Abstract

Ti6Al4V is one of the vital metal alloys used in various industries including aerospace, especially at high-temperature applications, because of having high strength-to-weight ratio, and high melting temperature. Manufacturing these metal parts by the conventional subtractive methods have been challenging due to the difficulty involved with the cutting and machining it. However, additive manufacturing (AM) offers a convenient way for shaping this metal into the desired complex parts. Although different powder bed fusion (PBF) AM processes are time and cost effective, degradation of mechanical properties during high-temperature applications could be a concern for parts produced by them. Therefore, this study focuses on the anisotropic and high-temperature elastic and plastic behaviors of Ti6Al4V parts made using electron beam powder bed fusion (EB-PBF) process. Mechanical properties, like modulus of elasticity, 0.2% yield strength, ultimate tensile strength (UTS), and percent elongation, have been determined at 200 °C, 400 °C, and 600 °C temperatures from the samples produced in different build orientations. Considerable anisotropic behavior and temperature dependency were observed for all the analyzed properties. At 600 °C, various softening mechanisms such dislocation glide, grain boundary slip, and grain growth were anticipated to be activated reducing the flow stress and increasing the elasticity. Fractography analysis on fractured surfaces of the samples reveals various defects, including partially melted or unmelted powder particles near the surface and subsurface areas. Those internal and external defects are analyzed further using X-ray computed tomography (CT) and surface profilometer to show their effect on the anisotropic behaviors.

References

References
1.
Rafi
,
H. K.
,
Karthik
,
N. V.
,
Gong
,
H.
,
Starr
,
T. L.
, and
Stucker
,
B. E.
,
2013
, “
Microstructures and Mechanical Properties of Ti6Al4V Parts Fabricated by Selective Laser Melting and Electron Beam Melting
,”
J. Mater. Eng. Perform.
,
22
(
12
), pp.
3872
3883
. 10.1007/s11665-013-0658-0
2.
Roy
,
L.
,
2013
,
“Variation in Mechanical Behavior Due to Different Build Directions of Ti6Al4V Fabricated by Electron Beam Additive Manufacturing Technology,” Electronic Thesis or Dissertation
,
The University of Alabama
,
Tuscaloosa, AL
.
3.
Ngo
,
T. D.
,
Kashani
,
A.
,
Imbalzano
,
G.
,
Nguyen
,
K. T. Q.
, and
Hui
,
D.
,
2018
, “
Additive Manufacturing (3D Printing): A Review of Materials, Methods, Applications and Challenges
,”
Compos. Part B Eng.
,
143
(
15
), pp.
172
196
. 10.1016/j.compositesb.2018.02.012
4.
Najmon
,
J. C.
,
Raeisi
,
S.
, and
Tovar
,
A.
,
2019
, “2 - Review of Aditive Manufacturing Technologies and Applications in the Aerospace Industry,”
Additive Manufacturing for the Aerospace Industry
,
F.
Froes
, and
R.
Boyer
, eds.,
Elsevier Inc.
,
Philadelphia, PA
, pp.
7
31
.
5.
Arcam
, “
Ti6Al4V Titanium Alloy
,” http://www.arcam.com/wp-content/uploads/Arcam-Ti6Al4V-Titanium-Alloy.pdf, Accessed March 12, 2020.
6.
Safdar
,
A.
,
2010
,
Microstructures and Surface Roughness of EBM Produced Ti-6Al-4V
, Licentiate Thesis, Comprehensive Summary,
Malmö University
,
Malmö, Sweden
.
7.
Lee
,
W. S.
, and
Lin
,
C. F.
,
1998
, “
Plastic Deformation and Fracture Behaviour of Ti-6Al-4V Alloy Loaded With High Strain Rate Under Various Temperatures
,”
Mater. Sci. Eng. A
,
241
(
1–2
), pp.
48
59
. 10.1016/S0921-5093(97)00471-1
8.
Kim
,
J.
,
Kim
,
K. H.
, and
Kwon
,
D.
,
2016
, “
Evaluation of High-Temperature Tensile Properties of Ti-6Al-4V Using Instrumented Indentation Testing
,”
Met. Mater. Int.
