Aerospace
FEELING ULTRASONIC WORDS: Laura Griffiths
Laura speaks to engineers at NASA JPL about deploying Fabrisonic’s metal additive manufacturing technology for space. Sometimes, inspiration can come from the unlikeliest of sources. Take, for example, a Stradivarius that became the spark for an additive manufacturing (AM) project for engineers at NASA’s Jet Propulsion Laboratory (JPL). It all started back in 2012. A.J. Mastropietro, Thermal Systems Engineer at NASA JPL in Southern California was just coming off the Mars Curiosity Rover mission having developed a challenging thermal control system to manage heat transfer across the largest rover ever sent to the Red Planet. It was a momentous achievement but also a ‘fabrication nightmare,’ as Mastropietro candidly puts it, consisting of a maze of aluminum tubing on flat plates designed to acquire and reject heat as needed. ‘There has to be a better way,’ the engineer thought. An article in The Economist, which talked about the 3D printing of a Stradivarius, appeared to offer one.
SHOWN: DEPLOYMENT OF CUBESAT IN SPACE (CREDITS: NASA)
“It ignited my passion immediately,” Mastropietro told TCT. “I knew about additive manufacturing with plastics but in my field of work, that's not directly applicable and this was really focused on additive manufacturing from metallics. So, I began a deep dive on that and explored many different avenues.”
coming out of a company in Ohio which offered ‘a very different technique’ to 3D printing metals. Fabrisonic, a spinout company of EWI since 2011, with its low temperature metal deposition Ultrasonic Additive Manufacturing (UAM) process, which leverages solid-state ultrasonic bonding using high-frequency vibrations to fuse together thin layers of metal with no change to metal microstructure, combined with traditional CNC milling, seemed like a good way to improve reliability of crucial metal components for spacecraft without the limitations of more established powderbased AM processes.
While polymers were more common, Mastropietro recalls the focus on printing metal around that time being mostly in direct laser sintering, and while JPL had successfully deployed DMLS, the engineer was instead intrigued by a technology
Mastropietro reached out and quickly put together a spontaneous JPL R&D proposal to explore improvements to the manufacturing of heat exchangers and radiators. The team secured the award and went to work with Fabrisonic using the UAM process to embed cooling channels into billets of aluminum.
With an initial concept in 2014, Mastropietro says they were ‘able to prove some of the basic metrics right out the gate’ and the technology was then pushed through several stages of NASA’s Small Business Innovation Research (SBIR) program and tested on more complex, flight-like parts where Mastropietro says they were encouraged by how well they tested. Also overseeing this was Scott Roberts, Materials Technologist at NAS JPL, who, by his own admission, remembers the reaction around the lab to some of those early welds, albeit successful, being ‘this will never fly.’ But they worked on it, collaborating with Fabrisonic and NASA’s SBIR office, overcoming challenges around thermal and pressure tests to get to a point where now, Roberts says, when the team have shown UAM parts to those unfamiliar with the process, they often question where additive was even used.
VOL 8 ISSUE 3 / www.tctmagazine.com / 09
