Additive manufacturing has progressed far beyond brackets

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LONG BEACH, Calif. — When space companies began adopting additive manufacturing, the process was deemed high risk and reserved for relatively straightforward parts like satellite brackets.

Now, spacecraft developers are more likely to print sophisticated engine nozzles and other complex spacecraft components.

“Additive manufacturing opens the window to make very complex parts very rapidly,” Stan Bouslog, NASA Johnson Space Center Entry Descent & Landing and Thermal Protection System discipline lead, said May 25 at the Space Tech Expo here.

Instead of designing complex parts in pieces for later assembly, additive manufacturing allows engineers to produce parts and test them in overall systems.

“If it doesn’t work, I can change that very complex part very quickly and replace it with another part,” Bouslog said. “It makes iteration in your system design process much more rapid.”

Still, additive manufacturing will be employed alongside traditional subtractive-manufacturing processes for the foreseeable future.

“Subtractive is not going anywhere,” said Paul Davies, Sandvik Additive Manufacturing technical solutions manager. “But there is an excellent synergy with additive manufacturing, because there’s still requirements for engineering interfaces, for threads. How to machine additively manufacturing parts is actually new knowledge that needs to be gathered.”

Relativity Space was founded on the idea of flying the world’s first entirely 3D-printed rocket.

Employees recognized early on, though, that the first iteration of the rocket “was probably not going to be fully 3D printed because not all the materials were available for 3D printing and not all the additive manufacturing processes were ready for what we wanted to do,” said Eliana Fu, former Relativity Space senior engineer for additive technologies and current aerospace industry manager for German machine manufacturer Trumpf. “So there was going to be a mixture of traditional and additive manufacturing. As a team, you have to look at what makes sense on a case-by-case basis.”

Additive manufacturing technology is progressing rapidly for various materials.

Metal additive manufacturing is mature and ceramics “are an up and coming technology,” said Mark Shaw, GE Additive government programs and technology director. “With our composite manufacturing capability we actually incorporate carbon fibers, for example, into the ceramic matrix.”

GE Aviation won FAA certification for an additively manufactured heat exchanger for the GE9X engine that is smaller, lighter and offers higher thermal density than previous heat exchangers. That’s the type of complex part that makes sense for additive manufacturing, Shaw said.

Still, there are times when it makes sense to additively manufacture simple parts like brackets.  Some military aircraft built decades ago can no longer fly because of a lack of parts.

“It actually does make sense to print that bracket if there’s no other way to do it,” Shaw said.