NASA’s Marshall team develops new additive manufacturing technique
Laser Wire Direct Closeout (LWDC) uses a freeform-directed energy wire deposition process to fabricate material in place.
A team of engineers at NASA’s Marshall Space Flight Center in Huntsville, Alabama, developed a new additive manufacturing technique.
A new process called Laser Wire Direct Closeout (LWDC) was developed and advanced at NASA to solve manufacturing challenges associated with engine nozzle fabrication. This will allow them to build less expensive nozzles in significantly less time.
LWDC is unlike traditional powder bed 3D printing methods, it uses a freeform-directed energy wire deposition process to fabricate material in place. This new NASA-patented technology has the potential to reduce build time from several months to several weeks.
The LWDC method uses a wire-based additive manufacturing process to precisely close out the nozzle coolant channels, which contain the high pressure coolant fluid that protects the walls from the high temperatures a nozzle must withstand.
In order to prevent overheating, the nozzles are actively cooled buy routing propellant later used in the combustion cycle through the nozzle to properly cool the walls. A series of channels are fabricated within the nozzle, but then must be closed out, or sealed, to contain the high-pressure coolant. The new patented process using the LWDC technology closes out the coolant channels and forms a support jacket in place, reacting structural loads during engine operation.
After Marshall co-developed and patented the LWDC process, Keystone Synergistic of Port St. Lucie, Florida, used the technology to fabricate and test a nozzle. The engineers put this nozzle through its paces, accumulating more than 1,040 seconds at high combustion chamber pressures and temperatures.
This technology is being licensed and considered in commercial applications across the industry.