Development of Arc Welding Process Applied to Construction and Repair of Space Vehicles and Structures in Space.

Abstract

The need to develop space welding technology as fast as possible is stressed for efficient repair and construction of space development projects. It is shown that in a vacuum like in space conventional GTA welding in which the solid tungsten electrode is used could not be applied. To solve this problem, the authors propose the GHTA process using a hollow tungsten electrode. An arc discharge could be started and maintained by flowing a trace amount of argon gas from the end of the electrode. In the proposed GHTA process, the stationary arc discharge which can be used as the welding heat source, starts after several seconds of the transient arc discharge. Also, the characteristics of arc discharges and penetrations due to the GHTA process in a vacuum are clarified.