The National Aeronautics and Space Administration (NASA) reported it 3D-printed and tested a new rocket engine nozzle as part of its Reactive Additive Manufacturing for the Fourth Industrial Revolution (RAMFIRE) project. Now in its 13th year, the project has applied various metal additive manufacturing (AM, or 3D printing) technologies to design, develop, and test liquid rocket engine components.
In the RAMFIRE project, NASA engineers and material developer Elementum 3D collaborated to define and produce a weldable aluminum (A6061-RAM2) that possesses the required heat-resistance for rocket engines, plus the low density necessary to print high-strength, lightweight structures. NASA and Elementum 3D also co-developed specialized powder for use in the laser powder direct energy deposition (LP-DED) process.
LPDED uses a laser for localized melting of powdered material, to build or clad a defined structure. The metal and/or ceramic powder is supplied by an injected stream, and the laser is guided by a printer head fixed to an articulating device.
Directed energy deposition specialists RPM Innovations also partnered with NASA on the RAMFIRE nozzle development and produced the structures on its LP-DED system.
NASA engineers will use the nozzle as "proof of concept" for future component designs.
According to NASA, the RAMFIRE rocket engine nozzle is lighter than conventional nozzles, which is an advantage for missions with heavy payloads. “Mass is critical for NASA’s future deep space missions,” stated John Vickers, principal technologist for STMD advanced manufacturing. “Projects like this mature additive manufacturing along with advanced materials, and will help evolve new propulsion systems, in-space manufacturing, and infrastructure needed for NASA’s ambitious missions to the Moon, Mars, and beyond.”
The RAMFIRE nozzle was designed and printed to incorporate small, internal cooling channels that will prevent aluminum from overheating and melting. The unitary structure also minimizes manufacturing time compared to typical engine nozzles that require numerous components to be individually assembled and bonded together.
“We’ve reduced the steps involved in the manufacturing process, allowing us to make large-scale engine components as a single build in a matter of days,” offered Paul Gradl, RAMFIRE principal investigator at NASA Marshall Space Flight Center.
