Single-bead, laser-deposited Inconel® 718 tracks atop substrates of the same composition were studied to ascertain the influence of laser power, processing speed, working distance, and substrate preheat on the fusion zone geometry, microstructure, and hardness. Modifying working distance encompassed both a change in powder flow distribution and beam diameter. Laser power and processing speed linearly affected fusion zone width and area, though laser power was found to have the most significant effect of all processing parameters. Preheating the substrates increased the width of the fusion zone by an average of 16% and led to a more uniform hardness throughout. The fusion zone cross-section was found to morph from semicircular to double-parabolic (wavy) with increasing laser power. This was attributed to surface tension induced Marangoni flow and the influence of surface-activated species on surface tension. The applicability of coupled parameters, including linear heat input and normalized enthalpy were investigated. Given the limited data available on the influence of processing parameters, particularly working distance and substrate temperature, on fusion zone geometry and hardness, results reported here may aid experimentalists and modelers working on cladding and additive manufacturing processes.

1.
R.
Vilar
, “
Laser cladding
,”
J. Laser Appl.
11
,
64
(
1999
).
2.
I.
Tabernero
,
A.
Lamikiz
,
S.
Martínez
,
E.
Ukar
, and
J.
Figueras
, “
Evaluation of the mechanical properties of Inconel 718 components built by laser cladding
,”
Int. J. Mach. Tools Manuf.
51
,
465
470
(
2011
).
3.
M.
Zhong
and
W.
Liu
, “
Laser surface cladding: the state of the art and challenges
,”
Proc. Inst. Mech. Eng. Part C J. Mech. Eng. Sci.
224
,
1041
1060
(
2010
).
4.
P. A.
Kobryn
,
E. H.
Moore
, and
S. L.
Semiatin
, “
Effect of laser power and traverse speed on microstructure, porosity, and build height in laser-deposited Ti-6Al-4V
,”
Scr. Mater.
43
,
299
305
(
2000
).
5.
T.
Vilaro
,
C.
Colin
, and
J. D.
Bartout
, “
As-fabricated and heat-treated microstructures of the Ti-6Al-4V alloy processed by selective laser melting
,”
Metall. Mater. Trans. A Phys. Metall. Mater. Sci.
42
,
3190
3199
(
2011
).
6.
L. L.
Parimi
,
G.
Ravi
,
D.
Clark
, and
M. M.
Attallah
, “
Microstructural and texture development in direct laser fabricated IN718
,”
Mater. Charact.
89
,
102
111
(
2014
).
7.
M.
Ma
,
Z.
Wang
, and
X.
Zeng
, “
Effect of energy input on microstructural evolution of direct laser fabricated IN718 alloy
,”
Mater. Charact.
106
,
420
427
(
2015
).
8.
J.
Lambarri
,
J.
Leunda
,
V.
García Navas
,
C.
Soriano
, and
C.
Sanz
, “
Microstructural and tensile characterization of Inconel 718 laser coatings for aeronautic components
,”
Opt. Lasers Eng.
51
,
813
821
(
2013
).
9.
Q. L.
Zhang
,
J. H.
Yao
, and
J.
Mazumder
, “
Laser direct metal deposition technology and microstructure and composition segregation of Inconel 718 superalloy
,”
J. Iron Steel Res. Int.
18
,
73
78
(
2011
).
10.
H.
Qi
,
M.
Azer
, and
A.
Ritter
, “
Studies of standard heat treatment effects on microstructure and mechanical properties of laser net shape manufactured INCONEL 718
,”
Metall. Mater. Trans. A
40
,
2410
2422
(
2009
).
11.
P. L.
Blackwell
, “
The mechanical and microstructural characteristics of laser-deposited IN718
,”
J. Mater. Process. Technol.
170
,
240
246
(
2005
).
12.
