An apparatus to study arc-wire direct energy metal deposition additive manufacturing process in a drop tower microgravity platform.

This article focuses on the design and demonstration of an experimental apparatus to study molten metal droplet transfer in a consumable electrode wire-based Directed Energy Deposition arc (DED-arc) process under microgravity conditions using a 30.5-meter drop tower. The setup integrates a compact Gas Metal Arc Welding (GMAW) system, a linear traverse stage for single bead deposition, high-speed imaging, sensors (including accelerometers, thermocouples, and Hall effect sensors), and wireless communication modules within a capsule engineered to withstand high deceleration forces during free fall and landing. The apparatus successfully captured synchronized high-speed images and sensor data during 2.5 seconds of microgravity, providing foundational insights into metal transfer dynamics critical for advancing additive manufacturing capabilities in space. Future work aims to expand the system for 3D metal printing and explore varied welding parameters and materials to further understand microgravity effects on droplet transfer and weld quality.