,
22
(
2
), pp.
209
215
. 10.1007/s12540-016-5619-3
9.
Kumar
,
S.
,
Sankara Narayanan
,
T. S. N.
,
Ganesh Sundara Raman
,
S.
, and
Seshadri
,
S. K.
,
2010
, “
Thermal Oxidation of Ti6Al4V Alloy: Microstructural and Electrochemical Characterization
,”
Mater. Chem. Phys.
,
119
(
1–2
), pp.
337
346
. 10.1016/j.matchemphys.2009.09.007
10.
Frazier
,
W. E.
,
2014
, “
Metal Additive Manufacturing: A Review
,”
J. Mater. Eng. Perform.
,
23
(
6
), pp.
1917
1928
. 10.1007/s11665-014-0958-z
11.
Liu
,
R.
,
Wang
,
Z.
,
Sparks
,
T.
,
Liou
,
F.
, and
Newkirk
,
J.
,
2016
, “13 - Aerospace Applications of Laser Additive Manufacturing,”
Laser Additive Manufacturing: Materials, Design, Technologies, and Applications
,
M.
Brandt
, ed.,
Elsevier Ltd.
,
Amsterdam, The Netherlands
, pp.
351
371
.
12.
Stephens
,
R. I.
,
Fatemi
,
A.
,
Stephens
,
R. R.
, and
Fuchs
,
H. O.
,
2001
,
Metal Fatigue in Engineering
, 2nd ed.,
Wiley-lnterscience
,
New York
.
13.
Murr
,
L. E.
,
Gaytan
,
S. M.
,
Ramirez
,
D. A.
,
Martinez
,
E.
,
Hernandez
,
J.
,
Amato
,
K. N.
,
Shindo
,
P. W.
,
Medina
,
F. R.
, and
Wicker
,
R. B.
,
2012
, “
Metal Fabrication by Additive Manufacturing Using Laser and Electron Beam Melting Technologies
,”
J. Mater. Sci. Technol.
,
28
(
1
), pp.
1
14
. 10.1016/S1005-0302(12)60016-4
14.
Ahsan
,
F.
, and
Ladani
,
L.
,
2020
, “
Temperature Profile, Bead Geometry, and Elemental Evaporation in Laser Powder Bed Fusion Additive Manufacturing Process
,”
Jom
,
72
(
1
), pp.
429
439
. 10.1007/s11837-019-03872-3
15.
Chastand
,
V.
,
Quaegebeur
,
P.
,
Maia
,
W.
, and
Charkaluk
,
E.
,
2018
, “
Comparative Study of Fatigue Properties of Ti-6Al-4V Specimens Built by Electron Beam Melting (EBM) and Selective Laser Melting (SLM)
,”
Mater. Charact.
,
143
(
1
), pp.
76
81
. 10.1016/j.matchar.2018.03.028
16.
Facchini
,
L.
,
Magalini
,
E.
,
Robotti
,
P.
,
Molinari
,
A.
,
Höges
,
S.
, and
Wissenbach
,
K.
,
2010
, “
Ductility of a Ti-6Al-4 V Alloy Produced by Selective Laser Melting of Prealloyed Powders
,”
Rapid Prototyp. J.
,
16
(
6
), pp.
450
459
. 10.1108/13552541011083371
17.
Persenot
,
T.
,
Martin
,
G.
,
Dendievel
,
R.
,
Buffiére
,
J. Y.
, and
Maire
,
E.
,
2018
, “
Enhancing the Tensile Properties of EBM As-Built Thin Parts: Effect of HIP and Chemical Etching
,”
Mater. Charact.
,
143
(
1
), pp.
82
93
. 10.1016/j.matchar.2018.01.035
18.
Foehring
,
D.
,
Chew
,
H.
, and
Lambros
,
J.
,
2018
, “
Materials Science & Engineering A Characterizing the Tensile Behavior of Additively Manufactured Ti-6Al-4V Using Multiscale Digital Image Correlation
,”
Mater. Sci. Eng. A
,
724
(
2
), pp.
