Laser-Based Directed Energy Deposition with Mullite: A Necessary Step For Lunar Regolith Printing

Abstract

Additive manufacturing (AM) is pivotal in advancing in-situ resource utilization (ISRU) technologies for space exploration, enabling the construction of lunar infrastructure directly from local resources such as lunar regolith. Laser-based direct energy deposition(DED-LB) has shown potential for fabricating large-scale structures using regolith; however, the limited availability of lunar regolith necessitates the use of simulants. Mullite, a ceramic with chemical and thermal similarities to regolith, is a promising candidatefor such simulations. Despite progress in AM research, there remain critical gaps in understanding the high-temperature behavior and process parameters required for effective DED-based fabrication with mullite. This study investigates the high-temperaturecharacterization of mullite in the powder DED-LB process to determine optimal parameter sets, e.g., laser power, scanning speed, and substrate material, necessary for achieving a sound component. Using a combination of in-situ monitoring using short waveinfrared (SWIR) and microstructural analysis, the research defines a feasible process window and assesses the quality of printed parts. The results demonstrate mullite’s suitability as a lunar regolith simulant in DED-LB, contributing to the broader goal of developingISRU technologies for lunar base construction. This work advances the application of DED-based AM in space exploration and supports future lunar infrastructure development.

Keywords: Additive Manufacturing, Directed energy deposition, in-situ resource utilization, lunar regolith, mullite