NASA engineers have developed the first full-scale, 3-D printed copper rocket engine part - a combustion chamber liner that operates at extreme temperatures and pressures.
"Building the first full-scale, copper rocket part with additive manufacturing is a milestone for aerospace 3-D printing," said Steve Jurczyk, associate administrator for the Space Technology Mission Directorate at NASA Headquarters.
"Additive manufacturing is one of many technologies we are embracing to help us continue our journey to Mars and even sustain explorers living on the Red Planet," said Jurczyk.
Numerous complex parts made of many different materials are assembled to make engines that provide the thrust that powers rockets.
Additive manufacturing has the potential to reduce the time and cost of making rocket parts like the copper liner found in rocket combustion chambers where super-cold propellants are mixed and heated to the extreme temperatures needed to send rockets to space, NASA said.
A selective laser melting machine in Marshall Space Flight Centre's Materials and Processing Laboratory fused 8,255 layers of copper powder to make the chamber in 10 days and 18 hours.
Before making the liner, materials engineers built several other test parts, characterised the material and created a process for additive manufacturing with copper.
"Copper is extremely good at conducting heat," said Zach Jones, the materials engineer who led the manufacturing at Marshall.
"That's why copper is an ideal material for lining an engine combustion chamber and for other parts as well, but this property makes the additive manufacturing of copper challenging because the laser has difficulty continuously melting the copper powder," said Jones.
Only a handful of copper rocket parts have been made with additive manufacturing, so NASA is breaking new technological ground by 3-D printing a rocket component that must withstand both extreme hot and cold temperatures and has complex cooling channels built on the outside of an inner wall that is as thin as a pencil mark.
The part is built with GRCo-84, a copper alloy created by scientists at NASA's Glenn Research Centre in Ohio, where extensive materials characterisation helped validate the 3-D printing processing parameters and ensure build quality.
"Our goal is to build rocket engine parts up to 10 times faster and reduce cost by more than 50 per cent," said Chris Protz, the Marshall propulsion engineer leading the project.
"We are not trying to just make and test one part. We are developing a repeatable process that industry can adopt to manufacture engine parts with advanced designs. The ultimate goal is to make building rocket engines more affordable for everyone," said Protz.
