3D printing or additive manufacturing is ongoing revolution in manufacturing with its potential to fabricate any complex object and is being utilized from aerospace components to human organs, textiles, metals, buildings and even food. Additive manufacturing, is defined by ASTM International as the process of joining materials together, layer by layer, based on three-dimensional model data.
The annual growth rate of the global market of additive technologies exceeds 100%. This can be explained by the advantages of additive technologies for metals compared to traditional industrial technologies: casting, powder metallurgy etc. This includes the ability to create complex 3D-details, reduce the weight of the detail by optimizing the design, increase the strength of the details, as well as the technology for fast and situational production of small-scale details of complex shape.
3D printing is revolutionizing defence by printing small components to full drones on naval vessels, replacement parts for fighter aircrafts to printing ammunition. Substantial improvements have been made in 3D printing with the fabrication of 3D objects from metals, ceramics, plastics, and even multi-material capabilities.
3D printing can make military equipment faster accelerating product development and with less cost than other processes. It increases design possibilities, enhances the speed of innovation, and offers an alternative for creating shapes closer to what an engineer might need, with fewer constraints.
3D printing is also revolutionizing in Aerospace from stealth fighter jets to scramjet engines. One of the most popular directions is the development of methods of 3D-aluminum printing for aerospace.NASA and the US military used 3D printed components to successfully test advanced prototype airplanes, spacecraft and even ground vehicles.
Team of scientists from NUST MISIS Center for Industrial Prototyping of High Complexity obtained the first samples of 3D aluminum composite details with ceramic filler, manufactured by laser melting. In the nearest future, the obtained composites will be used to grow the spacecraft parts for Russian aircraft industry.
British Royal Air Force made history when one of their Tornado fighter jets took off with 3D printed replacement parts. “It’s long term, but it’s certainly our end goal to manufacture an aerial vehicle in its entirety using 3D printing technology,” Matt Stevens, who heads BAE’s 3D printing division, told AFP. In the future, a plane shall be able to print another plane inside itself and then launching it from its undercarriage.
There may be as many as 800 3D printed parts on the JSF (Joint Strike Fighter, Lockheed Martin F-35 Lightning). Plastics 3D printing technologies, high-temperature plastic 3D printing and multiple metal 3D printing were all commercialized for aviation for the JSF.
The US Air Force (USAF) has installed a metallic 3D printed aircraft part on an operational F-22 Raptor fighter. The printed part is designed to replace a corrosion-prone aluminium component in the kick panel assembly of the cockpit. The advantages offered by the printed bracket are that it will not corrode and can be ordered and delivered for installation quickly. The bracket is manufactured using a powder bed fusion process that involves the use of a laser to build the part layer by layer from titanium powder. The service is also planning many other metallic additive manufactured parts through public-private partnerships. At least five additional metallic 3D printed parts are planned for validation on the F-22.
Miguel Angel Castillo, VP, Technical Development, Speaking for Aernnova, said “We are not constrained [with 3D printing] as we were in tooling parts. This can enable 30-40% weight reduction, add new functional enhancements, produce more highly integrated parts, and see ecosystem savings in terms of energy and raw materials,” he said.
In two short years, 3-D printing has spread across the Air Force. Today, we print thousands of spare aircraft parts from metals and polymers, lowering operating cost by tens of millions while getting planes back to the fight faster, said Will Roper, the assistant secretary of the Air Force for acquisition, technology and logistics. The need is severe: For example, three C-5s are grounded, awaiting exhaust ducts because our purchase offer of more than $430,000 for eight units did not entice a single supplier for months, forcing us to cannibalize parts from the “aircraft boneyard” at Davis-Monthan Air Force Base. When we finally received a bid, the earliest delivery was 34 weeks.
3D printing in Aerospace
In aviation 3D printed parts let you save weight which means that the performance of the aircraft will increase dramatically and directly as a result. You can also reduce your number of parts significantly saving on production time, storage, risk and up front investment. You can iterate faster, improve faster and costs will be lower. Since you are adding material rather than removing material, this process also drastically reduces waste during manufacturing. Air ducts, wall panels, seat frameworks and even engine components have all benefited from reduced weight enabled by 3D printing.
“Additive manufacturing can address a multitude of challenges for us, and there is a big pull to implement these processes from the logistics community,” said Dr. Jonathan Miller, a materials scientist and the additive manufacturing lead for the AFRL directorate. “The fleet is aging, and replacement parts for planes built 30 years ago often no longer exist. Rapid production of a small number of hard-to-find parts is extremely valuable.”
The US Air Force’s (USAF) Oklahoma City Air Logistics Complex (OC-ALC) is set to implement its strategic plan to integrate 3-D printing technology into every aspect of its airpower sustainment mission. The 3-D printing machines will be able produce replacement engine parts directly at repair and overhaul sites from the provided raw materials, including metal pellets, ceramics and gypsum, the USAF stated.