536
546
. 10.1016/j.msea.2018.03.091
19.
Bilgin
,
G. M.
,
Esen
,
Z.
,
Akın
,
ŞK
, and
Dericioglu
,
A. F.
,
2017
, “
Optimization of the Mechanical Properties of Ti-6Al-4V Alloy Fabricated by Selective Laser Melting Using Thermohydrogen Processes
,”
Mater. Sci. Eng. A
,
700
(
R1–R2
), pp.
574
582
. 10.1016/j.msea.2017.06.016
20.
Xu
,
W.
,
Lui
,
E. W.
,
Pateras
,
A.
,
Qian
,
M.
, and
Brandt
,
M.
,
2017
, “
In Situ Tailoring Microstructure in Additively Manufactured Ti-6Al-4V for Superior Mechanical Performance
,”
Acta Mater.
,
125
(
15
), pp.
390
400
. 10.1016/j.actamat.2016.12.027
21.
Ali
,
H.
,
Ma
,
L.
,
Ghadbeigi
,
H.
, and
Mumtaz
,
K.
,
2017
, “
In-Situ Residual Stress Reduction, Martensitic Decomposition and Mechanical Properties Enhancement Through High Temperature Powder Bed Pre-Heating of Selective Laser Melted Ti6Al4V
,”
Mater. Sci. Eng. A
,
695
(
17
), pp.
211
220
. 10.1016/j.msea.2017.04.033
22.
Ladani
,
L.
,
Razmi
,
J.
, and
Choudhury
,
S. F.
,
2014
, “
Mechanical Anisotropy and Strain Rate Dependency Behavior of Ti6Al4V Produced Using E-Beam Additive Fabrication
,”
ASME J. Eng. Mater. Technol.
,
136
(
3
), p.
031006
.10.1115/1.4027729
23.
Yadroitsev
,
I.
,
Krakhmalev
,
P.
,
Yadroitsava
,
I.
, and
Du Plessis
,
A.
,
2018
, “
Qualification of Ti6Al4V ELI Alloy Produced by Laser Powder Bed Fusion for Biomedical Applications
,”
Jom
,
70
(
3
), pp.
372
377
. 10.1007/s11837-017-2655-5
24.
Ladani
,
L.
,
2015
, “
Local and Global Mechanical Behavior and Microstructure of Ti6Al4V Parts Built Using Electron Beam Melting Technology
,”
Metall. Mater. Trans. A Phys. Metall. Mater. Sci.
,
46
(
9
), pp.
3835
3841
. 10.1007/s11661-015-2965-6
25.
Aliprandi
,
P.
,
Giudice
,
F.
,
Guglielmino
,
E.
, and
Sili
,
A.
,
2019
, “
Tensile and Creep Properties Improvement of Ti-6Al-4V Alloy Specimens Produced by Electron Beam Powder Bed Fusion Additive Manufacturing
,”
Metals (Basel).
,
9
(
11
), pp.
1
22
. 10.3390/met9111207
26.
Zong
,
Y. Y.
,
Shan
,
D. B.
,
,
Y.
, and
Guo
,
B.
,
2007
, “
Effect of 0.3 wt%H Addition on the High Temperature Deformation Behaviors of Ti-6Al-4V Alloy
,”
Int. J. Hydrogen Energy
,
32
(
16
), pp.
3936
3940
. 10.1016/j.ijhydene.2007.04.032
27.
Zhu
,
J. H.
,
Liaw
,
P. K.
,
Corum
,
J. M.
, and
McCoy
,
H. E.
,
1999
, “
High-Temperature Mechanical Behavior of Ti-6Al-4V Alloy and TiCp/Ti-6AI-4V Composite
,”
Metall. Mater. Trans. A Phys. Metall. Mater. Sci.
,
30
(
6
), pp.
1569
1578
. 10.1007/s11661-999-0094-9
28.
Nagarjuna
,
S.
, and
Srinivas
,
M.
,
2002
, “
High Temperature Tensile Behaviour of a Cu-1.5 wt% Ti Alloy
,”
Mater. Sci. Eng. A
,
335
(
1–2
), pp.
