In order to comprehensively reveal the evolutionary dynamics of the molten pool and the state of motion of the fluid during the high-precision laser powder bed fusion (HP-LPBF) process, this study aims to deeply investigate the specific manifestations of the multiphase flow, solidification phenomena, and heat transfer during the process by means of numerical simulation methods. Numerical simulation models of SS316L single-layer HP-LPBF formation with single and double tracks were constructed using the discrete element method and the computational fluid dynamics method. The effects of various factors such as Marangoni convection, surface tension, vapor recoil, gravity, thermal convection, thermal radiation, and evaporative heat dissipation on the heat and mass transfer in the molten pool have been paid attention to during the model construction process. The results show that the molten pool exhibits a “comet” shape, in which the temperature gradient at the front end of the pool is significantly larger than that at the tail end, with the highest temperature gradient up to 1.69 × 108 K/s. It is also found that the depth of the second track is larger than that of the first one, and the process parameter window has been determined preliminarily. In addition, the application of HP-LPBF technology helps to reduce the surface roughness and minimize the forming size.

1.
S. L.
Sing
and
W. Y.
Yeong
, “
Laser powder bed fusion for metal additive manufacturing: Perspectives on recent developments
,”
Virtual Phys. Prototyping.
15
,
359
370
(
2020
).
2.
A. M.
Khorasani
,
I. G.
Jithin
,
J. K.
Veetil
, and
A. H.
Ghasemi
, “
A review of technological improvements in laser-based powder bed fusion of metal printers
,”
Int. J. Adv. Manuf. Technol.
108
,
191
209
(
2020
).
3.
Y.
Qin
,
A.
Brockett
,
Y.
Ma
,
A.
Razali
,
J.
Zhao
,
C.
Harrison
,
W.
Pan
,
X.
Dai
, and
D.
Loziak
, “
Micro-manufacturing: Research, technology outcomes and development issues
,”
Int. J. Adv. Manuf. Technol.
47
,
821
837
(
2010
).
4.
B.
Nagarajan
,
Z.
Hu
,
X.
Song
,
W.
Zhai
, and
J.
Wei
, “
Development of micro selective laser melting: The state of the art and future perspectives
,”
Engineering.
5
,
702
720
(
2019
).
5.
Y.
Wei
,
G.
Chen
,
W.
Li
,
Y.
Zhou
,
Z.
Nie
,
J.
Xu
, and
W.
Zhou
, “
Micro selective laser melting of SS316L: Single tracks, defects, microstructures and thermal/mechanical properties
,”
Opt. Laser Technol.
145
,
107469
(
2022
).
6.
Y.
Wei
,
G.
Chen
,
W.
Li
,
M.
Li
,
Y.
Zhou
,
Z.
Nie
, and
J.
Xu
, “
Process optimization of micro selective laser melting and comparison of different laser diameter for forming different powder
,”
Opt. Laser Technol.
150
,
107953
(
2022
).
7.
H.
Zhiheng
,
B.
Nagarajan
,
X.
Song
,
R.
Huang
,
W.
Zhai
, and
J.
Wei
, “
Formation of SS316L single tracks in micro selective laser melting: Surface, geometry, and defects
,”
Adv. Mater. Sci. Eng.
2019
,
9451406
.
8.
B.
Nagarajan
,
Z.
Hu
,
S.
Gao
,
X.
Song
,
R.
Huang
,
M.
Seita
, and
J.
Wei
, “
Effect of in-situ laser remelting on the microstructure of SS316L fabricated by micro selective laser melting
,” in
Advanced Surface Enhancement
, edited by
Sho
Itoh
and
Shashwat
Shukla
, Lecture Notes in Mechanical Engineering (
Springer Singapore
,
Singapore
,
2020
), pp.
330
336
.
9.
H.
Zhiheng
,
B.
Nagarajan
,
X.
Song
,
R.
Huang
,
W.
Zhai
, and
J.
Wei
, “
Tailoring surface roughness of micro selective laser melted SS316L by in-situ laser remelting
,” in
Advanced Surface Enhancement
, edited by
Sho
Itoh
and
Shashwat
Shukla
, Lecture Notes in Mechanical Engineering (
Springer Singapore
,
Singapore
,
2020
), pp.
