A. Brimmer, E. Choi, W. McAuley, B. Panton, A. Ramirez
The Ohio State University,
United States
Keywords: Laser welding, space, space welding, vacuum welding, autonomous, ICME, ISAM
Summary:
Welding and joining are critical enabling processes for the rapidly growing in-space servicing, assembly, and manufacturing (ISAM) sector. However, there are currently no metallurgical joining processes that have been proven fit-for-service for applications in outer space, on the moon, or on mars. The last American work on in space welding processes was conducted in 1973 aboard Skylab, causing a lack of fundamental understanding of the effects of the environments of space (e.g. gravity, vacuum, temperature) on the welding process and the metallurgy and properties of the resultant joint. The inability to weld in space is a significant impediment to the advancement of in-space manufacturing, which is of key interest to both the US government and American industry. This work seeks to investigate the impacts of these three space conditions on laser welding by building on prior studies of the impact of high vacuum on the behavior of laser welds. A 1kW, 1070nm Yb fiber laser has been fit onto a vacuum chamber inherited from NASA Langley for parabolic flight experiments. To mimic the conditions present in low earth orbit, a pressure range of 10-2 to 10-6 torr was considered for the impacts on weld penetration, width, and vapor characteristics. Results gathered from this experimentation provide the basis for continued work with changes in gravity and temperature to further mimic the conditions present in space. In August 2024, this experiment will ride aboard a Zero-G parabolic plane to experiment in high vacuum and zero or lunar gravity. This work will serve to inform current integrated computational materials engineering (ICME) efforts for laser welding in space to qualify in-space welding as a viable ISAM technique. From interest from NASA and the Air Force Research Laboratory (AFRL), investigations into the behavior of aerospace aluminum and titanium alloys will be completed in the future.