Abstract
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.
| Original language | English |
|---|---|
| Article number | 107866 |
| Journal | Materials and Design |
| Volume | 179 |
| DOIs | |
| Publication status | Published - 2019 Oct 5 |
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All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Mechanics of Materials
- Mechanical Engineering
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Effects of sulfur concentration and Marangoni convection on melt-pool formation in transition mode of selective laser melting process. / Le, Trong Nhan; Lo, Yu-Lung.
In: Materials and Design, Vol. 179, 107866, 05.10.2019.Research output: Contribution to journal › Article
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
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.
UR - http://www.scopus.com/inward/record.url?scp=85066253465&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85066253465&partnerID=8YFLogxK
U2 - 10.1016/j.matdes.2019.107866
DO - 10.1016/j.matdes.2019.107866
M3 - Article
AN - SCOPUS:85066253465
VL - 179
JO - Materials and Design
JF - Materials and Design
SN - 0264-1275
M1 - 107866
ER -