| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Additive Manufacturing: Processing Effects on Microstructure and Material Performance
|
| Presentation Title |
A-155: Thermoelectric Magnetohydrodynamic Effects in Laser Additive Manufacturing: Coupled Macro-microscale Numerical Modelling |
| Author(s) |
Andrew Kao, Teddy Gan, Catherine Tonry, Ivars Krastins, Koulis Pericleous |
| On-Site Speaker (Planned) |
Andrew Kao |
| Abstract Scope |
Strong fluid flow appears in laser additive manufacturing weld pools, with large thermal gradients introducing buoyancy and Marangoni forces. The large thermal gradients also generate significant thermoelectric currents, which in the presence of a magnetic field drive flow, the so called thermoelectric magnetohydrodynamics (TEMHD) phenomenon.
TESA, the purpose-built Thermoelectric Solidification Algorithm, uses a lattice Boltzmann enthalpy based method to capture the macroscopic melt pool dynamics. There is competition between Marangoni and the magnetically induced flows, where the orientation and strength of the magnetic field leads to a deepening, widening or even a deflection in the melt pool. The macroscopic model is coupled to a microscopic crystal growth model that predicts the resulting microstructure, accounting for flow, multiple additive layers, time/spatially varying magnetic fields and scanning strategy. The results show that judicious use of the magnetic field can disrupt key defects, such as that of epitaxial growth. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |