|About this Abstract
||2022 TMS Annual Meeting & Exhibition
||Materials Processing Fundamentals
||Thermoelectric Magnetohydrodynamic Control of Melt Pool Dynamics and Microstructure Evolution in Direct Energy Deposition Additive Manufacturing
||Xianqiang Fan, Tristan G. Fleming, David T. Rees, Yuze Huang, Yunhui Chen, Sebastian Marussi, Robert C. Atwood, Andrew Kao, Peter D. Lee
|On-Site Speaker (Planned)
Large thermal gradients in the melt pool during additive manufacturing (AM) generate large thermoelectric currents. The application of an external magnetic field introduces a Lorentz force which drives fluid flow in the melt pool, known as thermoelectric magnetohydrodynamics (TEMHD). However, the relative magnitude of TEMHD flow to Marangoni and buoyancy flow is poorly understood. To investigate this, a system to apply a magnetic field with a variable-orientation was developed and mounted into a DED-AM process replicator. A magnetic field of 230 mT is shown to increase the melt pool depth when applied parallel to scan direction. Further, when the polarity of the magnetic field was reversed normal to the scan direction, alternating thin and thick layers were produced. This is shown to be caused by the influence of magnetic field orientation on TEMHD flow by comparison to computational modelling of the flow and microstructure development, revealing the underlying hydrodynamic mechanisms.
||Additive Manufacturing, Solidification, Modeling and Simulation