Abstract
The present paper focuses on the metallurgical and microstructural characterization of the laser beam-welded T-joints between commercially pure titanium (CP-Ti) and Ti-6Al-4V alloy. The weld regions were comprehensively studied and the mechanisms leading to the final morphology within each weld region were described. The link between microstructural features and local mechanical properties was demonstrated. Owing to different constitution, the responses of the two titanium alloys to thermal cycles imposed by laser welding are completely different. A strong interface with no dilution zone between the two alloys was observed. The cooling rate during the welding process is high enough for diffusionless martensitic transformation in the Ti-6Al-4V part of the fusion zone. In contrast, no evidence of martensite was found in the CP-Ti because of low solute content and, consequently, much higher critical cooling rate. Plausible reason for some controversy found in the literature on the resulting transformation products after laser processing of CP-Ti was given. The present findings might have important industrial implications because careful microstructural characterization revealed the real position of the skin fusion line, which is of great importance for fulfillment of the weld quality criteria.
![](http://media.springernature.com/lw685/springer-static/image/art%3A10.1007%2Fs00170-018-1968-z/MediaObjects/170_2018_1968_Figa_HTML.gif)
ᅟ
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
Change history
13 August 2018
The article Metallurgical aspects of joining commercially pure titanium to Ti-6Al-4V alloy in a T-joint configuration by laser beam welding by Fedor Fomin, Martin Froend, Volker Ventzke, Pedro Alvarez, Stefan Bauer and Nikolai Kashaev, was originally published electronically.
References
Dawes C (1992) Laser welding, a practical guide, 1st ed. Woodhead Publishing Ltd, Cambridge
Froend M, Fomin F, Riekehr S, Alvarez P, Zubiri F, Bauer S, Klusemann B, Kashaev N (2017) Fiber laser welding of dissimilar titanium (Ti-6Al-4V/cp-Ti) T-joints and their laser forming process for aircraft application. Opt Laser Technol 96:123–131
Boyer R, Welsch G, Collings EW, (ed) (1994) Materials properties handbook: titanium alloys, 1st ed. ASM International, Materials Park
Lathabai S, Jarvis BL, Barton KJ (2001) Comparison of keyhole and conventional gas tungsten arc welds in commercially pure titanium. Mater Sci Eng A 299:81–93
Chen J, Pan C (2011) Welding of Ti-6Al-4V alloy using dynamically controlled plasma arc welding process. T Nonferr Metal Soc 21(7):1506–1512
Wu M, Xin R, Wang Y, Zhou Y, Wang K, Liu Q (2016) Microstructure, texture and mechanical properties of commercial high-purity thick titanium plates jointed by electron beam welding. Mater Sci Eng A 677:50–57
Squillace A, Prisco U, Ciliberto S, Astarita A (2012) Effect of welding parameters on morphology and mechanical properties of Ti-6Al-4V laser beam welded butt joints. J Mater Process Tech 212:427–436
Kashaev N, Ventzke V, Fomichev V, Fomin F, Riekehr S (2016) Effect of Nd:YAG laser beam welding on weld morphology and mechanical properties of Ti–6Al–4V butt joints and T-joints. Opt Laser Eng 86:172–180
Li X, Xie J, Zhou Y (2005) Effect of oxygen contamination in the argon shielding gas in laser welding of commercially pure titanium thin sheet. J Mater Sci 40:3437–3443
Maawad E, Gan W, Hofmann M, Ventzke V, Riekehr S, Brokmeier HG, Kashaev N, Mueller M (2016) Influence of crystallographic texture on the microstructure, tensile properties and residual stress state of laser-welded titanium joints. Mater Des 101:137–145
Liu H, Nakata K, Yamamoto N, Liao J (2011) Mechanical properties and strengthening mechanisms in laser beam welds of pure titanium. Sci Technol Weld Joi 16(7):581–585
