TY - JOUR
T1 - Effects of sulfur concentration and Marangoni convection on melt-pool formation in transition mode of selective laser melting process
AU - Le, Trong Nhan
AU - Lo, Yu Lung
N1 - Funding Information:
The authors gratefully acknowledge the financial support provided to this study by the Ministry of Science and Technology, Taiwan under Grant No. MOST 107-2218-E-006-051 . Additionally, this research was, in part, supported by the Ministry of Education , Taiwan, Headquarter of University Advancement to the Intelligent Manufacturing Research Center (iMRC), National Cheng Kung University (NCKU).
Funding Information:
The authors gratefully acknowledge the financial support provided to this study by the Ministry of Science and Technology, Taiwan under Grant No. MOST 107-2218-E-006-051. Additionally, this research was, in part, supported by the Ministry of Education, Taiwan, Headquarter of University Advancement to the Intelligent Manufacturing Research Center (iMRC), National Cheng Kung University (NCKU).
Publisher Copyright:
© 2019 The Authors
PY - 2019/10/5
Y1 - 2019/10/5
N2 - A three-dimensional thermal-fluid model is constructed to investigate the effects of Marangoni convection on the melt-pool formation during the Selective Laser Melting of SS316 powder. The model takes account of the heat-and-mass transfer effects and the melt-pool flow dynamics. In the model, the surface tension gradient in the melt-pool is estimated as a function of the sulfur content of the metal powder based on the reported experimental data. The validity of the model is demonstrated by comparing the simulated melt-pool dimensions under a wide range of laser powers and scanning speeds with the experimental results presented for CL20ES stainless steel powder in the literature and SUS420 stainless steel powder obtained in the present study. The results show that besides the conduction mode, in which the melt-pool formation is dominated by thermal conduction, and the keyhole mode, in which the melt-pool formation is determined mainly by the recoil pressure, an additional transition mode exists between these two modes, in which the melt-pool formation is driven mainly by the Marangoni convection effect. In particular, for stainless steel powders with a higher sulfur content, an inward Marangoni flow occurs, which results in a deeper melt-pool and a lower porosity of the built part.
AB - A three-dimensional thermal-fluid model is constructed to investigate the effects of Marangoni convection on the melt-pool formation during the Selective Laser Melting of SS316 powder. The model takes account of the heat-and-mass transfer effects and the melt-pool flow dynamics. In the model, the surface tension gradient in the melt-pool is estimated as a function of the sulfur content of the metal powder based on the reported experimental data. The validity of the model is demonstrated by comparing the simulated melt-pool dimensions under a wide range of laser powers and scanning speeds with the experimental results presented for CL20ES stainless steel powder in the literature and SUS420 stainless steel powder obtained in the present study. The results show that besides the conduction mode, in which the melt-pool formation is dominated by thermal conduction, and the keyhole mode, in which the melt-pool formation is determined mainly by the recoil pressure, an additional transition mode exists between these two modes, in which the melt-pool formation is driven mainly by the Marangoni convection effect. In particular, for stainless steel powders with a higher sulfur content, an inward Marangoni flow occurs, which results in a deeper melt-pool and a lower porosity of the built part.
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U2 - 10.1016/j.matdes.2019.107866
DO - 10.1016/j.matdes.2019.107866
M3 - Article
AN - SCOPUS:85066253465
VL - 179
JO - International Journal of Materials in Engineering Applications
JF - International Journal of Materials in Engineering Applications
SN - 0264-1275
M1 - 107866
ER -