中国科学院地球化学研究所机构知识库

Space metallurgy is an interdisciplinary field that combines planetary space science and metallurgical engineering. It involves systematic and theoretical engineering technology for utilizing planetary resources in situ. However, space metallurgy on the Moon is challenging because the lunar surface has experienced space weathering due to the lack of atmosphere and magnetic field, making the microstructure of lunar soil differ from that of minerals on the Earth. In this study, scanning electron microscopy and transmission electron microscopy analyses were performed on Chang’e-5 powder lunar soil samples. The microstructural characteristics of the lunar soil may drastically change its metallurgical performance. The main special structure of lunar soil minerals include the nanophase iron formed by the impact of micrometeorites, the amorphous layer caused by solar wind injection, and radiation tracks modified by high-energy particle rays inside mineral crystals. The nanophase iron presents a wide distribution, which may have a great impact on the electromagnetic properties of lunar soil. Hydrogen ions injected by solar wind may promote the hydrogen reduction process. The widely distributed amorphous layer and impact glass can promote the melting and diffusion process of lunar soil. Therefore, although high-energy events on the lunar surface transform the lunar soil, they also increase the chemical activity of the lunar soil. This is a property that earth samples and traditional simulated lunar soil lack. The application of space metallurgy requires comprehensive consideration of the unique physical and chemical properties of lunar soil.