Thermoelectric Magnetohydrodynamic Control of Melt Pool Flow During Laser Directed Energy Deposition Additive Manufacturing
Thermoelectric Magnetohydrodynamic Control of Melt Pool Flow During Laser Directed Energy Deposition Additive Manufacturing
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DOI：
10.2139/ssrn.4329316
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发表时间：
2023-05
期刊：
影响因子：
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通讯作者：
Xianqiang Fan;Tristan G. Fleming;David Tien Rees;Yuze Huang;S. Marussi;C. L. Leung;R. Atwood;
中科院分区：
文献类型：
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作者：
Xianqiang Fan;Tristan G. Fleming;David Tien Rees;Yuze Huang;S. Marussi;C. L. Leung;R. Atwood;
熔体流动对于增材制造（AM）过程中的构建质量至关重要。当施加外部磁场时，它会通过热电磁流体动力学（TEMHD）效应产生改变流动的力，从而可能改变最终的微观结构。然而，TEMHD力量的范围及其潜在机制仍不清楚。我们使用原位高速同步辐射X射线照相术和非原位层析术追踪钨粒子的流动，以揭示定向能量沉积AM（DED-AM）过程中TEMHD诱导的流动结构。当没有施加磁场时，马兰戈尼对流占主导地位，导致相对均匀的颗粒分布。在磁场平行于扫描方向的情况下，诱导TEMHD流，在横截面中循环，导致颗粒分离到池的底部和侧面。此外，向下的磁场引起水平循环，将颗粒分离到另一侧。我们的研究结果表明，TEMHD可以破坏DED-AM过程中的熔池流动。
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.