Using 3D computer technology, the additive manufacturing technology of building objects by layer-by-layer accumulation of materials is increasingly becoming the forefront of space equipment manufacturing. Scientists believe that 3D printing can significantly accelerate the development of extraterrestrial space. How to optimize the "space manufacturing" of 3D printers and improve the safety of printed components? How to use new technologies to create ultra-light optical systems for nanosatellites? Researchers from Russian universities (members of the "5-100" project) introduced their latest developments.
One of the main advantages of the new method is that a 3D printer can replace a large number of equipment in a traditional factory. In November 2020, Forbes magazine included additive manufacturing technology (from the Latin additivus-add) on the list of five revolutionary new technologies worthy of the attention of entrepreneurs. The author of the article pointed out that additive manufacturing technology will bring huge benefits to the aerospace industry. In this field, product weight is usually the most important factor affecting transportation costs.
Space 3D printing can significantly accelerate the development of extraterrestrial space; additive manufacturing technology is also actively penetrating the rocket manufacturing industry.
On May 30, 2020, the helmets of astronauts Robert Bacon and Doug Hurley who participated in the launch of the Crew Dragon spacecraft and Falcon 9 rocket were tailored using 3D printing technology.
Elon Musk, head of SpaceX Aerospace Corporation, said that using 3D printing, durable high-performance engine parts can be manufactured, and the time and money spent are only a small part of using traditional manufacturing methods. In 2014, SpaceX had already manufactured the first 3D printed component.
"Blue Origin" aerospace company Jeff Bezos uses additive manufacturing technology to print BE-4 engine components. Young rocket companies from the United States (Relativistic Space) and the United Kingdom (Obex) also plan to take full advantage of the possibilities of 3D printers.
Improve the safety of 3D-components
At the same time, even the smallest defects in 3D printed components are vital to the safety of the equipment created. Scientists at the National Research University of Technology MISIS (NUST MISIS) were able to improve the 3D printing technology of aluminum and increase the hardness of the product by 1.5 times.
NUST MISIS researchers believe that the main risk of such defects is the high porosity of the material, one of the reasons is the characteristics of the original aluminum powder. In order to ensure that the microstructure of the printed product is uniform and dense, scientists have proposed a method of adding carbon nanofibers to aluminum powder to ensure low porosity of the material and increase its hardness by 1.5 times. The research results are published in the "Composites Communications" magazine.
Professor Alexander Gromov of NUST MISIS said: "Carbon nanofibers have high thermal conductivity, which helps to minimize the temperature gradient between the printing layers during the selective laser melting stage during the product synthesis process. Therefore, the material The inhomogeneity of the microstructure can be almost completely eliminated."
The carbon nanofibers used are a by-product of processing oilfield associated gas. During its catalytic decomposition process, carbon accumulates in the form of nanofibers on the metal particles dispersed by the catalyst. Scientists also pointed out that the associated gas is usually "vented and burned" in oil and gas fields, causing harm to the environment, so the use of this new method has important environmental protection significance.
Optimize "Space Manufacturing"
Elon Musk and other experts are convinced that 3D printing can help future space development, such as colonizing Mars.
To survive on Mars, you need to be able to start production there, and best use local materials. The 3D printer can be used to build a base and build a living environment there.
Even now, in the work of the International Space Station (ISS), the problem of obtaining materials is still serious, and the astronauts of the next cargo spacecraft have to wait several months. Sometimes important small parts are damaged or lost, for example, the plastic plug of the electrical contact is often lost. In this case, 3D printers can solve this problem by printing plastic products in space. In the future, during interstellar flights, availability issues will become more acute, and the demand for such printers will inevitably increase.
In 2016, NASA commissioned Made in Space to install a permanent 3D printer on the International Space Station to produce tools, equipment, and anything else that astronauts might need. Subsequently, some European, Chinese and other companies also announced the manufacture of similar machines.
The researcher who developed the 3D printer, a scientist at Tomsk University of Technology (TPU), said that the 3D printer produced in Russia will enter space in 2021. Its advantage is a more advanced modular system that can realize equipment upgrades and maintenance. Therefore, when 3D printing materials switch from simple plastics to superstructures or composite materials, engineers will not have to build new printers like their American colleagues today and then deliver them to ISS.
Vasily Fedorov, head of TPU's modern production technology science and production laboratory, said: "Now, the work layout of the 3D printer is in the final stage. The equipment sent to the ISS has strict resistance to machinery, weather and other loads. Requirement. In addition, to ensure that the 3D printer is absolutely safe for astronauts. Now, all of this is under inspection, and a series of tests and inspections have been carried out. At the same time, the software set up specifically for the printer has been improved."
Create ultra-light optical systems for nanosatellites
The possibility of 3D printing allows scientists at Samara University to create a unique ultra-light optical system for nanosatellites with diffractive optics. Researchers say this will be the world's first lens with diffractive optics to enter space.
The core of the optical system is the plane diffractive lens developed in the university, which has unique characteristics. The lens based on this lens replaces the lens system of the modern long-range lens, and its characteristics are light weight (with optical components weighing less than 100 grams) and small size.
The lens has an innovative bionic shape shell and is designed with the best technology to minimize weight while maintaining strength characteristics. The complex external shape and internal structure of the spacecraft components are 3D printed on the SLM280HL selective laser fusion equipment.
According to scientists, in order to reduce the weight of the components as much as possible, topology optimization has been carried out in its internal structure, as a result of which special honeycomb blocks have been added. The size of the part is 70×80×100 mm. Due to the use of additive manufacturing technology, its weight is about 40% lighter than similar parts manufactured by traditional methods.
Vitaly Smailov, an associate professor in the Teaching and Research Office of Engine Production Technology at Samara University, said: "The lens shell is made of AlSi10Mg aluminum alloy powder. The alloy produced in Russia enjoys a high reputation both in Russia and abroad. In the field of aerospace and aviation , Weight is the main feature, and the industry has been trying to reduce this indicator."
Scientists performed multi-stage topology optimization of the original structure, obtained and analyzed several forms.
Anton Agapovich, a researcher at the University of Samara, said: "We have cooperated with experts in the field of CADFEM CIS topology optimization and additive manufacturing technology and have done a lot of work to obtain a new type of structure to meet the needs of the world aerospace industry Modern requirements."
According to scientists, similar products, such as the lens of the CubeSat Gecko Imager (Gecko Imager), cost 23,000 Euros, and the price of the optical system they are developing will be much lower.
The "5-100" plan implemented within the framework of the national "education" project aims to help Russian universities increase their scientific research potential and improve their competitive position in the global education service market.