Real-time synchrotron X-ray lmaging of laser additive manufactured lunar Regolith simulant

For the successful development of a sustainable lunar base, autonomous in situ manufacturing is critical, with lunar laser additive manufacturing (2L-AM) emerging as a pivotal technology. Although laser powder bed fusion (LPBF) has demonstrated its potential to fabricate small components from lunar Regolith, significant challenges remain in producing larger structural parts with uniform mechanical properties due to the complex nature of the LPBF process and variability in Regolith powder composition. Here, an advanced in situ synchrotron X-ray imaging technique is used to investigate substrate influence and process instabilities during LPBF of lunar Mare Regolith simulant (LMS-1). The results show that LPBF of LMS-1 on Al6062 substrate can enhance melt pool formation due to its higher thermal conductivity, while fused silica is mostly transparent to the incoming near infrared laser beam. Laser scan speed significantly affects melt pool stability and melt pool geometry; with a stable conduction mode at 400 mm/s (depth of 231 ± 2 μm). The laser scan speed significantly impacts melt pool depth, increasing by 46 % when reduced to 300 mm/s. These findings provide crucial data for validating numerical models and optimising LPBF for lunar applications. • Substrate material choice impacts the manufacturing; Al6062 enables higher laser energy transfer than fused silica. • High laser energy causes process instabilities, demanding parameter optimisation. • Melt pool data aids in validating multiphysics models for Regolith laser manufacturing.