金属3D打印关键部件助力中国火星探测任务着陆与巡视

  5月15日7时18分，由中国航天科技集团五院总研制的天问一号火星探测器成功着陆火星，迈出了我国星际探测征程的重要一步，实现了从地月系到行星系的跨越。

  May 15th, the Tianwen-1 Mars rover developed by the fifth institute of China Aerospace Science and Industry Corporation successfully landed on Mars, taking an important step in China’s interstellar exploration journey and realizing the transition from the Earth-Moon system to the planets system.

  安装在中国火星探测器“天问一号”前方的避障摄像机拍摄的黑白图像表明，着陆器上的坡道已延伸至火星表面。 在图像中清晰可见流动站前进方向的地形，并且由于广角镜的作用，火星的地平线显得弯曲了。 来源：新华网

  Picture:The black and white image taken by an obstacle avoidance camera installed in front of the rover of China’s Mars probe Tianwen-1 shows that a ramp on the lander has been extended to the surface of Mars. The terrain of the rover’s forward direction is clearly visible in the image, and the horizon of Mars appears curved due to the wide-angle lens. Source: XInhuaNet

  © 中国国家航天局/China National Space Administration

  火星距离地球遥远、昼夜环境温差大，对深空探测器的结构轻量化和多功能一体化提出了更高要求，传统结构技术难以满足其性能指标要求，金属3D打印实现了火星探测任务关键技术支撑。

  Mars is far away from the earth and the temperature difference between day and night is large, which puts forward higher requirements for deep space probes with the extreme lightweight and integration of multi-functional design concept. Hence traditional technology cannot meet the requirements of such performance requirements.

  设计、材料、设备、工艺多方面攻关

  五院总体设计部作为火星探测器的抓总单位和结构机构分系统研制单位，采用金属3D 打印技术和跨尺度结构优化设计方法，联合北京卫星制造厂、北京理工大学、大连理工大学、西北工业大学、南京航空航天大学、西安铂力特增材技术股份有限公司、沈阳精合数控科技开发有限公司等国内优势团队，围绕面向3D打印结构设计、3D打印专用材料研发、3D打印专用装备研制及制造工艺开展联合攻关。

三、四、六折旋转对称的第二、第三、第四、第四级点阵单元的设计

  /Design of the second, third, fourth hierarchical level lattice cells with (a) three-, (b) four-, (C) six-fold rotational symmetries

  来源：Paper of <Design of self-supporting lattices for additive manufacturing>, Journal of the Mechanics and Physics of Solids

  The overall design department of the fifth institute of China Aerospace Science and Industry Corporation as the project leader of the development of the Mars rover and the development of the sub-system of the structure, has developed cross-scale structural optimization design methods, and by cooperation with Beijing Satellite Manufacturing Factory, Beijing Institute of Technology, Dalian University of Technology, Northwestern Polytechnical University, Nanjing University of Aeronautics and Astronautics, Xi’an BLT Additive Technology Co., Ltd, Shenyang TSC Numerical Control Technology Development Co., Ltd. and other domestic partners. The team have put great efforts to focus on further development of the 3D printing structure design, 3D printing special material research, 3D printing special equipment research and 3D printing manufacturing technology control.

   金属3D打印实现火星探测任务关键技术支撑

  项目突破了基于金属3D打印的轻量化三维点阵结构技术，解决了深空探测器复杂结构部件的轻量化设计、功能集成与整体制造难题。完成了祝融号火星车相变储能装置结构及承载结构合计30余套关键部件的设计与正样应用。大幅减少结构件数量，实现了产品减重40%~60%，研制周期缩短50%。

  The joint research has achieved some broken through in the ultra-lightweight metal three-dimensional lattice structure technology, and solve the lightweight design of the complex structure of the deep space detector, and realize the function integration of extremely complex structures. The team finalized the design and application of totaling above 30 pieces/set of key components. The number of structural parts is greatly reduced, the weight of the product is reduced by 40% to 60%, and the development cycle is shortened by 50%.

相变储能装置结构（图片为研制阶段示意图）

/Phase change energy storage device structure

  Note: The picture is the schematic diagram of the development stage

  © 中国空间技术研究院总体设计部

  连接角盒结构（图片为研制阶段示意图）

  /Connecting corner box structure

  Note: The picture is the schematic diagram of the development stage

  © 中国空间技术研究院总体设计部

  上述金属 3D打印部件在天问一号探测器及祝融号火星车的成功应用，体现了金属 3D 打印先进结构技术对于我国自主火星探测任务的关键技术支撑，具有标志性意义。

  The successful application of the metal 3D printed parts in the Tianwen-1 probe and Zhurong Mars rover demonstrates metal 3D printing played the key role to pave the technical way out for the successful Mars exploration mission.

  该研究成果得到了国家重点研发计划、装发共用技术项目、国防基础科研项目、国家自然科学基金和中国科协青年人才托举工程等项目的支持。

航天科技五院总体设计部是我国组建成立最早、总体领域最多、专业技术最齐备的空间飞行器研制核心总体单位，该部结构与机构技术研究室在3D 打印结构技术方面开展了大量研究工作，提出了增材制造自支撑三维点阵结构设计方法，相关成果发表在JMPS、IJSS、AIAA Journal、CJA等国内外高影响力学术期刊，并且实现了在火星探测器、中国空间站、千乘一号卫星、高分十四号卫星、中巴地球资源04A 卫星等型号的在轨应用，大幅提升结构产品的功能性能。

  [1] Zhou, H., et al. 2021. Design of self-supporting lattices for additive manufacturing. J. Mech. Phys. Solid. 148, 104298.

  [2] Li, C., et al. 2020. Architecture design of periodic truss-lattice cells for additive manufacturing. Addit. Manuf. 34, 101172.

  [3] Zhou, H., et al. 2019. Lightweight structure of a phase-change thermal controller based on lattice cells manufactured by SLM. Chinese J. Aeronaut. 32(7), 1727-1732.

  [4] Zhang, X., et al. 2018. Vibration Tests of 3D Printed Satellite Structure Made of Lattice Sandwich Panels. AIAA J. 56(10):4213-4217.

  [5] Liu, C. et al. 2020. Optimal design of shell-graded-infill structures by a hybrid MMC-MMV approach. Comput. Methods Appl. Mech. Engrg. 369, 113187.