337
343
.
10.
J.
Fu
,
Z.
Hu
,
X.
Song
,
W.
Zhai
,
Y.
Long
,
H.
Li
, and
M.
Fu
, “
Micro selective laser melting of NiTi shape memory alloy: Defects, microstructures and thermal/mechanical properties
,”
Opt. Laser Technol.
131
,
106374
(
2020
).
11.
E.
Abele
and
M.
Kniepkamp
, “
Analysis and optimisation of vertical surface roughness in micro selective laser melting
,”
Surf. Topogr.: Metrol. Prop.
3
,
034007
(
2015
).
12.
S.
Qu
,
J.
Ding
,
J.
Fu
,
M.
Fu
,
B.
Zhang
, and
X.
Song
, “
High-precision laser powder bed fusion processing of pure copper
,”
Addit. Manuf.
48
,
102417
(
2021
).
13.
Y.
Wei
,
G.
Chen
,
M.
Li
,
W.
Li
,
Y.
Zhou
,
J.
Xu
, and
Z.
wei
, “
High-precision laser powder bed fusion of 18Ni300 maraging steel and its SiC reinforcement composite materials
,”
J. Manuf. Process.
84
,
750
763
(
2022
).
14.
B.
Liu
,
R.
Wildman
,
T.
Christopher
,
I.
Ashcroft
, and
H.
Richard
, “
Investigation the effect of particle size distribution on processing parameters optimisation in selective laser melting process
,” in
2011 International Solid Freeform Fabrication Symposium
(
University of Texas at Austin
,
2011
).
15.
T. D.
McLouth
,
G. E.
Bean
,
D. B.
Witkin
,
S. D.
Sitzman
,
P. M.
Adams
,
D. N.
Patel
,
W.
Park
,
J.-M.
Yang
, and
R. J.
Zaldivar
, “
The effect of laser focus shift on microstructural variation of Inconel 718 produced by selective laser melting
,”
Mater. Des.
149
,
205
213
(
2018
).
16.
Y.
Qian
,
Y.
Wentao
, and
L.
Feng
, “
Mesoscopic simulations of powder bed fusion: Research progresses and conditions
,”
Electromachining Mould
06
,
46
52
(
2017
).
17.
J.
Fu
,
S.
Qu
,
J.
Ding
,
X.
Song
, and
M. W.
Fu
, “
Comparison of the microstructure, mechanical properties and distortion of stainless Steel 316L fabricated by micro and conventional laser powder bed fusion
,”
Addit. Manuf.
44
,
102067
(
2021
).
18.
N. T.
Aboulkhair
,
I.
Maskery
,
C.
Tuck
,
I.
Ashcroft
, and
N. M.
Everitt
, “
The microstructure and mechanical properties of selectively laser Melted AlSi10Mg: The effect of a conventional T6-like heat treatment
,”
Mater. Sci. Eng. A
667
,
139
146
(
2016
).
19.
S. Y.
Chen
,
J. C.
Huang
,
C. T.
Pan
,
C. H.
Lin
,
T. L.
Yang
,
Y. S.
Huang
,
C. H.
Ou
,
L. Y.
Chen
,
D. Y.
Lin
,
H. K.
Lin
,
T. H.
Li
,
J. S. C.
Jang
, and
C. C.
Yang
, “
Microstructure and mechanical properties of open-cell porous Ti-6Al-4V fabricated by selective laser melting
,”
J. Alloys Compd.
713
,
248
254
(
2017
).
20.
Y.
Bai
,
Y.
Yang
,
D.
Wang
, and
M.
Zhang
, “
Influence mechanism of parameters process and mechanical properties evolution mechanism of Maraging steel 300 by selective laser melting
,”
Mater. Sci. Eng. A
703
,
116
123
(
2017
).
21.
Y.
Bai
,
Y.
Yang
,
Z.
Xiao
,
M.
Zhang
, and
D.
Wang
, “
Process optimization and mechanical property evolution of AlSiMg0.75 by selective laser melting
,”
Mater. Des.