Y. C.
Zhang
,
Z. G.
Li
,
P. L.
Nie
, and
Y. X.
Wu
, “
Effect of ultrarapid cooling on microstructure of laser cladding IN718 coating
,”
Surf. Eng.
29
,
414
418
(
2013
).
13.
Y. N.
Zhang
,
X.
Cao
,
P.
Wanjara
, and
M.
Medraj
, “
Fiber laser deposition of INCONEL 718 using powders
,”
Mater. Sci. Technol. Conf. Exhib.
1
,
37
49
(
2013
).
14.
Y. S.
Lee
and
D. F.
Farson
, “
Surface tension-powered build dimension control in laser additive manufacturing process
,”
Int. J. Adv. Manuf. Technol.
85
,
1035
1044
(
2015
).
15.
D. M.
Goodarzi
,
J.
Pekkarinen
, and
A.
Salminen
, “
Effect of process parameters in laser cladding on substrate melted areas and the substrate melted shape
,”
J. Laser Appl.
27
,
S29201
(
2015
).
16.
D. B.
Hann
,
J.
Iammi
, and
J.
Folkes
, “
A simple methodology for predicting laser-weld properties from material and laser parameters
,”
J. Phys. D: Appl. Phys.
44
,
445401
(
2011
).
17.
J. J.
Blecher
,
T. A.
Palmer
, and
T.
DebRoy
, “
Solidification map of a nickel-base alloy
,”
Metall. Mater. Trans. A
45
,
2142
2151
(
2013
).
18.
K. C.
Mills
,
Recommended Values of Thermophysical Properties for Selected Commercial Alloys
(
Woodhead Publishing
,
Cambridge, England
,
2002
).
19.
D. J.
Corbin
,
A. R.
Nassar
,
E. W.
Reutzel
,
A. M.
Beese
, and
N. A.
Kistler
, “
Effect of directed energy deposition processing parameters on laser deposited Inconel® 718: External morphology
,”
J. Laser Appl.
29
,
022001
(
2017
).
20.
A. R.
Nassar
,
E. W.
Reutzel
,
S. W.
Brown
,
J. P.
Morgan
,
J. P.
Morgan
,
D. J.
Natale
,
R. L.
Tutwiler
,
D. P.
Feck
, and
J. C.
Banks
, “
Sensing for directed energy deposition and powder bed fusion additive manufacturing at Penn State University
,”
Laser 3D Manuf.
9738
,
97380R
(
2016
).
21.
Y. S.
Lee
,
M.
Nordin
,
S. S.
Babu
, and
D.
Farson
, “
Influence of fluid convection on weld pool formation in laser cladding
,”
Weld. J.
93
,
292
300
(
2014
); available at https://app.aws.org/wj/supplement/WJ_2014_08_s292.pdf.
22.
W.
Pitscheneder
,
T.
DebRoy
,
K.
Mundra
, and
R.
Ebner
, “
Role of sulfur and processing variables on the temporal evolution of weld pool geometry during multikilowatt laser beam welding of steels
,”
Weld. J.
75
,
71s
80s
(
1996
); available at https://app.aws.org/wj/supplement/WJ_1996_03_s71.pdf.
23.
A.
Arora
,
G. G.
Roy
, and
T.
DebRoy
, “
Unusual wavy weld pool boundary from dimensional analysis
,”
Scr. Mater.
60
,
68
71
(
2009
).
24.
O. O.
Diniz Neto
and
R.
Vilar
, “
Physical–computational model to describe the interaction between a laser beam and a powder jet in laser surface processing
,”
J. Laser Appl.
14
,
46
–51 (
2002
).
25.
D.
Tabor
,
The Hardness of Metals
(
Clarendon Press
,
Oxford
,
1951
).
26.
J. F.
Radavich
, “
The physical metallurgy of cast and wrought alloy 718
,” in
Superalloy 718
, Metallic Application, edited by
E. A.
Loria
(
Minerals
,
Metals & Materials Society, Warrendale, PA
,
1989
), pp.
229
240
.
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