Elmer JW, Wong J, Ressler T (1998) Spatially resolved X-ray diffraction phase mapping and α→β→α transformation kinetics in the heat-affected zone of commercially pure titanium arc welds. Metall Mater Trans A 29:2761–2773
AMS 4902E (1986) Titanium sheet, strip, and plate, commercially-pure, annealed 40.0 ksi (276 MPa) yield strength. SAE International. doi:https://doi.org/10.4271/AMS4902E
AMS 4911F (1988) Titanium alloy, sheet, strip, and plate, 6Al - 4V, annealed. SAE International. https://doi.org/10.4271/AMS4911F
Petzow G (1994) Metallographisches, keramographisches, plastographiches Ätzen. Gebrüder Bornträger, Berlin, Stuttgart
Duley WW (1998) Laser welding. John Wiley & Sons, INC., New York
Lütjering G, Williams JC (2003) Titanium, 1st ed. Springer-Verlag, Berlin, Heidelberg
Salem AA (2009) Texture separation for α/β titanium alloys. In: Schwartz AJ, Kumar M, Adams BL, Field DP (eds) Electron backscatter diffraction in materials science, 2nd ed. Springer Publishers, New York
Banerjee S, Mukhopadhyay P (2007) Phase transformations, examples from titanium and zirconium alloys. Elsevier, Oxford
Kim SK, Park JK (2011) In-situ measurement of continuous cooling β→α transformation behavior of CP-Ti. Metall Mater Trans A 33:1051–1056
Pilchak AL, Broderick TF (2013) Evidence of a massive transformation in a Ti-6Al-4V solid-state weld. J Met 65:636–642
Cromier M, Claisse F (1974) Beta-alpha phase transformation in Ti and Ti-O alloys. J Less-Common Met 34:181–189
Amaya-Vazquez MR, Sanchez-Amaya JM, Boukha Z, Botana FJ (2012) Microstructure, microhardness and corrosion resistance of remelted TiG2 and Ti6Al4V by a high-power diode laser. Corros Sci 56:36–48
Sun Z, Annergren I, Pan D, Mai TA (2003) Effect of laser surface remelting on the corrosion behavior of commercially pure titanium sheet. Mater Sci Eng A 345:293–300
Zhang J, Fan D, Sun Y, Zheng Y (2007) Microstructure and hardness of the laser surface treated titanium. Key Eng Mater 353-358:1745–1748
Aaronson HI, Enomoto M, Lee JK (2010) Mechanisms of diffusional phase transformations in metals and alloys. CRC Press, Boca Raton
Massalski TB (2002) Massive transformations revisited. Metall Mater Trans A 33:2277–2283
Ahmed T, Rack HJ (1998) Phase transformations during cooling in α+β titanium alloys. Mater Sci Eng A 243:206–211
Fomin F, Ventzke V, Dorn F, Levichev N, Kashaev N (2017) Effect of microstructure transformations on fatigue properties of laser beam welded Ti-6Al-4V butt joints subjected to postweld heat treatment. In: Tanski T, Borek W (eds) Study of grain boundary character. InTech, Rijeka
Paton NE, Mahoney MW (1976) Creep of titanium-silicon alloys. Metall Trans A 7:1685–1694
Murakami Y (2002) Metal fatigue: effects of small defects and nonmetallic inclusions, 1st edn. Elsevier, Oxford
Acknowledgements
The authors would like to thank Mr. R. Dinse, Mr. F. Dorn, and Mr. S. Riekehr from the Department of “Joining and Assessment” of Helmholtz-Zentrum Geesthacht for their valuable technical support.
Funding
This work was carried out within the framework of an EU Project and was funded by the European Union (Clean Sky 2 EU-JTI Platform) under the thematic call JTI-CS2-2014-CFP01-LPA-01-03 “Development of advanced laser based technologies for the manufacturing of titanium HLFC structures/DELASTI” (grant agreement no: 687088).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits use, duplication, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.
About this article
Cite this article
Fomin, F., Froend, M., Ventzke, V. et al. Metallurgical aspects of joining commercially pure titanium to Ti-6Al-4V alloy in a T-joint configuration by laser beam welding. Int J Adv Manuf Technol 97, 2019–2031 (2018). https://doi.org/10.1007/s00170-018-1968-z
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00170-018-1968-z