Spark plasma sintering of HUST-1 lunar regolith simulant and its thermal shock resistance properties

Abstract

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 °C (±60 °C) and another from −120 to 120 °C (±120 °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 °C and ± 120 °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.