In a first, NASA engineers have used 3D printing to make the first full-scale copper 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 3D printing," said Steve Jurczyk, associate administrator for the space Technology Mission Directorate at NASA headquarters in Washington, DC."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," he added.
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.On the inside of the paper edge-thin copper liner wall, temperatures soar to over 2760 degrees Celsius."We have to keep it from melting by recirculating gases cooled to less than 100 degrees above absolute zero on the other side of the wall," noted Chris Singer, director of the engineering directorate at NASA's Marshall Space Flight Centre in Huntsville, Alabama.
To circulate the gas, the combustion chamber liner has more than 200 intricate channels built between the inner and outer liner wall."Making these tiny passages with complex internal geometries challenged our additive manufacturing team," Singer pointed out.A selective laser melting machine 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.
Only a handful of copper rocket parts have been made with additive manufacturing."NASA is breaking new technological ground by 3D 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 US space agency said in a statement."Our goal is to build rocket engine parts up to 10 times faster and reduce cost by more than 50 percent," noted Chris Protz, the Marshall propulsion engineer leading the project.