Physical, mechanical and thermal properties of vacuum sintered HUST-1 lunar regolith simulant

Establishing a base on the Moon is one of the new goals of human lunar exploration in recent years. Sintered lunar regolith is one of the most potential building materials for lunar bases. The physical, mechanical and thermal properties of sintered lunar regolith are vital performance indices for the structural design of a lunar base and analysis of many critical mechanical and thermal issues. In this study, the HUST-1 lunar regolith simulant (HLRS) was sintered at 1030, 1040, 1050, 1060, 1070, and 1080 °C. The effect of sintering temperature on the compressive strength was investigated, and the exact value of the optimum vacuum sintering temperature was determined between 1040 and 1060 °C. Then, the microstructure and material composition of vacuum sintered HLRS at different temperatures were characterized. It was found that the sintering temperature has no significant effect on the mineral composition in the temperature range of 1030–1080 °C. Besides, the heat capacity, thermal conductivity, and coefficient of thermal expansion (CTE) of vacuum sintered HLRS at different temperatures were investigated. Specific heat capacity of sintered samples increases with the increase of test temperature within the temperature range from −75 to 145 °C. Besides, the thermal conductivity of the sintered sample is proportional to density. Finally, the two temperatures of 1040 and 1050 °C were selected for a more detailed study of mechanical properties. The results showed that compressive strength of sintered sample is much higher than tensile strength. This study reveals the effects of sintering temperature on the physical, mechanical and thermal properties of vacuum sintered HLRS, and these material parameters will provide support for the construction of future lunar bases.