The mechanical and thermal properties of the fabricated structures composed of lunar regolith are of great interest due to the urgent demand for in situ construction and manufacturing on the Moon for sustainable human habitation. This work demonstrates the great enhancement of the mechanical and thermal properties of CUG-1A lunar regolith simulant samples using spark plasma sintering (SPS). The morphology, chemical composition, structure, mechanical and thermal properties of the molten and SPSed samples were investigated. The sintering temperature significantly influenced the microstructure and macroscopic properties of these samples. The highest density (similar to 99.7%), highest thermal conductivity (2.65 W.m(-1).K-1 at 1073 K), and the best mechanical properties (compressive strength: 370.2 MPa, flexural strength: 81.4 MPa) were observed for the SPSed sample sintered at 1273 K. The enhanced thermal and mechanical properties of these lunar regolith simulant samples are attributed to the compact structure and the tight bonding between particles via homogenous glass.

The construction of lunar bases has become a new target for lunar exploration by many space powers worldwide. Sintered lunar regolith is one of the most promising building materials for in situ resource utilization (ISRU). Spark plasma sintering (SPS) technology has the advantageous features of a fast sintering speed and high density. This study explored the feasibility of sintering a HUST-1 lunar regolith simulant using SPS technology. The physical, mechanical, and thermal properties, as well as the microstructure and phase composition of the sintered samples were investigated at multiple scales. In addition, the effects of the SPS conditions on the sintering results were studied, including the sintering temperature, heating rate, and applied pressure. The test results indicated that the sintering conditions significantly affected the sintered products. Finally, the thermal shock resistances of the sintered samples were investigated at simulated lunar temperatures. The samples were treated at two different temperature ranges, one from -60 to 60 degrees C (+60 degrees C) and another from -120 to 120 degrees C (+120 degrees C). The results showed that the sintered samples exhibited excellent thermal shock resistance in the extreme temperature environment of the lunar surface. After 100 thermal test cycles at + 60 degrees C and + 120 degrees C, the compressive strength increased by 16.0 % and 33.4 %, respectively. The reason for the increase in strength remains unclear. The Brunauer-Emmett-Teller (BET) test results showed that this may be caused by the gradual disappearance of micropores smaller than 10 nm during thermal cycling. (c) 2023 COSPAR. Published by Elsevier B.V. All rights reserved.