中文摘要：

空间3D打印技术对航天器维护及深空探测具有重要意义。结合金属材料3D打印技术的特点及空间的微重力环境,从热源适应性、材料适应性、成形工艺适应性等方面探讨了金属空间3D打印所面临的困难。在此基础上,提出了空间3D打印宜选取电子束或激光为热源、丝材为原料的技术方案,并简述了目前国际上3D打印技术在微重力环境下金属材料制备方面的研究现状,分析了微重力条件下金属材料凝固时气孔等凝固缺陷的形成及元素偏析行为。围绕空间站建设和载人深空探测需求,讨论了金属材料空间3D打印在空间站自我修复及金属构件在轨制备等方面的应用前景。

英文摘要：

3D printing technology in space is of great significance to the maintenance of spacecraft and deep space exploration. The difficulties of metal 3D printing in space were discussed from several aspects including the heat source adaptability,the material adaptability,the process adaptability and so on. On this basis,it is proposed that 3D printing in space should choose electron beam or laser as the heat source and wire as the input material state. The current status of 3D printing for metal hardware under micro-gravity was briefly introduced. The influence of reduced gravity on the solidification behavior and microstructures of metals was analyzed. Finally,the prospect of 3D printing in space station construction and manned deep space exploration was discussed.