Hostname: page-component-8448b6f56d-c4f8m Total loading time: 0 Render date: 2024-04-24T08:57:35.677Z Has data issue: false hasContentIssue false
  • English
  • Français

The formation of α + β microstructure in as-fabricated selective laser melting of Ti–6Al–4V

Published online by Cambridge University Press:  25 July 2014

Marlo Simonelli ,
Yau Yau Tse  and
C. Tuck
Marlo Simonelli*
Affiliation:
Department of Materials, Loughborough University, Loughborough LE11 3TU, United Kingdom
Yau Yau Tse
Affiliation:
Department of Materials, Loughborough University, Loughborough LE11 3TU, United Kingdom
C. Tuck
Affiliation:
Additive Manufacturing and 3D Printing Research Group, Department of Mechanical, Materials and Manufacturing Engineering, Faculty of Engineering, The University of Nottingham, Nottingham NG7 2RD, United Kingdom
*
a)Address all correspondence to this author. e-mail: M.Simonelli@lboro.ac.uk
Get access

Abstract

Ti–6Al–4V parts made by the additive manufacturing (AM) technique selective laser melting (SLM) generally show poor ductility due to their fine martensitic microstructure. This study was designed to assess whether a more suitable microstructure can be obtained when long laser/material interaction times are used. As-fabricated components with an α + β microstructure were produced and characterized with various microscopy techniques. The microstructural evolution was discussed in relation to the build platform temperature, the cyclic reheating, and the thermal stresses that developed during the process. The hardness of the samples was also evaluated and discussed. The hardness varied in relation to the different microstructure morphologies observed in the samples and different partitioning of the alloying elements. This study indicates a methodology through SLM to obtain Ti–6Al–4V with an as-deposited α + β microstructure which is more desirable than that the typical fully martensitic microstructure typically obtained after SLM.

