Welding Phenomenon of Stainless Steel by the Space Diode Laser Welding Process in Various Pressures

Abstract

The authors develop the space Gas Hollow Tungsten Arc (GHTA) welding which can be performed in a vacuum, since 1993. In order to establish the space welding technologies necessary for the space development, we are also developing the space Diode Laser (DL) welding process in which the welding principle is completely different from the space GHTA welding. The paper describes the welding results by the perpendicular irradiation and oblique irradiation of the laser light in a vacuum. The DL welding experiments using the stainless steel clarified the melting characteristics and the evaporating phenomena in molten metal. And also, it has been clarified that the mass of the metal vapor during welding increases with the reduction of the environmental pressure and the radiation distribution of evaporation metal follows the cosine law.