|About this Abstract
||2021 TMS Annual Meeting & Exhibition
||Additive Manufacturing of Metals: Applications of Solidification Fundamentals
||Quantifying the Influence of Local Layer Thickness on Pore Evolution during Laser Powder Fusion Using High-speed X-ray Imaging
||Chu Lun Alex Leung, Yuze Huang, Samuel J. Clark, Yunhui Chen, Sebastian Marussi, Lorna Sinclair, Iain Todd, Margie P. Olbinado, Elodie Boller, Alexander Rack, Peter D. Lee
|On-Site Speaker (Planned)
||Chu Lun Alex Leung
Laser powder bed fusion additive manufacturing (LPBF) produces complex net-shape parts from alloy powders, in a layer-by-layer manner. Synchrotron X-ray imaging studies of pore evolution to date have mostly been in single-layer tracks on substrates, missing key interactions between the laser beam and pre-existing pores and other features in prior tracks. Here, we used an <i>in situ</i> and <i>operando</i> process replicator (ISOPR) and X-ray imaging to monitor the process dynamics during a multilayer build. We quantify the changes in keyhole geometry, porosity, and remelting zone, as a function of time, layer number, and local layer thickness. Our results demonstrate that the local layer thickness strongly influences surface topology, altering remelting, and pore evolution mechanisms. We use the extracted information to build a novel physical model accounting for the effect of layer-based thickness on heat transfer mechanisms, elucidating its impact on pore formation during multilayer LPBF additive manufacturing.