140
,
257
266
(
2018
).
22.
Y.
Liu
,
M.
Zhang
,
W.
Shi
,
Y.
Ma
, and
J.
Yang
, “
Study on performance optimization of 316L stainless steel parts by high-efficiency selective laser melting
,”
Opt. Laser Technol.
138
,
106872
(
2021
).
23.
D.
Gu
,
Y.-C.
Hagedorn
,
W.
Meiners
,
G.
Meng
,
R. J. S.
Batista
,
K.
Wissenbach
, and
R.
Poprawe
, “
Densification behavior, microstructure evolution, and wear performance of selective laser melting processed commercially pure titanium
,”
Acta Mater.
60
,
3849
3860
(
2012
).
24.
N.
Read
,
W.
Wang
,
K.
Essa
, and
M. M.
Attallah
, “
Selective laser melting of AlSi10Mg alloy: Process optimisation and mechanical properties development
,”
Mater. Des.
65
,
417
424
(
2015
).
25.
I. A.
Roberts
,
C. J.
Wang
,
R.
Esterlein
,
M.
Stanford
, and
D. J.
Mynors
, “
A three-dimensional finite element analysis of the temperature field during laser melting of metal powders in additive layer manufacturing
,”
Int. J. Mach. Tools Manuf.
49
(
12–13
),
916
923
(
2009
).
26.
K.
Dai
and
L.
Shaw
, “
Finite element analysis of the effect of volume shrinkage during laser densification
,”
Acta Mater.
53
(
18
),
4743
4754
(
2005
).
27.
K.
Carolin
,
E.
Attar
, and
P.
Heinl
, “
Mesoscopic simulation of selective beam melting processes
,”
J. Mater. Process. Technol.
211
(
6
),
978
987
(
2011
).
28.
F.-J.
Gürtler
,
M.
Karg
,
K.-H.
Leitz
, and
M.
Schmidt
, “
Simulation of laser beam melting of steel powders using the three-dimensional volume of fluid method
,”
Phys. Procedia
41
,
881
886
(
2013
).
29.
P.
Meakin
and
R.
Jullien
, “
Restructuring effects in the rain model for random deposition
,”
J. Phys. France
48
(
10
),
1651
1662
(
1987
).
30.
J-m
Wang
,
G-h
Liu
,
Y-l
Fang
, and
W-k
Li
, “
Marangoni effect in nonequilibrium multiphase system of material processing
,”
Rev. Chem. Eng.
32
(
5
),
551
585
(
2016
).
31.
W.
Ye
,
S.
Zhang
,
L. L.
Mendez
,
M.
Farias
,
J.
Li
,
B.
Xu
,
P.
Li
, and
Y.
Zhang
, “
Numerical simulation of the melting and alloying processes of elemental titanium and boron powders using selective laser alloying
,”
J. Manuf. Process.
64
,
1235
1247
(
2021
).
32.
U. S.
Bertoli
,
A. J.
Wolfer
,
M. J.
Matthews
,
J.-P. R.
Delplanque
, and
J. M.
Schoenung
, “
On the limitations of volumetric energy density as a design parameter for selective laser melting
,”
Mater. Des.
113
,
331
340
(
2017
).
33.
W. E.
King
,
H. D.
Barth
,
V. M.
Castillo
,
G. F.
Gallegos
,
J. W.
Gibbs
,
D. E.
Hahn
,
C.
Kamath
, and
A. M.
Rubenchik
, “
Observation of keyhole-mode laser melting in laser powder-bed fusion additive manufacturing
,”
J. Mater. Process. Technol.
214
(
12
),
2915
2925
(
2014
).
34.
L.
Cao
, “
Numerical simulation of the impact of laying powder on selective laser melting single-pass formation
,”
Int. J. Heat Mass Transfer
141
,
1036
1048
(
2019
).
35.
L.
Huang
,
X.
Hua
,
D.
Wu
, and
F.
Li
, “
Numerical study of keyhole instability and porosity formation mechanism in laser welding of aluminum alloy and steel
,”
J. Mater. Process. Technol.
252
,
421
431
(
2018
).
36.
K. Q.
Le
,
C.