Keywords

microstructureannealinghardness
Type
Articles
Information
Journal of Materials Research , Volume 29 , Issue 17: Focus Issue: The Materials Science of Additive Manufacturing , 14 September 2014 , pp. 2028 - 2035
Copyright
Copyright © Materials Research Society 2014 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Baumers, M., Tuck, C., Wildman, R., Ashcroft, I., and Hague, R.: Energy inputs to additive manufacturing: Does capacity utilization matter?. Proceedings of the Solid Freeform Fabrication Symposium, 2011. (EOS, 1000, 270, 2011); pp. 30-40. Google Scholar
Qiu, C., Adkins, N., and Attallah, M.M.: Microstructure and tensile properties of selectively laser-melted and of HIPed laser-melted Ti-6Al-4V. Mater. Sci. Eng., A 578, 230 (2013).Google Scholar
Facchini, L., Magalini, E., Robotti, P., Molinari, A., Höges, S., and Wissenbach, K.: Ductility of a Ti-6Al-4V alloy produced by selective laser melting of prealloyed powders. Rapid Prototyping J. 16, 450 (2010).Google Scholar
Vilaro, T., Colin, C., and Bartout, J.D.: As-fabricated and heat-treated microstructures of the Ti-6Al-4V alloy processed by selective laser melting. Metall. Mater. Trans. A 42, 3190 (2011).CrossRefGoogle Scholar
Chlebus, E., Kuźnicka, B., Kurzynowski, T., and Dybała, B.: Microstructure and mechanical behaviour of Ti―6Al―7Nb alloy produced by selective laser melting. Mater. Charact. 62, 488 (2011).CrossRefGoogle Scholar
Banerjee, D. and Williams, J.C.: Perspectives on titanium science and technology. Acta Mater. 61(3), 844 (2013).CrossRefGoogle Scholar
Lütjering, G.: Influence of processing on microstructure and mechanical properties of α+ β titanium alloys. Mater. Sci. Eng., A 243(1), 32 (1998).CrossRefGoogle Scholar
Vrancken, B., Thijs, L., Kruth, J.P., and Humbeeck, J.V.: Heat treatment of Ti-6Al-4V produced by selective laser melting: Microstructure and mechanical properties. J. Alloys Compd. 541, 177 (2012).CrossRefGoogle Scholar
Thijs, L., Verhaeghe, F., Craeghs, T., Humbeeck, J.V., and Kruth, J.P.: A study of the microstructural evolution during selective laser melting of Ti–6Al–4V. Acta Mater. 58, 3303 (2010).CrossRefGoogle Scholar
Sercombe, T., Jones, N., Day, R., and Kop, A.: Heat treatment of Ti-6Al-7Nb components produced by selective laser melting. Rapid Prototyping J. 14, 300 (2008).CrossRefGoogle Scholar
Simonelli, M., Tse, Y.Y., and Tuck, C.: On the texture formation of selective laser melted Ti-6Al-4V. Metall. Mater. Trans. A 45(6), 2863 (2014).CrossRefGoogle Scholar
Yasa, E. and Kruth, J.P.: Microstructural investigation of selective laser melting 316L stainless steel parts exposed to laser re-melting. Procedia Eng. 19, 389 (2011).Google Scholar
Al-Bermani, S.S., Blackmore, M.L., Zhang, W., and Todd, I.: The origin of microstructural diversity, texture, and mechanical properties in electron beam melted Ti-6Al-4V. Metall. Mater. Trans. A 41, 3422 (2010).CrossRefGoogle Scholar
Gibson, I., Rosen, D.W., and Stucker, B.: Additive Manufacturing Technologies: Rapid Prototyping to Direct Digital Manufacturing (Springer, New York, NY, 2010), pp. 103–142.CrossRefGoogle Scholar
Crespo, A. and Vilar, R.: Finite element analysis of the rapid manufacturing of Ti–6Al–4V parts by laser powder deposition. Scr. Mater. 63, 140 (2010).CrossRefGoogle Scholar
Shiomi, M., Osakada, K., Nakamura, K., Yamashita, T., and Abe, F.: Residual stress within metallic model made by selective laser melting process. CIRP Ann.-Manuf. Technol. 53, 195 (2004).CrossRefGoogle Scholar
Mercelis, P. and Kruth, J.P.: Residual stresses in selective laser sintering and selective laser melting. Rapid Prototyping J. 12, 254 (2006).CrossRefGoogle Scholar
Kobryn, P.A. and Semiatin, S.L.: The laser additive manufacture of Ti-6Al-4V. JOM 53, 40 (2001).Google Scholar
Kobryn, P.A. and Semiatin, S.L.: Microstructure and texture evolution during solidification processing of Ti–6Al–4V. J. Mater. Process. Technol. 135, 330 (2003).CrossRefGoogle Scholar
Murr, L.E., Quinones, S.A., Gaytan, S.M., Lopez, M.I., Rodela, A., Martinez, E.Y., Hernandez, D.H., Martinez, E., Medina, F., and Wicker, R.B.: Microstructure and mechanical behavior of Ti–6Al–4V produced by rapid-layer manufacturing, for biomedical applications. J. Mech. Behav. Biomed. Mater. 2, 20 (2009).Google Scholar
Ahmed, T. and Rack, H.J.: Phase transformations during cooling in α+β titanium alloys. Mater. Sci. Eng., A 243, 206 (1998).CrossRefGoogle Scholar
Qazi, J.I., Rahim, J., Fores, F.H., Senkov, O.N., and Genc, A.: Phase transformations in Ti-6Al-4V-xH alloys. Metall. Mater. Trans. A 32, 2453 (2001).Google Scholar
Kelly, S.M. and Kampe, S.L.: Microstructural evolution in laser-deposited multilayer Ti-6Al-4V builds: Part I. Microstructural characterization. Metall. Mater. Trans. A, 35, 1861 (2004).CrossRefGoogle Scholar
Baufeld, B., Brandl, E., and Biest, O.V.: Wire based additive layer manufacturing: Comparison of microstructure and mechanical properties of Ti–6Al–4V components fabricated by laser-beam deposition and shaped metal deposition. J. Mater. Process. Technol. 211, 1146 (2011).CrossRefGoogle Scholar