Determining the feasible conditions for processing lunar regolith simulant via laser powder bed fusion

Additive manufacturing shows an intrinsic compatibility with building in extra-terrestrial colonization. The use of raw materials found in situ can drastically reduce the complexity of the material supply chain. Laser Powder Bed Fusion (LPBF) is a flexible option for producing components starting from powder feedstock. However, further understanding of the technological capabilities is required to resolve both deposition issues and process applicability in space. This work addresses the processability of lunar highlands regolith simulant NU-LHT-2 M by Laser Powder Bed Fusion on an open prototypal system. The investigation into the influence of process parameters and different base plate materials (carbon steel, self-supporting deposition and refractory clay) was enabled by the in-house developed LPBF machine. The process feasibility window for multi-layer deposition was determined on the refractory clay base plate which ensured stable deposition. Finally, process parameters were studied to produce multi-layer cubical samples which were further analysed for their mechanical properties. Specimens presented compressive yield stress values in excess of 31.4 MPa and micro hardness values in excess of 680 HV, showing the potential of the technology for the deposition of lunar regolith components. The results were also interpreted to assess the technological feasibility of future LPBF machines which may operate in micro gravity conditions.