3D Systems have been awarded two different research contracts worth in excess of $1 million by the US Air Force Research Laboratory (AFRL). Per the contracts, 3D Systems would develop advanced aerospace and defense 3D printing manufacturing capabilities at a large scale for possible uses within the US Air Force. “The main advantage of the printer is that you are no longer limited in geometry, for example, when you want to create a space inside a block of aluminum or a ring inside a ring.”
Despite years of development and research into additive manufacturing processes, there are a number of implementation challenges that AFRL researchers need to address in order to enable greater Air Force benefit from the technology, both now and in the future. “Fundamentally, it comes down to a materials processing problem,” said Berrigan.
However, the need to develop consistent, quality materials for additive manufacturing still remains a challenge that AFRL researchers are working diligently to address. Engineers need to have full confidence in additive manufactured part alternatives as they implement them as replacements in aging fleets or as system-level enablers in new weapon systems.
The lack of standardized production processes, quality assurance methods, significant material variability and reduced material performance are just some of the factors AFRL researchers need to overcome. Depending on the application, material performance can be related to the strength of a part. For example, the electronic properties of an additive manufactured circuit may be worse than those of ones traditionally manufactured.
Another issue centers on basic materials compatibility. “There are a lot of different interfaces in additive manufacturing, and ensuring that materials adhere to one another or that a part can support a certain stress or withstand a certain temperature—these are all challenges we need to address,” said Miller.
SRI LANKA to buy 3D printed Aircraft from China
The government of Sri Lanka has recently revealed its plan to purchase a Chinese aircraft Xian Y-20. This aircraft will be used for the both transport and military purposes. The Xian Y-20 is the first ever cargo plane, which is being made with 3D printing technology. The sale of this aircraft will make Sri Lanka the first country to import the Xian Y-20 aircraft.
The Sri Lankan Prime Minister, Ranil Wickremesinghe, said in a statement that the Chinese Xian Y-20 aircrafts are “good workhorses.” Sri Lanka already has a number of Chinese aircrafts, which includes Xian MA60, Shaanxi Y-8 and Harbin Y-12. The country is looking for versatile options, where cargo and transport aircrafts can also serve the purpose of military planes, if the situation arises. The current Air Force of Sri Lanka includes Israeli and Russian bomber jets, which needs to be replaced soon as these have been utilizing from a long time. Though Sri Lanka is considering the Chinese plane Xian Y-20, the country has other options too. Russia, India, and Sweden have also made offers to Sri Lanka.
3D printing contributed a significant role in the manufacturing of the aircraft Xian Y-20. This also lowered the budget of the plane. It has been reported that the plane can hold 40 to 73 short tons of cargo. If Sri Lanka buys this aircraft, the country can also use this plane for domestic purposes managed by the Sri Lankan Air Force. It is being expected that the Xian Y-20 will cost about $160 million per plane.
Advanced 3D printed titanium enables lighter, stronger, complex parts for improved J-20 stealth fighter plane components
A team of scientists in China has developed a metal 3D printing technology called “smart micro casting & forging.” The technology combines 3D printing and forging, uses metal wire “1/10 the cost” of AM powders, and could be used in the aerospace, automotive, and molding industries.
The Micro Forging & Casting Sync Composite Device, a new product developed by Zhang Haiou and his team, offers an alternative to metal 3D printing methods like selective laser melting and sintering, combining 3D printing, casting, and forging in one. This amalgamation of techniques contributes to increased part strength and toughness, improved product lifecycle, and higher reliability. According to its developers, the technology can also be used to create thin-walled metal components while eliminating excess material and equipment costs.
The casting and forging process has already been used to create a titanium 3D printed joints for a new fighter aircraft, which would have been impossible to create as a single piece using any subtractive manufacturing technique. In the past, the only method was to reduce the design standards, split it into multiple parts, and then assemble it, affecting the performance of the fighter and shortening its life cycle. Zhang Haiou and his team have used their new technology to 3D print TC4 titanium alloy parts whose tensile strength, yield strength, ductility, and toughness are much better than the traditional forging parts.
Zhang Haiou commented: “In the past, conventional 3D printing has been fatally flawed in the following areas: first, without forging, metal parts have a serious chance of wearing; second, the performance of 3D printed parts has not been high; a third problem is the presence of pores and unfused portions; and the fourth is that using a laser or electron beam as a heat source is very costly.”
