Electrochemical Characterization of Ti6Al4V Components Produced by Additive Manufacturing

Abstract:

The investigation of the corrosion resistance of Ti6Al4V alloy components produced by additive technology is still lacking in the literature. This paper aims to study the electrochemical behaviour of Ti6Al4V components fabricated by laser powder-bed fusion additive manufacturing process. The metallographic analysis was carried out by an optical microscope. The electrochemical behaviour has been evaluated in 3.5 wt. % of natural aerated NaCl aqueous solution by potentiodynamic polarization test. The results have been compared to a conventionally manufactured Ti6Al4V component. The typical martensitic structure has been shown by the additive manufactured sample. As expected, the metallographic analysis revealed a martensitic microstructure. The electrochemical tests carried out on the surface of the as-received additive manufactured specimen showed an influence of its morphology on the values of passive current density, higher than that recorded for the conventionally manufactured sample, used as the control. After mechanical polishing, the electrochemical tests were repeated on the "bulk" of the samples. The open circuit potential values were higher than the value recorded for the conventionally manufactured sample. The conditions of the additive process affect the corrosion resistance of the components due to the roughness of the surface and to the microstructure created.

• Periodical: Key Engineering Materials (Volume 813)
• Pages: 86-91
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.813.86
• Online since: July 2019
• Authors: Annalisa Acquesta*, Anna Carangelo, Paolo Di Petta, Tullio Monetta
• Keywords: Electrochemical Characterization, Laser Powder-Bed Fusion Additive Manufacturing, Microstructural Analysis, Ti6Al4V Alloy

References

[1] P.T. D.M. Brunette, Marcus Textor, P. Thomsen, Titanium in Medicine, Springer-Verlag Berlin Heidelberg2001.

[2] T. Monetta, A. Acquesta, F. Bellucci, Evaluation of roughness and electrochemical behavior of titanium in biological environment, Metallurgia Italiana 106(9) (2014) 13-21.

[3] A. Acquesta, A. Carangelo, T. Monetta, TiO2 Nanotubes on ti dental implant. Part 3: Electrochemical behavior in hank's solution of titania nanotubes formed in ethylene glycol, Metals 8(7) (2018).

DOI: 10.3390/met8070489

[4] L.E. Murr, S.M. Gaytan, D.A. Ramirez, E. Martinez, J. Hernandez, K.N. Amato, P.W. Shindo, F.R. Medina, R.B. Wicker, Metal Fabrication by Additive Manufacturing Using Laser and Electron Beam Melting Technologies, Journal of Materials Science & Technology 28(1) (2012) 1-14.

DOI: 10.1016/s1005-0302(12)60016-4

[5] L.-C. Zhang, H. Attar, Selective Laser Melting of Titanium Alloys and Titanium Matrix Composites for Biomedical Applications: A Review Advanced Engineering Materials 18(4) (2016) 463-475.

DOI: 10.1002/adem.201500419

[6] J. Yang, H. Yang, H. Yu, Z. Wang, X. Zeng, Corrosion Behavior of Additive Manufactured Ti-6Al-4V Alloy in NaCl Solution, Metallurgical and Materials Transactions A 48(7) (2017) 3583-3593.

DOI: 10.1007/s11661-017-4087-9

[7] D.H. Abdeen, B.R. Palmer, Corrosion evaluation of Ti-6Al-4V parts produced with electron beam melting machine, Rapid Prototyping Journal 22(2) (2016) 322-329.

DOI: 10.1108/rpj-09-2014-0104

[8] N. Dai, L.-C. Zhang, J. Zhang, Q. Chen, M. Wu, Corrosion behavior of selective laser melted Ti-6Al-4V alloy in NaCl solution, Corrosion Science 102 (2016) 484-489.

DOI: 10.1016/j.corsci.2015.10.041

[9] A.C. A. Acquesta, P. Di Petta, T. Monetta, Corrosion resistance of Ti6Al4V components produced by Direct Metal Laser Sintering process, submitted (2019).

[10] S.L.d. Assis, S. Wolynec, I. Costa, Corrosion characterization of titanium alloys by electrochemical techniques, Electrochimica Acta 51(8) (2006) 1815-1819.

DOI: 10.1016/j.electacta.2005.02.121

[11] N. Dai, J. Zhang, Y. Chen, L.-C. Zhang, Heat Treatment Degrading the Corrosion Resistance of Selective Laser Melted Ti-6Al-4V Alloy, Journal of The Electrochemical Society 164(7) (2017) C428-C434.

DOI: 10.1149/2.1481707jes