If you love the acronyms for 3D printing technologies, you might enjoy this new one: RDAM, which is short for Radiant Deposition Additive Manufacturing. And, if it does what NASA’s Jet Propulsion Lab (JPL) suggests it can do, it will dramatically change the face of metal 3D printing by introducing the possibility to laser melt three dimensional components formed with gradient metals alloys. That is, single components in which different portions are made up of different metal materials.
Researchers from JPL, the California Institute of Technology in Pasadena, and Pennsylvania State University at University Park have published a study in Nature’s Scientific Reports, titled “Developing Gradient Metal Alloys Through Radiant Deposition Additive Manufacturing”. In it, they describe a 3D printing technique that consists of depositing layers of metal onto a rotating rod, thus transitioning metals from the inside of a print outwards, rather than adding layers from bottom to top. Then, a laser melts the metal powder to create subsequent layers.
“We’re taking a standard 3D printing process and combining the ability to change the metal powder that the part is being built with on the fly,” said Douglas Hofmann, a researcher in material science and metallurgy at JPL, and visiting associate at Caltech. “You will constantly be able to change the composition of the material.”
The implications for such a technology are huge, especially in a complex field such as space exploration, in which manufacturing complex parts as single components can guarantee higher durability during long space missions, where repairs are not possible. With RDAM, engineers will be able to develop components that have varying compositions. For example they may have high melting temperatures on the outer edges and low densities at the center. Or they could be magnetic on one end, but not on the other.
With traditional manufacturing techniques, similar results could be achieved by welding different metal parts together. The weld itself, however, would result in structural weakness, not present with JPL’s RDAM 3D printing method.
Although applications of this technology will one day find their way into more “down-to-earth” applications in the automotive and commercial aerospace industries, this will likely not happen anytime soon. Currently, most companies operating in these fields have not even begun to scrape the surface of the possibilities offered by 3D printing with individual metals, let alone more than one metal simultaneously. Nevertheless, it will happen: we will 3D print in multiple metal alloys and we will conquer space.