89
93
. 10.1016/S0921-5093(01)01945-1
29.
Yang
,
C. T.
,
Lu
,
Y. C.
, and
Koo
,
C. H.
,
2002
, “
The High Temperature Tensile Properties and Microstructural Analysis of Ti-40Al-15Nb Alloy
,”
Intermetallics
,
10
(
2
), pp.
161
169
. 10.1016/S0966-9795(01)00123-6
30.
Liu
,
D.
,
Zhang
,
S. Q.
,
Li
,
A.
, and
Wang
,
H. M.
,
2010
, “
High Temperature Mechanical Properties of a Laser Melting Deposited TiC/TA15 Titanium Matrix Composite
,”
J. Alloys Compd.
,
496
(
1–2
), pp.
189
195
. 10.1016/j.jallcom.2010.02.120
31.
Wang
,
S. H.
,
Wei
,
M. D.
, and
Tsay
,
L. W.
,
2003
, “
Tensile Properties of LBW Welds in Ti-6Al-4V Alloy at Evaluated Temperatures Below 450 °C
,”
Mater. Lett.
,
57
(
12
), pp.
1815
1823
. 10.1016/S0167-577X(02)01074-1
32.
ASTM International
,
2016
, “
ASTM International E8/E8M-16ae1 Standard Test Methods for Tension Testing of Metallic Materials
,”
ASTM International
,
West Conshohocken, PA
,
ASTM No. C
, pp.
1
28
.
33.
ASTM International
,
2017
, “
E21-17e1 Standard Test Methods for Elevated Temperature Tension Tests of Metallic Materials
,”
ASTM International
,
West Conshohocken, PA
, https://compass.astm.org/EDIT/html_annot.cgi?E21, Accessed March 4, 2020.
34.
Arcam AB
,
2017
, “
Electron Beam Melting—EBM Process, Additive Manufacturing | Arcam AB
,”
ArcamEBM
, https://www.ge.com/additive/additive-manufacturing/machines/ebm-machines, Accessed November 12, 2020.
35.
ISO
, “
ISO/ASTM 52921:2013—Standard terminology for additive manufacturing—Coordinate Systems and Test Methodologies
,” https://www.iso.org/standard/62794.html, Accessed May 28, 2020.
36.
Ladani
,
L.
, and
Roy
,
L.
,
2013
, “
Mechanical Behavior of Ti-6Al-4V Manufactured by Electron Beam Additive Fabrication
,”
ASME 2013 International Manufacturing Science and Engineering Conference Collocated With 41st North American Manufacturing Research Conference
,
Madison, WI
,
June 10–14
, pp.
1
5
.
37.
Wang
,
X.
,
Gong
,
X.
, and
Chou
,
K.
,
2015
, “
Scanning Speed Effect on Mechanical Properties of Ti-6Al-4V Alloy Processed by Electron Beam Additive Manufacturing
,”
Procedia Manuf.
,
1
(
1
), pp.
287
295
. 10.1016/j.promfg.2015.09.026
38.
Schmieder
,
A.
,
2009
, “Measuring the Apparatus Contribution to Bending in Tension Specimens,”
Elevated Temperature Testing Problem Areas
,
H.
Voorhees
,
D.
Faurschou
, and
G.
Smith
, eds.,
ASTM International
,
West Conshohocken, PA
, pp.
15
28
. 10.1520/STP26903S
39.
NDT Resource Center
,
2019
, “
Property Modification—Strengthening/Hardening Mechanisms
,” https://www.nde-ed.org/EducationResources/CommunityCollege/Materials/Structure/strengthening.htm, Accessed November 27, 2019.
40.
Carroll
,
B. E.
,
Palmer
,
T. A.
, and
Beese
,
A. M.
,
2015
, “
Anisotropic Tensile Behavior of Ti-6Al-4V Components Fabricated With Directed Energy Deposition Additive Manufacturing
,”
Acta Mater.
,
87
(
1
), pp.
309
320
. 10.1016/j.actamat.2014.12.054
41.
