A microscope image reveals how the two metals mix and interlock to form a strong bond created by the 3D printing process during manufacturing of the igniter prototype. (NASA/UAH/Judy Schneider)

NASA engineers tested a 3D-printed rocket engine prototype part made of two different metal alloys via an advanced manufacturing process. The part was low-pressure, hot-fire-tested more than 30 times to demonstrate the functionality of the igniter.

The two metals – a copper alloy and Inconel – were joined together using a unique hybrid 3D printing process called automated blown powder laser deposition. The prototype igniter was made as one single part instead of four distinct parts that were brazed and welded together in the past.