At 18:00 on May 5, 2020, Changzheng No. 5 B carried a new-generation manned spacecraft test ship and a flexible inflatable cargo return cabin test cabin, and ignited from the Wenchang space launch site. After about 488 seconds, the load combination and the rocket successfully separated into the predetermined orbit, and the first flight mission of China's space station stage was successful.
In this task, the space application system led by the Chinese Academy of Sciences has arranged three scientific practical (test) tests on the new spacecraft test ship, such as on-orbit fine forming experiments, material friction behavior experiments, and microgravity measurement experiments. China's space station construction and operation, as well as moving to a more distant deep space, carry out prospective scientific research and technical verification.
The stereolithography 3D printing technology of the research team of the Space Application Center of the Chinese Academy of Sciences performs on-orbit manufacturing equipment for metal / ceramic composite materials with micron-level precision
Research on Space 3D Printing of Space Application Center of Chinese Academy of Sciences
The Long March 5B rocket successfully put China's new-generation manned spacecraft test ship into a predetermined orbit, which can provide a good research opportunity for China's space 3D printing.
In order to further improve the manufacturing accuracy and expand the spectrum of materials that can be used in space manufacturing, the "On-orbit Fine Forming Experimental Device" developed by the research team of the Space Application Center of the Chinese Academy of Sciences will innovatively use stereolithography 3D printing technology to perform micron-scale metal / ceramic composite materials. Precision on-track manufacturing.
Space weightlessness environment is one of the main challenges faced by stereolithography technology. Ordinary printing paste cannot maintain a stable shape under weightlessness conditions, and wall climbing will cause liquid level fluctuations to affect printing; through weightless aircraft at home and abroad, several 100 times of experiments under microgravity environment, the rheological behavior and internal mechanism of the slurry under weightlessness were analyzed, and the slurry was optimized by chemical and physical methods to change it from liquid to soft substance, which is unique to soft substances. Its yield stress resists deformation under weightless conditions, inhibits wall climbing, and it can restore good fluidity under the action of higher shear forces, ensuring smooth 3D printing.
In 2018, the Key Laboratory of Space Manufacturing Technology of the Chinese Academy of Sciences tested 3D printing under microgravity
It is understood that the CAS Key Laboratory of Space Manufacturing Technology (SMT) was established at the end of 2017. Relying on the Space Application Engineering and Technology Center of the Chinese Academy of Sciences, it is a scientific research centered on "space manufacturing technology". entity.
As early as June 13, 2018, researchers in the Key Laboratory of Space Manufacturing Technology of the Chinese Academy of Sciences (relying on the space application center) in Dubendorf, Switzerland, successfully completed the first international stereolithography of ceramic materials in a microgravity environment using European weightless aircraft Forming technology test and casting technology test under microgravity environment of metal material based on ceramic mold, obtained many intact manufacturing samples and rich experimental data.
Light-cured 3D printed ceramic samples under microgravity
3D printing metal samples under microgravity
The role and advantages of space 3D printing In general, when a certain tool or component is missing in the International Space Station, astronauts have to spend weeks or even months waiting for supplies to be sent from the ground. With a space 3D printer, technicians set up manufacturing procedures (that is, design model files) on the earth and send them to the International Space Station by email. The entire process takes less than a week; the actual printing time is only about 4 hour. The Antarctic Bear 3D Printing Network has learned that no matter whether it is the United States, Europe, or Russia, it has invested enthusiastic research in the field of space 3D printing.
The space 3D printer on the NASA International Space Station in the United States uses FDM melt extrusion. The polymer wire is melted into a liquid state by heating the nozzle and then extruded from the nozzle by mechanical force. Layer by layer. Image source NASA In 2014, the world's first space 3D printer developed by NASA arrived at the International Space Station, unveiling the prelude to human "space manufacturing".
The operating environment of 3D printing technology in space is very different from that of the earth, and the technical difficulty is also different. On the earth, relying on gravity, the heated plastic, metal or other materials extruded by the 3D printer can be naturally deposited, printing three-dimensional objects layer by layer. Under zero gravity in space, it is necessary to use a centrifuge that rotates at a given rate to ensure that the material is deposited in place, or modify the 3D printing process to make the device run smoothly. However, the original 3D printing technology based on the earth is easier to adapt to the moon and Mars with microgravity environment.