The construction of a lunar base requires a huge amount of material, which cannot be entirely transported from Earth. Therefore, technologies are needed to build with locally available resources, such as the lunar regolith. One approach is to directly melt the lunar regolith on the surface and under the vacuum condition of the Moon, using laser radiation. In this article, a lunar regolith simulant is laser beam melted to two-dimensional single-layer-structures using different ambient pressures from 0.05 mbar to 2000 mbar, laser process parameters from 60 W to 100 W laser power, and 1 mm s−1 to 3 mm s−1 feed rates. Additionally, the influence of the ambient gas was investigated using argon as an air alternative. The results show that the ambient pressure on the Moon is not negligible when studying the melting processes of lunar regolith on Earth. With decreasing ambient pressure, the appearance of the melted regolith simulant varies from a shiny to a matt surface. At the highest laser energy density, the thickness of a single-layer increases from 2.6 ± 0.4 mm to 5.3 ± 0.3 mm and the porosity of the melted regolith increases from 17.2 % to 52.2 % with decreasing ambient pressure. Additionally, mechanical properties are determined using 3-point bending tests. The maximum bending strength decreases by 60 % with the increased ambient pressure from 10 mbar to 2000 mbar. Consequently, the development of in-situ resource utilization technologies, which process the lunar regolith directly on the lunar surface, must consider the ambient pressure on the Moon. Otherwise, the processes will not work as expected from the experiments in Earth-based laboratories.

中文翻译：

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环境压力对模拟月球风化层激光束熔化的影响


月球基地的建设需要大量的材料，这些材料不能完全从地球运输。因此，需要使用当地可用的资源进行建造的技术，例如月球风化层。一种方法是在月球表面和真空条件下，使用激光辐射直接熔化月球风化层。在本文中，使用 0.05 mbar 至 2000 mbar 的不同环境压力、60 W 至 100 W 激光功率的激光加工参数以及 1 mm s-1 至 3 mm s-1 的进给速率，将月球风化层模拟物激光束熔化为二维单层结构。此外，使用氩气作为空气替代品研究了环境气体的影响。结果表明，在研究地球上月球风化层的熔化过程时，月球上的环境压力不可忽视。随着环境压力的降低，熔化的风化层模拟物的外观从有光泽的表面变为无光泽的表面。在最高的激光能量密度下，单层的厚度从 2.6 ± 0.4 mm 增加到 5.3 ± 0.3 mm，随着环境压力的降低，熔化风化层的孔隙率从 17.2 % 增加到 52.2 %。此外，机械性能是使用 3 点弯曲测试确定的。随着环境压力从 10 mbar 增加到 2000 mbar，最大弯曲强度降低 60%。因此，直接在月球表面处理月球风化层的原位资源利用技术的开发必须考虑月球上的环境压力。否则，这些过程将无法像地球实验室实验中预期的那样进行。