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Engineers at Raytheon Missile Systems have made an almost entirely 3D printed missile, including the rocket engines, fins and parts for the guidance and control systems.
The US-based defence company is heavily researching 3D printing with the aim of reducing costs, creating lightweight structures and enabling the printing of missiles in the field.
Jeremy Danforth, a business systems support engineer at Raytheon, said: “You could potentially have these in the field. Machines making machines. The user could print on demand. That’s the vision.
“There are folks in industry printing warheads. We are printing demos of many of the seeker components. And we demonstrated a printed rocket motor. We’ve already printed 80% of what would go into a missile.”
Raytheon said its engineers had used commercially available high-end equipment and specially modified versions of low-cost 3-D printers for the project.
The company is also developing 3D printing techniques to lay down conductive materials for electrical circuits, create housings for the company's revolutionary gallium nitride transmitters, and fabricate fins for guided artillery shells.
3D printed rocket boosters being fired in a test
Research being conducted at the Raytheon University of Massachusetts Lowell Research Institute is developing 3D printing techniques that can produce the circuits and microwave components used to make radar systems for us in its missile systems, such as the Patriot.
Missile electronics use microscopic circuits, which are made by removing material to create a circuit pathway. In contrast, 3D printing lays down the material needed to build the electronic pathway.
One of Raytheon's research goals is to print complex circuits in 3D, with the high resolution and performance of silicon, said Chris McCarroll, Raytheon director for the institute.
McCarroll said: “When we make integrated circuits now, it’s all subtractive. We put down very expensive materials and wash away everything we don’t need.
“There’s currently a hierarchy in our manufacturing. We make the structures, the housings, the circuit cards, with the right materials, and then we integrate them into a system.
“What we see in the near future is printing the electronics and printing the structures, but still integrating. Eventually, we want to print everything together. An integrated system.”
Engineers at the research institute have so far laid down the conductors and dielectrics needed for printed electronics and have used carbon nanotubes, to align them, added McCarroll.
However, he admitted that the print and assembly of missiles in the field is still some way off. He said: “Before a warfighter can print a missile in the field,” he said, “you need quality, controlled processes to fabricate all the component materials: the metallic strongbacks, and the plastic connectors, the semiconductors for processors, and the energetics and propulsion systems.
“The hard part is then making the connections between these components, as an example, the integrated control circuit that receives the command to light the fuse. At some relatively near-term point you may have to place chips down and interconnect them with printing. Or, in the future, maybe you’ll just print them.”