The lunar base is not only an experimental station for extraterrestrial space exploration but also a dwelling for humans performing this exploration. Building a lunar base presents numerous obstacles and requires environmental perception, feedback design, and construction methods. An integrated fabrication process that incorporates design, 3D printing workflow, and construction details to build a bionic, reconfigurable and high-performance lunar base prototype is presented in this paper. The research comprises the study of the lunar regolith 3D printing mechanism, the real-time control of powder laying and compaction procedure, and the development of a 3D printing tool end system. In this paper, many scientific questions regarding in situ fabrication on the lunar surface are raised and addressed with the proposal of a progressive optimization design method, the molding principle, and gradation strategy of lunar soil-polyaryletherketone (PAEK) hybrid powder, and the principle of dual-light field 3D laser printing. The feasibility of the technical strategy proposed in this paper is verified by the presented empirical samples.
A martensitic stainless steel AISI420 fabricated by selective laser melting (SLM) and post-processed by austenitizing and tempering heat treatment was investigated in this study. The as-fabricated SLMed AISI420 showed a strong mechanical property anisotropy and low ductility in the longitudinal direction. Detailed microstructural characterization revealed the presence of austenite and a relatively sharp solidification texture in the as-fabricated state, while the sharp texture was considered as the cause for the mechanical property anisotropy. In contrast, a fully martensitic microstructure with a very weak texture was achieved after the austenitizing and tempering heat treatment. The mechanical property anisotropy was also fully eliminated, witnessing a significant improvement in the ductility, and thus, comparable mechanical performance with the wrought product was achieved in this study.