Tang
, and
C. H.
Wong
, “
On the study of keyhole-mode melting in selective laser melting process
,”
Int. J. Therm. Sci.
145
,
105992
(
2019
).
37.
J.-H.
Cho
and
S.-J.
Na
, “
Theoretical analysis of keyhole dynamics in polarized laser drilling
,”
J. Phys. D: Appl. Phys.
40
(
24
),
7638
(
2007
).
38.
W.
Ye
, “
Mechanism analysis of selective laser melting and metallurgy process based on base element powder of titanium and boron
,” Ph.D. dissertation (
Nanchang University
,
2021
).
39.
R.
Ammer
,
M.
Markl
,
U.
Ljungblad
,
C.
Körner
, and
U.
Rüde
, “
Simulating fast electron beam melting with a parallel thermal free surface lattice Boltzmann method
,”
Comput. Math. Appl.
67
(
2
),
318
330
(
2014
).
40.
H.
Chen
,
Q.
Wei
,
S.
Wen
,
Z.
Li
, and
Y.
Shi
, “
Flow behavior of powder particles in layering process of selective laser melting: Numerical modeling and experimental verification based on discrete element method
,”
Int. J. Mach. Tools Manuf.
123
,
146
159
(
2017
).
41.
F.
Verhaeghe
,
T.
Craeghs
,
J.
Heulens
, and
L.
Pandelaers
, “
A pragmatic model for selective laser melting with evaporation
,”
Acta Mater.
57
(
20
),
6006
6012
(
2009
).
42.
C. H.
Fu
and
Y. B.
Guo
, “
Three-dimensional temperature gradient mechanism in selective laser melting of Ti-6Al-4V
,”
J. Manuf. Sci. Eng.
136
(
6
),
061004
(
2014
).
43.
Y.
Xiang
,
Z.
Shuzhe
,
L.
Junfeng
,
W.
Zhengying
,
Y.
Lixiang
, and
J.
Lihao
, “
Numerical simulation and experimental verification for selective laser single track melting forming of Ti6Al4V
,”
J. Zhejiang Univ. (Eng. Sci.)
53
(
11
),
2102
2109 + 2117
(
2019
).
44.
Q.
He
,
H.
Xia
,
J.
Liu
,
X.
Ao
, and
S.
Lin
, “
Modeling and numerical studies of selective laser melting: Multiphase flow, solidification and heat transfer
,”
Mater. Des.
196
,
109115
(
2020
).
45.
L.
Cao
, “
Mesoscopic-scale numerical simulation including the influence of process parameters on SLM single-layer multi-pass formation
,”
Metall. Mater. Trans. A
51
,
4130
4145
(
2020
).
46.
L.
Cao
, “
Mesoscopic-scale numerical investigation including the influence of process parameters on LPBF multi-layer multi-path formation
,”
Comput. Model. Eng. Sci.
126
(
1
),
5
23
(
2021
).
47.
H.
Yin
and
S. D.
Felicelli
, “
Dendrite growth simulation during solidification in the LENS process
,”
Acta Mater.
58
(
4
),
1455
1465
(
2010
).
48.
P.
Nie
,
O. A.
Ojo
, and
Z.
Li
, “
Numerical modeling of microstructure evolution during laser additive manufacturing of a nickel-based superalloy
,”
Acta Mater.
77
,
85
95
(
2014
).
49.
Z.
Liu
and
H.
Qi
, “
Effects of substrate crystallographic orientations on crystal growth and microstructure formation in laser powder deposition of nickel-based superalloy
,”
Acta Mater.
87
,
248
258
(
2015
).
50.
L.
Wei
,
L.
Xin
,
W.
Meng
, and
H.
Weidong
, “
Cellular automaton simulation of the molten pool of laser solid forming process
,”
Acta Phys. Sin.
64
(
01
),
018103
018363
(
2015
).
51.
R.
Acharya
,
J. A.
Sharon
, and
A.
Staroselsky
, “
Prediction of microstructure in laser powder bed fusion process
,”
Acta Mater.
124
,
360
371
(
2017
).
52.
M. R.
Rolchigo
and
R.
