|About this Abstract
||2022 TMS Annual Meeting & Exhibition
||Additive Manufacturing: Advanced Characterization with Synchrotron, Neutron, and In Situ Laboratory-scale Techniques II
||Controlling Interdependent Meso-nanosecond Dynamics and Defect Generation Using a Digital Twin
||Saad Khairallah, Brian Simonds, Tao Sun, Michael Stokes, Alexey Volkov, Aiden Martin, John Lee, Gabe Guss, Nicholas Calta, Joshua Hammons, Michael Nielsen, Kevin Chaput, Edwin Schwalbach, Megna Shah, Michael Chapman, Trevor Willey, Alexander Rubenchik, Andrew Anderson, Y. Morris Wang, Manyalibo Matthews, Wayne King
|On-Site Speaker (Planned)
We used ALE3D high-fidelity multi-physics model, which was verified with in-situ X-ray and other diagnostics experiments, to study laser-powder and laser-melt pool interactions at short time scales. We captured different modes of laser interactions that involve expulsion of spatter, shadowing and oscillations in absorptivity. We report on self-replicating spatter, that once formed, become hard to get rid of due to a self-replication mechanism that involves loose particles in the powder layer. We explain how pre-sintering the powder could be a strategy to mitigate this effect. Spatter beyond a size threshold can cause pores due to laser shadowing. We identified the laser scan strategy as one source of these large spatter sizes and derived a stability criterion to prevent them. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract DE- AC52-07NA27344. Lawrence Livermore National Security, LLC. LLNL-ABS-799067.
||Additive Manufacturing, Computational Materials Science & Engineering, Other