Dieter
,
G. E.
,
1961
,
MechanicaL Metallurgy
,
McGraw-Hill Book Company
,
New York
.
42.
Gong
,
X.
,
Anderson
,
T.
, and
Chou
,
K.
,
2013
, “
Review on Powder-Based Electron Beam Additive Manufacturing Technology
,”
ASME/ISCIE 2012 International Symposium on Flexible Automation
,
St. Louis, MO
,
June 18–20
.
43.
Wei
,
S.
,
Deng
,
P.
,
Jiangtong
,
Q.
, and
Jin
,
Y.
,
2019
, “
Tensile Deformation Behavior of Ti-6Al-4V Sheet at Elevated Temperature
,”
Mater. Res. Express
,
6
(
11
), p.
116585
. https://doi.org/10.1088/2053-1591/ab4b83
44.
Quan
,
G. Z.
,
Luo
,
G. C.
,
Liang
,
J. T.
,
Sen Wu
,
D.
,
Mao
,
A.
, and
Liu
,
Q.
,
2015
, “
Modelling for the Dynamic Recrystallization Evolution of Ti-6Al-4V Alloy in Two-Phase Temperature Range and a Wide Strain Rate Range
,”
Comput. Mater. Sci.
,
97
(
1
), pp.
136
147
. 10.1016/j.commatsci.2014.10.009
45.
Bai
,
Q.
,
Lin
,
J.
,
Dean
,
T. A.
,
Balint
,
D. S.
,
Gao
,
T.
, and
Zhang
,
Z.
,
2013
, “
Modelling of Dominant Softening Mechanisms for Ti-6Al-4V in Steady State Hot Forming Conditions
,”
Mater. Sci. Eng. A
,
559
(
1
), pp.
352
358
. 10.1016/j.msea.2012.08.110
46.
Ding
,
R.
,
Guo
,
Z. X.
, and
Wilson
,
A.
,
2002
, “
Microstructural Evolution of a Ti-6Al-4V Alloy During Thermomechanical Processing
,”
Mater. Sci. Eng. A
,
327
(
2
), pp.
233
245
. 10.1016/S0921-5093(01)01531-3
47.
Zhang
,
Z. X.
,
Qu
,
S. J.
,
Feng
,
A. H.
,
Shen
,
J.
, and
Chen
,
D. L.
,
2017
, “
Hot Deformation Behavior of Ti-6Al-4V Alloy: Effect of Initial Microstructure
,”
J. Alloys Compd.
,
718
(
25
), pp.
170
181
. 10.1016/j.jallcom.2017.05.097
48.
Zherebtsov
,
S.
,
Murzinova
,
M.
,
Salishchev
,
G.
, and
Semiatin
,
S. L.
,
2011
, “
Spheroidization of the Lamellar Microstructure in Ti-6Al-4V Alloy During Warm Deformation and Annealing
,”
Acta Mater.
,
59
(
10
), pp.
4138
4150
. 10.1016/j.actamat.2011.03.037
49.
Babu
,
B.
, and
Lindgren
,
L. E.
,
2013
, “
Dislocation Density Based Model for Plastic Deformation and Globularization of Ti-6Al-4V
,”
Int. J. Plast.
,
50
(
1
), pp.
94
108
. 10.1016/j.ijplas.2013.04.003
50.
Kurzynowski
,
T.
,
Madeja
,
M.
,
Dziedzic
,
R.
, and
Kobiela
,
K.
,
2019
, “
The Effect of EBM Process Parameters on Porosity and Microstructure of Ti-5Al-5Mo-5V-1Cr-1Fe Alloy
,”
Scanning
,
2019
(
1
), pp.
1
12
. 10.1155/2019/2903920
51.
Galarraga
,
H.
,
Lados
,
D. A.
,
Dehoff
,
R. R.
,
Kirka
,
M. M.
, and
Nandwana
,
P.
,
2016
, “
Effects of the Microstructure and Porosity on Properties of Ti-6Al-4V ELI Alloy Fabricated by Electron Beam Melting (EBM)
,”
Addit. Manuf.
,
10
(
1
), pp.
47
57
.
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