Additive manufacturing is currently a topic of considerable interest at both academic and industrial levels. While a significant amount of data exists on the mechanical properties and structure–property relationships of traditional wrought alloys, less information is available on alloys manufactured by additive manufacture. This review examines current state-of-the-art manufacture of titanium-based Ti–6Al–4V alloys by powder bed additive manufacture. Published mechanical properties to date are collected which include tensile strength, yield strength, hardness, wear, fracture toughness and fatigue. Differences in microstructure and properties compared to conventional wrought alloys of the same composition are described.
FrazierW. E.: ‘Metal additive manufacturing: a review’, J. Mater. Eng. Perform., 2014, 23, 1917–1928. doi: 10.1007/s11665-014-0958-z
2.
GockelJ., FoxJ., BeuthJ. and HafleyR.: ‘Integrated melt pool and microstructure control for Ti–6Al–4V thin wall additive manufacturing’, Mater. Sci. Tech.-Lond., 2015, 31, 912–916. doi: 10.1179/1743284714Y.0000000704
3.
WilliamsS. W., MartinaF., AddisonA. C., DingJ., PardalG. and ColegroveP.: ‘Wire + arc additive manufacturing’, Mater. Sci. Tech.-Lond., 2016, DOI:10.1179/1743284715Y.0000000073
4.
ThompsonS. M., BianL., ShamsaeiN. and YadollahiA.: ‘An overview of direct laser deposition for additive manufacturing; part I: transport phenomena, modeling and diagnostics', Addit. Manuf., 2015, 8, 36–62. doi: 10.1016/j.addma.2015.07.001
5.
SeydaV., KaufmannN. and EmmelmannC.: ‘Investigation of aging processes of Ti–6Al–4V powder material in laser melting’, Physics Procedia, 2012, 39, 425–431. doi: 10.1016/j.phpro.2012.10.057
6.
KruthJ. P., MercelisP., Van VaerenberghJ., FroyenL. and RomboutsM.: ‘Binding mechanisms in selective laser sintering and selective laser melting’, Rapid Prototyping J., 2005, 11, (1), 26–36. doi: 10.1108/13552540510573365
7.
DeprezK., VandenbergheS., Van AudenhaegeK., Van VaerenberghJ. and Van HolenR.: ‘Rapid additive manufacturing of MR compatible multipinhole collimators with selective laser melting of tungsten powder’, Med. Phys., 2012, 40, (1), 012501.
8.
LiuQ. C., ElambasserilJ., SunS. J., LearyM., BrandtM. and SharpP. K.: ‘The effect of manufacturing defects on the fatigue behaviour of Ti–6Al–4V specimens fabricated using selective laser melting’, Adv. Mater. Res., 2014, 891–892, 1519–1524. doi: 10.4028/www.scientific.net/AMR.891-892.1519
9.
GuD. and ShenY.: ‘Balling phenomena in direct laser sintering of stainless steel powder: metallurgical mechanisms and control methods', Mater. Design, 2009, 30, 2903–2910. doi: 10.1016/j.matdes.2009.01.013
10.
ManvatkarV., DeA. and DebRoyT.: ‘Spatial variation of melt pool geometry, peak temperature and solidification parameters during laser assisted additive manufacturing process', Mater. Sci. Tech.-Lond., 2015, 31, 924–930. doi: 10.1179/1743284714Y.0000000701
11.
SercombeT., JonesN., DayR. and KopA.: ‘Heat treatment of Ti–6Al–7Nb components produced by selective laser melting’, Rapid Prototyping J., 2008, 14, (5), 300–304. doi: 10.1108/13552540810907974
12.
ChlebusE., KuzźnickaB., KurzynowskiT. and DybaƪaB.: ‘Microstructure and mechanical behaviour of Ti–6Al–7Nb alloy produced by selective laser melting’, Mater. Charact., 2011, 62, (5), 488–495. doi: 10.1016/j.matchar.2011.03.006
13.
AbeF., Costa SantosE., KitamuraY., OsakadaK. and ShiomiM.: ‘Influence of forming conditions on the titanium model in rapid prototyping with the selective laser melting process', Proc. Inst. Mech. Eng. Part C J. Mech. Eng. Sci., 2003, 217, (1), 119–126. doi: 10.1243/095440603762554668
14.
SantosE., AbeF., KitamuraY., OsakadaK. and ShiomiM.: ‘Microstructure and mechanical properties of pure titanium models fabricated by selective laser melting’, Proc. Inst. Mech. Eng. Part C J. Mech. Eng. Sci., 2004, 218, (7), 711–719. doi: 10.1243/0954406041319545
15.
OsakadaK. and ShiomiM.: ‘Flexible manufacturing of metallic products by selective laser melting of powder’, Int. J. Mach. Tool. Manu., 2006, 46, (11), 1188–1193. doi: 10.1016/j.ijmachtools.2006.01.024
16.
GuD., WangH., DaiD., ChangF., MeinersW., HagedornY.-C., WissenbachK., KelbassaI. and PopraweR.: ‘Densification behavior, microstructure evolution, and wear performance of selective laser melting processed commercially pure titanium’, Acta Mater., 2012, 60, (9), 3849–3860. doi: 10.1016/j.actamat.2012.04.006
17.
A. Standard: F2792, ‘Standard terminology for additive manufacturing technologies’, ASTM F2792-12a, 2012.
18.
A. Standard: F2924, ‘Standard specification for additive manufacturing titanium–6 aluminum–4 vanadium with powder bed fusion’, 2014.
19.
FlowerH. M.: ‘Microstructural development in relation to hot working of titanium alloys', Mater. Sci. Tech.-Lond., 1990, 6, 1082–1092. doi: 10.1179/mst.1990.6.11.1082
20.
LütjeringG. and WilliamsJ. C.: ‘Titanium’; 2007, Berlin, Springer.
21.
DonachieM. J.Jr: ‘Titanium, a technical guide’; 2000, Materials Park, OH, ASM International.
22.
SieniawskiJ., ZiajaW., KubiakK. and MotykaM.: ‘Microstructure and mechanical properties of high strength two-phase titanium alloys, titanium alloys – advances in properties control’, in ‘Titanium alloys–advances in properties control’, (eds. J. Sieniawski and W. Ziaja), 69–80; 2013, Croatia, InTech.
23.
PolmearI. J. and PolmearI.: ‘Light alloys: metallurgy of the light metals'; 1989, London, Edward Arnold.
24.
LeeY. T. and WelschG.: ‘Young's modulus and damping of Ti–6Al–4V alloy as a function of heat treatment and oxygen concentration’, Mat. Sci. Eng. A-Struct., 1990, 128, 77–89. doi: 10.1016/0921-5093(90)90097-M
25.
FacchiniL., MagaliniE., RobottiP., MolinariA., HögesS. and WissenbachK.: ‘Ductility of a Ti–6Al–4V alloy produced by selective laser melting of prealloyed powders’, Rapid Prototyping J., 2010, 16, (6), 450–459. doi: 10.1108/13552541011083371
26.
Gil MurF., RodriguezD. and PlanellJ.: ‘Influence of tempering temperature and time on the α′-Ti–6Al–4V martensite’, J. Alloy. Compd., 1996, 234, (2), 287–289. doi: 10.1016/0925-8388(95)02057-8
27.
RiceR. C.: ‘Metallic materials properties development and standardization (MMPDS): scientific report’, Vol. 1; 2003, Springfield, VA, National Technical Information Service [distributor].
28.
VranckenB., ThijsL., KruthJ.-P. and HumbeeckJ. V.: ‘Heat treatment of Ti6Al4V produced by selective laser melting: microstructure and mechanical properties', J. Alloy. Compd., 2012, 541, 177–185. doi: 10.1016/j.jallcom.2012.07.022
29.
Al-BermaniS. S., BlackmoreM. L., ZhangW. and ToddI.: ‘The origin of microstructural diversity, texture, and mechanical properties in electron beam melted Ti–6Al–4V’, Metall. Mater. Trans. A, 2010, 41, (13), 3422–3434. doi: 10.1007/s11661-010-0397-x
30.
MandilG., LeV. T., ParisH. and SuardM.: ‘Building new entities from existing titanium part by electron beam melting: microstructures and mechanical properties', Int. J. Adv. Manuf. Tech.,2015, 1–12, DOI:10.1007/s00170-015-8049-3
31.
MurrL. E., QuinonesS. A., GaytanS. M., LopezM. I., RodelaA., MartinezE. Y., HernandezD. H., MartinezE., MedinaF. and WickerR. B.: ‘Microstructure and mechanical behavior of Ti–6Al–4V produced by rapid-layer manufacturing, for biomedical applications', J. Mech. Behav. Biomed. Mater., 2009, 2, (1), 20–32. doi: 10.1016/j.jmbbm.2008.05.004
32.
MakiewiczK., BabuS. S., KellerM. and ChaudharyA.: ‘Microstructure evolution during laser additive manufacturing of Ti6Al4V’, Trends in welding research, Proceedings of the 9th Int. Conf., June 4–8, 2012, Chicago, IL, USA.
33.
ThijsL., VerhaegheF., CraeghsT., HumbeeckJ. V. and KruthJ.-P.: ‘A study of the microstructural evolution during selective laser melting of Ti–6Al–4V’, Acta Mater., 2010, 58, 3303–3312. doi: 10.1016/j.actamat.2010.02.004
34.
MartinaM. F., MehnenJ., WilliamsS. W., ColegroveP. and WangF.: ‘Investigation of the benefits of plasma deposition for the additive layer manufacture of Ti–6Al–4V’, J. Mater. Process. Tech., 2012, 212, 1377–1386. doi: 10.1016/j.jmatprotec.2012.02.002
35.
MartinaF., ColegroveP. A., WilliamsS. W. and MeyerJ.: ‘Microstructure of interpass rolled wire + arc additive manufacturing Ti–6Al–4V components', Metall. Mater. Trans. A, 2015, 46, 6103–6118. doi: 10.1007/s11661-015-3172-1
36.
CarrollB. E., PalmerT. A. and BeeseA. M.: ‘Anisotropic tensile behavior of Ti–6Al–4V components fabricated with directed energy deposition additive manufacturing’, Acta Mater., 2015, 87, 309–320. doi: 10.1016/j.actamat.2014.12.054
37.
QiuC., AdkinsN. J. E. and AttallahM. M.: ‘Anisotropic tensile behavior of Ti–6Al–4V components fabricated with directed energy deposition additive manufacturing’, Mater. Sci. Eng. A-Struct., 2013, 578, 230–239. doi: 10.1016/j.msea.2013.04.099
38.
MowerT. M. and LongM. J.: ‘Mechanical behavior of additive manufactured, powder-bed laser-fused materials', Mater. Sci. Eng. A-Struct., 2016, 651, 198–213. doi: 10.1016/j.msea.2015.10.068
39.
HollanderD. A., von WalterM., WirtzT., SelleiR., Schmidt-RohlfingB., PaarO. and ErliH. J.: ‘Structural, mechanical and in vitro characterization of individually structured Ti–6Al–4V produced by direct laser forming’, Biomaterials, 2006, 27, (7), 955–963. doi: 10.1016/j.biomaterials.2005.07.041
40.
‘Specification for wrought titanium–6aluminum–4vanadium ELI (extra low interstitial) alloy for surgical implant applications (UNS R56401)’, ASTM International, 2013.
KoikeM., GreerP., OwenK., LillyG., MurrL. E., GaytanS. M., MartinezE. and OkabeT.: ‘Evaluation of titanium alloys fabricated using rapid prototyping technologies – electron beam melting and laser beam melting’, Materials, 2011, 4, (10), 1776–1792. doi: 10.3390/ma4101776
43.
FacchiniL., MagaliniE., RobottiP. and MolinariA.: ‘Microstructure and mechanical properties of Ti–6Al–4V produced by electron beam melting of pre-alloyed powders', Rapid Prototyping J., 2009, 15, (3), 171–178. doi: 10.1108/13552540910960262
44.
ThöneM., LeudersS., RiemerA., TrösterT. and RichardH. A.: ‘Influence of heat-treatment on selective laser melting products – e.g. Ti6Al4V’, Solid freeform fabrication symposium SFF, Austin, Texas, 2012, 492–499.
45.
VandenbrouckeB. and KruthJ. P.: ‘Selective laser melting of biocompatible metals for rapid manufacturing of medical parts', Rapid Prototyping J., 2007, 13, (4), 196–203. doi: 10.1108/13552540710776142
46.
XuW., BrandtM., SunS., ElambasserilJ., LiuQ., LathamK., XiaK. and QianM.: ‘Additive manufacturing of strong and ductile Ti–6Al–4V by selective laser melting via in situ martensite decomposition’, Acta Mater., 2015, 85, 74–84. doi: 10.1016/j.actamat.2014.11.028
47.
GongH., RafiK., StarrT. and StuckerB.: ‘Effect of defects on fatigue tests of as-built Ti–6Al–4V parts fabricated by selective laser melting’, Twenty Third Annual Int. Solid Freeform Fabrication Symp., 2012, Austin, Texas, USA.
48.
EylonD.: ‘Fatigue crack initiation in hot isostatically pressed Ti–6Al–4V castings', J. Mater. Sci., 1979, 14, (8), 1914–1922. doi: 10.1007/BF00551032
49.
DasS., BeamaJ. J., WohlertM. and BourellD. L.: ‘Direct laser freeform fabrication of high performance metal components', Rapid Prototyping J., 1998, 4, (3), 112–117. doi: 10.1108/13552549810222939
50.
WiedingJ., JonitzA. and BaderR.: ‘The effect of structural design on mechanical properties and cellular response of additive manufactured titanium scaffolds', Materials, 2012, 5, (12), 1336–1347. doi: 10.3390/ma5081336
51.
