Sintering of HUST-1 lunar regolith simulant

Abstract

Sintering is a feasible method for the in situ manufacturing of lunar construction materials with high utilization rates and good service durability. To investigate a feasible in situ sintering method for lunar construction materials, the HUST-1 lunar regolith simulant (LRS) was used as the only raw material in this study, and we compared the apparent state and physicomechanical properties of samples at different calcination temperatures in atmospheric and vacuum environments and explored the influence of the calcining environment and temperature on the mineral composition and morphology. The results indicated that the appropriate sintering temperature range of LRS in an atmospheric environment was 1050–1100 ℃, whereas under a vacuum environment it was 1000–1050 ℃. The main minerals of the vacuum-sintered HUST-1 LRS were consistent with the raw material below 1050 ℃, and the compaction of the microstructure improved with increasing sintering temperature. Finally, the influence of rough forming and sintering pressure in a vacuum environment was investigated. Starting with a powdery rough cylindrical body pre-compacted under 20 kN and sintered for 2 h at 1050 ℃ with 25 kPa vertical pressure resulted in an apparent density of 2768.56 kg/m3, with 89.83% compactness and 58.45–67.68 MPa compressive strength.