Application of 3D Printing Technology in the Military Field

Application of 3D Printing Technology in the Military Field

3D printing technology has emerged since the 1980s, primarily used for creating models and prototypes. With the improvement of printer resolution and material strength, 3D printing technology has developed rapidly and has been widely applied in the military field, which will have a disruptive impact on future combat support.

1. The Connotation, Development History, and Advantages of 3D Printing Technology

1.1 The Connotation of 3D Printing Technology

3D printing technology, also known as additive manufacturing, is a type of rapid prototyping technology. It is a technology that constructs objects layer by layer using powdery metals or plastics as binding materials based on digital model files, integrating electronic drawing, remote data transmission, laser scanning, and material melting technologies. 3D printing is typically implemented using digital technology material printers and has been used in various fields such as mold manufacturing, industrial design, aerospace, medicine, and civil engineering. Common materials used in 3D printing include nylon fiber, durable nylon, gypsum, aluminum, titanium alloy, stainless steel, and rubber materials.

The working principle of 3D printing is similar to that of ordinary printing. The printer is equipped with liquid or powder “printing materials” and is connected to a computer. The computer controls the layering of the “printing materials,” turning the blueprint on the computer into a physical object. This technology is referred to as 3D stereoscopic printing technology. The operation process can be roughly divided into three steps: creating data, printing, and post-processing: 1) Creating data, which involves creating a three-dimensional model of the material to be produced and processing the model into layers. This operation is achieved using computer-aided design software, and a 3D scanner generates a model of the object by scanning the finished product. Layer processing divides the three-dimensional structure into multiple two-dimensional sections, laying the groundwork for later production. 2) The printing process involves using printing equipment to professionally integrate the data from the model, then layering the materials according to the device’s requirements, completing the layering of each section, and finally fusing them in order to reveal the final product’s shape. 3) Post-processing mainly includes the removal of the finished product from the support material, polishing, and other treatments. Some materials may require reinforcement processing, which can be flexibly adjusted according to the different workpieces.

1.2 Development History of 3D Printing Technology

In 1986, American scientist Charles Hull developed the first commercial 3D printer. In 1993, the Massachusetts Institute of Technology obtained a patent for 3D printing technology. In 1995, ZCorp obtained exclusive authorization from MIT to develop 3D printers. In 2005, ZCorp successfully developed the world’s first high-definition color 3D printer, the Spectrum Z510. In November 2010, the Jim Kor team in the USA created the world’s first car, Urbee, made entirely from a 3D printer. In August 2011, engineers at the University of Southampton developed the world’s first 3D-printed airplane. In November 2012, Scottish scientists printed artificial liver tissue using human cells for the first time with a 3D printer. In May 2013, engineers at Princeton University used 3D printing technology to create the world’s first bionic ear, capable of receiving sound and ultrasound signals. In November 2013, Solid Concepts in Austin, Texas, designed and manufactured a 3D-printed metal handgun. In November 2014, 3D printing technology was named one of the best inventions of the year by Time magazine.

On December 10, 2018, Russian astronauts used a 3D bioprinter on the International Space Station to print a thyroid gland of a laboratory mouse in zero gravity. On January 14, 2019, researchers at the University of California, San Diego, published a paper in Nature Medicine, reporting the first use of rapid 3D printing technology to create a spinal cord scaffold mimicking the structure of the central nervous system, which successfully helped rats with severely damaged spinal cords regain motor function after being implanted with neural stem cells. On April 15, 2019, researchers at Tel Aviv University in Israel 3D printed the world’s first “complete” heart with cells, blood vessels, ventricles, and atria using the patient’s own tissues, a first in the world.

1.3 Advantages of 3D Printing Technology

3D printing technology integrates “concept design,” “technical verification,” and “production manufacturing,” with advantages in simplicity, ease of operation, and customization according to demand. Specifically, this is reflected in the following aspects:

1) Unlimited Design Space.Traditional manufacturing technologies limit the shapes of products, constrained by the tools used. For example, traditional wooden lathes can only make circular items, and mills can only process components assembled with milling cutters. However, 3D printers can break through these limitations, opening vast design spaces and creating products that are difficult or impossible to process using traditional techniques.

2) Improved Product Design.Traditional prototypes are handmade using foam or clay. Rapidly creating concept models through 3D printing allows better communication between designers and clients, enabling quick adjustments to initial designs and continuous improvements. Items made with 3D printing possess properties such as high-temperature resistance and chemical corrosion resistance, allowing various performance tests to refine final product design parameters, significantly shortening the time from design to production. 3D printing accelerates the design process and continually improves aspects such as product safety, ergonomic design, marketing, and design.

