Mechanical and Microstructural Evolutions of the Laser Deposited Titanium Layers under Various Shielding Atmospheres

Abstract:

Direct laser melting process is a kind of prototyping process whereby a 3-D part is built layer-wise by melting the metal powder with laser scanning. The properties of laser melted layer are found to be strongly dependent upon the types of shielding gas used. In this study, the effects of shielding gases on the mechanical and microstructural properties of the deposited titanium layers have been investigated. The laser remelting process has also been implemented at various shielding atmospheres to investigate the changes in surface roughness and hardness of deposited layers. The characterization of laser processing parameters, such as laser power, scan rate, gas flow rate, powder layer thickness, beam spot size and hatch distance, is proved to be useful in controlling the mechanical and microstructural properties of the deposited layer.

• Periodical: Materials Science Forum (Volume 920)
• Pages: 58-63
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.920.58
• Online since: April 2018
• Authors: Tae Woo Hwang, Sang Wook Han, Dong Myeong Seo, Young Hoon Moon*
• Keywords: Direct Laser Melting, Hardness, Shielding Gas, Surface Roughness

References

[1] J. H. Jang, B. D. Joo, S. M. Mun, C. J. Van Tyne, Y. H. Moon, Application of a direct laser melting process for fabricating a micropattern in bipolar plates used in direct methanol fuel cells, J. Eng. Manuf. 225 (2011) 1784-1791.

DOI: 10.1177/0954405410395859

[2] M. Van Stappen, K. De Bruyn, C. Quaeyhaegens, L. Stals, V. Poulek, Deposition and properties of thick corrosion and wear-resistant Ti2N coatings, Surf. Coat. Technol. 74 (1995) 143-146.

DOI: 10.1016/0257-8972(95)08225-5

[3] H. Li, Z. Cui, Z. Li, S. Zhu, X. Yang, Effect of gas nitriding treatment on cavitation erosion behavior of commercially pure Ti and Ti− 6Al− 4V alloy, Surf. Coat. Technol. 221 (2013) 29-36.

DOI: 10.1016/j.surfcoat.2013.01.023

[4] A. Zhecheva, W. Sha, S. Malinov, A. Long, Enhancing the microstructure and properties of titanium alloys through nitriding and other surface engineering methods, Surf. Coat. Technol. 200 (2005) 2192-2207.

DOI: 10.1016/j.surfcoat.2004.07.115

[5] J. Kaspar, J. Bretschneider, S. Jacob, S. Bonß, B. Winderlich, B. Brenner, Microstructure, hardness and cavitation erosion behaviour of Ti–6Al–4V laser nitrided under different gas atmospheres, Surf. Eng. 23 (2007) 99-106.

DOI: 10.1179/174329407x169430

[6] S. Mridha, T. N. Baker, Effects of nitrogen gas flow rates on the microstructure and properties of laser-nitrided IMI318 titanium alloy (Ti–4V–6Al), J. Mater. Process. Technol. 77 (1998) 115-121.

DOI: 10.1016/s0924-0136(97)00408-1

[7] H. C. Man, N. Q. Zhao, Z. D. Cui, Surface morphology of a laser surface nitrided and etched Ti–6Al–4V alloy, Surf. Coat. Technol. 192 (2005) 341-346.

DOI: 10.1016/j.surfcoat.2004.07.076

[8] J. H. Abboud, A. F. Fidel, K. Y. Benyounis, Surface nitriding of Ti–6Al–4V alloy with a high power CO2 laser, Opt. Laser. Technol. 40 (2008) 405-414.

DOI: 10.1016/j.optlastec.2007.07.005

[9] l. Yadroitsev, l. Smurov, Surface morphology in selective laser melting of metal powders, Physics Procedia. 12 (2011) 264-270.

DOI: 10.1016/j.phpro.2011.03.034

[10] K. Guan, Z. Wang, M. Gao, X. Li, X. Zeng, Effects of processing parameters on tensile properties of selective laser melted 304 stainless steel, Mater. Des. 50 (2013) 581-586.

DOI: 10.1016/j.matdes.2013.03.056

[11] W. Liu, J. N. Dupont, Fabrication of functionally graded TiC/Ti composites by laser engineered net shaping, Scr. Mater. 48 (2003) 1337-1342.

DOI: 10.1016/s1359-6462(03)00020-4