Study of the Microstructure and Mechanical Properties Obtained by Laser Boost in SLM Process for the Ti-64 Alloy

Abstract:

Selective laser melting (SLM) is one of the new additive manufacturing techniques in which complex parts can be created directly by selectively melting layers of powder. If the productivity of the process is too fast, defects (porosity, partially melted powder, spatters …) are generated inside the fabricated parts and can deteriorate the mechanical properties of the product. A new Laser Boost strategy with a larger melting area and a productivity of 43.20 cm3/h has been compared to a Linear Classic strategy. Ti-64 alloy samples were elaborated with both strategies to study their influence on microstructure and mechanical properties. Laser Boost strategy leads to the formation of Ti-64 prior β grains that are larger than the Linear Classic strategy. Mechanical properties obtains are similar with both strategies with a maximum strength average around 1250MPa and an elongation at failure between 3 and 9%. A thermal post-processing by Hot Isostatic Pressure have been carried out on samples made by Laser Boost to increase the ductility of the material up to 15%.

• Periodical: Materials Science Forum (Volume 1016)
• Pages: 1611-1617
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.1016.1611
• Online since: January 2021
• Authors: Caroline Widomski*, Denis Solas, François Brisset, Anne Laure Helbert, Thierry Baudin, Sébastien Lebel
• Keywords: Additive Manufacturing, HIP, Mechanical Properties, Microstructure, SLM, Ti64, Titanium

References

[1] J. Kruth, L. Froyen, J. Vaerenbergh, P. Mercelis, M. Rombouts and B. Lauwers, Selective laser melting of iron-based powder,, Journals of Materials Processing Technology, vol. 149, pp.616-622, (2004).

DOI: 10.1016/j.jmatprotec.2003.11.051

[2] D. Teng, D. Pal, H. Gong, K. Keng, K. Briggs and N. Patil, A review of defectmodeling in laser material processing,, Additive Manufacturing, vol. 14, pp.137-147, (2017).

DOI: 10.1016/j.addma.2016.10.009

[3] J. Choi, G. Shin, S. Yang, D.-Y. Yang and J.-S. Lee, Densification and microstructural investigation of Inconel 718 parts fabricated by selective laser melting,, Powder Technology, vol. 310, pp.60-66, (2017).

DOI: 10.1016/j.powtec.2017.01.030

[4] T. DebRoy, H. Wei, J. Zuback, T. Muckherjee, J. Elmer, J. Milewski, A. Beese, A. Wilson-Heid, A. De and W. Zhang, Additive manufacturing,, Progress in Materials Science, vol. 92, pp.112-224, (2018).

DOI: 10.1016/j.pmatsci.2017.10.001

[5] L. Thijs, F. Verhaeghe, T. Craeghs, J. Van Humbeeck and J.-P. Kruth, A study of the microstructural evolution uring selective laser melting of Ti-6Al-4V,, Acta Materialia, vol. 158, pp.3303-3312, (2010).

DOI: 10.1016/j.actamat.2010.02.004

[6] D. Banerjee and J. Williams, Perspectives on Titanium Science and Technology,, Acta Materialia, vol. 61, pp.844-879, (2013).

DOI: 10.1016/j.actamat.2012.10.043

[7] C. Cai, B. Song, P. Xue, Q. Wei, J.-m. Wu and Y. Shi, Effect of hot isostatic pressing procedure on performance of Ti6Al4V: Surface qualities, microstructure and mechanical properties,, Journal of Alloys and Compounds, vol. 686, pp.55-63, (2016).

DOI: 10.1016/j.jallcom.2016.05.280

[8] Y. Combres, Traitements thermiques des alliages de titane," Techniques de l,ingénieur, vol. 3, no. 1335, (2013).

DOI: 10.51257/a-v3-m1335

[9] C. Cayron, ARPGE: a computer program to autolatically reconstruct the parent grains from electron backscatter diffraction data,, Journal of Applied Crystallography, vol. 40, p.1183–1188, (2007).

DOI: 10.1107/s0021889807048777

[10] J. Yang, Y. Hanchen, J. Yin, M. Gao, Z. Wang and X. Zeng, Formation and control of martensite in Ti-6Al-4V alloy produced by selective laser melting,, Materials & Design, vol. 108, pp.308-318, (2016).

DOI: 10.1016/j.matdes.2016.06.117

[11] C. Qiu, N. Adkins and M. Attallah, Qiu_2013_Microstructure and tensile properties of selectively laser-melted and of HIPed laser-melted Ti–6Al–4V,, Materials Science & Engineering, vol. A, no. 578, pp.230-239, (2013).

DOI: 10.1016/j.msea.2013.04.099