Fan, Xianqiang and Fleming, Tristan G. and Rees, David T. and Huang, Yuze and Marussi, Sebastian and Leung, Chu Lun Alex and Atwood, Robert C. and Kao, Andrew and Lee, Peter D. (2023) Thermoelectric magnetohydrodynamic control of melt pool flow during laser directed energy deposition additive manufacturing. Additive Manufacturing, 71: 103587. ISSN 2214-8604
Full text not available from this repository.Abstract
Melt flow is critical to build quality during additive manufacturing (AM). When an external magnetic field is applied, it causes forces that alter the flow through the thermoelectric magnetohydrodynamic (TEMHD) effect, potentially altering the final microstructure. However, the extent of TEMHD forces and their underlying mechanisms, remain unclear. We trace the flow of tungsten particles using in situ high-speed synchrotron X-ray radiography and ex situ tomography to reveal the structure of TEMHD-induced flow during directed energy deposition AM (DED-AM). When no magnetic field is imposed, Marangoni convection dominates the flow, leading to a relatively even particle distribution. With a magnetic field parallel to the scan direction, TEMHD flow is induced, circulating in the cross-sectional plane, causing particle segregation to the bottom and side of the pool. Further, a downward magnetic field causes horizontal circulation, segregating particles to the other side. Our results demonstrate that TEMHD can disrupt melt pool flow during DED-AM.