3) Diversified Production Without Increased Costs.For traditional manufacturing, the more complex the shape of an object, the higher the manufacturing cost. However, for 3D printers, the cost of producing complex-shaped items does not increase accordingly. Additionally, traditional manufacturing equipment has limited functions, resulting in a limited variety of product shapes. A single 3D printer can print different shapes, enabling diverse production without increasing costs.

4) No Need for Assembly.3D printing features integrated forming, reducing labor and transportation costs. Traditional mass production relies on industrial chains and assembly lines; the more components a product has, the longer the supply chain and product line, leading to higher time and cost for assembly and transportation. 3D printing’s integrated forming feature eliminates the need for reassembly, thus shortening the supply chain and saving on labor and transportation costs.

5) Shortened Delivery Time.3D printing can produce items on demand, significantly reducing inventory levels for businesses. Companies can start 3D printers based on user needs, creating customized products to meet customer demands. If the required items can be produced nearby on demand, this zero inventory, zero time delivery production method can also reduce long-distance transportation costs.

6) Lower Manufacturing Skill Barriers.Traditional manufacturing machines require skilled professionals for machine adjustments and calibrations, often taking years to train a proficient worker. The operational skills required for 3D printers are significantly lower than traditional equipment, greatly reducing the barriers to production skills and providing printing services in remote or extreme environments.

7) Space Saving, Portable Manufacturing.3D printers can move freely and create objects larger than their own size. For example, injection molding machines can only produce much smaller objects, while some 3D printers can create much larger items. This is due to the smaller physical space required for 3D printers.

8) Material Conservation.Traditional metal processing has significant waste, with some refined production even leading to a 90% loss of raw materials. The waste from 3D printers is significantly reduced, and with advancements in printing materials, 3D printing “net shaping” manufacturing will become a greener and more environmentally friendly processing method.

9) Unlimited Material Combinations.Traditional manufacturing machines find it challenging to combine multiple raw materials during cutting or mold forming processes, while raw materials for 3D printing can be combined freely to create desired performance structures. For example, nylon-glass fiber or nylon-carbon fiber composites can enhance nylon’s mechanical properties, while adding 50% titanium metal to nickel alloy powder can significantly improve performance.

10) Accurate Physical Replication.3D printing technology is expected to extend digital precision into the physical world across the entire manufacturing field. 3D scanning and 3D printing technologies will jointly enhance the resolution of shape transformations between the physical and digital worlds, narrowing the gap between the physical world and the digital age.

2. The Disruptive Impact of 3D Printing Technology on the Military Field

In January 2014, the Bulletin of the Atomic Scientists in the USA stated that five military technologies, including unmanned systems, autonomous systems, network weapons, 3D printing technology, and directed energy weapons, will have a profound impact on the US military in the next decade. In November 2014, National Defense Magazine in the USA considered that ten disruptive technologies, including laser communication technology, 3D printing technology, new energy technologies, new biomedical technologies, autonomous unmanned systems, hypersonic weapons, and holographic training technologies, would significantly impact future military construction and command operations.

The US Department of Defense has established a task force for additive manufacturing to develop an integrated strategic vision, promoting tactical implementation of 3D printing technology cooperation to support the Department of Defense’s global weapon system maintenance plans. The activities of this enhanced manufacturing task force include selecting and prioritizing opportunities for 3D printing technology applications, coordinating and standardizing 3D printing manufacturing activities, and incorporating 3D printing technology into the Department of Defense’s maintenance processes and procedures. The US Army has deployed two mobile remote laboratories to Afghanistan, which can quickly produce required parts by processing aluminum, plastic, and steel using 3D printers and computer numerical control devices, achieving rapid prototyping in the combat zone.

Scientists and engineers at BAE Systems in the UK predict that in the future, if pilots need drone support during combat missions, they will be able to print the required equipment on-site using 3D printing technology, with relevant technology expected to be realized before 2040. The specific process involves: the pilot requests a drone; engineers at the rear send technical data to the 3D printer on the aircraft, usually the 3D printing engineering drawings of the required drone’s components; the pilot uses the 3D printer to print a drone that meets the mission requirements in terms of size, flight distance, and payload.

