| Abstract Scope |
Welding is critical to 90% of durable goods manufacturing in America, but there are no welding processes proven for the In-space Servicing, Assembly, and Manufacturing (ISAM) sector. Studies are needed to develop basic capabilities and enhance process knowledge, which will support efforts to mature in-space welding for use in commercial, defense, and other aerospace applications. The current research seeks to build on past flights and improve understanding of materials joining in space conditions using laser beam welding (LBW). LBW offers several advantages compared to prior in-space electron beam welding experiments, amongst others: reduced electromagnetic interference, less exposure to ionizing radiation, and flexible delivery through optical fibers supporting unique workpieces and joints. This effort addresses LBW through parabolic flights augmented with data collection to enable modeling efforts that capture the physical effects of space environments. Future efforts will focus on LBW in low earth orbit (LEO) laboratories.
A team of Capstone and graduate students supported by NASA, the AFRL, and industry partners modified a vacuum chamber apparatus. The device was originally developed by NASA Langley Research Center for electron beam free-form fabrication, and the team replaced its electron gun with a 1 kW, 1070 nm Yb fiber laser to simulate vacuum, reduced gravity, and microgravity conditions. The apparatus was further instrumented with thermocouples and high-speed welding cameras to record changes in the thermal state of the workpiece, melt pool, laser penetration level, and development and orientation of spatter and plumes. The system will operate autonomously, demonstrating its utility to uncrewed missions. During upcoming parabolic flights in August 2024, this LBW equipment will weld aerospace alloys of aluminum, stainless steel, and titanium under conditions representative of in-space environments. This data will guide future integrated computational materials engineering efforts for LBW in space to qualify in-space welding as a viable ISAM technique. |