Material and process development for additive manufacturing of high performance copper-nickel RF components

The fabrication of high performance radiofrequency (RF) and microwave communication system components, ultra-high vacuum (UHV) technologies, and thermal management devices routinely involves time-consuming and multi-step manual metal forming and joining processes. Additive manufacturing (AM) is increasingly seen as a route for direct fabrication of complex shaped, high performance components that would be impossible or too expensive to fabricate using traditional techniques. The US Navy has identified a need to use AM to produce components from copper-nickel alloys that can withstand the high thermal and mechanical loads required in these RF applications. In this project effort, Elementum 3D and Ohio State University propose to co-develop a robust, capable, and economical manufacturing process for copper-nickel-based RF and UHV components. In the Base period, the team demonstrated excellent printability of the selected cupronickel material, with high as-printed density (>99.8%), good surface finish (4-5 um Ra) and tensile properties comparable or better than wrought material, as well as excellent insertion loss performance exceeding that of an equivalent traditionally manufactured off the shelf component. In the Phase I Option period, the team will perform initial outgas and vacuum leak rate testing and explore conformal surface finishing treatments for minimizing insertion loss. The planned Phase II Base period work involves in-depth studies to finalize and generate specifications for the feedstock composition and characteristics, AM and post-processing (heat treatment and surface finishing) methods followed by specimen level testing and fabrication. In collaboration with Navy and industry stakeholders, we will select five RF/microwave/UHV components for fabrication using the developed facility and will print and post-process one to two in the Base period. The Phase II Option period will focus on fabrication of the additional selected components followed by functional testing and benchmarking against currently fielded technology. Finally, an economic case study for one of the selected components will be carried out using real world cost data to accurately evaluate the economic feasibility of transitioning RF/microwave/UHV component production to AM.