Phenomena in GTA and GHTA Welding under like Mars Atmosphere

Abstract

NASA is advancing the project of manned Mars exploration. In the future, Martian outposts and structures will be constructed. To realize this, welding technology is expected to be applied. The main atmospheric component of Mars is carbon dioxide, and the atmospheric pressure is approximately 700 Pa. In this study, welding experiments were carried out in a simulated Mars atmosphere of 99.5% carbon dioxide and a pressure of 700 Pa. Conventional Gas Tungsten Arc (GTA) welding and Gas Hollow Tungsten Arc (GHTA) welding, in which arc operating gas is allowed only to flow out from the electrode tip of a hollow tungsten electrode, were investigated. The arc discharge behavior and the melting characteristics in the simulated Mars atmosphere were studied. As a result, it was shown that GTA welding and GHTA welding might be applicable even in the Mars atmosphere.