In weapon equipment development and production, engineers can use 3D printing technology for creative validation and mold production according to actual requirements, directly printing some special and complex structural parts while effectively achieving lightweight structural components. 3D printing technology integrates concept design, technical verification, and production manufacturing, allowing anything designed in three dimensions using a computer to be manufactured by a 3D printer. This will greatly shorten the time difference from “concept” to “finalization” of weapon equipment, significantly reducing the design and development cycle of new weapons and greatly saving defense expenditures, fundamentally enhancing the performance and production efficiency of weapon equipment. In the production process of weapon equipment and its accessories, there is no need for original blanks and molds; 3D printers can directly “print” high-precision weapon equipment and accessories based on computer graphic data, with almost no waste in the entire production process. Assessments indicate that if the 3,100 F-35 fighter jets planned for production by the US military were entirely manufactured using 3D technology, it could save billions of dollars in costs.

In weapon equipment maintenance, 3D printing technology will disrupt traditional material support methods. The flexible maintenance capabilities of 3D printing technology play a significant role in weapon equipment maintenance, allowing for the rapid manufacturing of spare parts and maintenance tools during wartime, greatly enhancing the efficiency of wartime weapon equipment maintenance support. Once a part is damaged, as long as there is 3D model data for the part, it can be produced and applied to the equipment in the shortest time possible, without waiting for the supplier’s factory to manufacture it, ensuring emergency repairs of weapon equipment during wartime. Using the same amount of consumables to produce maintenance equipment, the production efficiency of 3D printers is three times that of traditional methods. In August 2012 and January 2013, the US military deployed mobile 3D printing laboratories to Afghanistan, producing required parts on-site from materials such as aluminum, plastic, and steel, including individual protective equipment and weapon parts. Optomec, an American company, used 3D printing technology to repair high-value aerospace metal components for the US Air Force; the Anniston Army Depot repaired the gas turbine of the M1 Abrams tank, achieving significant results. The US Navy’s Undersea Warfare Center has already utilized 3D printing technology for the repair of old parts and tools. Today’s battlefield support mainly relies on rear supply; in the future, it will shift to a “DIY” (Do It Yourself) model on the front lines, where soldiers can use 3D printing technology to perform real-time repairs of parts, providing supplies, food, and medicine.

The application scenarios of 3D printing technology in military electronics have begun to emerge. Researchers at the University of California, Berkeley, have used 3D printing technology to create organic bottom gate field-effect transistors. The University of Illinois has printed three-dimensional micro curved antennas. Shenzhen Weihang Magnetic Electric Co., Ltd. in China used 3D printing technology in 2013 to create Hilbert satellite GPS antennas, achieving better performance than four-arm spiral antennas. The US military’s “Flexible Electronics and General Armament Manufacturing” program is developing 3D printing technology for the production of various components and materials to be integrated into typical munitions, including metal casings, new conductive “inks” for electronic tracking and capacitors, and improved energetic material formulations compatible with printing. Directly printing electronic devices can utilize space more effectively than conventional methods and reduce waste. For example, simplifying electronic devices inside or outside weapon systems into printable formats can reduce weight and size while freeing up internal space; printing radio antennas on soldiers’ helmets and embedding electronic components into soldiers’ uniforms not only reduces carrying weight but also aids the wearer’s mobility.

3. The Future Prospects of 3D Printing Technology in the Military Field

3.1 Application in Military Aviation

Lockheed Martin in the USA has used 3D-printed titanium alloy parts from Sciaky on the wing beams of the F-35 fighter jet, which have undergone flight testing. The two companies have also jointly developed titanium alloy supports for the F-22 fighter jet, which have passed full-life spectrum fatigue tests and load tests. Using 3D printing technology for reverse replication, obsolete fighter jets can produce parts that are no longer in stock. Additionally, existing fighter jet components can be redesigned and remanufactured. To maintain aircraft and enhance their combat capabilities, the US Air Force and OC-ALC are developing a strategic plan to incorporate 3D printing technology into current air power. OC-ALC aims to optimize workflows using 3D printing technology, including additive manufacturing of aircraft engine components and 3D printing of modern electronic components designed by the 76th Software Maintenance Group. In August 2014, a research team at the University of Virginia manufactured nine body parts of a 0.8 kg “Razor” small drone using 3D printing technology, taking a total of 31 hours. The manufacturing process utilized fused deposition modeling, where molten materials were layered to form the required structure, and the drone’s motors, servo systems, autopilot, and batteries were commercial products.

The University of Southampton in the UK completed the manufacturing of the first 3D-printed airplane, which has passed testing. The airplane has a wingspan of 2 meters, a maximum speed of 100 meters/min, and is equipped with automated driving devices for cruising. A Tornado fighter jet equipped with 3D-printed metal parts successfully completed its test flight, with the 3D-printed components including a radio protection cover for the cockpit, landing gear protection devices, and intake strut. In 2013, the European Aeronautic Defence and Space Company used 3D printing technology to manufacture prototypes of micro-drones and temporary parts for drones using thermoplastic materials. In January 2014, a “Tornado” fighter jet, which included 3D-printed parts (including the cockpit radio protection cover, landing gear protection devices, and intake struts), completed its test flight and was regarded by British media as a landmark event in the large-scale use of 3D printing technology in aerospace manufacturing, marking the first successful test flight of a fighter jet equipped with 3D-printed components.

On June 22, 2015, the Russian Technology Group Company manufactured a prototype drone weighing 3.8 kg, with a wingspan of 2.4 meters and a flight speed of 90 to 100 kilometers, with a range of 1 to 1.5 hours, using 3D printing technology. The company achieved a leap from concept to prototype in two and a half months, with the actual production taking only 31 hours at a cost of less than $3,700. The unique feature of this drone is its ability to take off and land on any surface, with a control range of up to 2,500 kilometers at an altitude of 6,000 meters, and an effective payload of 300 kilograms, capable of carrying 2-3 passengers or luggage or carrying detection and monitoring equipment; the air cushion can be recovered during flight mode for military operations, such as carrying small guided missiles and high-precision bombs as offensive weapons, and can also perform reconnaissance missions.

China’s first aircraft carrier, the Liaoning, widely uses 3D printing technology to manufacture titanium alloy main load-bearing components, including the entire front landing gear. China has also adopted 3D printing technology in the development of the J-20 and J-31 fighter jets. COMAC and Northwestern Polytechnical University have jointly tackled the challenge of using 3D printing technology to manufacture the central wing edge strips of the C919 large passenger aircraft. The components of this passenger aircraft were processed using laser-formed parts with a maximum size of 3070 mm and a maximum deformation of less than 0.8 mm. All mechanical properties passed the tests conducted by the aircraft manufacturer, and the material properties, structural performance, part sampling performance, and segment strength all met the design requirements for the domestically produced large passenger aircraft C919, with comprehensive performance, including fatigue performance, also superior to traditional forging technology. AVIC and the Beijing University of Aeronautics and Astronautics have collaborated to combine full three-dimensional digital design technology with 3D printing technology, successfully printing multiple aircraft components that meet strength, stiffness, and functional requirements.

3.2 Application in Military Aerospace

In 2012, a research team from Washington State University in the USA conducted exploratory research on using 3D printing technology to produce metal and ceramic components for small scientific satellites. The research team demonstrated the relevant work of using 3D printing equipment and lunar rock materials to produce components, marking an important step forward for the United States’ “space manufacturing” program. NASA’s Marshall Space Flight Center is conducting reverse replication based on an integrated manufacturing process combining 3D scanning and 3D printing to shorten development cycle times from design to manufacturing. In September 2014, NASA completed its first imaging telescope, with all components manufactured primarily through 3D printing technology, becoming the first unit to attempt to manufacture an entire instrument using 3D printing technology. This space telescope is fully functional, with a 50.8 mm camera that fits into a cube satellite; the outer tube, outer baffle, and optical mirror frame are all directly printed as separate structures. In the 3D-printed telescope, the instrument baffle designed to reduce stray light can be made with angles, a feature that traditional manufacturing methods cannot achieve in a single part.

On August 31, 2014, NASA completed testing of a 3D-printed rocket injector, aimed at improving the performance of a certain component of the rocket engine. The liquid oxygen and gaseous hydrogen mix and react in the injector, reaching a combustion temperature of 3315 degrees Celsius and producing about 9 tons of thrust, validating the feasibility of 3D printing technology in rocket engine manufacturing. Manufacturing rocket engine injectors requires high precision processing technology; using 3D printing technology can reduce manufacturing complexity by establishing a three-dimensional image of the injector in a computer, with materials being metal powder and laser. There are dozens of injection elements in the rocket engine’s injector, and constructing similarly sized elements requires a certain level of machining precision. After successful testing, this technology will be used to manufacture RS-25 engines as the main power for NASA’s future space launch system. Engineers are utilizing additive manufacturing technology to manufacture the first full-size copper alloy rocket engine parts to save costs.

