending humans to the Red Planet in the 2030s. Outposts and habitats will be set up in the future by welding technique. In this study, effectiveness of previous AC-GTA welding was investigated in a like Mars atmosphere consisting only CO2 gas with pressure range from 600 to 1000Pa. In order to observe the AC-GTA phenomena, the arc appearances were filmed by a high-speed video camera. Furthermore, the arc voltage and the welding current waveforms were recorded to evaluate the AC-GTA stability. It was found that the cathode spots distribution area spreads and the AC-GTA stability decreases in the less pressure. In conclusion, the AC-GTA welding in the Mars atmosphere can be applicable by considering the ambient pressure and the EP time ratio.