While they seem like a simple component, the nozzles on rocket engines require complex production methods to withstand the extreme temperatures and pressures they encounter during the combustion process. And with additional complexity comes extra costs.
Both cost and complexity have played critical roles in the advancement of 3D printing and additive manufacturing technology. And just as numerous manufacturers have saved time and money by incorporating 3D printing into their production flows, NASA's Marshall Space Flight Center looked to realize the same benefits via a new additive manufacturing technique for nozzle fabrication.
The process is called Laser Wire Direct Closeout (LWDC), and it differs from other 3D-printing approaches in that it uses a freeform-directed energy wire deposition process to fabricate material in place. This NASA-patented technology has the potential to reduce build time from months to weeks.
The LWDC technique employs a wire-based additive manufacturing process that helps address the high operating pressures faced by these nozzles. The new process also allows for fabricating a series of channels within the nozzle that play an important role in guarding against overheating. Using 3D printing for the nozzles, which are only as thick as a couple of sheets of paper, allows for accurately building a part that can withstand a harsh operating environment.
Keystone Synergistic of Port St. Lucie, Florida used the technology to fabricate and test a nozzle. The LWDC approach is currently being licensed for commercial applications, and was developed through NASA's Small Business Innovation Research program.