文献类型：期刊文献

英文题名：Effect of Combined Direct Current Electric Field and Pulsed Magnetic Field on the Melt Thermal Fluid Behavior During the Process of Laser Powder Bed Fusion

作者：Zeng, Chao Huang, Fang Xue, Jiutian Jia, Yun

机构：[1] School of Aerospace Engineering, Guizhou Institute of Technology, Guiyang, 550003, China

第一机构：贵州理工学院

年份：2022

外文期刊名：SSRN

收录：EI(收录号：20220426859)

语种：英文

外文关键词：Additives - Electric fields - Grain size and shape - Microstructure - Phase interfaces - Solidification - Titanium alloys

摘要：The application of a pulsed magnetic field (PMF) during a metallurgy solidification process has proven to be an effective method in refining the grain size and improving the mechanical performance of the material. However, fewer works were reported in the realm of laser additive manufacturing and the effect of PMF on the thermal fluid behavior of the transient melt pool is still unclear. In the present work, numerical models were developed to study the thermal fluid characteristics in the Ti-alloy melt pool generated during the laser powder bed fusion (LPBF) process under the effect of a combined direct current (DC) electric field and PMF. The temperature field, melt pool evolution and magneto-oscillation effect in the melt pool were discussed to elucidate the resultant microstructure evolution. The results show that the application of a combined DC electric field and PMF could decrease the maximum temperature in the melt pool and the duration of the melt pool but increase the temperature gradient at the liquid-solid interface. Shapes of the melt pool were conspicuously different when the electric-magnetic field was employed. The length and width of the melt pool were reduced but its volume was increased. Moreover, it is found that the electric-magnetic field can lead to a notable increase in the magnitude of the fluid velocity and a greater fluctuation in the magnitude. A more refined microstructure is expected to be obtained, of which the mechanism may be ascribed to not only the increased temperature gradient, solidification growth rate, and cooling rate at the liquid-solid interface, but also the enhanced fluid convection and continuous impulse force in the melt. For better grain refinement, preferable duty cycles of the PMF are proposed to be less than 50%. The findings of this study may give a new insight into the electromagnetic controlling methods for laser additive manufacturing of Ti-alloy parts. ? 2022, The Authors. All rights reserved.