Integrated optimization of Martian regolith Sintering: Tailoring microstructure and performance in a mineralogically replicated simulant

Leveraging in-situ resource utilization (ISRU) to enable sustainable construction on Mars critically depends on understanding the inherent heterogeneity in particle size distribution and mineral composition of Martian soil. This study explores the vacuum sintering dynamics for mineralogically replicated BH-Mars-S simulant, unraveling the intricate interplay between granulometric characteristics and thermal processing parameters (1175–1250°C). Through comparative analysis of two distinct particle systems - fine (d₅₀ ≈ 12.7 μm) versus coarse (d₅₀ ≈ 127 μm) fractions - a remarkable 102 % enhancement in densification efficiency and 300 % enhancement in compressive strength was demonstrated through particle size optimization. Detailed microstructural investigations reveal that densification predominantly occurs via liquid-phase mechanisms facilitated by selective melting of plagioclase and pyroxene, while olivine and chromite maintain structural stability throughout the process. Particularly noteworthy is the precise control of sintering conditions, which also allows for modulation of thermal conductivity, providing additional design flexibility for Martian infrastructure. The study articulates a refined mineral-specific sintering mechanism, offering a comprehensive framework for optimizing the mechanical and thermal performance of regolith-based building materials for future Mars exploration.