MiniMelt: An instrument for real-time tracking of electron beam additive manufacturing using synchrotron x-ray techniques
Hans-Henrik König, Nick Semjatov, Gabriel Spartacus, Pidassa Bidola, Chrysoula Ioannidou, Jihui Ye, Jakob Renner, Ulrich Lienert, Guilherme Abreu Faria, Benjamin Wahlmann, Martin Wildheim, Ulf Ackelid, Felix Beckmann, Peter Staron, Peter Hedström, Carolin Körner, Greta Lindwall
Abstract
The development of a sample environment for in situ x-ray characterization during metal Electron Beam Powder Bed Fusion (PBF-EB), called MiniMelt, is presented. The design considerations, the features of the equipment, and its implementation at the synchrotron facility PETRA III at Deutsches Elektronen-Synchrotron, Hamburg, Germany, are described. The equipment is based on the commercially available Freemelt ONE PBF-EB system but has been customized with a unique process chamber to enable real-time synchrotron measurements during the additive manufacturing process. Furthermore, a new unconfined powder bed design to replicate the conditions of the full-scale PBF-EB process is introduced. The first radiography (15 kHz) and diffraction (1 kHz) measurements of PBF-EB with a hot-work tool steel and a Ni-base superalloy, as well as bulk metal melting with the CMSX-4 alloy, using the sample environment are presented. MiniMelt enables time-resolved investigations of the dynamic phenomena taking place during multi-layer PBF-EB, facilitating process understanding and development of advanced process strategies and materials for PBF-EB.