3-d printed rocket engines increase production capability.

• Author: Munnell, Christina
• Position: SPACE

A rocket engine made entirely with additive manufacturing could enable Aerojet Rocketdyne Co. to increase its production from 12 to 100 engines per year.

Aerojet Rocketdyne is one of many companies in the defense and aerospace industry that is employing additive manufacturing, commonly called 3-D printing, to cut costs and improve efficiency.

The company built a liquid-fueled Bantam rocket engine comprising three printed components instead of 12 traditionally-manufactured parts, said Jeff Haynes, Aerojet Rocketdyne's program manager for advanced materials and manufacturing. It follows a process called selective laser melting, which uses a laser to melt layers of powdered metal to form a component.

The 3-D printed engine took only 15 days to build, while a traditionally manufactured engine is constructed over a period of 14 months, Haynes said. Part of the reason for such drastic reduction in construction time is injectors can be made much more quickly by using additive manufacturing. Normally there are many components in an injector that take a long time to weld and forge together, but a printed part can be made in one piece.

The engine was micro-welded instead of forged, enabling a simpler design, Haynes said. "You are only printing material where you need to have the material, so in reality, you can have a lighter weight ... engine. And for rocket engines that is a key...