BorggreenK. and WilsonI.: ‘Use of postweld heat treatments to improve ductility in thin sheets of Ti–6Al–4V’, Weld. J., 1980, 59, (1), 1–6.
52.
OkazakiY., ItoY., ItoA. and TateishiT.: ‘Effect of alloying elements on mechanical properties of titanium alloys for medical implants’, Mater. Trans., JIM, 1993, 34, (12), 1217–1222. doi: 10.2320/matertrans1989.34.1217
53.
KumarS. and KruthJ. P.: ‘Wear performance of SLS/SLM materials', Adv. Eng. Mater., 2008, 10, (8), 750–753. doi: 10.1002/adem.200800075
54.
SafdarA., HeH. Z., WeiL. Y., SnisA. and Chavez de PazL. E.: ‘Effect of process parameters settings and thickness on surface roughness of EBM produced Ti–6Al–4V’, Rapid Prototyping J., 2012, 18, (5), 401–408. doi: 10.1108/13552541211250391
55.
SpieringsA. B., HerresN. and LevyG.: ‘Influence of the particle size distribution on surface quality and mechanical properties in AM steel parts', Rapid Prototyping J., 2011, 17, (3), 195–202. doi: 10.1108/13552541111124770
56.
PykaG., BurakowskiA., KerckhofsG., MoesenM., Van BaelS., SchrootenJ. and WeversM.: ‘Surface modification of Ti6Al4V open porous structures produced by additive manufacturing’, Adv. Eng. Mater., 2012, 14, (6), 363–370. doi: 10.1002/adem.201100344
57.
FurumotoT., UedaT., AminoT., KusunokiD., HosokawaA. and TanakaR.: ‘Finishing performance of cooling channel with face protuberance inside the molding die’, J. Mater. Process. Tech., 2012, 212, (10), 2154–2160. doi: 10.1016/j.jmatprotec.2012.05.016
58.
CooperD. E., StanfordM., KibbleK. A. and GibbonsG. J.: ‘Additive manufacturing for product improvement at Red bull Technology’, Mater. Design, 2012, 41, 226–230. doi: 10.1016/j.matdes.2012.05.017
59.
Van HoorewederB., MoensD., BoonenR., KruthJ. P. and SasP.: ‘Analysis of fracture toughness and crack propagation of Ti6Al4V produced by selective laser melting’, Adv. Eng. Mater., 2012, 14, (1–2), 92–97. doi: 10.1002/adem.201100233
60.
YasaE., DeckersJ., KruthJ. P., RomboutsM. and LuytenJ.: ‘Charpy impact testing of metallic selective laser melting parts', Virtual and Physical Prototyping, 2010, 5, (2), 89–98. doi: 10.1080/17452751003703894
61.
ChanK. S., KoikeM., MasonR. L. and OkabeT.: ‘Fatigue life of titanium alloys fabricated by additive layer manufacturing techniques for dental implants', Metall. Mater. Trans. A, 2012, 44, (2), 1010–1022. doi: 10.1007/s11661-012-1470-4
62.
LeudersS., ThöneM., RiemeraA., NiendorfT., TrösterT., RichardH. A. and MaierH. J.: ‘On the mechanical behaviour of titanium alloy TiAl6V4 manufactured by selective laser melting: fatigue resistance and crack growth performance’, Int. J. Fatigue, 2012, 48, 300–307. doi: 10.1016/j.ijfatigue.2012.11.011
63.
EdwardsP., O'ConnerA. and RamuluM.: ‘Electron beam additive manufacturing of titanium components: properties and performance’, J. Manuf. Sci. E.-T. ASME, 2013, 135, 061016. doi: 10.1115/1.4025773
64.
BrandlE., LeyensC. and PalmF.: ‘Mechanical properties of additive manufactured Ti–6Al–4V using wire and powder based processes', IOP Conf. Ser. Mater. Sci. Eng., 2011, 26, 012004. doi: 10.1088/1757-899X/26/1/012004
65.
ISO Standard 1143:2010, Metallic materials–rotating bar bending fatigue testing, ISO International, 2010.
66.
KruthJ. P., DeckersJ., YasaE. and WauthléR.: ‘Assessing and comparing influencing factors of residual stresses in selective laser melting using a novel analysis method’, Proc. Inst. Mech. Eng. Part B J. Eng. Manuf., 2012, 226, (6), 980–991. doi: 10.1177/0954405412437085
67.
Tammas-WilliamsS., ZhaoH., LéonardF., DergutiF., ToddI. and PrangnellP. B.: ‘XCT analysis of the influence of melt strategies on defect population in Ti–6Al–4V components manufactured by selective electron beam melting’, Mater. Charact., 2015, 102, 47–61. doi: 10.1016/j.matchar.2015.02.008