LeSar
, “
Modeling of binary alloy solidification under conditions representative of additive manufacturing
,”
Comput. Mater. Sci.
150
,
535
545
(
2018
).
53.
S.
Geng
,
P.
Jiang
,
L.
Guo
,
X.
Gao
, and
G.
Mi
, “
Multi-scale simulation of grain/sub-grain structure evolution during solidification in laser welding of aluminum alloys
,”
Int. J. Heat Mass Transfer
149
,
119252
(
2020
).
54.
W. L.
Wang
,
W. Q.
Liu
,
X.
Yang
,
R. R.
Xu
, and
Q. Y.
Dai
, “
Multi-scale simulation of columnar-to-equiaxed transition during laser selective melting of rare earth magnesium alloy
,”
J. Mater. Sci. Technol.
119
,
11
24
(
2022
).
55.
Q.
Xia
,
J.
Yang
, and
Y.
Li
, “
On the conservative phase-field method with the N-component incompressible flows
,”
Phys. Fluids
35
,
012120
(
2023
).
56.
Q.
Xia
,
G.
Sun
,
J.
Kim
, and
Y.
Li
, “
Multi-scale modeling and simulation of additive manufacturing based on fused deposition technique
,”
Phys. Fluids
35
,
034116
(
2023
).
57.
A.
Hussein
,
L.
Hao
,
C.
Yan
, and
R.
Everson
, “
Finite element simulation of the temperature and stress fields in single layers built without-support in selective laser melting
,”
Mater. Des.
52
,
638
647
(
2013
).
58.
J.
Ding
,
P.
Colegrove
,
J.
Mehnen
,
S.
Ganguly
,
P. M.
Sequeira Almeida
,
F.
Wang
, and
S.
Williams
, “
Thermo-mechanical analysis of wire and arc additive layer manufacturing process on large multi-layer parts
,”
Comput. Mater. Sci.
50
(
12
),
3315
3322
(
2011
).
59.
Y.
Du
,
X.
You
,
F.
Qiao
,
L.
Guo
, and
Z.
Liu
, “
A model for predicting the temperature field during selective laser melting
,”
Results Phys.
12
,
52
60
(
2019
).
60.
X.
Luo
,
M.
Liu
,
L.
Zhenhua
,
H.
Li
, and
J.
Shen
, “
Effect of different heat-source models on calculated temperature field of selective laser melted 18Ni300
,”
Chin. J. Lasers
48
(
14
),
1402005
1402062
(
2021
).
61.
J. F.
Li
,
L.
Li
, and
F. H.
Stott
, “
Thermal stresses and their implication on cracking during laser melting of ceramic materials
,”
Acta Mater.
52
(
14
),
4385
4398
(
2004
).
62.
P.
Aggarangsi
and
J. L.
Beuth
, “
Localized preheating approaches for reducing residual stress in additive manufacturing
,” paper presented at the 2006 International Solid Freeform Fabrication Symposium, The University of Texas in Austin on August 14–16, 2006.
63.
K.
Dai
and
L.
Shaw
, “
Thermal and mechanical finite element modeling of laser forming from metal and ceramic powders
,”
Acta Mater.
52
(
1
),
69
80
(
2004
).
64.
A. H.
Nickel
,
D. M.
Barnett
, and
F. B.
Prinz
, “
Thermal stresses and deposition patterns in layered manufacturing
,”
Mater. Sci. Eng. A
317
(
1–2
),
59
64
(
2001
).
65.
M. F.
Zaeh
and
G.
Branner
, “
Investigations on residual stresses and deformations in selective laser melting
,”
Prod. Eng.
4
(
1
),
35
45
(
2010
).
66.
P.
Bian
,
J.
Shi
,
Y.
Liu
, and
Y.
Xie
, “
Influence of laser power and scanning strategy on residual stress distribution in additively manufactured 316L steel
,”
Opt. Laser Technol.
132
,
106477
(
2020
).
67.
B. M.
Marques
,
C. M.
Andrade
,
D. M.
Neto
,
M. C.
Oliveira
,
J. L.
Alves
, and
L. F.
Menezes
, “
Numerical analysis of residual stresses in parts produced by selective laser melting process
,”
Procedia Manuf.
