Electron beam welding in microgravity environment

Abstract

The purposes of this study are to perform the welding in a microgravity environment and to investigate the differences in welding phenomena such as the bead shape, the grain structure, the Vickers hardness and the microstructure between in a terrestrial environment and in a microgravity environment. A small sized electron beam welding apparatus was developed and aluminum-copper alloys, A2219, were welded using the developed apparatus under microgravity of approximately 10-5G. As a result, it was found that a stable electron beam was obtained in both terrestrial and microgravity environments. A much flatter weld bead was formed in the microgravity environment than in the terrestrial environment. The grain size in the middle part of the weld bead was smaller in the microgravity environment than in the terrestrial environment. However, the Vickers hardness were similar in both terrestrial and microgravity environments. © 2000 ISIJ.