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Manufacturing
Advanced Thermal Management for ISRU (In-Situ Resource Utilization) Additive Manufacturing
Lunar regolith presents unique challenges for laser-based additive manufacturing. Unlike conventional metal or ceramic powders, regolith is a heterogeneous mixture of ceramics, metals, metal oxides, and minerals. During laser processing, each constituent undergoes independent phase transitions, creating material behavior variations between layers. Excessive heat causes dissociation and gas bubble formation, while rapid cooling traps porosity. The glassy components are particularly sensitive; once melted, they cannot return to their original state, and improper thermal management during re-melting causes crystalline structure failures and anisotropy throughout parts.
This methodology addresses these challenges through coordinated thermal control across the build. Custom scan patterns and beam-shaping optics maintain target temperature ranges across the processing area while controlling heating and cooling rates. Layer height, hatch spacing, scan pattern, re-heating intervals, laser power, and inter-layer dwell times are precisely coordinated to manage the sequential phases of melting, nucleation, grain growth, and annealing. Previous layers of unsintered regolith act as insulation and as a controlled quench medium, maintaining temperature and preheating subsequent layers.
A dedicated build plate is not required; a firebrick build plate has been used to support rapid, quick-turn parameter development in a laboratory setting. Real-time thermal imaging monitors the process. The methodology has been demonstrated in sustained operation within a thermal vacuum chamber at 10e-6 Torr, replicating the operational environments for lunar and Martian surface manufacturing. The amorphous vitrified glass process is at TRL 5; glass-ceramic components are currently undergoing validation for final strength claims. This advanced thermal management process is available for patent licensing.



