Advanced manufacturing of torsionally flexible vacuum bellows

Metal bellows are thin-walled cylindrical components with a corrugated structure perpendicular to the cylinder axis. Bellows are used in numerous applications requiring flexible connections between vessels which must be sealed in a pressure-, temperature- and media-resistant manner. Conventional bellows geometries are highly flexible during axial, lateral and angular motion, but generally do not allow for rotational flexibility, i.e. torsion. As such, bellows users requiring rotation are often required to add expensive, custom in-vacuum motion systems to meet their alignment and/or processing needs. In this Technology Transfer Opportunity(TTO), RadiaBeam Technologies will partner with Argonne National Lab (ANL), Castheon and Servometer to qualify, industrialize and market a torsionally flexible bellows design. This design is based on a 2020 ANL patent which incorporates hollow, re-entrant shoulders helically wound around a central bore, meant to uniformly distribute the torsionally stress. While this geometry would be extremely difficult to manufacture using conventional methods, it is perfectly suited for Additive Manufacturing, otherwise known as 3D printing. This proposal concerns the fabrication of torsionally flexible bellows using a combination of metal additive manufacturing and conventional bellows electroforming. In Phase I, we will review current bellows design with researchers at Argonne National Lab. We will 3D print both test cylinders and bellows in aluminum using the laser-powder bed fusion process. Test cylinders will be used to rapidly optimize downstream processes as well as inform our design for manufacturability. The electroformed bellows will be joined to vacuum flanges then subjected to mechanical and vacuum testing. In Phase II, the design and fabrication will be further optimized based on a series of mechanical failure tests. At the conclusion of this project, we will have developed a complete bellows fabrication process with well- characterized properties (dimensional stability, cleanliness, functionality, service life, etc). Bellows are used whenever components must retain some flexibility while also sealing in a pressure-, temperature- and media-resistant manner. Current bellows only allow for lateral, angular and axial displacement; torsional displacement is not possible. We aim to qualify and commercialize a torsionally flexible bellows design invented by Argonne National Lab. These bellows can be used to simplify the installation and alignment of vacuum systems, a key labor consideration for next generation accelerators. Furthermore, torsionally flexible bellows can be used for other vacuum-related process (analytical instrumentation, semiconductor production, etc). With further market research and product development, our first-of-its-kind product can be expanded to other markets including medical and energy.