Experts have verified that parts made by 3D printing, casting and forging all-in-one technique are more stable than those made by traditional casting. Furthermore, the Chinese scientists say that the new technique is 80% more efficient than SLM 3D printing, with material costing around one-tenth that of metal additive manufacturing powders. The material used in the forging and casting technique is a kind of metal wire, which is heated by an energy-efficient electric arc which uses one-tenth the energy of a laser beam. This method, which can simultaneously control the size and shape of performance parts, can reportedly save time as well as energy, with two-ton metal castings taking only 10 days to produce, previously three months. The technology can also be used to create thin-walled metal components that can be used in jet aircraft.
Novel 3D-Composite Material for Aerospace Reducing the Weight of Details by 20% Developed in NUST MISIS
Scientists from the National University of Science and Technology MISIS, led by Professor Alexandr Gromov developed a method of 3D-printing of alumomatrix (aluminum-based) composite materials with ceramic fillers (aluminum oxide and nitride). The research was conducted in the framework of the project of the Russian Science Foundation. The use of additive technologies allowed increasing the strength of the resulting powder materials by 20%.
“For 3D-printing of aluminum details, so-called silumins (alloys of aluminum with silicon, in particular, the compound Al-Si-10Mg) are mainly used as raw materials,” Alexander Gromov comments. “However, the demands of the aerospace industry are growing, and scientists are now actively searching for new compositions of alumomatrix composites (including doped ones) to obtain details with improved performance (strength, hardness, resistance to cracking) and low cost, compared to alloys that contain rare earth elements.”
In this case, the main task of material scientists is to reduce the detail weight while maintaining the strength characteristics. Nowadays, the metal primarily used in aircraft is titanium. It is a durable, corrosion- and load-resistant material, the only significant disadvantage of which is the high density, 5.4 g/mm. Lightweight and ductile aluminum at the same time has a density of 2.7 g/mm, that is, it is twice as light. However, it is far less strong than titanium. Scientists are actively looking for ways to strengthen aluminum.
“We managed to increase the strength of aluminum powders due to hardening ceramic additives directly in the process of 3D-printing. Previously, it was believed that obtaining such composites on printers such as SLM is impossible. However, the group was able to create experimental samples of the new powder material on a conventional printer SLM-280 HL, i.e. using selective laser melting,” Professor Gromov adds.
The proposed methods allow increasing the flexibility of design, reducing the production time of functional prototypes, reducing the weight of the resulting details by 10-20 %.
Advancing composites: CdA company’s breakthrough technology attracting interest from big players
Traditional composite manufacturing requires layering materials with resins in a mold, which is then put into an autoclave that applies heat and pressure to cure the resins. Sometimes, the finished product requires hand sanding. This results in higher costs.
Continuous Composites’ breakthrough is using 3D printing and a robotic arm to build composite parts, which its owners say could revolutionize manufacturing, dramatically lowering the costs for fiberglass, Kevlar and carbon fiber composites. Continuous Composites has 11 patents and another 90 pending patent applications under review in the U.S., and international patents as well. The process (shown on the company’s website) doesn’t require a mold, and the use of rapidly curing resin eliminates the need for hours of baking in an autoclave.
A carbon fiber bicycle, he said, costs thousands of dollars not because of the cost of the raw materials but because of the process to manufacture carbon fiber composites. “It’s very manual, extremely labor-intensive,” Tyler Alvarado, the company’s chief executive officer. “Low output, high costs.”
Continuous Composites and Autodesk worked together on an eight-month demonstration of the technology at mHUB, Chicago’s nonprofit lab for manufacturing and product development. Visitors could watch the robotic arm building the composites. It’s a manufacturing strategy that will change how we create stuff,” Moruzzi said. “You can create shapes in thin air.”
Composites are lightweight, strong and corrosion-free, said Tom Dobbins, president and chief executive officer for the American Composites Manufacturers Association in Virginia. However, “the challenge with composites is the speed with which you can produce the part,” he said. “Some parts are still made by hand.”
Building composite parts without a mold opens up lots of design possibilities, the two men said. Boeing’s 787 Dreamliner is 80 percent composite by volume to reduce the weight of the long-haul jetliner. “We could print an airplane wing right into the fuselage,” Alvarado said, cutting out the cost of titanium fasteners. The ability to embed copper wire, lights, sensors and fiber optics into the composite parts also is a plus, Moruzzi said. Airplane wings could have sensors that would send an alert to a central system when the wings needed to be deiced. “It’s like a nervous system,” he said.
Lockheed Martin has a contract to build a wing structure for the Air Force Research Laboratory Materials and Manufacturing Directorate in Dayton, Ohio. Continuous Composites is a subcontractor on part of the project, which is focused on newer, emerging technologies. The Air Force is particularly interested in the potential to integrate fiber optics and copper wire into composite structures, Neslen said. “I think we’re just scratching the surface of what could be done,” he said.