47
,
1170
1177
(
2020
).
68.
W.
Mu
, “
Numerical simulation of SLM forming process and research and prediction of forming properties
,” MA thesis (
Anhui Jianzhu University
,
2022
).
69.
Y.
Zhang
, “
Multi-scale multi-physics modeling of laser powder bed fusion process of metallic materials with experiment validation
,” Ph.D. dissertation (
Purdue University
,
2018
).
70.
Y.
Qian
, “
Mesoscopic simulation studies of key processing issues for powder bed fusion technology
,” Ph.D. dissertation (
Tsinghua University
,
2019
).
71.
N. V.
Brilliantov
,
S.
Frank
,
J.-M.
Hertzsch
, and
T.
Pöschel
, “
Model for collisions in granular gases
,”
Phys. Rev. E
53
(
5
),
5382
5392
(
1996
).
72.
Z.
Xiao
, “
Research on microscale selective laser melting process of high strength pure copper specimens
,” MA thesis (
Hunan University
,
2022
).
73.
Z.
Li
,
K.
Mukai
,
M.
Zeze
, and
K. C.
Mills
, “
Determination of the surface tension of liquid stainless steel
,”
J. Mater. Sci.
40
(
9–10
),
2191
2195
(
2005
).
74.
R.
Scardovelli
and
S.
Zaleski
, “
Analytical relations connecting linear interfaces and volume fractions in rectangular grids
,”
J. Comput. Phys.
164
(
1
),
228
237
(
2000
).
75.
D.-W.
Cho
,
W.-I.
Cho
, and
S.-J.
Na
, “
Modeling and simulation of arc: Laser and hybrid welding process
,”
J. Manuf. Process.
16
(
1
),
26
55
(
2014
).
76.
Flow3D
.
Version 11.1.0: User Manual
(
FlowScience
,
Santa Fe, NM, USA
,
2015
).
77.
Y.
Tian
,
L.
Yang
,
D.
Zhao
,
Y.
Huang
, and
J.
Pan
, “
Numerical analysis of powder bed generation and single track forming for selective laser melting of ss316l stainless steel
,”
J. Manuf. Process.
58
,
964
974
(
2020
).
78.
C.
Tang
,
K. Q.
Le
, and
C. H.
Wong
, “
Physics of humping formation in laser powder bed fusion
,”
Int. J. Heat Mass Transfer
149
,
119172
(
2020
).
79.
L.
Cao
, “
Mesoscopic-scale simulation of pore evolution during laser powder bed fusion process
,”
Comput. Mater. Sci.
179
,
109686
(
2020
).
80.
R.
Li
,
J.
Liu
,
Y.
Shi
,
W.
Li
, and
W.
Jiang
, “
Balling behavior of stainless steel and nickel powder during selective laser melting process
,”
Int. J. Adv. Manuf. Technol.
59
(
9–12
),
1025
1035
(
2012
).
81.
S. A.
Khairallah
and
A.
Anderson
, “
Mesoscopic simulation model of selective laser melting of stainless steel powder
,”
J. Mater. Process. Technol.
214
(
11
),
2627
2636
(
2014
).
82.
J.
Liu
,
D.
Gu
,
H.
Chen
,
D.
Dai
, and
H.
Zhang
, “
Influence of substrate surface morphology on wetting behavior of tracks during selective laser melting of aluminum-based alloys
,”
J. Zhejiang Univ. Sci. A
19
(
2
),
111
121
(
2018
).
83.
L.
Li
,
J.
Li
, and
T.
Fan
, “
Phase-field modeling of wetting and balling dynamics in powder bed fusion process
,”
Phys. Fluids
33
,
042116
(
2021
).
84.
X.
Nie
,
Z.
Hu
,
H.
Zhu
,
Z.
Hu
,
L.
Ke
, and
X.
Zeng
, “
Analysis of processing parameters and characteristics of selective laser melted high strength Al-Cu-Mg alloys: from single tracks to cubic samples
,”
J. Mater. Process. Technol.
256
,
69
77
(
2018
).
You do not currently have access to this content.