Production of Exotic Metal Powders for 3D Printing of Accelerator Components

Accelerators are necessary for the fundamental study of matter and its origins. A critical component of accelerators are the niobium superconducting radio frequency (SRF) cavities, which are used to accelerate the particles. Because of the significant number of niobium SRF cavities required for each accelerator, innovative manufacturing techniques are needed to reduce fabrication costs and to ensure high quality cavities are produced. Recently, 3D Additive Manufacturing (AM) methods have been shown to reduce the cost and fabrication time of complex components using conventional metals such as aluminum, ferrous metals, nickel based superalloys, and titanium alloys. However, the high melting temperatures, sensitivity to interstitial impurities, and difficulty of obtaining suitable feedstock materials have limited the 3D printing of refractory metals and other exotic materials. Plasma Processes, a leader in the fabrication of near-net-shape refractory metal components, recently developed innovative Plasma Alloying and Spheroidization (PAS) techniques, which enable the production of high purity, spherical refractory metal powders. Building on its unique capabilities and expertise, Plasma Processes will use its PAS processing methods to produce exotic metal powders for 3D printing of accelerator cavities. During Phase I, niobium will used to baseline the PAS process. After producing the PAS niobium powders, Plasma Processes will partner with North Carolina State University, a leader in the development of AM processing methods, to produce 3D printed samples for preliminary characterization. During Phase II, Plasma Processes and NCSU will work together to 3D print SRF cavities from PAS niobium powder. In addition, the PAS and AM processing of materials with higher critical temperature than bulk niobium will also be evaluated during Phase II. The PAS and AM techniques to be developed during this effort will result in SRF cavities that enable the use of high performance accelerators. The size of the market for industrial accelerators is currently in the tens of thousands units worldwide, and it is likely to increase as more efficient, high performance accelerators are developed. In addition, the techniques will be used to produce high purity components for nuclear power generation, propulsion, chemical processing, corrosion protection, aerospace, liquid metal heat pipes, high temperature furnace components, and many other commercial, aerospace and government applications.