In current space research, technicians typically need to use launch tools as a medium to transport various essentials, such as equipment, parts, and backup components needed in space, to the space station. However, the failure of this method is unpredictable and technicians cannot take effective measures to respond. To solve this problem, NASA is leveraging the capabilities of 3D printing technology to resolve this issue, sending the equipment into space and assigning the task of production to astronauts, which not only successfully addresses cost issues but also significantly enhances the safety of astronauts during operations. On April 19, 2016, the 3D printing technology research center at the Chongqing Institute of Green and Intelligent Technology of the Chinese Academy of Sciences announced the successful development of China’s first space-based 3D printer. This 3D printer can print parts with a maximum size of 200×130 mm, helping astronauts create necessary parts in a microgravity environment, greatly enhancing the flexibility of experiments on the space station, reducing the variety and quantity of spare parts and operating costs, and decreasing the space station’s dependence on ground supplies.

3.3 Application on Naval Vessels

The US Navy plans to transform aircraft carriers, cruisers, and destroyers into mobile sea-based 3D printing factories, enabling on-demand printing of weapon equipment and improving space utilization on ships. For a long time, during the development of certain classes of ships or submarines, parts manufactured by original manufacturers have long ceased production, leading to costly and lengthy procurement processes, causing some ships to be unable to set sail. The US Navy’s fleet readiness centers and regional maintenance centers are utilizing 3D printing technology in various ways, saving time and money while ensuring fleet readiness. On July 1, 2014, the US Navy tested the rapid manufacturing of ship parts using 3D printing and other advanced manufacturing technologies, hoping to enhance operational speed and reduce costs.

Utilizing 3D printing and other advanced manufacturing methods can significantly enhance operational speed and readiness, reduce costs, and avoid the need to procure ship parts from around the world. Considering the cost, existing vulnerabilities in Navy logistics and supply chains, and resource constraints, the application of advanced manufacturing and 3D printing on naval vessels will become increasingly widespread. The US Navy envisions a global network of advanced manufacturers supported by skilled sailors to identify problems and produce products. The Navy’s armaments department is also actively seeking to leverage 3D printing technology to address the shrinking manufacturing base of the United States, improve weapon performance and enhance safety, while shortening the time for installing new energy systems on the fleet.

3.4 Application in Light Weaponry

American Solid Concepts Company used 3D printing technology to manufacture the world’s first metal handgun, which was successfully tested. This 3D-printed metal handgun consists of over 30 parts, and while its range is slightly less than that of conventional handguns, its accuracy is comparable. The magazine and other components of the AR-15 semi-automatic rifle have also been manufactured using 3D printing technology, capable of firing over 600 rounds with good overall performance. Currently, the limiting issue for 3D printing technology is materials; if the issues with metal powder materials can be resolved, 3D printing technology will find widespread application in the design, manufacture, and repair of light weapons, enhancing the lethality of small arms while reducing the time and costs required for replenishing and updating critical components.

The US military envisions that in future battlefields, soldiers equipped with 3D printers will not have to worry about supply issues even when far from rear bases. Unmanned transport helicopters or vehicles can continuously deliver raw materials to the base, and guided by three-dimensional images or designs transmitted over wireless battlefield networks, 3D printers can quickly produce the needed equipment and supplies. Colonel Kevin Felix, director of future warfare studies at the US Army Training and Doctrine Command, believes that 3D printing technology will make the US Army lighter and more agile. The Army plans to enhance the sustainability of individual combat operations, area patrols, and small frontline combat bases through this approach.

3.5 Application in Logistics Support

Using 3D printing technology, whether for weapon equipment or military supplies, combat personnel can produce the necessary equipment and materials on-site in the battlefield. During the Afghanistan War, the US military deployed significant combat forces to ensure smooth supply lines and personnel safety. The military believes that if 3D printers had been used in conjunction with battlefield networks and unmanned transport helicopters or vehicles at that time, it could have completely resolved these issues, leading to a revolutionary change in logistics support. The US military also has bases such as Robins Air Force Base in Georgia and Hill Air Force Base in Utah, each developing plans to integrate 3D printing technology into equipment maintenance and development capabilities within logistics complexes. The incorporation of additive manufacturing technology will trigger profound changes in logistics support and operational models, greatly enhancing the logistics support capabilities of military bases. In the future, as technology matures, almost everything needed on the battlefield can be satisfied by 3D printing. With this “mobile factory” that can “clone” logistics materials, rapid replenishment of combat consumption during wartime can significantly improve the efficiency of logistics supply and support.

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