Researchers at NASA have developed a new 3D printed copper alloy material and made a rocket propulsion part from the material and selected laser melting 3D printing equipment.
The new material is GRCop-42, a high-strength, high-conductivity copper-based alloy created by a team at NASA's Marshall Space Flight Center (MSFC) and NASA's Glen Research Center (GRC) in Ohio. .
Photo: NASA Marshall Space Flight Center conducts 3D printed nozzle thermal test. Source: NASA / MSFC.
High thermal conductivity, creep and high temperature strength
GRCop-42 copper alloy powder can be used to produce almost completely dense 3D printed parts such as rocket combustion chamber linings and fuel injector panels.
GRCop-42 3D printed copper alloy powder also has a "predecessor" -GRCop-84. According to 3D Scientific Valley's market observation, NASA began developing this GRCop-84 3D printed copper alloy powder for the manufacture of rocket combustion chambers in 2014.
After 2016 and 2017, NASA conducted thermal tests on 3D printed GRCop-84 components at the Marshall Space Flight Center, and the team began developing GRCop-42. NASA hopes that this material will have similar strength to GRCop-84, but with higher thermal conductivity. NASA researchers said that additive manufacturing of engine combustor components made from the material would "exceed the previous generation of traditional methods."
Throughout 2018, the NASA team tested GRCOp-42 metal powder and demonstrated its processability through selective laser melting 3D printing technology. This type of additive manufacturing equipment has previously been used to make GRCop-84 copper alloy powder materials.
During the test, the NASA research team used the Concept Laser M2 metal additive manufacturing system to make 25 small components, and the print layer thickness was 50% (0.045mm) of the GRCop-84 material.
Researchers have observed that 3D printed components cooled faster with GRCop-42 material. NASA researchers post-processed with a hot isostatic press (HIP) to reduce metal porosity, and then sent the components to the Glen Research Center for additional post-processing and room temperature tensile testing.
NASA test results found that 3D printed metal parts made of GRCop-42 exhibit high thermal conductivity, excellent creep (deformation) and high temperature strength.
The NASA team expects to test the parameter set of GRCop-42 copper alloy powder by building larger 3D printed components.
3D Science Valley Review
Copper is a material with excellent thermal conductivity and reflectivity. This attribute also makes selective laser melting technology challenging for additive manufacturing of copper alloy parts. Copper metal has a low absorption rate during the laser melting process, and it is difficult for the laser to continuously melt the copper metal powder, which results in low forming efficiency and difficult to control the metallurgical quality.
According to the market observation of 3D Science Valley, a number of rocket manufacturing companies are developing copper alloy 3D printing processes and using this technology to manufacture functionally integrated rocket engine components.
Aerojet Rocketdyne's breakthrough in the field of 3D printing of the rocket copper alloy thrust chamber opens up the possibility of manufacturing a new generation of RL10 engines. 3D printed copper alloy thrust chamber parts will replace the previous RL10C-1 thrust chamber parts. The replaced thrust chamber parts are manufactured by traditional processes and welded from multiple stainless steel parts, while the 3D printed copper alloy thrust chamber parts are composed of two copper alloy parts.
Compared with the traditional manufacturing process, the selective laser melting 3D printing technology brings a higher degree of freedom to the design of the thrust chamber, so that designers can try advanced structures with higher thermal conductivity. The enhanced heat transfer capability makes the design of the rocket engine more compact and lightweight, which is exactly what the rocket launch technology needs.
Launcher, a small space rocket manufacturing and launcher, also tested copper alloy rocket engine components. Launcher has been working on the proof-of-concept engine E-1 since last year. This is a 3D printed copper alloy (Cucrzr) engine component with integrated cooling channels. This design will improve engine cooling efficiency.
NASA made progress in 3D printing of copper alloy parts in 2015. The manufacturing technology is also selective laser melting 3D printing. The printing material is GRCo-84 copper alloy. The 3D printed parts made by NASA using this technology line the rocket combustion chamber. The part is divided into a total of 8,255 layers and printed layer by layer. The printing time is 10 days and 18 hours.
There are more than 200 complicated channels between the inner and outer walls of this copper alloy combustion chamber component. Manufacturing these tiny, internal channels with complex geometries is a big challenge even for additive manufacturing technology. After the part was printed, NASA researchers used an electron beam free-manufacturing facility to coat it with a nickel-containing superalloy. The ultimate goal of NASA is to make the manufacturing speed of rocket engine parts significantly faster, while reducing manufacturing costs by at least 50%.
According to the market research of 3D Science Valley, domestic metal 3D printing company Platinum has made progress in the field of copper metal laser forming, developed 3D printing processes for refractory metals and highly thermally conductive and highly reflective metals, achieving complex flow channels. The 3D printed copper alloy tail nozzle was successfully prepared using the copper material manufacturing process.